Enhanced EIRP and Reconfigurable Polarization Multi-Feed Active Antenna Module for Millimeter-Wave Beamforming Phased Arrays

This paper introduces a novel enhanced effective isotropic radiated power (EIRP) and polarization reconfigurable multi-feed active antenna module (MAAM). The proposed MAAM consists of a dual-differential patch antenna element excited by four coaxial feeds connected to the outputs of a beamforming integrated circuit (BFIC). EIRP enhancement is achieved by utilizing on-antenna power combining. Furthermore, by capitalizing on the variable gain and phase shift circuits within the BFIC, the polarization state reconfigurability is enabled. These states comprise both linear (vertical or horizontal) and circular polarization (left- or right-handed). A proof-of-concept prototype was fabricated for operation in the 37–40 GHz frequency band. The fabricated prototype demonstrated good return loss performance, with a measured 10 dB impedance bandwidth covering 36–41 GHz for all polarization states. Additional measurements showed excellent on-antenna power combining efficiency of 92%, validating the design’s enhanced EIRP. When excited with an 800 MHz 256-QAM orthogonal frequency-division multiplexing (OFDM) signal and using linearization technique, the proposed MAAM was able to achieve an EIRP of 22 dBm while maintaining an error vector magnitude (EVM) less than 2%.