Single-pole double-throw CMOS switches for 900-MHz and 2.4-GHz applications on p-silicon substrates

A 900-MHz single-pole double-throw (SPDT) switch with an insertion loss of 0.5 dB and a 2.4-GHz SPDT switch with an insertion loss of 0.8 dB were implemented using 3.3-V 0.35-μm NMOS transistors in a 0.18-μm bulk CMOS process utilizing 20-Ω·cm p^- substrates. Impedance transformation was used to reduce the source and load impedances seen by the switch to increase the power handling capability. SPDT switches with 30-Ω impedance transformation networks exhibit 0.97-dB insertion loss and 24.3-dBm output P_1dB when tuned for 900-MHz operation, and 1.10-dB insertion loss and 20.6-dBm output P_1dB when tuned for 2.4-GHz operation. The 2.4-GHz switch is the first bulk CMOS switch which can be used for 802.11b wireless local area network applications.