A 5.2-GHz CMOS T/R Switch for Ultra-Low-Voltage Operations

A novel CMOS transmit/receive (T/R) switch suitable for ultra-low-voltage operations is presented in this paper. Due to the use of $LC$ resonators in the receiving and transmitting paths, enhanced performance in terms of insertion losses and isolation can be achieved. In addition, the forward-body-bias and body-floating techniques are also introduced to minimize the on-resistance of the MOSFETs at a reduced bias voltage. Using a standard 0.18-$mu{hbox {m}}$ CMOS process, a 5.2-GHz asymmetric T/R switch based on the proposed architecture is implemented. With a supply voltage of 0.6 V, the fabricated circuit exhibits 1.56-dB insertion loss, 17-dB isolation, and 11.2-dBm $P_{{rm in}-1 {rm{dB}}}$ in the receiving mode while the measured results in the transmitting mode are 2.02 dB, 31 dB, and 29.6 dBm, respectively.