Low insertion loss and high linearity PHEMT SPDT and SP3T switch ICs for WLAN 802.11 a/b/g applications

GaAs SPDT and SP3T antenna switch ICs for IEEE 802.11 a/b/g applications are developed. By using advanced Skyworks PHEMT technologies, it is possible to achieve an insertion loss as low as 0.55 dB for SPDT switch, 0.5 dB lower than any previously reported DC-6 GHz band switch, and high linearity with 55 dBm input IP3 and a high isolation over 20 dB at 3 V; the SP3T switch also exhibits excellent performance with an insertion loss of 0.9 dB, input IP3 of 47 dBm and isolation over 25 dB throughout DC-6 GHz band. The high performance comes from the following technologies: series and shunt topology with dual-gate FETs, AlGaAs/InGaAs/AlGaAs 0.5 μm EPI-based process with a fully selective dual recess etch, and the relatively shallow pinch off voltage of -0.5 V (Y. Tkachenko et al., Euro. Microwave Conf. Dig., pp. 1041-1045, 1997).