An Envelope Model for Efficient Prediction of the Impact of Wideband Signals on Power Amplifier Performance

This paper presents a simplified simulation method for estimating the impact of baseband terminations in advanced power amplifier architectures when used with wideband signals. Previous work has introduced the idea of using the baseband signal as a separate domain from the RF signal in order to estimate continuous wideband power amplifier performance with different baseband terminations. In this paper, this idea is expanded, the underpinning equations are generalized, and a new circuit simulator is designed utilizing the idea of baseband, or envelope, domain. The results are compared to 2-tone simulations using a commercial harmonic balance solver. The new envelope model appears to be able to predict issues with baseband impedance matching for wideband signals. It allows for efficient simulations of complex wideband signals without the escalation of harmonics as required for N-tone harmonic balance solvers, and allows for more complex amplifier architectures, such a Doherty power amplifier, to be studied.