A Ka-Band Compact Active Switch With Broadband Amplifiers for Phased-Array Transceiver in 65-nm CMOS

This letter presents a compact active switch together with broadband amplifiers for phased-array transceiver in 65-nm CMOS. The active switch is composed of cascaded common-gate stage in transmitter (TX) mode and common-drain stage in receiver (RX) mode. It relies on the device terminal impedance and is easily controlled by turning on and off their bias voltages. Compared with prior-art passive switches, the proposed active switch reduces the area overhead and features competitive performance in terms of switch loss and bandwidth. The implemented active switch together with broadband amplifiers provides 16.4 dB gain in TX mode and 12.8 dB in RX mode with -3 dB bandwidth of over 10 GHz (30-40 GHz). In TX/RX modes, the measured return loss is better than 10 dB and the switch isolation achieves 29 dB across the bandwidth. The overall design occupies 0.52 mm
²
including pads, where the core area is 0.2 mm
²
.