A GaN Gain Enhancement PA with Peak Power Combining

This paper presents a novel approach for increasing the gain of a pair of parallel amplifiers by introducing a series connection between them on the input side. The resulting structure, referred to here as a gain enhancement PA (GEPA), has higher gain than each individual amplifier while maintaining the output power and efficiency from the parallel combination of the amplifiers. An initial prototype operating at 2.03 GHz with 42.6 dBm output power, 20.1 dB small signal gain, and 57.1 % peak PAE is reported. The GEPA is made up of two identically performing amplifiers that have 40.4 dBm output power, 16.0 dB small signal gain, and 59.2 % peak PAE. The GEPA has 4 dB higher gain than either component amplifier, the sum of the output powers of the two component amplifiers, and equivalent peak PAE, making this technique valuable for applications where high amplifier gain is required.