| Popis: |
An X-band power amplifier using harmonic tuning and a GaAs FET is described. The amplifier has demonstrated 36% power-added efficiency with 5 W of output power and a 6.0-dB gain at 10 GHz. The key to this design is determining and matching the optimum load impedance for power-added efficiency at the first two harmonics. Nonlinear models were used to study the effects of harmonic tuning and to determine the optimum harmonic terminations. Two amplifiers were designed that demonstrated high-efficiency power amplification at the 0.5-W and 5-W power levels, respectively. The effects of harmonic loading were demonstrated in the 0.5-W amplifier, where the maximum efficiency measured for a device tuned only at the fundamental was 44%, while the measured efficiency of the amplifier with optimum harmonic tuning was 49.3%. > |
