Multi-decade GaN feedback power amplifiers in common-source and cascode topology

This paper presents the realization and performance of two multi-decade GaN feedback power amplifiers from 10 kHz to at least 12 GHz. The common-source feedback power amplifier achieves a gain of about 13 dB with a bandwidth of 12 GHz while maintaining an input and output matching of better than −10 dB. The equivalent cascode design possess a bandwidth of 17 GHz, which is ≈ 40 % more than the common-source design. At a bias of 20V/150mA, both designs offer a Psat of >1 W and an OIP3 of about 37 dBm for the common-source design and even 39 dBm for the cascode design. Furthermore, noise figures of less than 5 dB were obtained for the common-source and the cascode topology.