This article presents a high-power and high-efficiency saturated Doherty amplifier using a GaN high electron mobility transistor for 3.5 GHz Worldwide Interoperability for Microwave Access application. The saturated Doherty amplifier is a Doherty amplifier based on class-F amplifiers, resulting in higher efficiency than a conventional Doherty amplifier. The distributed-type harmonic control circuit is located between a power transistor and an output matching circuit. From the measured results for a continuous wave of 3.5 GHz, the saturated Doherty amplifier attains a high P3dB of 45 dBm and a power gain of about 8.8 dB. Also, the proposed Doherty amplifier provides a high power-added-efficiency (PAE) of 37.7% and a drain efficiency of 42.7% at 6-dB back-off output power region from P3dB, which are 8.7% and 5.7% higher than those of the conventional Doherty amplifier. Compared to the single class-AB amplifier, we obtain 17.7% and 19.7% improvement of PAE and drain efficiency, respectively.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering