A Novel Intergration Method for Wideband Radar via Mainlobe Broadening

In order to enhance the extended target detectability, a novel mismatched filter characterized by a forced broadening of the 3 dB mainlobe width (MW) of the output response is designed. Similar to the target energy accumulation of the narrowband radar, the designed filter is able to concentrate the energy of the scattering centers into the same resolution unit. To this end, 3 dB MW, mismatched filter gain, and signal-noise ratio (SNR) constraints are forced on the mismatched filter, while integration sidelobe level (ISL) is taken as the figure of merit to minimize. To handle the resulting non-convex problem, a polynomial-time method based on sequential convex approximation (SCA) which slacks the non-convex constraint is proposed to decrease ISL. Numerical results are provided to show that the 3 dB MW can be successfully broadened in a certain range, and the extended target energy can be accumulated efficiently.