Amplitude and phase calibration of digital array radar using frequency stepped signals

The application of modulated stepped frequency signal in digital array radar is discussed based on the High-Resolution image algorithms. The effects of phase error in every single-channel on high resolution range are analyzed, that is , the nonlinear increase in interpulse frequency will result in distorted main lobe and increased sidelobe, which affects the quality of radar imaging. Also, inconsistent slope characteristics and phase error between different channels will result in the shifting of pattern beam and increase of sidelobe, thereby affects the quality of the angle measurement. In this paper, linear fitting of the phase and adjustment of the slopes are carried. The simulation and experimental results have demonstrated the effectiveness of the method.