Mixed time and frequency-domain identification of Radio Frequency Power Amplifiers

This paper presents a modeling and identification procedure for Radio Frequency Power Amplifier (PA) in continuous time representation. The proposed method is based on a combined approach using time and frequency domain. The microwave PA dynamics are described by the continuous Hammerstein model. The distortion function coefficients were estimated using Least Mean Squares (LMS) method that minimizes the squared error based on baseband output data. The coefficients of dynamic block are extracted using an iterative instrumental variable applied to experimental PA frequency responses. To demonstrate the feasibility of the identification method in experimental results we used a standard mobile PA at 1.85GHz.