Electrically small antennas are ubiquitous, yet their true importance is still about to be revealed with the upcoming Internet of Things (IoT). Other technologies relying on small radiators such as implantable antennas, directional nanoscatterers, or field concentrators and absorbers are developed too. For all of them, the performance nontrivially depends on shape of the structure, material distribution, and excitation.
Various metrics relevant mainly in the electrically small regime are studied and formulated in terms of method of moments operators. A few examples are stored energy, ohmic losses, electric and magnetic moments, total active reflection coefficient and others.
Figure: A meanderline situated in a radiansphere of radius a as a typical representant of planar electrically small antenna.
