28-GHz Bidirectional RF CMOS Amplifier Employing Body-Effect Control

This letter presents a 28-GHz bidirectional amplifier that operates as a low-noise amplifier (LNA) and a drive amplifier in the receiver (RX) (forward) and transmitter (TX) (backward) modes, respectively. In the proposed design, the bidirectional operation is realized through supply switching (SS) by utilizing the symmetric structure of a complementary metal–oxide–semiconductor (CMOS) device. Additionally, the body voltage control of an n-type MOS (nMOS) device is applied to attain symmetric and enhanced performance in both the forward and backward operations. The proposed design was fabricated using the 65-nm CMOS process and primarily characterized in the 28-GHz band. It achieves a nearly identical performance in both the forward and backward modes.