Continuous Class E Power Amplifier Mode in the Presence of Nonlinear Output Capacitance

This paper presents the impact of nonlinear parasitic capacitors at the output of GaN HEMT on the performance of continuous class E (CCE) power amplifier (PA) mode. The nonlinear output capacitor generates harmonic currents and modifies the harmonic impedances seen by the intrinsic current source. In this paper, an analytical study is performed on the CCE mode in the presence of a nonlinear output capacitor <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(C_{out})$</tex>. It is noted that active second and third harmonic terminations can be presented to the intrinsic current source due to the nonlinear <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$c_{\text{out}}$</tex>. This paper proposes a methodology to harness the harmonic currents due to nonlinear parasitic capacitors and improve the efficiency in CCE PA mode.