Abstract
The letter reports a 57-67 GHz bidirectional low-noise amplifier power amplifier (LNAPA) design. To eliminate the use of T/R switches, the bidirectional matching networks are introduced to connect LNA and PA core circuits in parallel and satisfy the isolation requirements with full consideration of input/output matching of the LNA and PA. Thus, the operation modes are simply selected by gate biasing of the LNA and PA core circuits. Fabricated in a commercial 65-nm CMOS technology, the Rx mode features peak gain of 21.5 dB with gain of > 17 dBover 57-67 GHz, NF of 6.7 dB with P-DC of 39.6 mW, while Tx mode achieves peak gain of 24.5 dB with gain of > 17 dB over 57-65 GHz, P-SAT of 8.4 dBm, PAE of 8.7% with PDC of 71.1 mW. The reverse isolation in both modes is better than 43 dB. The circuit occupies a compact size of 0.22 mm(2).