A 2–18 GHz Integrated 4-Channel Transmit/Receive Beamformer in 65-nm CMOS

This paper presents an ultra-wideband integrated phased-array beamformer chip integrating 4 transmit/receive (TRX) channels in 65-nm CMOS process. Each channel features 16.2 dB TX gain over a 12:1 3-dB bandwidth from 1.5 GHz to 18.1 GHz, and 16.3 dB RX gain over a 9:1 3-dB bandwidth from 1.9 GHz to 18 GHz, respectively. By employing vector modulation scheme for phase shifting and designing an impedance-invariant variable gain amplifier (IIVGA), the chip provides 6-bit phase control and 20 dB gain control for both transmit and receive modes. To the best of our knowledge, this work achieves the widest operating bandwidth among TRX beamformers for applications in wideband radars and wireless communication systems.