Simulation of a power amplifier used for TD-SCDMA mobile terminal

In this paper, a PA (Power Amplifier) used for TD-SCDMA terminal is simulate and measured, and the simulation results are verified by measurement results. Firstly, PHD (Poly-Harmonic Distortion) nonlinear behavioral model, which is referred to as X-parameters, of the PA extracted from Agilent NVNA (Nonlinear Vector Network Analyzer) measurement is imported to Agilent ADS (Agilent Advance Design System) to simulate its performance and distortion under TD-SCDMA signal stimulation, which is referred to as PHD model simulation. Secondly, the TD-SCDMA signal used for PHD model simulation is downloaded into the Agilent E4438C signal generator to be as the input for PA during measurement. Thirdly, the signal output from PA is caught and recorded by Vector Signal Analyzer under control of 89600 vector Signal analyzer software, and the signal recorded is imported to ADS to be analyzed by the same method used in PHD model simulation. At last, results such as output power, available gain, spectrum, ACPR (Adjacent Channel Power Ratio), RMS (Root Mean Square) EVM (Error Vector Magnitude) and signal constellation from PHD model simulation and measurement are compared, and it can be found that the PHD model simulation results agree very well with measurement results. As a result, the simulation method designed in this paper can be used to evaluate PA performance and PA distortion correctly.