2x64 Dual-Polarized Dual-Beam Single-Aperture 28 GHz Phased Array with High Cross-Polarization Rejection for 5G Polarization MIMO

This paper presents a 5G 28-32 GHz 2x64 dual-polarized dual-beam transmit/receive (TRX) phased array. The dual-beam array is based on a SiGe 2x4 TRX dual-beamformer chip with 6 bits of phase control and 25 dB of gain control. The chip can deliver 11-12 dBm/channel in the TX-mode and attains a NF of 4.8 dB in the RX-mode. Sixteen chips are used for the construction of a low-cost PCB-based 2x64 dual-beam array using flip-chip technology. The array PCB encompasses isolated 1:16 dual Wilkinson networks as well integrated microstrip antennas with rotated feeds for beam cross-coupling cancellation. The array demonstrates a measured EIRP at Psat of 52 dBm for each beam and is capable of scanning ±50° in azimuth and ±25° in elevation with > 30 dB cross-polarization rejection. Moreover, simultaneous dual-beam operation is demonstrated with near-ideal patterns and cross-polarization rejection of 30 dB indicating good beam-decoupling in the active state and suitability of this array for 2x2 polarization-MIMO links.