Signal nonlinear distoration magnitude detection method and device

The present invention relates to a method for detecting signal nonlinear distortion magnitude, used for extracting and detecting the nonlinear distortion output by a radio frequency power amplifier, characterized in respectively extracting input signal and output signal, and performing square after matching the amplitudes and frequencies of the input signal and output signal respectively, obtaining respective low frequency components of the squared input signal and output signal, therefore, the carrier component of the signals can be filtered, and the low frequency components can characterize the distorted signal feature as well as facilitate handling. The present invention performs square after matching the input signal and output signal, extracts the low frequency component, and then the relativity with the frequency and bandwidth of the signal is low, therefore, the difficulty in detecting the distortion can be reduced greatly. In addition, the square is equivalent to amplify the distortion, which is favorable to improve the detection sensitivity of output distortion.