The Selection Of The Optimal Behavior Model Of RF Power Amplifier And The Identification Of Fingerprint Features

RF Power Amplifier which consists of memory characteristic and nonlinear characteristic is an indispensable part in the communication system. The behavioral model of RF Power Amplifier is a mathematical approach to study the corresponding system. It is a meaningful work to compute the parameters such as memory degree and nonlinear order of the system through behavioral model and to regard the parameters as the important indicator of the system. On one hand, behavioral model contributes to reducing the operating cost, protecting intellectual property by encapsulating the physical model, predicting, evaluating and quantizing the performance of the communication system and enhancing the fitting precision of the output signal. On the other hand, once acquire the optimal behavioral model of the enemy in the electronic countermeasures environment, the parameters of the behavioral model namely the fingerprints which does not vary with the outside environment are able to achieve the individual recognition between RF Power Amplifiers.This paper proposes several approaches of selecting the optimal behavioral model and figuring out the fingerprint of the RF Power Amplifiers. Firstly, aiming at Wiener model, Hammerstein model and Nonlinear Auto-Regressive and Moving Average model(NARMA), the paper proposes an algorithm which is based on weighted least squares method and present a numerical simulation for RF Power Amplifiers in the real world. The algorithm is able to obtain the optimal behavioral model and the parameters of the behavioral model namely the fingerprints with a detailed mathematical explanation. Secondly, the paper replaces the Taylor series which describe the nonlinear amplifier in the classic model with different orthogonal polynomials. Hence, a modified Hammerstein model based on orthogonal polynomials is present. At last, regarding the optimal behavioral model of Wiener model, Hammerstein model and NARMA model, the paper present the optimal behavioral model of the RF Power Amplifiers in the real world through analyzing and comparing.