Phaseless method of gain characterization for circularly polarized antennas for mmWave and THz band

Millimeter wave and terahertz band antennas are of growing interest due to applications in radar, imaging and communications. Specifically, circularly polarized (CP) antennas find special interest in satellite communications and applications involving mobile transceivers. For mm-Wave and THz band, gain characterization for CP antennas is a difficult task due to phase errors in alignment. To avoid practical difficulties in traditional CP gain measurement method, we propose a simple, phase-less measurement method. The method relies only on amplitude based measurements, utilizing scattering from readily available structures. In this work, we develop the theory and demonstrate the measurement results for a radial line slot array antenna (RLSA) operating at 106 GHz.