A wide range monolithic pHEMT SPDT switch

In this study, we propose the design, fabrication, and measurement results of a −6 V single pole double throw (SPDT) switch in the frequency band of DC‐20 GHz. We use a pseudomorphic high electron mobility transistor (pHEMT) GaAs technology. This technology has a gate width of 0.15 μm and a cutoff frequency of 85 GHz. A high yield and good performance switch based on pHEMT transistor is presented for using in SPDT circuit. In this method, we can reduce the off mode capacitor of transistor (Coff) and optimize the transistor in switch mode. Therefore, this method increases the transistor isolation in “off” mode with no change in the resistance of transistor in “on” mode (Ron). Measurement results show that the insertion loss is 1 dB with variation of ±0.1 dB in the frequency bandwidth and its isolation is better than 35 dB. The linear power range of the circuit is 28 dBm. The chip size is 0.2 mm2and very low power consumption of 25 μ w is achieved.