15-GHz fully integrated nMOS switches in a 0.13-μm CMOS process

Two fully integrated nMOS switches have been demonstrated at 15 GHz in a 0.13-μm CMOS foundry process. One incorporates on-chip LC impedance transformation networks (ITNs) while the second one does not. The switches with and without ITNs achieve the same 1.8-dB insertion loss at 15 GHz, but 21.5 and 15 dBm input P_1dB, respectively. The degradation of insertion loss due to use of ITNs is compensated by reducing the mismatch loss caused by the bond pad parasitics. The switch without ITNs is suitable for 3.1-10.6 GHz ultra-wide-band (UWB) applications. The switch with ITNs has ∼5 dB worse isolation than the switch without. The difference is due to the larger transistor size of the switch with ITNs, which introduces lower parasitic impedance path between Tx/Rx ports and antenna port.