A D-Band Scalable 128-Channel Dual-Polarized Receive Phased-Array with On-Chip Down Converters for 2x2 MIMO Achieving 2x42 Gbps

This paper demonstrates a scalable 8x8 dual-polarized receive phased array at D-band (132-142 GHz) with on-chip down converters. RF beamforming is employed with 4-bit phase and gain controls on every element having an intermediate-frequency (IF) interface at 9-14 GHz. Two 64:1 Wilkinson combiners are employed for the RF distribution network with signal amplification within the combining network. The 8×8 dual-polarization chip is fabricated in the GlobalFoundries CMOS 45RFSOI process and occupies an overall area of 9.7×9.6mm^2. To construct the phased array, the chip is flipped on a low loss organic interposer (RF PCB) containing the RF transitions, LO, and IF distribution networks, and which feeds an 8×8 dual-polarized microstrip antenna array with a spacing of 0.57λ×0.57λ (at 140 GHz) in azimuth and elevation planes. The array scans to ±45degree in all planes for both polarizations, and the measured response supports 64 QAM operation with 2×42 Gb/s links.