Large Dynamic Range Wideband Interferometer Receiver for Lightning Detection

A blind nonlinear identification based adaptive software radio receiver architecture is proposed and validated.Since the time-frequency domain characteristics of the lightning signal being unknown or time-varying,the harmonic and inter-modulation components in the output signal of the wideband digital receiver are automatically identified and extracted in the frequency domain,then a blind identification criterion for minimizing the short-time energy is designed.The steepest descent method is applied to iteratively extract and update the parameters of the nonlinear behavior model of the wideband digital receiver.Finally,the updated model is utilized to compensate the nonlinear distortion of the receiver in real-time.The experimental results show that the spurs free dynamic range(SFDR) of the blind identification digital receiver could achieve about 20 dB higher than that of the traditional receiver under multi-tone signal or band-pass modulating signal exciting.