A 22–28 GHz Polarization-Reconfigurable Flat-Panel 8 × 8 Tx/Rx Phased Array Antenna With Uniquely Arranged Novel Radiating Elements for CubeSat Communication

In this article, a wideband (22–28 GHz), polarization reconfigurable, flat panel, $8\times $ 8 transmit (Tx)/receive (Rx) phased array antenna (PAA) is proposed. The array offers a realized gain of 22–23 dBi/dBic in the broadside direction and scans to approximately ±50° while maintaining 3-dB gain drop/scan loss, low cross-polarized fields, and axial ratio (AR) below 3 dB [in the case of circular polarization (CP)] over the entire bandwidth within the given scan range. By utilizing the amplitude and phase control mechanism of the radio frequency integrated circuits (RFICs) employed for the beamforming network (BFN), every single radiating element of the array can work in four polarization cases, such as horizontal ( $X$ -), vertical ( $Y$ -), left-hand circular and right-hand circular polarizations (CPs). The single element is a novel stacked patch configuration with text L-shaped stubs at the two opposite corners of the driven patch and stubs on radiating edges of both the driven and parasitic patches. The radiator offers a wideband performance in addition to resolving the poor isolation between the two ports, thereby improving the text cross-polarized fields and AR over the entire bandwidth. The radiating elements are arranged in a unique way in the array such that the benefit of element mirroring is achieved during the dual linear cases, whereas the benefit of sequential rotation of elements is achieved in dual CP cases, which further improves cross-polarized fields and AR. The simulated results are validated through the measurement results for a fabricated PAA prototype for the scanned radiation patterns for all four polarizations in the Rx mode, the antenna gain-to-noise temperature (G/T) in the Rx mode, and effective isotropic radiated power (EIRP) in the Tx mode.