A high power CMOS switch using substrate body switching in multistack structure

A novel high power CMOS RF switch using the substrate body switching technique in a multistack structure is designed, implemented, and characterized in a standard 0.18-mu m triple-well CMOS process. One of the stacked devices in the receive side has a body switch at the bulk port in order to provide high power handling capability to the transmit switch side without compromising insertion loss to the receiver switch. The body switch connected to the bulk port at one of the receiver switches turns on in Tx mode to minimize leakage current into Rx path. In the meanwhile, that switch turns off in Rx mode so that the bulk port can have body floating to reduce leakage current to substrates. Experimental data show that the switch using the body-switching technique has P I dB of 31.5 dBm that is 2.5 dB higher than the one using the body floating technique. Insertion loss is 1.5 dB at 1.9 GHz in the transmit switch and 1.8 dB in the receiver switch. Isolation is less than 30 dB for Rx switch and 20 dB for Tx switch at 1.9 GHz.