Wideband High Efficiency Power Amplifier Design Using Precise High Frequency GaN-HEMT Parasitics Modeling/Compensation

In this paper, a design approach for broadband, high efficiency power amplifiers is presented. The proposed technique is based on deductive de-embedding of the parasitics of packaged GaN-HEMT devices. This technique exploits a new parasitics equivalent network, together with a model-based extraction flow. Then, a simple two-element compensation network is proposed to compensate the device output parasitics; this enables optimum load resistance to be presented to the transistor current generator using simple real-to-real matching networks rather than complex-to-real matching ones. As proof of concept, a 25-W linear, highly-efficient, broadband, power amplifier is implemented. The designed circuit achieves an average drain efficiency of 67% while presenting 2
^nd
and 3
^rd
harmonic output levels of -22 dBc and - 40 dBc at full output power, respectively, across the operation bandwidth extending from 1.7 to 3 GHz.