A 50 W low distortion GaAs MESFET for digital cellular base stations

A 50 W low distortion GaAs MESFET for L-band has been successfully developed by optimizing chip design and adopting nearly B-class push-pull operation. The newly developed FET achieved a P/sub 1 dB/ of 47.1 dBm (51.3 W) with a linear gain (GL) of 13.1 dB and the maximum drain efficiency of 57% (at freq=1.5 GHz, V/sub DS/=10 V, set I/sub DS/=3%Idss). A saturation output power of 47.3 dBm (53.7 W) has also been obtained. This is the highest output power reported so far of GaAs FETs considering an operation at nearly class B. In addition, the FETs exhibited both good linearity and distortion performances. The newly developed FETs will contribute to the improvement in performance of digital cellular base station systems.