FIR-filter-based method for the calibration of model errors in wideband digital array radar

Wideband digital array radar (WDAR) has the potential of achieving high resolution and providing multi-function simultaneously, but it is limited in practical use due to the effects of frequency-dependent array model errors. A method to jointly calibrate gain-phase perturbations and mutual coupling effects in WDRA is presented. First, a sparse-based method is deployed to calculate the narrowband calibration matrices at a set of discrete frequencies. Moreover, using a group of finite-impulse response filters, a wideband calibration matrix is constructed, which is capable of compensating the imperfections of array at any frequency in the band. The proposed method is simple and feasible for actual applications, which can be applied to arbitrary array geometries. Simulations and experimental results with measured data demonstrate the validity and effectiveness of the proposed method.