A 25-29 GHz 64-Element Dual-Polarized/Dual-Beam Small-Cell with 45 dBm 400 MHz 5GNR Operation and High Spectral Purity

This paper presents a 25–29 GHz 64-element small-cell (RF to IF) dual-polarized/dual-beam phased-array for 5G communication systems. The small-cell includes dual-polarized antennas, sixteen 2 × 2 beamformers, a dual-channel driver (TX/RX), a dual-channel transceiver, filters, and a local oscillator (LO) on the printed-circuit board. This small-cell provides a measured EIRPPsat of 55 dBm for each polarization with <-40 dBc LO leakage at an IF of > 4 GHz, and 40–140 dBc single-sideband rejection at an IF of 2–8 GHz. The TX output spectrum is measured at an IF of 5 and 6 GHz, and all the spurs are < -55 dB lower than the desired RF signal at 10-dB back-off operation. A complex modulation measurement using OFDM 5GNR 64-QAM 400 MHz waveform (PAPR = 11–12 dB) is performed and a 43–45 dBm EIRP is achieved at 4-5% EVMRMS (- 28 to -26 dB) for the small-cell. To our knowledge, this is the first demonstration of a high-performance, low-spur phased-array for 25–29 GHz 5G systems.