Persons
Ing. Viktor Adler, Ph.D.
All publications
Low Latency Digital Radar Target Simulator Design
- Authors: Ing. Jan Sobotka, Ph.D., Ing. Viktor Adler, Ph.D.,
- Publication: 2024 IEEE International Workshop on Metrology for Automotive. Halifax: IEEE, 2024. p. 24-28. ISBN 979-8-3503-8498-7.
- Year: 2024
- DOI: 10.1109/MetroAutomotive61329.2024.10615445
- Link: https://doi.org/10.1109/MetroAutomotive61329.2024.10615445
- Department: Department of Electromagnetic Field, Department of Measurement
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Annotation:
During the digital simulation of the synthetic target to the automotive radar sensor, low latency is an important parameter. This parameter defines the minimum range of the simulated obstacle. Each 6.67 ns of latency increases the minimum target distance per meter. The primary source of latency is the conversion of the radar signal between the analog and digital domains. This paper thoroughly analyzes delay sources in digital radar simulation. On the basis of this analysis, the low latency simulator design is presented. The design was evaluated with an FPGA based target simulator. The experimental results present the overall system latency and comparison with similar solutions.
Directly-Modulated 1310 nm Laser TOSA Developed for Seamless Millimeter Wave Radio Over Fiber Transmission
- Authors: doc. Ing. Matěj Komanec, Ph.D., Halmo, L., Ing. Viktor Adler, Ph.D., Ing. Jan Bohata, Ph.D., Botella-Campos, M., Zvěřina, J., prof. Ing. Stanislav Zvánovec, Ph.D.,
- Publication: IEEE Access. 2023, 11 63895-63903. ISSN 2169-3536.
- Year: 2023
- DOI: 10.1109/ACCESS.2023.3288281
- Link: https://doi.org/10.1109/ACCESS.2023.3288281
- Department: Department of Electromagnetic Field
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Annotation:
We present for the first time a directly-modulated high-frequency laser transmitter optical sub-assembly (TOSA) in a commercially-available TO-can packaging working in the 1310nm band capable of digital transmission at 25Gb/s and analog transmission up to 25GHz. We show a step-by-step assembly procedure starting from the TO-can package high-frequency characterization, followed by a bare laser chip analysis and the supporting PCB evaluation to the final TOSA assembly step. We verify the developed TOSA long-term stability by shock and aging tests which had no impact on the TOSA bandwidth or output optical power. We reveal the optimal forward current for digital transmission at 60mA, and for analog transmission, we operate below the forward current of 40mA to suppress unwanted laser side modes. We test the TOSA performance by a successful 25Gb/s on-off keying (OOK) data transmission over a passive optical network with BER of 3.2E-3 and 2.0E-8 for 25Gb/s, and 10.3Gb/s, respectively. Finally, we demonstrate analog millimeter wave radio transmission at 25GHz of a 16-QAM orthogonally frequency division multiplexing (OFDM) signal with 20MHz bandwidth over a 5km-long optical fronthaul with a seamless wireless link providing EVM below the 12.5% limit to show real-case scenario performance.
Sub-clock Digital Delay for Radar Target Simulation
- Authors: Ing. Jan Sobotka, Ph.D., Ing. Viktor Adler, Ph.D., doc. Ing. Jiří Novák, Ph.D.,
- Publication: 2023 IEEE International Workshop on Metrology for Automotive (MetroAutomotive). Halifax: IEEE, 2023. p. 170-174. ISBN 9798350321876.
- Year: 2023
- DOI: 10.1109/MetroAutomotive57488.2023.10219094
- Link: https://doi.org/10.1109/MetroAutomotive57488.2023.10219094
- Department: Department of Electromagnetic Field, Department of Measurement
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Annotation:
Simulation of an artificial target is essential for developing and evaluating systems based on radar sensors. The simulation usually covers three fundamental principles. Signal delaying to simulate the target in a certain distance. Frequency shifting to give the target a speed according to the Doppler phenomenon. Moreover, adjusting signal magnitude to mimic the Radar cross-section (RCS) of the simulated object. For digital Radar Target Simulation, the tiniest step in signal delaying is determined by the clock period. This paper presents an idea of how to implement sub-clock period signal delaying to increase delay resolution. The idea is evaluated on FPGA based target simulator.
Broadband Target Simulator for FMCW Radar Sensors With Mirror Target Suppression
- Authors: Ing. Viktor Adler, Ph.D., Ouředník, P., doc. Ing. Přemysl Hudec, CSc., prof. Ing. Karel Hoffmann, CSc.,
- Publication: 2021 20th International Conference on Microwave Techniques (COMITE). Praha: IEEE Czechoslovakia Section, 2021. p. 1-5. ISBN 978-1-6654-1454-8.
- Year: 2021
- DOI: 10.1109/COMITE52242.2021.9419874
- Link: https://doi.org/10.1109/COMITE52242.2021.9419874
- Department: Department of Electromagnetic Field
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Annotation:
This article describes a target simulator for FMCW radar sensors which, working on the frequency shift principle, deals with the presence of an unwanted (mirror) target. A simple method is proposed to suppress the mirror target by utilizing an IQ mixer in simulator circuitry which enables single-sideband modulation. Achievable combinations of speed and distance of simulated targets are also presented. In addition, the generation of targets closer than the physical distance of the simulator, a radar parameter estimation and a simulator calibration are included. All presented principles were verified by a laboratory experiment with a 24 GHz FMCW radar module and other commercially available components.
On the Testing of Advanced Automotive Radar Sensors by Means of Target Simulators
- Authors: doc. Ing. Přemysl Hudec, CSc., Ing. Viktor Adler, Ph.D.,
- Publication: Sensors. 2020, 20(9), ISSN 1424-8220.
- Year: 2020
- DOI: 10.3390/s20092714
- Link: https://doi.org/10.3390/s20092714
- Department: Department of Electromagnetic Field
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Annotation:
The rapid development and wide commercial implementation of automotive radar sensors are strengthening the already considerable interest in matching radar target simulators. Such simulators boast promising results when used for both essential functional inspections of active sensors and the high-speed testing of numerous traffic scenarios while examining complex reactions of automobile electronic systems. For these purposes, advanced versions of target simulators enabling a generation of multiple targets moving at different velocities and ranges are required. The design, practical implementation and system programming of advanced sensor simulator setups require a detailed analytical description concerning all important technical aspects. An abundance of detailed information on the behavior and parameters of automotive radar sensors can be found in the references, but similar knowledge on sensor simulator setups is lacking. This article presents detailed analyses of the all-important RF parameters, where special attention is paid to phase noise, and its analytical description takes into account an even greater number of simulated targets. The derived analytical formulas enable both an optimal setup implementation and system programming of a wide range of practical testing procedures.
Design of a Scalar Free-Space Measurement System
- Authors: Ing. Viktor Adler, Ph.D., prof. Ing. Karel Hoffmann, CSc.,
- Publication: Proceedings of European Microwave Conference in Central Europe (EuMCE 2019). Louvain-la-Neuve: European Microwave Association (EuMA), 2019. p. 594-597. ISBN 978-2-87487-066-8.
- Year: 2019
- Department: Department of Electromagnetic Field
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Annotation:
This article offers insight into the design andrealization of a scalar free-space measurement system applicableto inverse synthetic aperture imaging purposes. The basics of themeasurement method are reminded and a calibration procedureof the main hardware (HW) imperfection is proposed. Themajority of the article is devoted to correctly choosing the HWcomponents, modulation scheme, assembly of the system and itscharacterisation. The functionality of the system was carried outvia the imaging of a metallic plate.
AToM: A Versatile MATLAB Tool for Antenna Synthesis
- Authors: prof. Ing. Miloslav Čapek, Ph.D., doc. Ing. Pavel Hazdra, Ph.D., Ing. Viktor Adler, Ph.D., Kadlec, P., Šeděnka, V., Marek, M., Mašek, M., Losenický, V., Štrambach, M., prof. Ing. Miloš Mazánek, CSc., Rýmus, J.
- Publication: 2018 12th European Conference on Antennas and Propagation. Bruxelles: The European Association on Antennas and Propagation, 2018. ISSN 0537-9989. ISBN 978-1-78561-815-4.
- Year: 2018
- Department: Department of Electromagnetic Field
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Annotation:
The Antenna Toolbox For MATLAB (AToM), originally an in-house academic tool, has been transformed into a complete MATLAB toolbox, capable of modeling, discretizing and calculating arbitrarily shaped planar radiators while analysing the results. All tasks can be performed directly in MATLAB. The majority of the code allows its direct modification. AToM supports the latest features, used predominantly in the realm of electrically small antennas, namely modal decompositions, evaluation of fundamental bounds, and other techniques based on the source concept.
TRL-based measurement of active antennas and other more complex microwave structures
- Authors: Ouředník, P., doc. Ing. Přemysl Hudec, CSc., Ing. Viktor Adler, Ph.D.,
- Publication: Proceedings of 89th ARFTG Microwave Measurement Conference. Piscataway (New Jersey): IEEE, 2017. ISBN 978-1-5386-2747-1.
- Year: 2017
- DOI: 10.1109/ARFTG.2017.8000834
- Link: https://doi.org/10.1109/ARFTG.2017.8000834
- Department: Department of Electromagnetic Field
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Annotation:
A common approach to active antenna design consists of a passive radiator (intrinsic antenna) and an output or input amplifier; all situated on a single microwave board. Such designs show higher radiated power or lower noise floor resulting from low interconnecting line losses. However, since more microwave circuits are connected directly together on a single board, their testing is more difficult. In the given case, this concerns measurement of reflection coefficient of the passive radiator. Methods developed in frames of this work employ the VNA measurement and TRL cahbration, and enable one to evaluate radiator input reflection coefficient in a complete structure without need of any disconnecting or switching. Performed practical measurements show that results can be satisfactorily precise. Generally, the method can be applied for measurement of individual microwave circuits embedded in more complex system PCBs.
High Resolution Range Imaging Via Model-based Compressed Sensing
- Authors: Ing. Viktor Adler, Ph.D., Moll, J., Kuhnt, M., Hils, B., Krozer, V., prof. Ing. Karel Hoffmann, CSc.,
- Publication: Proceedings of PIERS 2015 in Prague. Cambridge: Electromagnetics Academy, 2015. p. 248-252. ISSN 1559-9450. ISBN 978-1-934142-30-1.
- Year: 2015
- Department: Department of Electromagnetic Field
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Annotation:
The paper proposes a method for high resolution range imaging at millimeter wave frequencies (85 GHz to 100 GHz) based on model-based compressed sensing (CS). A detailed description of the underlying CS-theory, the experimental setup and radar sensor are presented along with experimental results for one-dimensional range imaging. The proposed method is based on motorized reference measurements, which form the dictionary matrix for subsequent CS-processing. These reference measurements are tested against measurements from a glass fiber reinforced polymer (GFRP) component. A comparison of the CS-processed data to a classical Fourier-domain analysis revealed superior ranging performance of the CS-approach at the expense of a higher signal processing load.
Six-Port Spatial Electromagnetic Wave Measurement
- Authors: Ing. Viktor Adler, Ph.D., prof. Ing. Karel Hoffmann, CSc.,
- Publication: IEEE Transactions on Microwave Theory and Techniques. 2014, 62(12), 3161-3171. ISSN 0018-9480.
- Year: 2014
- DOI: 10.1109/TMTT.2014.2365024
- Link: https://doi.org/10.1109/TMTT.2014.2365024
- Department: Department of Electromagnetic Field
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Annotation:
A new method for measuring free-space electromagnetic waves, based ona scalar interferometric measurement principle similar to the six-port concept, is presented. A proof of concept was performed at frequency band 6-12 GHz. The corresponding measurement system contains both a reference channelfeaturing a transmitting antenna directly irradiating receiving antenna, and,a test channel which has a transmitting antenna irradiating a test object. A wave reflected or scattered by the test object, and the reference wave phaseshifted in several steps, both coherent, interfere in the receiving antenna. Redundancy is exploited via a multistate regime of measurement which enablesto reduce uncertainty of measurement. A geometrical representation of theapproach in the complex plane makes it possible to estimate measurement uncertainties. Precise computing of uncertainties based on the Monte Carlo Method is alsoperformed.
Spatial Vector Measurement Based on Six-Port Concept
- Authors: Ing. Viktor Adler, Ph.D., prof. Ing. Karel Hoffmann, CSc.,
- Publication: 81st ARFTG Microwave Measurement Conference Proceedings. New Jersey: IEEE, 2013. pp. 114-116. ISBN 978-1-4673-4982-6.
- Year: 2013
- DOI: 10.1109/ARFTG.2013.6579045
- Link: https://doi.org/10.1109/ARFTG.2013.6579045
- Department: Department of Electromagnetic Field
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Annotation:
A new vector measurement method of electromagnetic field distribution in space based on a scalar measurement similar to the six-port concept is presented. In addition to transmitting and receiving, the antenna system utilizes a reference antenna continuously irradiating the receiving antennas via a coherent signal with several phase shifts. The functionality of the method was verified experimentally using three antennas in the 8 – 12 GHz frequency band. The method is applicable to imaging systems or for measuring the near field of antennas, etc.