Dimensional Effects Affecting the Linearity of Active Superconducting Antennas

Active electrically small antennas (ESAs) based on superconducting quantum arrays (SQAs) exhibit similar sensitivity to the polarization direction as conventional magnetic ESAs. While active ESAs produce an output voltage independent of the size-to-wavelength ratio with respect to both the quantum cell and the SQA, distinct dimensional effects can appear and limit the linearity of the antenna output as this ratio increases. We analyze these dimensional effects in SQA-based active antennas of both transformer and transformer-free types.