A High-Efficiency GaN HEMT Hybrid Class-E Power Amplifier for 3.5 GHz WiMAX Applications

This paper represents a high-efficiency class-E power amplifier (PA) using a 10-W GaN HEMT for WiMAX applications of 3.5 GHz. The compensation elements to cancel parasitic components of a packaged device are used for an ideal class-E operation. The harmonic-suppression network using open-stub transmission lines is employed to obtain high output power level and high efficiency. For a 3.5 GHz continuous wave, the measured results show that a peak power-added efficiency (PAE) of 72.1% with a gain of 10.5 dB is achieved at an output power of 40.5 dBm, which delivers a drain efficiency of 79.2%. All harmonic components are suppressed below -57.1 dBc over a whole output power range. The PAE over 60% and the output power level over 40 dBm are maintained in 200 MHz bandwidth.