Comparison and implementation of variable fractional delay filters for wideband digital beamforming

Abstract

Digital delays represent one of the crucial elements in a digital Beam-forming system. If signals involved in the Beamforming are wideband signals, it is not possible to use a phase shifter for the delay generation. In this case, other solutions, like fractional delay filters, are required. This paper compares different fractional delay methods in terms of magnitude response, error phase response, computational costs and hardware complexity, considering as target a FPGA implementation.