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prof. Ing. Jiří Jakovenko, Ph.D.

Proděkan pro magisterské a kombinované studium

Všechny publikace

A Low Power Asynchronous Column-parallel 10-bit Analog to Digital Converter with a High Input Impedance

  • Autoři: Vančura, P., Gečnuk, J., prof. Ing. Jiří Jakovenko, Ph.D., Janoška, Z., Jirsa, J., Kafka, V., Korchak, O., Kostina, A., Lednický, D., Marčišovská, M., Marčišovský, M., Tomášek, L.
  • Publikace: Journal of Instrumentation. 2022, 17 ISSN 1748-0221.
  • Rok: 2022
  • DOI: 10.1088/1748-0221/17/05/T05016
  • Odkaz: https://doi.org/10.1088/1748-0221/17/05/T05016
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper proposes a low power 10-bit asynchronous fully-differential column analog to digital converter (ADC) with successive approximation (SAR) and charge redistribution in a 180 nm SoI technology. The ADC is designed for use in Spacepix-2 monolithic active pixel sensor.

Multi-threshold window discriminator based on SAR logic

  • DOI: 10.1088/1748-0221/17/01/C01042
  • Odkaz: https://doi.org/10.1088/1748-0221/17/01/C01042
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The new X-ray imaging detectors allow capturing an X-ray image in various photon energy ranges in one shot. This technique is called X-ray color imaging, and it is becoming a promising method in fields such as medical imaging, computed tomography, and non-destructive material testing. To measure the energy spectrum in one shot, discriminant circuits need to be integrated into the pixel front-end electronics. Several solutions of in-pixel discriminators exist. However, current designs suffer from a low number of discrimination bins and need to adjust each threshold separately, leading to relatively complicated calibration procedures. This work introduces a novel design of a multi-threshold window discriminator based on successive approximation register logic. This circuit realizes in-pixel binning to ten equidistant windows. Two variables are used for tuning the multi-threshold window discriminator: offset of the first window and width of the windows. Setting these parameters allows the user to fulfill the need of the target application.

Simulation of charge sharing effects in 70 μm pixelated CdTe sensor

  • Autoři: Jirsa, J., Havránek, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Journal of Physics: Conference Series. Bristol: IOP Institute of Physics, 2022. p. 1-4. vol. 2374. ISSN 1742-6596.
  • Rok: 2022
  • DOI: 10.1088/1742-6596/2374/1/012130
  • Odkaz: https://doi.org/10.1088/1742-6596/2374/1/012130
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Pixel detectors become an integral part of medical imaging, nondestructive testing, space science and particle physics. Sensors that are bump bonded to readout ASICs are made from various materials such as GaAs, Si, CdTe, and CdZnTe. Current research tends to use CdTe/CdZnTe as gamma-ray sensors due to its high absorption coefficient in the gamma spectrum. With decreasing size of pixel pitch, charge diffusion and secondary fluorescent photons cause charge sharing between neighboring pixels. That decreases the spatial and spectral resolution of the detector. This study simulated the effects of charge diffusion in a 2 mm thick 70 μm pixelated CdTe using TCAD. We created a 3D model of the sensor with an array of 5 × 5 pixels. We simulated the propagation of e-h pairs generated upon the absorption of gamma photons in CdTe. Based on the simulation outcome, we calculated the collection time, drift time and pixel capacitance. Finally, we propose a sensor model for use in analog front-end design.

Comparison of Measured Data Given by Automatized Measurement Methodology with the Analytical Expression of DLS MOSFET

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D., Barri, D.
  • Publikace: 2020 International Conference on Applied Electronics. Plzeň: Západočeská univerzita v Plzni, 2020. p. 3-8. ISSN 1803-7232. ISBN 978-80-261-0891-7.
  • Rok: 2020
  • DOI: 10.23919/AE49394.2020.9232796
  • Odkaz: https://doi.org/10.23919/AE49394.2020.9232796
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper introduces the latest modern automatized advanced measurement flow of the diamond layout shape MOS transistors (DLS MOSFETs) as well as the rectangular layout shape (RLS) MOSFETs directly on a wafer. There are presented photos of the DLS MOSFET, from the highest level of the wafer down to the lowest level of the wafer, where each photo is individually commented. The next part of this article presents each item of the proposed measurement flow, such as an air compressor, temperature forcing system, probe cards, and precision semiconductor parameter analyzer. Also, there is shown, a photo of the probe card used for the measurement, as well as planning of its needles. Besides others, there is describe four-points measurement strategy, and the last part of this paper recommends the minimum number of measurements in order to obtain relevant data. Finally, the measured data is compared with a theoretic analytical expression

Improvement of Column-Parallel Sampling for A Monolithic Pixel Detector

  • DOI: 10.1088/1748-0221/15/02/P02014
  • Odkaz: https://doi.org/10.1088/1748-0221/15/02/P02014
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Monolithic pixel detectors often use an on-chip analog to digital converter (ADC) with successive approximation register (SAR) to digitize the signal amplitude of the pixels. This paper solves the challenges of column-parallel sampling with respect to the layout, power consumption, process variability, speed, and the integration of fully differential ADC architecture with ADC driver.

MOSFETs’ Electrical Performance in the 160-nm BCD Technology Process With the Diamond Layout Shape

  • DOI: 10.1109/TED.2020.3000744
  • Odkaz: https://doi.org/10.1109/TED.2020.3000744
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This article introduces an innovative approach that describes the drain–source current improvements of MOS transistors. It is based on the geometrical modification of MOSFET’s channel from a rectangular layout shape (RLS) into a diamond layout shape (DLS). In this way, the drain–source current enhancement is increased up to 11% for the DLS MOS transistors with an effective aspect ratio (W/L)eff equal to 2.0 and an angle set to 80. Moreover, we present the comparison of 3-D TCAD simulations data, analytical model data based on Schwarz–Christoffel transformation (SCT), and measurement data given by the measurement of the MOS transistors fabricated in the Bipolar- CMOS-DMOS (BCD) 160-nm technology process. For this purpose, there have been fabricated 1124 samples, which were proportionally divided into RLS MOSFETs and DLS MOSFETs with the angles equal to 120, 100, and 80. For all studied aspect ratios, the presented model has an excellent analytic description in comparison with the 3-D TCAD simulation results with an error lower than 3%. So, it proves the quality of the analytical model based on the SCT approach and it is the recommended approach to use also for modeling other MOSFET gate layout shapes.

Simulation of New Charge Summing and Hit Allocation Algorithm

  • Autoři: Jirsa, J., Havránek, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Topical Workshop on Electronics for Particle Physics. Trieste: SISSA/ISAS, 2020. ISSN 1824-8039.
  • Rok: 2020
  • DOI: 10.22323/1.370.0007
  • Odkaz: https://doi.org/10.22323/1.370.0007
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Modern VLSI technology allows the development of new class X-ray imaging detectors capableof capturing an image in various energy ranges in one shot. Such spectroscopic imaging detectorshave a high demand for the spatial and energy resolution of individual photons. With decreas-ing size of pixels, the charge cloud generated by the primary photon interaction, and in high-Zmaterials also by the fluorescent photon interaction, is shared across several pixels. That limitsboth spatial and spectroscopy resolution. This paper presents a novel charge summing algorithmcalled Winner-Master-Slave and describes the functionality, implementation, and simulation ofthe proposed algorithm in Verilog-AMS.

Spatial Systematic Mismatch Assessment of Pre-arranged Layout Topologies

  • Autoři: Vančura, P., prof. Ing. Jiří Jakovenko, Ph.D., Kotě, V., Vacula, P., Kubačák, A.
  • Publikace: Solid-State Electronics. 2020, 170C ISSN 0038-1101.
  • Rok: 2020
  • DOI: 10.1016/j.sse.2020.107822
  • Odkaz: https://doi.org/10.1016/j.sse.2020.107822
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    A spatial systematic mismatch, occurring in the integrated circuit manufacturing process, leads to differences in parameters for two or more identical devices. It is widely accepted that placing devices into symmetrical patterns reduces the spatial systematic mismatch between their parameters. In this paper, a novel method based on linear and nonlinear parameter gradient modeling for the assessment of pre-arranged matched structures has been proposed. The direction of a parameter gradient against a layout topology on a wafer is unknown. The pre-arranged layout pattern is rotated against the modeled parameter gradient. In each step of the rotation, for example, with a 1-degree resolution, the mismatch between parameters is calculated. The peak mismatch value is then used for the comparison of the different pre-arranged patterns. The proposed method is independent of technology.

The proposal strategy to increase the quality and inclusion in education, its internationalization and modernization of administrative processes for The National Technical University of Ukra

  • Pracoviště: Katedra ekonomiky, manažerství a humanitních věd, Katedra elektromagnetického pole, Katedra mikroelektroniky
  • Anotace:
    The present proposal was developed in the frame of the project Strengthening capacities of the National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” in the field of quality and inclusion in education, internationalization and support of cooperation supported by the project of the Ministry of Foreign Affairs of the Czech Republic “Strengthening the capacity of public universities in developing countries”. It is focused on the development of a conceptual strategy and the transfer of Czech know-how in the field of quality and inclusion of the educational process, its management and internationalization.

Comparison of MOSFET Gate Waffle Patterns Based on Specific On-Resistance

  • DOI: 10.13164/re.2019.0598
  • Odkaz: https://doi.org/10.13164/re.2019.0598
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This article describes waffle power MOSFET segmentation and defines its analytic models. Although waffle gate pattern is well-known architecture for effective channel scaling without requirements on process modification, until today no precise model considering segmentation of MOSFETs with waffle gate patterns, due to bulk connections, has been proposed. Two different MOSFET topologies with gate waffle patterns have been investigated and compared with the same on-resistance of a standard MOSFET with finger gate pattern. The first one with diagonal metal interconnections allows reaching more than 40% area reduction. The second MOSFET with the simpler orthogonal metal interconnections allows saving more than 20% area. Moreover, new models defining conditions where segmented power MOSFETs with waffle gate patterns occupy less area than the standard MOSFET with finger gate pattern, have been introduced.

Design and Optimization of an Active OTA-C Filter Based on STOHE Algorithm

  • Autoři: Barri, D., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: 2019 International Conference on Applied Electronics. Pilsen: University of West Bohemia, 2019. ISSN 1339-3944. ISBN 978-80-261-0812-2.
  • Rok: 2019
  • DOI: 10.23919/AE.2019.8866997
  • Odkaz: https://doi.org/10.23919/AE.2019.8866997
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    With increasing demands on design and optimization of analog circuits in real applications, a limited number of algorithms for practical use have been presented. The drawbacks of already existing standard algorithms are in a possibility to stagnate in a not optimal solution and also big time consumption. These drawbacks have been overcome by our new proposed algorithm STOHE. The new algorithm is a combination of a STOchastic and HEuristic algorithms. As the stochastic respectively heuristic algorithm was chosen differential evolution algorithm respectively simplex algorithm. The algorithm has been verified by the design and optimization of an active OTA-C filter where the standard approach fails.

Improvements in the Electrical Performance of IC MOSFET Components Using Diamond Layout Style Versus Traditional Rectangular Layout Style Calculated by Conformal Mapping

  • DOI: 10.1109/TED.2019.2931090
  • Odkaz: https://doi.org/10.1109/TED.2019.2931090
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In the first part of this article, we have proposed an innovative approach to improve the drain current model of the MOSFETs implemented with the diamond layout style (DLS), regarding the longitudinal corner effect (LCE). The proposed model is more accurate than a previous model compared to 3-D TechnologyComputer-AidedDesign (3-D TCAD) simulation results. The new model has an innovative analytical description based on a conformal mapping theory. As a conformal mapping, there has been chosen a Schwarz–Christoffel transformation (SC). The maximal deviation values of the aspect ratio calculated by LCE are in the range from −27% to +38%. In counterpart with the new SC analytical description of DLS, the maximal deviation values are in the range from 0% to −5.5%. The second part of this article describes improvements in the electrical performance of the N-MOSFET components by using DLS counterpart to traditional rectangular layout style (RLS). Both layout style DLS, RLS, respectively, have the same process settings, as well as they are keeping the same gate area A, and an aspect ratio width to length W/L to preserve the same input conditions for their analysis. The maximal drain current increasing for the simulated DLS MOS transistor is over 20% for effective aspect ratio (W/L)eff equal to 2.0 and the angle is set to 60 grads. The presented model has a very good analytic description with the error level lower than 3%.

Thermal Management Strategies for Low- and High-Voltage Retrofit LED Lamp Drivers

  • Autoři: Perpina, X.P., Vellvehi, M.H., Werkhoven, R., prof. Ing. Jiří Jakovenko, Ph.D., Kunen, J., Bancken, P., Bolt, P., Jorda, X.
  • Publikace: IEEE Transactions on Power Electronics. 2019, 34(4), 3677-3688. ISSN 0885-8993.
  • Rok: 2019
  • DOI: 10.1109/TPEL.2018.2853119
  • Odkaz: https://doi.org/10.1109/TPEL.2018.2853119
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Several thermal management strategies for LED drivers designed for high lumen retrofit LED lamps are studied by simulation and experimentation means. Depending on the driver output, two scenarios are analyzed: Low Voltage-High Current (18V-620mA) and High Voltage-Low Current (110V-85mA). Experiments (infrared thermography and thermocouples) and multiscale simulation approaches are used to assist both the lamp and driver board thermal design, as well as the driver proper integration in the lighting system. As a result, a heatsink based on an Aluminum hollow cylinder with polymer axial fins is designed and evaluated. The heatsink assessement is carried out with an LED board, in which the LED junction temperature is modeled and extracted by monitoring the LED board backside temperature. Additional experimentation to better integrate the driver is performed aiming at reducing the contact thermal resistance between the driver and the heatsink and improving the heat removal in the driver housing by including a material with a high thermal conductivity (i.e., dry silica sand or magnesium oxide powder). The proposed solution reduces the LED junction temperature up to 18% with respect to a reference lamp, whereas both drivers depict working temperatures around or below 125°C, when a working temperature of 90°C is considered.

Time of flight measurements with the PH32 chip

  • Autoři: Janoška, Z., Benka, T., Havránek, M., Hejtmánek, M., prof. Ing. Jiří Jakovenko, Ph.D., Kafka, V., Kaschner, M., Marčišovská, M., Marčišovský, M., Neue, G., Tomášek, L., Švihra, P., Vančura, P., Vrba, V.
  • Publikace: Journal of Instrumentation. 2019, 2019(14), ISSN 1748-0221.
  • Rok: 2019
  • DOI: 10.1088/1748-0221/14/04/C04004
  • Odkaz: https://doi.org/10.1088/1748-0221/14/04/C04004
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The front-end readout chip PH32, that is suitable for the measurement of {X-rays}, beta radiation and ions, is primarily dedicated to the dose rate measurement and basic spectroscopy. This article is focused on the Time-of-Flight (ToF) functionality used in particle tracking or ion mass spectroscopy. The PH32 chip was manufactured using a commercial 180 nm CMOS process and contains various possibilities for ToF measurements including Time-of-Arrival (ToA) counter in each individual measurement channel, a global ToA counter controlled by internal trigger logic and a trigger output with a proprietary differential signaling driver. Along with the energy measurement using the Time-over-Threshold (ToT) method, the time-walk effect of ToF may be corrected. The chip is optimized for the strip sensor capacitance of 8 pF with AC coupling and the electronic noise is established at 1100 e−. The measurements presented in this paper are focused on channel response to an injected charge including a measurement of the channel dispersion and the time-walk effect caused by the varying of the injected charge together with the results provided by the global ToA counter and the trigger output. A discussion of the ToF measurements made using a laser light source is presented for the individual channel counter and the global ToA counter including the time-walk effect correction.

A Capacitor DAC for Charge Redistribution Analog to Digital Converter with Successive Approximation

  • Autoři: Vančura, P., Havránek, M., Benka, T., Janoška, Z., prof. Ing. Jiří Jakovenko, Ph.D., Vrba, V.
  • Publikace: A Capacitor DAC for Charge Redistribution Analog to Digital Converter with Successive Approximation. Proceedigns of Science, 2018. vol. 343. ISSN 1824-8039.
  • Rok: 2018
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The recent analog to digital converters, with the successive approximation (SAR ADC), are widely used for their high speed, low power operation, and accuracy. SAR ADC demands precise internal digital to analog converter (DAC). To save power, the DAC is mainly implemented using capacitors (CDAC). Its precision depends mostly on layout implementation which must minimize the various parasitic effects. This paper presents two new layout design approaches of CDAC for SAR ADC used in a pixel detector implemented in 180 nm SOI technology.

A True Random Number Generator with Time Multiplexed Sources of Randomness

  • DOI: 10.13164/re.2018.0796
  • Odkaz: https://doi.org/10.13164/re.2018.0796
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    A true random number generator (TRNG) with time multiplexed metastability-based sources of randomness, presented in this paper, is capable of generating random bit sequences formed from noise present in the electronic circuit. An incorporated time multiplexer interleaves digitized random signals coming from sources of randomness and increases output data rate. The proposed TRNGwas fabricated in a STMicroelectronics 130 nm bulk CMOS technology on an area of 0.029mm2. The quality of all random bit sequences has been verified by the FIPS and NIST statistical test suites. The fabricated TRNG generates random bit sequences up to the data rate of 20 Mb/s without any corrective mechanisms at power consumption of 72.48 uW. The changing environmental conditions do not influence the quality of random bit sequences.

An Automated ESD Model Characterization Method

  • DOI: 10.13164/re.2018.0784
  • Odkaz: https://doi.org/10.13164/re.2018.0784
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Novel automated simulator-independent ESD model characterization method based on Differential evolution and Nelder-Mead Simplex algorithms is presented in this paper. It offers an alternative for time and human-resources demanding manual characterization that is still widely used. The paper also presents stable macro-models of the four most often used snapback-based protection devices in CMOS technologies, i.e., NMOST and three variants of silicon-controlled rectifier structure. These macro-models were used for evaluation of the proposed method and the results are included and discussed.

Automated pre-placement phase as a part of robust analog-mixed signal physical design flow

  • DOI: 10.1016/j.vlsi.2018.04.018
  • Odkaz: https://doi.org/10.1016/j.vlsi.2018.04.018
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    A new pre-placement phase of integrated circuits (IC) analog-mixed-signal (AMS) physical design flow, introduced in this paper, automatically sorts electrical devices used in planar IC technologies according to their topological, structural and electrical properties. The presented design phase replaces human labour and allows to save design time and prevent human mistakes. Software implementation of the proposed method works with virtual objects of layout instances which are moved only once at the end of the script when creating the final pre-placement matrix. Algorithm complexity is decreased by a new way of virtual objects matrix indexing. The automatic pre-placement phase has been used during design of AMS circuits in 160 nm BCD8sP and SOIBCD8S technologies from STMicroelectronics and has been faster in the range of 3164 to 20099 times compared to manual sorting. The estimation of ratio between manual sorting time and automatic pre-placement time shows a growing time saving with increasing circuit complexity compared to standard layout flow. The introduced enhanced layout flow is able to prevent a creation of hardly detectable errors occurring at the beginning of AMS physical design, especially the wrong bulk connection errors of semiconductor devices. The automatic pre-placement phase saves hours of reworks and speeds up the entire design process.

Characterization of pixel sensor designed in 180 nm SOI CMOS technology

  • Autoři: Benka, T., Havránek, M., Hejtmánek, M., prof. Ing. Jiří Jakovenko, Ph.D., Janoška, Z., Marčišovská, M., Marčišovský, M., Neue, G., Tomášek, L., Vrba, V.
  • Publikace: Journal of Instrumentation. 2018, 13(01), ISSN 1748-0221.
  • Rok: 2018
  • DOI: 10.1088/1748-0221/13/01/C01025
  • Odkaz: https://doi.org/10.1088/1748-0221/13/01/C01025
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    A new type of X-ray imaging Monolithic Active Pixel Sensor (MAPS), X-CHIP-02, was developed using a 180 nm deep submicron Silicon On Insulator (SOI) CMOS commercial technology. Two pixel matrices were integrated into the prototype chip, which differ by the pixel pitch of 50 μm and 100 μm. The X-CHIP-02 contains several test structures, which are useful for characterization of individual blocks. The sensitive part of the pixel integrated in the handle wafer is one of the key structures designed for testing. The purpose of this structure is to determine the capacitance of the sensitive part (diode in the MAPS pixel). The measured capacitance is 2.9 fF for 50 μm pixel pitch and 4.8 fF for 100 μm pixel pitch at -100 V (default operational voltage). This structure was used to measure the IV characteristics of the sensitive diode. In this work, we report on a circuit designed for precise determination of sensor capacitance and IV characteristics of both pixel types with respect to X-ray irradiation. The motivation for measurement of the sensor capacitance was its importance for the design of front-end amplifier circuits. The design of pixel elements, as well as circuit simulation and laboratory measurement techniques are described. The experimental results are of great importance for further development of MAPS sensors in this technology.

An Algorithm for Assessment IC Matched Structure with Respecting nth_order Gradient Parameter Effects

  • Autoři: Barri, D., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: IMAPS flash conference 2017. Brno: Brno University of Technology, FEEC, Department of Electrical Power Engineering, 2017. p. 12-93. ISBN 978-80-214-5535-1.
  • Rok: 2017
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper describes a new methodology how to evaluate systematic mismatch due to inhomogeneous parameter gradient in IC fabrication process for passive and active devices. The gradient sensitivity is discussed for both linear and nonlinear (nth-order) parameter gradients. Effect of the threshold gradients is simulated for the current mirror in simple layout pattern. Simulation results show a significant impact gradients angles through the active area for the layout pattern for the realization of the precise current mirror. The realized structure can be not only current mirror but also other sensitive blocks as a differential pair, resistor divider for voltage reference and many other analog circuit blocks. This paper also refers two mismatch definitions, systematic errors (gradient effects) and random errors.

An Effect of Output Capacitor ESL on Hysteretic PLL Controlled Multiphase Buck Converter

  • DOI: 10.13164/re.2017.0515
  • Odkaz: https://doi.org/10.13164/re.2017.0515
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper provides analysis of output capacitor effects to phase stability of a hysteretic mode controlled buck converter. The hysteretic control method is a simple and fast control technique for switched-mode converters, but the hysteresis control is not oscillator referenced. It results in difficulty to achieve stable switching phase and frequency. In recent papers, the authors propose a use of phase locked loops (PLL) to permit interleaved multiphase operation where each voltage regulator (VR) module is coupled together via output node and leads to a strong loop interaction. In this work analysis of this interaction is studied by Matlab Simulink simulations and a new solution how to partially suppress this effect is given. The proposed method confirms the theoretical analysis.

Incremental Control Techniques for Layout Modification

  • Autoři: Vacula, P., Kotě, V., KUBAČÁK, A, LŽÍČAŘ, M, ZELENÝ, R, prof. Ing. Miroslav Husák, CSc., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: ASDAM 2016 Conference Proceedings - The 11th International Conference on Advanced Semiconductor and Microsystems. Bratislava: Slovenská akademie věd, 2016. p. 239-242. Proceedings. ISSN 2475-2916. ISBN 978-1-5090-3083-5.
  • Rok: 2016
  • DOI: 10.1109/ASDAM.2016.7805939
  • Odkaz: https://doi.org/10.1109/ASDAM.2016.7805939
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    During creation of analog layout in IC CAD environment layout engineers spend a lot of time by modifying objects in a database. By applying new control concept and targeting modern control approaches our solution unifies and simplifies control of any layout object to speed-up work. Discussed new control techniques are compatible with IC CAD environment and both current control devices as keyboard/mouse and new gesture tracking devices. New control concept is very intuitive and improves productivity of analog layout.

Modern Control Techniques for Layout Creation

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    During creation of analog layout in Cadence CAD environment layout engineers spend a lot of time by modifying objects in a database. By applying new control concept and targeting modern control approaches our solution unifies and simplifies control of any layout object to speed-up work. Discussed new control techniques are compatible with Cadence CAD environment and both current control devices as keyboard/mouse and new gesture tracking devices. Layout engineers experienced with new control concept prefer this flow to the classic one as object modification has been simplified. New control concept is very intuitive and improves productivity of analog layout.

Thermal Analysis of LED Lamps for Optimal Driver Integration

  • Autoři: Perpina, X., Werkhoven, RJ, Vellvehi, M., prof. Ing. Jiří Jakovenko, Ph.D., Jorda, X., Kunen, JMG., Bancken, P., Bolt, P.
  • Publikace: IEEE Transactions on Power Electronics. 2015, 7(30), 3876-3891. ISSN 0885-8993.
  • Rok: 2015
  • DOI: 10.1109/TPEL.2014.2346543
  • Odkaz: https://doi.org/10.1109/TPEL.2014.2346543
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper studies the thermal influence of a light-emitting diode (LED) driver on a retrofit LED lamp, also reporting on a procedure for its thermal characterization and multiscale modeling. In this analysis, temperature is measured by infrared thermography and monitoring specific locations with thermocouples. Experimental results point out that temperature increases considerably in all lamp parts when the driver is installed in the lamp (up to 15% for LED board). The multiscale simulation approach is set with thermal parameters (thermal conductivity, emissivity, and LED board thermal resistance) measured from several parts of the lamp, reaching an agreement between experiment and simulation smaller than 10%. With this model, the driver temperature is investigated under operational conditions accounting for two alternative thermal designs.

Enhanced Generic Architecture for Safety Increase of True Random Number Generators

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Conventionally used generic architecture of true random number generators does not allow testing of random numbers during their generation. This paper introduces an extension of the conventionally used generic architecture and describes mechanisms that can be implemented in new blocks and ensures safety increase of true random number generators. Objective of new architecture extension is detection of deliberate malicious attacks that are directed against noise source and revelation of a significant decrease of the approximate entropy in the subsequences of generated random number sequences. The enhanced generic architecture has been implemented into known software model. Obtained results show that described mechanisms allow increasing quality of the generated random numbers sequences.

Methods for Lifetime Characterization of Concentric Circuit Boards

  • Autoři: Formánek, J., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: 10th International Conference on Advanced Semiconductor Devices and Microsystems ASDAM 2014 Conference Proceedings. Bratislava: Slovak University of Technology in Bratislava, 2014. p. 237-240. ISSN 2475-2916. ISBN 978-1-4799-5475-9.
  • Rok: 2014
  • DOI: 10.1109/ASDAM.2014.6998687
  • Odkaz: https://doi.org/10.1109/ASDAM.2014.6998687
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper presents development of simulation method and measuring system for a lifetime characterization of concentric circuit boards. It brings a knowledge about modern approaches of structure lifetime estimation by using a FEM (finite element method) modelling. Methods known in the field of mechanical engineering and material engineering are extended by the author with the new knowledge and applied for development of new lifetime evaluation method. The testing is done by using the specific mechanical bending test apparatus which is designed to achieve equivalent results as can be achieved by the cyclic tests in the thermal chamber. The structure damage is generated by using a mechanical force generated by the pneumatic piston. Tested concentric circuit boards are mainly used in LED lamps. The boards are characterized by a circular shape, concentrically mounted components and high operating temperatures.

New Structure of True Random Number Generators with Protective Mechanisms

  • Autoři: Kotě, V., Molata, V., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Electronic Devices and Systems IMAPS CS International Conference 2014. Brno: VUT v Brně, Fakulta elektrotechniky a komunikačních technologií, 2014. pp. 19-24. ISBN 978-80-214-4985-5.
  • Rok: 2014
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper introduces an extension of the generic architecture of conventionally used true random number generators. The presented blocks help to increase safety of electronics systems. Implemented mechanisms allow detecting deliberate malicious attacks against the noise sources of true random number generators and revealing a significant decrease of the approximate entropy in the subsequences of generated random number sequences. The enhanced generic architecture has been implemented into the already published software model. The obtained results show that described mechanisms allow increasing quality of the generated random numbers sequences.

A powerful optimization tool for analog integrated circuits design

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper presents a new optimization tool for analog circuit design. The proposed tool is based on the robust version of the differential evolution optimization method. Corners of technology, temperature, voltage and current supplies are taken into account during the optimization. That ensures robust resulting circuits. Those circuits usually do not need any schematic change and are ready for the layout. The newly developed tool is implemented directly to the Cadence design environment to achieve very short setup time of the optimization task. The design automation procedure was enhanced by optimization watchdog feature. It was created to control optimization progress and moreover to reduce the search space to produce better design in shorter time. The optimization algorithm presented in this paper was successfully tested on several design examples.

Capacitor-less LDO regulator with NMOS power transistor

  • Autoři: Molata, V., Kotě, V., Nápravník, T., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proceedings - Electronic Devices and Systems - EDS '13. Brno: VUT v Brně, Fakulta elektrotechniky a komunikačních technologií, 2013. pp. 50-55. ISBN 9788021447547.
  • Rok: 2013
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    A 3.6 (4.3) V 50 mA capacitor-less low dropout (LDO) voltage regulator for system on chip (SoC) is introduced. It does not require any external component and is stable in a wide range of load current. This LDO uses an NMOS transistor as the power element. In order to increase the gate voltage of the power element switched floating capacitor is used. The proposed LDO has been designed in a commercial 0.13 μm CMOS technology. The variation of output voltage is less than 100 mV even a full load step is applied and current consumption of this LDO regulator is 150 μA regardless of the load current.

Capacitor-less Linear Regulator with NMOS Power Transistor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    A 3.6 (4.3) V 50 mA capacitor-less linear voltage regulator for system on chip (SoC) is introduced. It does not require any external component and is stable in a wide range of load current. This regulator uses an NMOS transistor as the power element. In order to increase the gate voltage of the power element switched floating capacitor is used. The proposed linear regulator has been designed in a commercial 0.13 μm CMOS technology. The variation of output voltage is less than 100 mV even if a full load step is applied and current consumption of this regulator is 150 μA regardless of the load current.

Design methodologies for reliability of SSL LED boards

  • DOI: 10.1016/j.microrel.2013.02.017
  • Odkaz: https://doi.org/10.1016/j.microrel.2013.02.017
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This work presents a comparison of various LED board technologies from thermal, mechanical and reliability point of view provided by an accurate 3-D modelling. LED boards are proposed as a possible technology replacement of FR4 LED boards used in 400 lumen retrofit SSL lamps. Presented design methodology can be used for other high power SSL lamp designs. The performance of new LED board designs were evaluated by numerical modeling. Modeling methodology was proven by measurement on reference FR4 LED board. Thermal performance was compared by extracting of LED boards thermal resistances and thermal stress has been inspected considering the widest temperature operating range according to standards (-40 to +125 °C). Thermo-mechanical and reliability analysis have been performed to study parameters of each LED board technology, using thermal boundary conditions extracted from the thermal simulation of a whole LED lamp. Elastic-plastic analysis with temperature dependent stress-strain material properties has been performed. The objective of the work is to optimize not only the thermal management by thermal simulation of LED boards, but also to find potential problems from mechanical failure point of view and to present a methodology to design SSL LED boards for reliability

Evaluating the 3D Energy Harvester

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper discusses the characterization and evaluation of an MEMS based electrostatic generator, a part of the power supply unit of the self-powered microsystem. The designed generator is based on electrostatic converter and uses the principle of conversion of non-electric energy into electrical energy by periodical modification of gap between electrodes of a capacitor. The structure is designed and modeled as three-dimensional silicon based MEMS. With innovative approach we reached a very low resonant frequency of the structure (about 100Hz.) The modified long cantilever spring design with minimum area of the chip, its ability to work in 3D mode, and the ability to be tuned to reach desired parameters, proves promising directions of possible further development.

In-situ measurements of material thermal parameters for accurate LED lamp thermal modelling

  • Autoři: Vellvehi, M., Perpiñà, X., Jordà, X., Werkhoven, R. J., Kunen, J., prof. Ing. Jiří Jakovenko, Ph.D., Bancken, P., Bolt, P. J.
  • Publikace: Thermal Investigations of ICs and Systems (THERMINIC). Stuttgart: Fraunhofer IRB Verlag, 2013. p. 381-384. ISBN 978-1-4799-2271-0.
  • Rok: 2013
  • DOI: 10.1109/THERMINIC.2013.6675206
  • Odkaz: https://doi.org/10.1109/THERMINIC.2013.6675206
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This work deals with the extraction of key thermal parameters for accurate thermal modelling of LED lamps: air exchange coefficient around the lamp, emissivity and thermal conductivity of all lamp parts. As a case study, an 8W retrofit lamp is presented. To assess simulation results, temperature is monitored on the lamp by infrared thermography and by monitoring specific locations with thermocouples. As a result, experimental and simulation results show differences below 15%.

Modelling of Reliability by Highly Accelerated Characterization Method for Solid State Lighting LED Boards

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D., Formánek, J.
  • Publikace: Computational Intelligence, Modelling and Simulation (CIMSim), 2013 Fifth International Conference. Los Alamitos: Conference publishing Services, 2013. pp. 384-389. ISSN 2166-8523. ISBN 978-1-4799-2308-3.
  • Rok: 2013
  • DOI: 10.1109/CIMSim.2013.68
  • Odkaz: https://doi.org/10.1109/CIMSim.2013.68
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Main goal of the work presented in this paper is modeling of reliability and development of an innovative fast accelerated LED board validation method based on mechanical cycling which may replace currently used thermal cycling test. The paper discusses the design of new LED board 3-D models for reliability simulation. Reliability calculation is based on thermal or mechanical cycling using constructive equation for creep modeling and FEM thermo-mechanical elastic-plastic simulation. The simulation results were verified on newly developed testing facilities.

Novel Model Calibration Method Based on Differential Evolution Used for SCR Model Fitting

  • Autoři: Nápravník, T., Žiška, P., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proc. of the 16th IEEE Symposium on Design and Diagnostics of Electronic Circuits and Systems. Brno: NOVPRESS, 2013. p. 297-298. ISSN 2334-3133. ISBN 978-1-4673-6135-4.
  • Rok: 2013
  • DOI: 10.1109/DDECS.2013.6549840
  • Odkaz: https://doi.org/10.1109/DDECS.2013.6549840
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper presents the possibility to use modern and very effective optimization algorithm called differential evolutionary optimization algorithm (DEOA) enhanced by Nelder--Mead Simplex algorithm (NMSA) for fully automatic ESD protection model calibration. This novel method requires only TLP measurement of specific protection device for optimal model calibration. Presented approach is currently being actively developed by authors and tested for various ESD protection devices to verify its robustness. It was in past successfully tested on electrostatic discharge (ESD) MOSFET cite{ja2}. Description of used macro-model and novel calibration method along with results of ESD Silicon-controlled rectifier (SCR) macro-model calibration to empirical data are presented.

Thermal characterization and lifetime prediction of LED boards for SSL lamp

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This work presents a detailed 3-D thermo-mechanical modeling of two LED board technologies to compare their performance. LED boards are considered to be used in high power 800 lumen retrofit SSL (Solid State Lighting) lamp. Thermal, mechanical and life time properties are evaluated by numerical modeling. Experimental results measured on fabricated LED board samples are compared to calculated data. Main role of LED board in SSL lamp is to transport heat from LED die to a heat sink and keep the thermal stresses in all layers as low as possible. The work focuses on improving of new LED board thermal management.

Thermal resistance investigations on new leadframe-based LED packages and boards

  • Autoři: Pardo, B., Gasse, A., Fergeix, A., prof. Ing. Jiří Jakovenko, Ph.D., Werkhoven, R. J., Perpina, X., Jorda, X., Vellvehi, M., Weelden, T., Bancken, P.
  • Publikace: Microelectronics Reliability. 2013, 8(53), 1084-1094. ISSN 0026-2714.
  • Rok: 2013
  • DOI: 10.1016/j.microrel.2013.02.016
  • Odkaz: https://doi.org/10.1016/j.microrel.2013.02.016
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In Solid State Lighting, thermal management is a key issue. Within the CSSL consortium, we have developed an advanced leadframe based LED package to reduce the thermal resistance of the component. Numerical simulations have been implemented using Ansys software and thermal measurements have been carried out using the forward voltage method to derive the thermal resistance. The T3ster transient thermal analysis has been used to determine the different thermal resistance contributions in the package and in the board, showing good correlation between experimental and simulation results. As a result, low thermal resistances of 5.5 K/W have been obtained on our advanced leadframe based LED package and have been compared with the standard configuration of multiple Rebel LEDs on FR4 board.

3D electrostatic energy harvester

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper discusses the design of an electrostatic generator, power supply component of the self-powered microsystem, which is able to provide enough energy to power smart sensor chains or if necessary also other electronic monitoring devices. One of the requirements for mis analyzer is the mobility, so designing the power supply expects use of an alternative way of getting electricity to power the device, rather than rely on periodic supply of external energy in the form of charging batteries, etc. In this case the most suitable method to use is so-called energy harvesting - a way how to gather energy. This uses the principle of non-electric conversion of energy into electrical energy in the form of converters. The present study describes the topology design of such structures of electrostatic generator. Structure is designed and modeled as a three-dimensional silicon based MEMS. Innovative approach involving the achievement of very low resonant frequency of the structure, while the minimum area of the chip, the ability to work in all 3 axes of coordinate system and ability to be tuned to reach desired parameters proves promising directions of possible further development of this issue. The work includes simulation of electro-mechanical and electrical properties of the structure, description of its behavior in different operating modes and phases of activity. Simulation results were compared with measured values of the produced prototype chip. These results can suggest possible modifications to the proposed structure for further optimization and application environment adaptation.

Capacitor-less LDO regulator in CMOS technology

  • Autoři: Molata, V., Kotě, V., Nápravník, T., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proceedings of Electronic Devices and Systems EDS 2012. Brno: VUT v Brně, FEKT, 2012. pp. 54-59. ISBN 978-80-214-4539-0.
  • Rok: 2012
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The aim of this work is the solution for Low Drop Out (LDO) voltage regulator designed for SoC applications. Increasing priority of optimized power management and consequently prolonging battery life of mobile devices is one of key reasons for chip design changes towards SoC solutions where aforementioned power management components are critical and therefore the main topic of work. Classic power management system consists of several LDO regulators, which provide specific voltage required by individual subsystems. For conventional regulators, independent dedicated capacitors are used. Those provide AC stability and enhance transient characteristics. On the other hand, the same capacitors consume valuable space and occupy pins of a chip. The main problem, which must be solved, is that capacitor-less LDO regulator does not have dedicated capacitor connected to its output, while LDO regulator does. Instead of such dedicated capacitors the capacitor-less regulator is loaded only with capacities of particular systems it powers. Absence of dedicated capacitor has adverse influence on transient properties of the regulator.

Design and Fabrication of 3D Electrostatic Energy Harvester

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper discusses the design of an electrostatic generator, power supply component of the self-powered microsystem, which is able to provide enough energy to power smart sensor chains or if necessary also other electronic monitoring devices. One of the requirements for this analyzer is the mobility, so designing the power supply expects use of an alternative way of getting electricity to power the device, rather than rely on periodic supply of external energy in the form of charging batteries, etc. In this case the most suitable method to use is so-called energy harvesting - a way how to gather energy. This uses the principle of non-electric conversion of energy into electrical energy in the form of converters. The present study describes the topology design of such structures of electrostatic generator. Structure is designed and modeled as a three-dimensional silicon based MEMS. Innovative approach involving the achievement of very low resonant frequency of the structure, while the minimum area of the chip, the ability to work in all 3 axes of coordinate system and ability to be tuned to reach desired parameters proves promising directions of possible further development of this issue. The work includes simulation of electro-mechanical and electrical properties of the structure, description of its behavior in different operating modes and phases of activity. Simulation results were compared with measured values of the produced prototype chip. These results can suggest possible modifications to the proposed structure for further optimization and application environment adaptation.

Design and life time evaluation of various LED boards for SSL lamp

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D., Formánek, J., Werkhoven, R., Kunen, J., Bancken, P., Bolt, P. J., Molata, V., Kotě, V., Nápravník, T., prof. Ing. Miroslav Husák, CSc.,
  • Publikace: Proceedings of Electronic Devices and Systems EDS 2012. Brno: VUT v Brně, FEKT, 2012. pp. 161-166. ISBN 978-80-214-4539-0.
  • Rok: 2012
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Main role of each LED board is to transport heat from LED die to heat sink and keep the thermal stresses in all layers as low as possible. Thermal stress has been studied for wide temperature range that can affect the LED boards (-40 to +125oC). Thermal stress cycles that can lead to the LED board failure have been calculated. Simulations have been completed with ANSYS structural analysis where temperature dependent stress-strain material properties have been taken into account.

DESIGN AND VALIDATION OF AN SMPS POWER DISTRIBUTION NETWORK

  • Autoři: Thomas, M., Vacula, P., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proceedings of Electronic Devices and Systems EDS 2012. Brno: VUT v Brně, FEKT, 2012. pp. 60-65. ISBN 978-80-214-4539-0.
  • Rok: 2012
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    For modern RF Power Amplifier switched mode power supply, size and pin count has become one of the main constraints. Common practice in step-down DC-DC converter is to split the control and power part supplies by having dedicated pin/ball for each part. We will show here that it is possible to share a single supply pin for powering both the output stage and the sensitive control part of a 0.65A Step Down converter. Sharing of the positive supply pin allows the circuit to fit in a WLCSP 9 balls package of 1.2mm x 1.2mm [1]. This approach has been implemented in a silicon chip and validated by measurement.

Design for reliability of solid state lighting systems

  • Autoři: Perpina, X., Werkhoven, R., prof. Ing. Jiří Jakovenko, Ph.D., Formánek, J., Vellvehi, M., Jorda, X., Kunen, J., Bancken, P., Bolt, P. J.
  • Publikace: Microelectronics Reliability. 2012, 9-10(52), 2294-2300. ISSN 0026-2714.
  • Rok: 2012
  • DOI: 10.1016/j.microrel.2012.06.068
  • Odkaz: https://doi.org/10.1016/j.microrel.2012.06.068
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This work presents a methodology to design an SSL system for reliability. An LED lamp is thermally characterised and its model thermally simulated, indicating that the LED board (FR4 board with thermal vias, copper tracks and LED package) is the thermally most stressed part. Therefore, a thermo-mechanical analysis is performed from a detailed LED board model to study reliability and lifetime limits, using thermal boundary conditions deduced from the thermal simulation of the whole LED lamp. Based on this analysis the weakest spots are identified as the metal vias in the LED package and the interconnection area between the LED package and copper tracks on the FR4 board.

Differential Evolutionary Optimization Algorithm Applied to ESD MOSFET Model Fitting Problem

  • Autoři: Nápravník, T., Kotě, V., Molata, V., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proceedings of the 2012 IEEE 15th International Symposium on Design and Diagnostics of Electronic Circuits and Systems (DDECS). New York: IEEE Computer Society Press, 2012. p. 155-158. ISBN 978-1-4673-1185-4.
  • Rok: 2012
  • DOI: 10.1109/DDECS.2012.6219043
  • Odkaz: https://doi.org/10.1109/DDECS.2012.6219043
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The aim of this paper is to present the utilization of modern optimization algorithm called Differential Evolution to automatically fit the appropriate Electrostatic discharge (ESD) model to the measured data from a test chip without the need of manual model-parameter tuning, which presents very time and resource-consuming process. In this paper, the optimization procedure and the results of fitting the generic process NMOST model to the piece-wise linear I-V characteristic are presented.

ESD MOSFET model calibration by differential evolutionary optimization algorithm

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The aim of this paper is to present the utilization of modern optimization algorithm called Differential Evolution to automatically fit the measured data from test chip to the appropriate electrostatic discharge (ESD) model without the need of manual model-parameters tuning. In contrast with proposed method the traditional approach can be very time and resource consuming. To the best knowledge of the authors, this novel approach has never been previously used. Short introduction to ESD NMOST function and properties are presented along with basic overview of differential evolutionary optimization algorithm. Results of fitting the technology-optimized macro-model of NMOST to the simple piece-wise linear model of MOSFET snapback I-V characteristic will be presented.

FEM Thermomechanical Simulation of Low Power LED Lamp for Energy Efficient Light Sources

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper presents modeling and simulation of thermal distribution, heat transfer, and mechanical stress are virtually essential for any design of structures and devices in electronic industry simulation tools make the design easier and enable optimization of many different parameters before fabrication of new structure. This paper presents simulation validation of 3D model of solid state lighting LED bulb for energy efficient and durable light sources. The modeling of structures was performed by CoventorWare tools utilizing finite the element method (FEM). The calculated thermal distribution has been validated with thermal measurement on a commercial LED lamp. Materials parametric study has been carried out to discover problematic parts for heat transfer from power LEDs to ambient.

FEM Thermomechanical Simulation of Low Power LED Lamp for Energy Efficient Light Sources

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper presents modeling and simulation of thermal distribution, heat transfer, and mechanical stress are virtually essential for any design of structures and devices in electronic industry simulation tools make the design easier and enable optimization of many different parameters before fabrication of new structure. This paper presents simulation validation of 3D model of solid state lighting LED bulb for energy efficient and durable light sources. The modeling of structures was performed by CoventorWare tools utilizing finite the element method (FEM). The calculated thermal distribution has been validated with thermal measurement on a commercial LED lamp. Materials parametric study has been carried out to discover problematic parts for heat transfer from power LEDs to ambient.

High Power Solid State Retrofit Lamp Thermal Characterization and Modelling

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Thermal and thermo-mechanical modelling and characterization of solid state lightening (SSL) retrofit LED Lamp are presented in this paper. Paramount importance is to design SSL lamps for reliability, in which thermal and thermo-mechanical aspects are key points. The main goal is to get a precise 3D thermal lamp model for further thermal optimization. Simulations are performed with ANSYS and CoventorWare software tools to compere different simulation approaches. Modelled thermal distribution has been validated with thermal measurement on a commercial 8W LED lamp. Materials parametric study has been carried out to discover problematic parts for heat transfer from power LEDs to ambient and future solutions are proposed. The objectives are to predict the thermal management by modelling of LED lamp, get more understanding in the effect of lamp shape and used materials in order to design more effective LED lamps and predict light quality, life time and reliability

Improved Structure of True Random Number Generator with Direct Amplification of Analog Noise

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Research in the sphere of random number generators is a dynamically evolving segment. The sequences of non-deterministic numbers with some specific probability distribution are especially required for the need of greater safety. This paper deals with the true random number generator (TRNG) that use direct amplification of analog noise for generation random number sequences. The true random number generators help to ensure the security of cryptographic and communication systems by the generation of different session keys. TRNGs can be also used in simulations of various physical and non-physical problems as so-called Monte Carlo technique. The proposed generator exploits a physical phenomenon - noise in semiconductor devices - that is purely random. Its structure is based on generic architecture. Noise source is created by noise amplifiers and core with bipolar transistors. For reduction of potential bias, the XOR corrector and the von Neumann corrector are implemented in the post-processing block. The proposed true random number generator is controlled by the microcontroller that also mediates communication TRNG with personal computer. Proposed structure was simulated and debugged using software model that was created in Verilog-A HDL language. Quality of output random number sequences was evaluated on the base of the Federal Information Processing Standards (FIPS) and the National Institute of Standards and Technologies (NIST) test suites. This work will serve as a base of following research of the reliable true random number generator that will be designed in CMOS technology and will be implemented in cryptographic applications for ensuring secure data transfers.

LED Driver Thermal Design Considerations for Solid-State Lighting Technologies

  • Autoři: Perpina, X., Werkhoven, R., Vellvehi, M., Jorda, X., Kunen, J., prof. Ing. Jiří Jakovenko, Ph.D., Bancken, P., Bolt, P. J.
  • Publikace: EuroSimE 2012 - Proceedings of the conference www.eurosime.org. Porto: IEEE, 2012. pp. 1-4. ISBN 978-1-4673-1511-1.
  • Rok: 2012
  • DOI: 10.1109/ESimE.2012.6191751
  • Odkaz: https://doi.org/10.1109/ESimE.2012.6191751
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper summarizes a study into the thermal influence of an LED driver board on an SSL Lamp. Full thermal characterization of an LED lamp and driver board is carried out by infrared thermography and by monitoring specific locations with thermocouples. The experimental results have been used to set up and validate a predictive simulation model for both the SSL lamp and the driver board. With the obtained simulation model the driver board temperature is investigated under operational conditions for two alternative designs

Pressure Sensor Package Simulation in Large Temperature Range

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Modeling and results of thermal cycling measurement of a high temperature pressure sensor packaging is presented. The packaging is based on the green-state milling of alumina to the desired geometry and conduits for the electrical conductors, followed by sintering of the ceramics with the electrical conductors inside. The electrical interconnections are based on silver. For short term operation, the package can be exposed to temperatures close to the melting temperature of silver (961 °C). It has shown operational in temperature cycling above 600 °C for more than 1800 hours. Modeling of the package shows that the stresses in the electrical interconnections are close to the yield stress of silver at 20 °C. The stress free temperature for simulation was set to 850 °C. Temperature induced stress and strains in the packaging and a fatigue simulation are performed. The package is generic and can be converted to fit most geometries and high temperature applications.

Structure, Modeling and Realization of True Random Number Generator with Analog Noise Amplification

  • Autoři: Kotě, V., Nápravník, T., Molata, V., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proceedings of Electronic Devices and Systems EDS 2012. Brno: VUT v Brně, FEKT, 2012. pp. 145-150. ISBN 978-80-214-4539-0.
  • Rok: 2012
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper deals with true random number generator (TRNG) with analog noise amplification. It is device with non-deterministic features that has to be able to generate random bits. Random number generators help to ensure the security of cryptographic and communication systems by the generation of different session keys or are also used in simulators of various problems, for example, in the simulators of electrical circuits. Generated sequences of random numbers have specific features such as uniform distribution and high entropy. Part of this paper is description of realized hardware generator and its software model. Base on the general architecture of TRNG, structure of this generator was proposed. For debugging of proposed structure, software model in Verilog-A HDL language was created. The hardware generator was realized on the printed circuit board. Quality of output random bit sequences from software model and from realized generator was tested by the FIPS and NIST test suites.

Thermal Resistance Investigations on New Leadframe-Based LED Packages and Boards

  • Autoři: Pardo, B., Gasse, A., Fargeix, A., prof. Ing. Jiří Jakovenko, Ph.D., Werkhoven, R., Perpina, X., Van Weelden, T., Bancken, P.
  • Publikace: EuroSimE 2012 - Proceedings of the conference www.eurosime.org. Porto: IEEE, 2012. pp. 1-4. ISBN 978-1-4673-1511-1.
  • Rok: 2012
  • DOI: 10.1109/ESimE.2012.6191750
  • Odkaz: https://doi.org/10.1109/ESimE.2012.6191750
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In Solid State Lighting, thermal management is a key issue. Within the C-SSL consortium, we have developed an advanced leadframe based package to reduce the thermal resistance of the component. Numerical simulations have been implemented using Ansys software and thermal measurements have been carried out using the forward voltage method to derive the thermal resistance. The T3ster? transient thermal analysis has been used to determine the different thermal resistance contributions in the package and in the board showing good correlation between experimental and simulation results. Low thermal resistances of 5.5 K/W have been obtained on our advanced leadframe based package and have been compared with standard Rebel LEDs on board

Thermo-mechanical evaluation and life time simulation of high power LED lamp boards

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D., Formánek, J., Perpina, X., Werkhoven, R., Kunen, J., Bancken, P., Bolt, P. J.
  • Publikace: EuroSimE 2012 - Proceedings of the conference www.eurosime.org. Porto: IEEE, 2012. pp. 1-4. ISBN 978-1-4673-1511-1.
  • Rok: 2012
  • DOI: 10.1109/ESimE.2012.6191760
  • Odkaz: https://doi.org/10.1109/ESimE.2012.6191760
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This work deals with a precise 3-D modelling of several LED board technologies mainly focused on thermal, thermo-mechanical evaluation and life time prediction to compare their performances. Main role of each LED board is to transport heat from LED die to heat sink and keep the thermal stresses in all layers as low as possible. Thermal stress has been inspected for the widest temperature range that can affect the LED boards (-40 to +125oC). Additionally, thermal stress cycles that lead to the LED board failure due to thermal fatigue have been calculated. Simulations have been completed with ANSYS structural analysis where temperature dependent stress-strain material properties have been taken into account. The objective of the analysis is to optimize not only the thermal management by thermal simulation of LED boards, but also to find potential problems from mechanical fatigue point of view.

Utilization fo Differential Evolutionary Optimization Algorithm for ESD MOSFET Model Fitting

  • Autoři: Nápravník, T., Kotě, V., Molata, V., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proceedings of Electronic Devices and Systems EDS 2012. Brno: VUT v Brně, FEKT, 2012. pp. 33-38. ISBN 978-80-214-4539-0.
  • Rok: 2012
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The aim of this paper is to present the utilization of modern optimization algorithm called Differential Evolution to automatically fit the measured data from test chip to the appropriate electrostatic discharge (ESD) model without the need of manual model-parameters tuning. In contrast with proposed method this traditional approach can be very time- and resource-consuming. Results of fitting the technology-optimized macro-model of NMOST to the simple piece-wise linear model of MOSFET snapback I-V characteristic will be presented.

Impact of ZnO gate interfacial layer on piezoelectric response of AlGaN/GaN C-HEMT based ring gate capacitor

  • DOI: 10.1016/j.sna.2011.09.028
  • Odkaz: https://doi.org/10.1016/j.sna.2011.09.028
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    We report on a piezoelectric response investigation of AlGaN/GaN circular high electron mobility transistor (C-HEMT) based ring gate capacitor as a new stress sensor device to be potentially applied for dynamic high-pressure sensing. A ring gate capacitor of C-HEMT with an additional ZnO gate interfacial layer was used to measure the changes in the piezoelectric charge induced directly by the variation of piezoelectric polarization of both gate piezoelectric layers (AlGaN, ZnO) for harmonic loading at different excitation frequences. Our experimental results show that about 10 nm thick piezoelectric ZnO layer grown on ring gate/AlGaN interface of C-HEMT can yield almost a 60% increase in the piezoelectric detection sensitivity of the device due to its higher piezoelectric coefficient.

MEMS prvky pro radioelektroniku

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Článek popisuje nové RF komponenty realizované mikroelektronickými technologiemi MEMS. Pozornost je věnována používaným základním principům řízení činnosti RF prvků. Příspěvek se věnuje RF spínačům a cívkám realizovaným v technologiích MEMS. Jsou popsány principy činnosti, konstrukce a typické parametry.

Nanotechnologie při výrobě integrovaných obvodů

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Na každodenní novinky v oblasti elektronických zařízení jsme si v poslední době zvykli tak, že nás prakticky nic nepřekvapí. Elektronika je v dnešní době všudypřítomná a málokoho dnes udiví stále dokonalejší komunikační zařízení, telefony, počítače, a takto bychom mohli pokračovat v nekonečném výčtu elektronických zařízení, které používáme v každodenním životě. Všechny tyto aplikace by však neexistovaly, nebýt neustálého zdokonalování výrobních polovodičových technologií, které se vyvíjejí v skrytu uzavřených hal několika elektronických gigantů. Přitom vynález integrovaného obvodu před dvěma lety oslavil teprve padesát let! V tomto článku se podíváme na moderní trendy ve výrobních technologiích v oblasti křemíkových integrovaných obvodů

Návrh osmibitového A/D převodníku s dvojí integrací

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Tento článek obsahuje kompletní postup návrhu osmibitového A/D převodníku s dvojí integrací. Zároveň jsou v něm uvedeny výsledky měření vyrobeného integrovaného obvodu. Cílem této práce bylo navrhnout obvod s rozlišením 8 bitů a přesností +/- 1/2LSB INL a DNL.

Piezoelectric response of AlGaN/GaN-based circular-HEMT structures

  • DOI: 10.1016/j.mee.2010.12.013
  • Odkaz: https://doi.org/10.1016/j.mee.2010.12.013
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This papers reports, for the first time, on a piezoelectric response investigation of AlGaN/GaN-based circular high electron mobility transistor (C-HEMT) structures, which can be potentially applied in new devices for dynamic pressure and stress sensing. We present the processing technology and a piezoelectric performance analysis of the C-HEMT devices. The analysis obtained experimentally is compared with the results of electro-mechanical simulation. The measurements and simulations revealed a good linearity in the piezoelectric response and excellent stress detection sensitivity that is independent from the frequency range measured.

Thermal simulation and validation of 8W LED lamp

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This work deals with thermal simulation and characterization of solid state lightening (SSL) LED Lamp in order to get precise 3D thermal models for further lamp thermal optimization. Simulations are performed with ANSYS-CFX and CoventorWare software tools. The simulated thermal distribution has been validated with thermal measurement on a commercial 8W LED lamp. Materials parametric study has been carried out to discover problematic parts for heat transfer from power LEDs to ambient. The objectives are to predict the thermal management by simulation of LED lamp and environment and to get more insight in the effect of lamp shape and materials used in order to design more effective LED lamps

Thermo-mechanical Modeling and Characterization of High Power Solid State LED Lamp

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D., Werkhoven, R., Formánek, J., Kunen, J., Bolt, P. J., Ing. Pavel Kulha, Ph.D., Bancken, P.
  • Publikace: Electronic Devices and Systems, IMAPS CS International Conference 2011 Proceedings. Brno: VUT v Brně, FEKT, 2011. p. 178-201. ISBN 978-80-214-4303-7.
  • Rok: 2011
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper describes thermal simulation and validation of solid state lighting (SSL) LED Lamp with a view to get accurate 3D thermal models for supplementary lamp thermal optimization. Simulations are made by ANSYS-CFX and CoventorWare software tools. The calculated thermal distribution has been validated with thermal measurement on a commercial 8W LED lamp. Materials parametric study has been carried out to discover problematic parts for heat transfer from power LEDs to ambient. Main goal of the work is to predict the thermal management by simulation of LED lamp to get more insight in the effect of lamp shape and materials used in order to design more effective and more power LED lamps

Vysokoteplotní MEMS struktury pro měření koncentrace plynů CO, H2, NOx a uhlovodíků

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Hlavním cílem prezentované práce je návrh, modelování a charakterizace nových Mikro-Elektro-Mechanických Struktur (MEMS) na bázi GaAs a GaN, které jsou určeny pro vysokoteplotní detektory koncentrace plynů. Navržené systémy mohou detekovat plyny CO, H2, NOx a uhlovodíky. Teplotní a mechanické vlastnosti navržených GaN a GaAs MEMS struktur jsou porovnány s vlastnostmi struktur založených na křemíkových technologiích. Byla navržena nová výrobní MEMS technologie pro volnou strukturu zavěšeného GaN ostrůvku. Provozní teplota struktur na bázi GaN může dosahovat až 1000°C. Navržený technologický postup výroby je vhodný i pro integraci MESFET a HEMT tranzistorů, které mohou integrovány společně s MEMS strukturami

Novel Analog Synthesis Tool Implemented to the Cadence Design Environment

  • Autoři: Kubař, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: The International Workshop on Symbolic and Numerical Methods, Modeling and Applications to Circuit Design 2010. Tunis: IEEE - Tunisia, 2010. ISBN 978-1-4244-6815-7.
  • Rok: 2010
  • DOI: 10.1109/SM2ACD.2010.5672330
  • Odkaz: https://doi.org/10.1109/SM2ACD.2010.5672330
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Analog synthesis is very hot topic at present. It can save enormous part of the design time. This paper presents work on novel analog synthesis tool capable of choosing circuit architecture and to size its devices by optimization to meet the design specification. This tool is implemented into Cadence design environment to be easily used by the analog designers.

Novel Methods of the Analogue Integrated Circuit Design Teaching

  • Autoři: Kubař, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Electronic Devices and Systems, IMAPS CS International Conference 2010 Proceedings. Brno: VUT v Brně, FEI, 2010. p. 190-195. ISSN 1862-6351. ISBN 978-80-214-4138-5.
  • Rok: 2010
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Integrated circuit design is one of the most progressive technical fields so the teaching of the students in this field must be also very progressive. This paper presents two methods of innovation in integrated circuits design teaching that was integrated in the lectures in the Czech Technical University - Cadence design system tutorial and analogue circuit's synthesizer.

One-chip MOS Structure for Temperature Flow Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    There is described a MOS structure in the use of flow sensor system in the paper. MOS structure as a temperature sensor allows measurement of temperature gradient. One allows computation of direction of air flow over the structure chip. Four MOS structure of temperature sensors has been used for the design of sensitivity flow sensor. Different arrangements of MOS structure have been designed. Software standard tools have been used for simulation and modeling of structure properties. Maximum values of structure sensitivity in dependence on operating temperature have been computed. The parameters have been used for the design. Suitable structure temperature was found during simulations. Circuit connection of sensor temperature matrix was designed. New results of sensitivity and resolution of MOS sensor systems were obtained. The working efforts were focused on the sensitivity, angle resolution and small power consumption.

Piezoelectric response of AlGaN/GaN based circular-HEMT structures

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In this work we have proposed for the first time a circular-HEMT (C-HEMT) device for external pressure and stress sensing. There are some advantages of this structure comparing to that of the conventional rectangular HEMT. First of all there is no ""MESA""- etching step needed to define C-HEMT, so the continuity of the top AlGaN barrier layer is not broken and therefore, no partial relaxation of the applied bending stress is there observed.

Simple Vertical Velocity Measurement System for Different Use

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The measurement of vertical velocity is based on principle of evaluating the change of an atmospheric pressure. The dependence which evaluates the vertical velocity is derived from the exponential form of the barometric equation which relates the air pressure versus the altitude. This relatively simple method has some drawbacks. First of all it is a nonlinearity of the exponential dependency of the pressure versus altitude. Also the air temperature plays a significant role in this method. Compensated methods for measuring the vertical velocity embrace the vertical velocity correction. The correction is calculated from the horizontal velocity change which induces another vertical velocity change. The acceleration is evaluated in the horizontal direction using the information about the dynamic pressure. The solution is based on the altitude equation, including the effects of temperature. The possibility of nonlinearity compensation and temperature compensation are used.

Temperature Dependence of the Pyroelectric Behaviour in GaN/AlGaN

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    So far the dependence of the spontaneous polarization coefficient for GaN and AlN on temperature has been measured to be minimal, which corresponds with expectation that the spontaneous polarization is reduced at the elevated temperatures of interest. There are also no reports on the piezoelectric polarization at higher temperature. This paper is initial study on the influence of temperature related behaviour in GaN/AlGaN. Summarize recent findings and consideration.

Use of Barometric Sensor for Vertical Velocity Measurement.

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The measure system is based on the principle of evaluating the change of an atmospheric pressure. The vertical velocity is derived from the exponential form of the barometric equation which relates the air pressure versus the altitude. The relatively simple method has some drawbacks (a nonlinearity of the exponential dependency of the pressure versus altitude, the air temperature plays a significant role). There are used the compensated methods for measuring the vertical velocity. The correction is calculated from the horizontal velocity change which induces another vertical velocity change. The solution is based on the altitude equation, including the effects of temperature. The acceleration is evaluated in the horizontal direction using the information about the dynamic pressure. The possibility of nonlinearity compensation and temperature compensation are used.

Versatile Engine for Virtual Testing of ADC/DAC Non-Linearity

  • DOI: 10.1109/SM2ACD.2010.5672327
  • Odkaz: https://doi.org/10.1109/SM2ACD.2010.5672327
  • Pracoviště: Katedra teorie obvodů, Katedra mikroelektroniky
  • Anotace:
    We propose a novel versatile engine for behavioral or transistor-level design verification of data converters. This tool is dedicated to IC designers to verify static performance of the converters during their design. It is based on advanced Servo-Loop method presented in and extended by features such as innovative DAC testing method. The environment proposed supports various converter resolutions and several types of digital coding.

Wireless Sensor Network Control System

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The core of the paper is the control system with a few electronic blocks (control, actuator, software, and RF wireless communication). The control block drives operations in the system, the wireless block ensures communication, and data transfer, the actuator part is drived by control block. The software drives all operations in the system. Sensors ensure basic information about environment. The number of sensor can be variable. The control block cooperates with wireless sensors, and wireless actuators. The heart of the system is the control microprocessor. The system communicates with PC, mobile phone etc. There was used a new architecture of a multisensor system for physical measurement using wireless data transfer in the paper. Different control software was designed for wireless parts.

Wireless Sensor System with Bidirectional Communications

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The system contains units: wireless, control, actuator, software equipment. RF wireless unit ensures wireless communication between control unit and sensors as well as wireless switch unit. The control unit controls system operation, i.e. communication transfer, sensor data processing as well as switching of actuator unit. Actuator switch unit is wireless controlled by control unit. There were hardware and software realized and tested in the designed system. The system was designed to operate with different type of physical sensors. The system can used PC, PDA or mobile phone to communication as well as signal processing. The control unit communicates with wireless temperature sensors and wireless switch units. The wireless temperature sensors measure temperature periodically and convey the measured data to the control unit. The actuator units communicate with the control unit. The main part is the control microprocessor. The run of the system is supported by the control programs.

AlGaN/GaN HEMT based micro-hotplate for high temperature gas sensors

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In this work we present a new approach in design and fabrication of MEMS micro-hotplate to be applied for high temperature metal oxide gas sensors. The micro-hotplate design concept uses high power and high temperature capability of AlGaN HEMT device.

Design and Measurement of the 8-bit dual-slope A/D Converter

  • Autoři: Kubař, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Electronic Devices and Systems, IMAPS CS International Conference 2009 Proceedings. Brno: VUT v Brně, FEI, 2009. pp. 325-330. ISBN 978-80-214-3933-7.
  • Rok: 2009
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The design and measurement of 8-bit dual-slope integrating A/D converter is presented in this paper. SAR and sigma-delta A/D converters are used in present RFID devices. The aim of this work is to introduce dual-slope conversion principle to RFID devices and to meet the requirement of 8-bit resolution with +/- 1/2LSB INL and DNL accuracy.

Experience in Virtual Testing of RSD Cyclic A/D converters

  • Autoři: Kubař, M., Ing. Ondřej Šubrt, Ph.D., Martinek, P., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proc. of 12th IEEE Design and Diagnostics of Electronic Circuits and Systems Workshop 2009 (DDECS'09). Los Alamitos: IEEE Computer Society Press, 2009. p. 178-181. ISSN 2334-3133. ISBN 978-1-4244-3339-1.
  • Rok: 2009
  • DOI: 10.1109/DDECS.2009.5012123
  • Odkaz: https://doi.org/10.1109/DDECS.2009.5012123
  • Pracoviště: Katedra teorie obvodů, Katedra mikroelektroniky
  • Anotace:
    This paper deals with the ADC non-linearity extraction using a newly developed Virtual Testing Environment (VTE). The VTE proposed is built on Verilog-A implementation of the Servo-Loop unit fully integrated into Cadence design environment. The Servo-Loop method used is aimed at the non-linearity extraction of static ADC transfer curve; in this paper, we prove an advanced Servo-Loop version focusing on behavioral and transistor-level example of the Residual Signed Digit (RSD) cyclic A/D converter design. Powerful capabilities of the proposed VTE were successfully confirmed by a large set of behavioral and transistor-level simulations in Spectre.

GaN MICRO-HOTPLATES FOR HIGH TEMPERATURE MEMS GAS SENSOR APPLICATIONS

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In this work we present a new approach in design and fabrication of MEMS micro-hotplate to be applied for high temperature metal oxide gas sensors.

GaN, GaAs and Silicon based Micromechanical Free Standing Hot Plates for Gas Sensors

  • DOI: 10.1016/j.proche.2009.07.200
  • Odkaz: https://doi.org/10.1016/j.proche.2009.07.200
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Main objective of the presented work deals with design, modelling and characterization of new micro machined GaAs and GaN based hot plate thermal converters which are considered to operate with high temperature metal oxide gas sensors, that can analyse various gases, such as CO, H2, NOx and hydrocarbons.

Microsystems, Microsensors and Microactuators: Research and Education

  • DOI: 10.1109/MSE.2009.5270814
  • Odkaz: https://doi.org/10.1109/MSE.2009.5270814
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The education involves nanomaterials and smart materials for sensor and smart micro and nanosystems. System of different interconnected laboratories is necessary for high quality education. Laboratories represent design flow (design, simulation, models and modelling, verifications, testing and corrected outputs). Direct research connection as well as development together with education and direct student participation in research is desirable. Student individual projects serve as a part of research. Several workplaces are used where students work on defined tasks. The use of special instrumentation, microscope and other nanotechnology workplaces in the different institutes is necessary. There have been established direct links to technological companies. Employment of students enables to increase cooperation with companies. Students participate in research projects as well. Individual student projects contribute to student professional shaping.

New Micromechanical Free Standing Hot Plates with HEMT Heater

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Main objective of the presented work deals with design, modelling and characterization of new micro machined GaAs and GaN based hot plate thermal converters. A new GaN based suspended membrane-type hot plate MEMS processing technology was developed for working temperature range up to 1000°C.

VIRTUAL TESTING METHOD FOR STATIC ADC NON-LINEARITY - RSD CYCLIC A/D CONVERTER CASE

  • Autoři: Ing. Ondřej Šubrt, Ph.D., Kubař, M., Martinek, P., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: XIX IMEKO World Congress 2009 - Fundamental and Applied Metrology. Lisbon: Instituto Superior Técnico/Instituto de Telecomunicaçoes Portugal, 2009. p. 690-693. ISBN 978-963-88410-0-1.
  • Rok: 2009
  • Pracoviště: Katedra teorie obvodů, Katedra mikroelektroniky
  • Anotace:
    One of the recent approaches to test A/D converter performance is the so-called Servo-Loop Method. This method is aimed at the non-linearity extraction of static ADC transfer curve. In this paper, we prove an advanced Servo-Loop version focusing on behavioral and transistor-level example of the Residual Signed Digit (RSD) cyclic A/D converter design. In this paper, we establish a Virtual Testing Environment (VTE) built on Verilog-A implementation of the Servo-Loop unit fully integrated into Cadence design environment.

Design of the state machine for A/D converter

  • Autoři: Kubař, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: ASDAM 2008 Conference Proceedings. Bratislava: Slovak University of Technology, 2008. p. 171-174. ISBN 978-1-4244-2325-5.
  • Rok: 2008
  • DOI: 10.1109/ASDAM.2008.4743309
  • Odkaz: https://doi.org/10.1109/ASDAM.2008.4743309
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The control logic design for A/D converter is presented I this paper. Control logic is the crucial part of each integrated circuits it manages all functions of the circuit. It is a digital part of the circuit. The way how to design this part without digital designer and without using digital design methods is presented in this paper. It is great help for analog designers who need to design it themselves because they have usually no experience in this area.

GaAs based micromachined thermal converter for gas sensors

  • DOI: 10.1016/j.sna.2007.05.014
  • Odkaz: https://doi.org/10.1016/j.sna.2007.05.014
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The micromachining technology and an electro-thermo-mechanical performance analysis of GaAs based micromachined thermal converter (MTC) device to be designed for metal oxide gas sensors are presented. MTC device introduced exhibits a low power consumption due to by high thermal resistance values (Rth = 15-21 K/mW), uniform temperature distribution, a fast temperature time response (τ ~ 1.5-1.8 ms), and good mechanical integrity and thermal stability. It is also fully compatible with the GaAs HEMT based signal-processing and controlling electronics to be monolithically integrated with the gas sensors. The both a simple analytical and three-dimensional thermal modeling of the MTC device was performed. It supported the high electro-thermal conversion efficiency and fast temperature time response of the MEMS device as evaluated by the experiments.

GaN and GaAs Micromechanical Thermal Converter for Gas Sensors

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    simulation fabrication and characterization of new GaN and GaAs Micromechanical Hotplate Gas Sensor (MHGSs). GaAs and GaN MHGSs seem to be very attractive for design of thermally based MEMS sensor devices

MEMS and NEMS research for education

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper describes methods of active involvement of students in research work and application of research work results in educational process. Individual tasks are parts of solutions of large research projects. Individual work contributes to their professional forming. The research in the area of nanoelectronics (MEMS and NEMS) is discussed. A new method for education in the area of nanotechnology, narrow connection research and education, use of the nanotechnology equipment (AFM, nanolitography, etc.). The effort is targeted at the connection of the research an education, connection different workplaces from the different institutes.

Pressure sensor data processing for vertical velocity measurement

Solution of Vertical Velocity Measurement Using Pressure Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The core of the paper describes a sensor system for vertical velocity measurement using pressure sensor. Problem of nonlinearity due to the exponential function of air pressure versus altitude is discussed in detail. The paper also deals with the possibility of nonlinearity compensation using a complementary function (electronic logarithm). The system solution must also include temperature compensation. The problem of increasing sensitivity is treated in the paper. The transient analysis of the electronic circuit connection was used for vertical velocity simulation.

Suspended Island MEMS Structure for High Temperature Gas Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    simulation and fabrication of new GaN and GaAs Micromechanical Thermal Converters (MTCs) developed for Gas sensors. GaAs and GaN MTCs seem to be very attractive for design of thermally based MEMS sensor devices. To achieve low power consumption in the sensor operation range of 200 to 500 oC we need to ensure high thermal isolation of sensing layers.

Temperature Wireless Sensor Network

Tutorial of the control logic design for analogue integrated circuits designers

  • Autoři: Kubař, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: SMACD 2008 Proceedings. Erfurt: Institut für mikroelektronik- und mechatronik-systeme gGmbH, 2008. p. 237-240. ISBN 978-3-00-025761-2.
  • Rok: 2008
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The tutorial of the control logic design for analog integrated circuits designers is presented I this paper. Control logic is the crucial part of each integrated circuits it manages all functions of the circuit. It is a digital part of the circuit. The way how to design this part without digital designer and without using digital design methods is presented in this paper. It is great help for analog designers who need to design it themselves because they have usually no experience in this area.

Tutorial of the design of the state machine for analogue integrated circuits

  • Autoři: Kubař, M., prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Electronics Devices and Systems Proceedings. Brno: Vysoké učení technické v Brně, 2008. pp. 336-340. ISBN 978-80-214-3717-3.
  • Rok: 2008
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The tutorial of the control logic design for analog integrated circuits designers is presented I this paper. Control logic is the crucial part of each integrated circuits it manages all functions of the circuit. It is a digital part of the circuit. The way how to design this part without digital designer and without using digital design methods is presented in this paper. It is great help for analog designers who need to design it themselves because they have usually no experience in this area.

Design and Characterization of MEMS Thermal Converter

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper presents design and characterization of a new GaAs based RF Microwave Power Sensor (RFMPS) microsystem. The main criteria for the RFMPS optimization are to keep the stable thermal distribution and minimize the thermal stress. The concept of absorbed power measurement is based on thermal conversion, where absorbed RF power is transformed into thermal power, inside a thermally isolated system.

Design and Characterization of new GaAs Micromechanical Thermal Converter developed for Microwave Power Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In this report we demonstrate the design of new GaAs based Micromechanical thermal converter (MTC) that creates heart of the RF power sensor microsystem. Transmitted power is the main quantity measured in RF systems. The classical approach to transmitted power measurement is based on the measurement of absorbed power waves (incident and reflected) that requires sophisticated multiple power meter structures and need complex calibration. A better technique of absorbed power measurement is based on thermal conversion, where absorbed RF power is transformed into thermal power, inside a thermally isolated system.

Design and Modeling of Micromechanical GaAs based Hot Plate for Gas Sensors

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper discusses design, simulation and fabrication of new Micromachined Thermal Converters (MTCs) based on GaAs developed for Gas sensors. Metal oxide gas sensors generally work in high temperature mode that is required for chemical reactions to be performed between molecules of the specified gas and the surface of sensing material. There is a low power consumption required to obtain the operation temperatures in the range of 200 to 500 oC.

Micromechanical GaAs Hot Plates for Gas Sensors

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper discusses the design, simulation and fabrication of new Micromachined Thermal Hot Plates (MTHPs) based on GaAs, which were designed for Gas sensors. High sensitivity and low power are expected for present metal oxide Gas sensors, which generally work in high temperature mode (which is essential for chemical reactions to be performed between molecules of the specified gas and the surface of sensing material). Because low power consumption is required, even for operation temperatures in the range of 200 to 500 oC, high thermal isolation of these devices are necessary.

Micromechanical GaAs Thermal Convertor for Gas Sensors

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper discusses design, simulation and fabrication of new Micromechanical Thermal Converters (MTCs) based on GaAs developed for Gas sensors. GaAs MTCs seem to be very attractive for design of thermally based MEMS sensor devices. High thermal isolation of these devices can be done by implementing of free micromechanical hot plates which is designed as thin as possible.

Multisensor Network for Distance Data Pick-Up

PVDF Self Powered Microsystem

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper describes concept of self powered microsystem. The main problem is how to supply the energy to the system. Nowadays, there is rising demand on wireless sensor systems where no direct connection to the outside world exists. Application of integrated battery all kinds is not appropriate because of determined service life and not suitable dimensions. Autonomous micro generator based on piezoelectric polymer material with ability to change the ambient mechanical energy to the electrical energy will be appropriate. Used material shows better properties then conventional ceramic materials (PZT). Several layouts of such micro generators were designed. The device is not optimized yet and significant improvements are envisaged in the future.

Characterization of MEMS sensor for RF Transmitted Power Measurement

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Thermo mechanical design and analysis of thermal GaAs-based MEMS devices. It will provide the procedure how thermal analysis should be made and model equations used to describe conduction, convection, radiation and mechanical effects caused by nonhomogenous temperature distribution. This is demonstrated on the design of Micromechanical thermal converter (MTC) that creates heart of the RF power sensor microsystem.

Characterization of MEMS sensor for RF Transmitted Power Measurement

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In this report we introduce the procedure for performing a thermo mechanical design and analysis of thermal GaAs-based MEMS devices. It will provide the procedure how thermal analysis should be made and model equations used to describe conduction, convection, radiation and mechanical effects caused by nonhomogenous temperature distribution.

Direction sensitivity matrix with PLL temperature sensor

  • DOI: 10.1109/ASDAM.2006.331183
  • Odkaz: https://doi.org/10.1109/ASDAM.2006.331183
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In the paper there is presented temperature transducer with PLL signal processing of sensor data. The principle of temperature sensor is based on the MOS structure behaviour in the temperature range. The strong and weak inversion modes are used. There is used matrix of temperature sensors in the design of air flow sensor. Various arrangements of temperature structure are designed. The new circuits design is used.

GaAs based micromachined thermal converter for gas sensors

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D., prof. Ing. Miroslav Husák, CSc., Lalinsky, T.L., Drzik, M.D., Vanko, G.V., Mozolova, Z.M., Hascik, S., Chlpik, J.C., Hotovy, I.H., Rehacek, V.R., Kostic, I.K., Matay, L.M.
  • Publikace: MicroMechanics Europe Workshop. Southampton: University of Southampton, 2006. pp. 113-116. ISBN 0-85432-848-3.
  • Rok: 2006
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Design, micromachining technology and an electro-thermo-mechanical performance analysis of GaAs based micromachined thermal converter (MTC) device as the heart of metal oxide gas sensors are presented. MTC device introduced exhibits a low power consumption (Rth~21 K/mW), uniform temperature distribution, a fast thermal response (τ~1.44 ms), and good mechanical integrity and thermal stability.

GaAs Thermally Based MEMS Devices - Fabrication Techniques, Characterization and Modeling

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Silicon based MicroElectroMechanical Systems are now well understood and widely used in various integrated micromachined microsensors and microactuators. In relation to this, gallium arsenide (GaAs) offers a number of material-related properties and technological advantages over Si. These include well know properties, such as direct band gap transition and high electron mobility. A very important feature of GaAs is the possibility of forming compatible ternary and quaternary compounds by alloying. Using GaAs as a substrate material, formation of AlxGa1-xAs is especially attractive, since their lattice constants are nearly equal, and aluminum and gallium atoms are easily substituted in the lattice without causing too much strain in the film. Thanks to this prominent feature, a number of interesting properties and phenomena, such as high-mobility two-dimensional carrier gases, resonant tunneling, and fractional quantum Hall effect, have been found in the GaAs heterostructure system

Strong and Weak Inversion Mode of MOS in the Design of Direction Sensitivity Matrix

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In the article there is presented a new arrangement of a temperature sensor system for air velocity and direction measurement. The system utilizes temperature dependence of the current through the channel of MOS structure. The geometric arrangement of temperature sensors allows measurement of temperature gradient. Temperature gradient allows to compute direction of air flow over the chip. Optimal operating modes of weak and strong inversion of MOS structure operation have been selected for the design of integrated temperature matrix. The matrix has been used for the design of a probe for measurement. Various arrangements of MOS sensor structures have been designed. CoventorWare and CADENCE software tools have been used for simulation and modeling of sensor properties.

Temperature CMOS Transducer

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper describes design of a temperature sensor with a CMOS temperature transducer and a circuit with phase lock determined for signal processing with PWM output. Two types of the CMOS temperature sensor operating in the weak and strong inversion region were designed.

Temperature CMOS Transducer

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper describes design of a temperature sensor with a CMOS temperature transducer and a circuit with phase lock determined for signal processing with PWM output. Two types of the CMOS temperature sensor operating in the weak and strong inversion region were designed.

Approach to Microsystem Design

Design of MEMS and Microsystems - Models and Simulation

Design of Temperature Matrix with Direction Sensitivity

Design of Temperature Matrix with Direction Sensitivity

Design of Temperature Matrix with Direction Sensitivity

Flow Measure Using of Anemometric Sensor Principle and Oscillator Probe Fluidic

Micromechanical Structures for Low Level Power Measurement in Medical Systems

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper presents the thermal and thermo-mechanical modelling carried on with the aim to find out the optimal temperature distribution of the RF Microwave Power Sensor (RFMPS) microsystem. The sensor can be used in medical wireless data transfer systems to measure and optimise the transmitted power from human body implemented sensors to the data evaluation unit. The main criteria of the RFMPS optimisation are bouth, keep the stable thermal distribution and minimise the thermal stress.

Micromechanical Thermal Converters Compatible with HEMT Technology

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This work discusses the thermo mechanical modelling performed with the aim to optimise the temperature distribution of the Microwave Power Sensor microsystem keeping the thermal stress as low as possible

Modeling of GaAs MEMS for RF Power Measurement in Telecommunications

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This report discusses the design of Thermo-mechanical converter that creates heart of the RF power sensor microsystem which can be used for transmitted power measurement in telecommunications.

Optimization of GaAs MEMS Structures for Microwave Power Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper discusses an improved technique of the absorbed power measurement which is based on thermal conversion principle where absorbed radio frequency (RF) power is transformed into thermal power inside of a thermally isolated Micromechanical Thermal Converter.

Optimization of GaAs MEMS Structures for Microwave Power Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper discusses an improved technique of the absorbed power measurement which is based on thermal conversion principle where absorbed radio frequency (RF) power is transformed into thermal power inside of a thermally isolated Micromechanical Thermal Converter.

Optimization of GaAs MEMS Structures for Microwave Power Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The paper discusses an improved technique of the absorbed power measurement which is based on thermal conversion principle where absorbed radio frequency (RF) power is transformed into thermal power inside of a thermally isolated Micromechanical Thermal Converter.

Sensor System with Differential Arrangement of Temperature MOS Sensor

  • DOI: 10.1109/ICIT.2005.1600678
  • Odkaz: https://doi.org/10.1109/ICIT.2005.1600678
  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In this article, an arrangement of a temperature sensor system is presented. The system utilizes temperature dependence of the current through the channel of MOS structure. Differential arrangement of the temperature sensor is designed. The arrangement allows measurement of temperature gradient. Using suitable geometric arrangement it is possible to compute direction from the temperature gradient, i.e. for example angle of air flow over the chip. Integrated structure of temperature sensors on the chip has orthogonal arrangement. Optimal operating modes have been selected for the design. There have been performed simulations of dependence of temperature sensitivity of the transistors as temperature sensor on changes of its basic parameters. Modes of weak and strong inversion of MOS structure operation have been simulated in the design. Optimal setup of operating mode has been selected for the design of integrated temperature matrix. The matrix has been used for the design of a probe for measurement of velocity and direction of the gas (air) flow over the chip. Various arrangements of MOS sensor structures have been designed. CoventorWare and CADENCE software tools have been used for simulation and modeling of sensor properties

Sensor System with Differential Arrangement of Temperature MOS Sensor

Systems of Models for MEMS Design and Realization

Thermo-Mechanical Optimization of Micromechanical Hot Plate for RF Power to Temperature Conversion

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This report discusses the optimization of micromechanical hot plate thermo converter that creates heart of the RF power sensor microsystem. The conception of absorbed power measurement is based on thermal conversion, where absorbed RF power is transformed into thermal power, inside a thermally isolated system.

Design and simulation of micromechanical thermal converter for RF power sensor microsystem

Integrated Pressure Sensor - Use of Microsystems Model Flow

Intelligent Sensor Structure for Tilt Measure

Macromodel of Intelligent Sensor Structure with Accelerometer

Macromodel of Intelligent Sensor Structure with Accelerometer

Microsystem Models in Integrated Pressure Sensor Design

Microsystem Models in Integrated Pressure Sensor Design

Properties of Strain Sensor with Piezoresistive Layers

Sensors with Implanted Layers for Using in Microsystems

The Design of Anemometric Sensor System for Measurement of Wind Velocity and Direction with Integrated Measure Probe

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    The Design of Anemometric Sensor System for Measurement of Wind Velocity and Direction with Integrated Measure Probe

The Design of Anemometric Sensor System for Measurement of Wind Velocity and Direction with Integrated Measure Probe

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    This paper describes the Design of Anemometric Sensor System for Measurement of Wind Velocity and Direction with Integrated Measure Probe

Thermally Isolated MEMS Thermo Converter for RF Power Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Work discusses the thermo mechanical simulations performed with the aim to optimise the temperature distribution of the Microwave Power Sensor (MPS) microsystem keeping the thermal stress as low as possible.

Výuka návrhu integrovaných obvodů, senzorů a mikrosystémů

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Výuka návrhu integrovaných obvodů, senzorů a mikrosystémů pomocí profesionálníh programů Cadence, Coventor Ware, H-spice.

Approach to Design and Modelling of Microsystems for Communication Use

Design and simulation of the GaAs Micromechanical Thermal Converter for Microwave Transmitted Power Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In this project we discuss the thermomechanical simulations performed in the aim of optimising the GaAs based Micromechanical Thermal Converter that creates heart of Microwave Transmitted power sensor. Conception of the absorbed power measurement is based on thermal conversion where absorbed RF power is transformed into thermal power inside a thermally isolated system. By means of thermal simulations we propose a GaAs Micromechanical Thermal Converter design and layout of the HFET heater and temperature sensor placed on thermally isolated cantilever beam or bridge. Spatial temperature dependences, thermal time constant and power to temperature dependences at different ambient atmospheres are calculated from the heat distribution. The 3D thermal and thermo-mechanical simulations of the sensor structures were performed using CoventorWare from Microcosm Technologies. Thermo-mechanical numerical modelling and simulation have significant influence on optimal topology design of the thermo converter. The main thermo converter characteristics have been optimised and evaluated. The most important ones are the temperature distribution over the sensing area, thermal time response, sensitivity analysis and evaluation of the mechanical stresses caused by deposition (initial stress) and by temperature changes in thermo converter structure. GaAs multilayer cantilever beam creates optimal conditions for both the monolithic integration of GaAs based Heterostructure Field Effect Transistors (HFETs) and thermal isolation of the microwave sensor elements.

Design and Simulation of the GaAs Micromechanical Thermal Converter for Microwave Transmitted Power Sensor

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Thermo mechanical simulations performed with the aim of optimising the temperature distribution of the Micromechanical Thermal Converter (MTC), designed for a Microwave Power Sensor Microsystem

Design of Microsystems using Equivalent Models Between Energy Domains

Mechanical, Thermal and Electrical Behaviour od Si Strain Guge

Mechanical, Thermal and Electrical Behaviour of Si Strain Gauge

Micromechanical Thermal Converter Device Based on Polyimide-Fixed Island Structure

Micromechanical Thermal Converter device Based on Polymide Fixed island Structure

Microsystem design for RF power measurement

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Design and measurement of absorbed power sensor microsystem based on thermal conversion, where absorbed RF power is transformed into thermal power, inside a thermally isolated system.

Modeling and Simulation of Mechanical, Thermal and Electrical behaviour of Si Cantilever with Implanted Strain Gauge

Modeling of Thermally Isolated Micromechanical Thermo Converter

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Design, simulation and measurement of absorbed power sensor microsystem based on thermal conversion, where absorbed RF power is transformed into thermal power, inside a thermally isolated system.

Modeling of Thermally Isolated Micromechanical Thermo Converter. Conference Proceedings

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Design, simulation and measurement of absorbed power sensor microsystem based on thermal conversion, where absorbed RF power is transformed into thermal power, inside a thermally isolated system.

Modelling and simulation of mechanical, thermal and electrical behaviour of Si cantilever with implanted strain gauge

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    In the paper there is characterized physical model of implanted strain gauges; various girder topologies are designed and basic technological steps during realization of cantilever are described. Simulation using CoventorWare (MEMCAD) program is used for verification of mechanical properties and temperature distribution in cantilever structures. At realized structures of cantilever with strain gauges, there have been measured basic parameters, as dependence of electric parameters of strain gauges on mechanical deformation, temperature dependence at different mechanical load, temperature stability of output parameters, temperature dependence of pn junctions in the structure. From measured data there have been calculated piezoresistive coefficients, coefficients of deformation sensitivity, linearity, hysteresis, temperature coefficients of resistance, etc. Based on measured data, there has been designed connection of a simple electric equivalent model of the structure.

Modelling and simulation of mechanical, thermal and electrical behaviour of Si cantilever with implanted strain gauge

Concept of an Intelligent Microsystem Structure for Communication with Real Surrounding Space

Concept of an Intelligent Microsystem Structure for Communication with Real Surrounding Space

Design of Strain Gauge Structure

Modeling of Micromechanical Structure of the Microwave Power Sensor

Structures of Cantilever with Implanted Strain Gauge

Structures of Cantilever with Implanted Strain Gauge

Thermal and Thermo-mechanical Modeling of GaAs Micromechanical Thermal Converter

Thermal and Thermo-mechanical Modelling of GaAs Micromechanical Thermal Converter

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Thermo-mechanical 3D simulation and measurement of Micromechanical Thermal Converter

Thermo-mechanical Simulation and Modeling of RF Power Sensor Microsystem

Thermo-mechanical Simulation of GaAs Based Microwave Power Sensor Microsystem

Thermo-mechanical Simulations of GaAs Based Microwave Power Sensor Microsystem

MEMCAD Thermal Simulation of GaAs Based Membrane Bridge

  • Pracoviště: Katedra mikroelektroniky
  • Anotace:
    Thermo-mechanical simulations performed in the aim of optimising the temperature distribution of microwave power sensor microsytems.

Model of Temperature Microsystem with Wireless Communication

Model of Temperature Microsystem with Wireless Communication

Sensor Systems with Wireless Data Communication

Thermo-Mechanical Simulation of GaAs power Sensor Microsystem

Electrocaloric Flow Monitoring

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Poster 1999. Praha: České vysoké učení technické v Praze, Fakulta elektrotechnická, 1999. pp. 9.
  • Rok: 1999

Noninvasive Flowmeter

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Advances in Systems, Signals, Control and Computers. Durban: IAAMSAD, 1998. p. 454-458. ISBN 0-620-23136-X.
  • Rok: 1998

Noninvasive Flowmeter

  • Autoři: prof. Ing. Jiří Jakovenko, Ph.D.,
  • Publikace: Proceedings of the 12th European Conference on Solid-State Transducers and the 9th UK Conference on Sensors and their Applications. Bristol: Institute of Physics Publishing, 1998. p. 787-789. ISBN 0-7503-0536-3.
  • Rok: 1998

Za stránku zodpovídá: Ing. Mgr. Radovan Suk