High isolation pHEMT MMIC switch for 60GHz-band applications

This paper describes the design, fabrication and measurement of a single-pole-double-throw(SPDT) MMIC switch applicable to IEEE 802.15.3c standard wireless local area network(WLAN) using an ETRI's 0.12um GaAs/AlGaAs pHEMT switch library and high isolation switch cell design technologies. This SPDT switch has a measured insertion loss of -3.1dB similar to-4.2dB and isolation of -41.7dB similar to-42.5dB in the 59 similar to 63GHz frequency band. Thermal test was also performed to evaluate the thermal stability of switching performances from 50 degrees C to +100 degrees C with a step of 20 degrees C in an atmosphere. The variations of insertion loss and isolation at a center frequency of 60 GHz were -2.17 +/- 0.15 dB and -41.07 +/- 0.85 dB, respectively. This means the SPDT switch is very stable at both high and low temperatures. Therefore we can conclude that the developed high isolation pHEMT SPDT MMIC switch is suitable for an Rx-Tx switch of WLAN system. However, the chip size of 3.0 mm x 0.99 mm is still large and then we need an additional work for developing a new switch cell to decrease the chip size.