Highly linear low voltage GaAs pHEMT MMIC switches for multimode wireless handset applications

A true 3 V highly linear low loss single pole five throw (SP5T) switch for multimode wireless handset applications is presented. By using advanced Filtronic pHEMT technology with extremely low leakage current and low channel resistance it is possible to achieve very low harmonic levels at maximum GSM power levels (P/sub 2ND/<-35 dBm at P/sub IN/=34.5 dBm) by using four FETs in series and yet still achieve insertion losses of 0.5 dB at 900 MHz. Increasing the number of FETs also allows for 24 dB of isolation to be achieved at 900 MHz.