Abstract:

A new method is developed to calibrate the non-ideal transfer function and IQ imbalances in quadrature modulate/demodulate systems which frequently occur in wideband radar systems, without changing the hardware of the radar calibration system. Based on analyzing channel errors in radar systems, two chirp signals with opposite chirp rate are adopted as calibration signals to acquire the true channel transfer function. And a calibration function is constructed to correct the erroneous echo due to the existence of the non-ideal transfer function and nonideal quadrature modulate/demodulate systems. Taking account of the noise in both the calibration system and the radar echo, the signal to noise ratio (SNR) after the pulse compression of the calibrated echo is analyzed. Simulation results the effectiveness of the proposed technique.