UWB virtual beamforming using hermite fractional delay filter sets combining autoregressive modeling

The digital beamforming (DBF) of ultra-wideband (UWB) radar is a challenging issue and its performance is closely affected by the delay compensation filters and the aperture of the antenna array. In this paper, a high-resolution DBF method for UWB signals utilizing Hermite fractional delay filter sets combining a virtual array created by a vector extrapolation algorithm on autoregressive(AR) models is presented. Theoretical analysis indicates that the magnitude response and the group delay of the Hermite fractional delay filter sets are much more accurate than that of the traditional method such as Lagrange fractional delay Alter over the whole frequency band, and the adopted virtual array creation algorithm can extend the aperture of the original array to 6 times. Simulation results of the DBF performance using UWB linear frequency modulated (LFM) signals for two different scenarios also demonstrate the superiority of the proposed method.