An Ultra-Compact Bidirectional Ka-Band Front-End Module With 3.8-dB NF and 13.5-dBm OP1 dB

This letter presents an ultra-compact bi-directional $Ka$ -band front-end module (FEM) in 65-nm CMOS technology. In this design, the receiver (RX) path is stacked into the transmitter (TX) path by using a magnetic self-canceling technique, improving area efficiency greatly with negligible performance penalty. Furthermore, a three-inductor coupled resonator is elaborately designed to realize the functions of the balun and input–output matching network (MN) of the RX/TX simultaneously. The measurement results demonstrate that the proposed FEM achieves 18.2-dB peak gain with a 3.8-dB minimum noise figure (NF) in RX mode, and 26-dB peak gain with 13.5-dBm 1-dB compression output power (OP $_{1\,{\mathrm {dB}}}$ ) in TX mode. The core size of this proposed design is only 0.06 mm2 which is only 20%–50% of the size occupied in prior works.