Modelowanie nieliniowej charakterystyki szerokopasmowych wzmacniaczy radiowych o zmiennym napięciu zasilania; Modeling Nonlinear Characteristics of Wideband Radio Frequency Amplifiers with Variable Supply Voltage
Kornelia Kostrzewska, Paweł Kryszkiewicz
TL;DR
The paper addresses the challenge of modeling the nonlinear AM/AM characteristics of wideband power amplifiers under envelope tracking with variable supply voltage and carrier frequency. It extends the traditional Rapp model by making the key parameters $G$, $V_{sat}$, and $p$ functions of both the supply voltage $V_{sup}$ and carrier frequency $f$, with parameters fitted via multivariate polynomial forms using MATLAB Curve Fitting. Validation on three amplifiers shows that the extended model can closely track linear-range behavior and improve AM/AM accuracy, particularly for ZX60-2534, where normalized errors drop to about 12% across conditions; however, universality is limited and device-specific tuning remains important. This approach enables frontend-aware design for next-generation 6G systems but also highlights the need for more universal formulations or per-device customization to achieve consistent performance across diverse PA architectures.
Abstract
The work aims to propose a new nonlinear characteristics model for a wideband radio amplifier of variable supply voltage. An extended Rapp model proposal is presented. The proposed model has been verified by measurements of three different amplifiers. This model can be used to design frontend-aware 6G systems. -- Praca ma na celu zaproponowanie nowego modelu dla nieliniowej charakterystyki wzmacniacza radiowego ze zmiennym napięciem zasilania pracującym w szerokim zakresie częstotliwości. Przedstawiona została propozycja rozszerzonego modelu Rappa. Zaproponowany model zweryfikowano na podstawie pomiarów charakterystyk trzech różnych wzmacniaczy. Model ten może być wykorzystany do projektowania systemów 6G "świadomych" niedoskonałości układów wejściowo-wyjściowych.