A GaAs SPDT switch IC operating at a low power supply voltage of 2.7 V has been developed for use in 1.9 GHz band personal handy phone system (PHS). In combination with MESFETs with low on-resistance and high breakdown voltage, the switch IC adopts parallel-LC resonant circuits and utilizes both stacked FETs and an additional shunt capacitor at the receiver side in order to realize low insertion loss, high isolation and low distortion characteristics. An insertion loss of 0.55 dB and an isolation of 35.8 dB were obtained at 1.9 GHz. The IC also achieved an output power of 25.0 dBm at 1 dB gain compression point, a second order distortion of -54.3 dBc and an adjacent channel leakage power of -66 dBc at 600 kHz apart from 1.9 GHz at 19 dBm output power.

Two approaches to the design of resonant-type switches with low distortion characteristics operating at a 2-V power supply voltage have been proposed for use in the 1. 9-GHz-band personal handy phone system (PHS). One approach is to use three stacked FETs at the receiver side. They are composed of a dual-gate FET and a single-gate FET. An insertion loss of 0. 41 dB and an isolation of 44. 0 dB were obtained at 1. 9 GHz. A third-order distortion value of -52 dBc was achieved at 19 dBm output power. Another approach is to insert a capacitor in the resonator. A third-order distortion of -49 dBc at 19-dBm output power when two stacked FETs were used at the receiver side. The layout area of the resonator is drastically reduced as compared with the above-mentioned case.