High frequency Class-DE push/pull power amplifier utilizing a parallel compensation inductance

In this paper the operational principle of a Push-Pull Class-DE PA utilizing a parallel compensation inductance is proposed and corresponding design equations are derived. The Push-Pull configuration has the advantage of having two low side switches, but it requires a transformer with its inherent parasitic parallel inductance. This parallel inductance is used as an integral part of the matching network, mitigating the demand for the conventional series compensation inductance and enabling efficient load modulation over a wide dynamic range. The derived design equations are verified by simulation and it is shown that the Push-Pull Class-DE PA in combination with Chireix outphasing is a suitable solution for achieving high efficiency also in back off.