A GaAs-based field-modulating plate HFET with improved WCDMA peak-output-power characteristics

A novel GaAs power FET with a field-modulating plate (FP-FET) and operated at a drain bias voltage of 24 V was developed. Regarding the power performance of an FP-FET under wideband code division multiple access (WCDMA) operation, its peak output power significantly degraded in the saturated-output-power region when its FP length was short. However, by introducing a sufficiently large FP length, it was demonstrated that the peak-power degradation can be significantly suppressed. In particular, an FP-FET amplifier fabricated with an FP length of 1.5 /spl mu/m exhibited no WCDMA peak-power degradation and delivered an output power of 120 W with a linear gain of 14.2 dB at 2.14 GHz.