A novel quadratic polynomial expansion of nonlinear scattering function for RF power amplifier modeling

Abstract

The design of high‐performance radio frequency power amplifiers requires accurate and simple characterization of power transistors. Behavioral modeling technique provides an efficient and convenient way to tackle this issue. This study presents a novel behavioral model, which is based on quadratic polynomial expansion of nonlinear scattering function with high‐order components included. This method was implemented in Computer Aided Design (CAD) program with the help of the frequency‐domain defined device component. The comparisons of the output voltage are presented and discussed under different load impedance and input power on a practical circuit operating at 20 GHz, and the results show that the model is capable of accurately characterizing the strong nonlinear behavior the device expressed while the fundamental and harmonic frequency load impedance located anywhere inside the Smith Chart.

A Digitally assisted nonlinearity suppression architecture using over‐the‐air beam cancelation

“…At present, many types of PA behavioral models have been proposed, 6 with many of them relying on Volterra series. 7 However, with the increase of signal bandwidth, more complex nonlinear characteristics and memory effects of PA are generated, which makes the behavioral model of PA based on Volterra series have a large error. As a practical matter, the PA's nonlinear behavior is subject to variation during operation due to fluctuations in input signal properties, including power and temperature alterations.…”

“…At present, many types of PA behavioral models have been proposed, 6 with many of them relying on Volterra series 7 . However, with the increase of signal bandwidth, more complex nonlinear characteristics and memory effects of PA are generated, which makes the behavioral model of PA based on Volterra series have a large error.…”