Flat topped radiation pattern synthesis based on FIR filter concept

Through comparing the spatial expression of radiation patterns of the uniform linear array (ULA) and the spectral expression of finite impulse response (FIR) filters, this paper reveals the correspondence between parameters in space domain of ULA and parameters in time domain for FIR. Then by applying the strategy of FIR filter to ULA beamforming, selected Kaiser Window design method is used to synthesize flat topped beam, and patterns with variable beamwidth can be achieved by tuning the order and shape of Kaiser Window. End-fire flat topped beams and broadside flat topped beam are designed based on the proposed approach, and verified by full-wave simulations, which shows that the proposed beamforming approach is very convenient and of great value for flat topped beamforming.