A Novel Design Approach for Highly Efficient Multioctave Bandwidth GaN Power Amplifiers

This letter presents a novel approach to design highly efficient multioctave bandwidth power amplifiers (PAs). The fundamental load impedances are slightly detuned out of their optimum values to reduce the in-band harmonics influence on output power and power-added efficiency. The design of the output matching network includes a 4:1 planar Guanella transformer for wide bandwidth and low complexity. In the frequency band 0.5-2.7 GHz, the PA achieves 9.2 ± 1.2 dB power gain and more than 20-W output power. The drain efficiency varies from 56% to 70% over the bandwidth.