Design of a Harmonically Tuned Two-Stage Broadband Power Amplifier in Discrete GaN Technology - A Harmonic Loadpull and Harmonic Termination Approach
Abstract
In this master's thesis a two-stage broadband power amplifier, along with the corresponding separate driver and power stages, has been designed with an in-depth analysis of the harmonic source- and loadpull methods and the harmonic termination technique. The power amplifiers were subsequently measured.
The power stage amplifier exhibit a mean transducer power gain of 13.5dB, a maximum linear output power of 25dBm, a mean saturated output power of 41.5dBm, and a mean peak \gls{PAE} of 54\% at a quiescent voltage bias of 28V and a quiescent current bias of 200mA; The driver stage amplifier exhibit a mean transducer power gain of 17.5dB, a maximum linear output power of 25dBm, a mean saturated output power of 37.8dBm, and a mean peak \gls{PAE} of 55\% at a quiescent voltage bias of 28V and a quiescent current bias of 165mA; and the two-stage amplifier exhibit a mean transducer power gain of 29.8dB, a maximum linear output power of 25dBm, a mean saturated output power of 41.3dBm, and a mean peak \gls{PAE} of 44.5\% at a quiescent voltage bias of 28V and a quiescent current bias of 165mA and 200mA.
The power amplifiers were designed for 2.4GHz application with a bandwidth of 800MHz, but also exhibited promising performance down to 1GHz given some modifications, thus virtually doubling the intended bandwidth. The power amplifiers were designed using the gallium nitride high electron mobility transistors CGH40006P and CGH40010F from Wolfspeed.