Compact X-band CMOS bidirectional gain amplifier without T/R switches

Presented is a compact X-band bidirectional gain amplifier in 0.18 mm CMOS, which eliminates two T/R switches in the conventional one. The gain of >;14 dB and the in/output return losses of >;8 dB are achieved at 8-14 GHz. The measured output P1dB is ~1 dBm at 10 GHz. The chip size is 0.62 × 0.60 mm², which is compact due to the removal of two T/R switches for the bidirectional operation. The DC power consumption is 54 mW at 1.8 V supply voltage. Nearly identical performance is achieved in the forward and reverse operations at X-band. To the authors´ knowledge, this is the first demonstration of an X-band CMOS bidirectional gain amplifier with the smallest size.