Digital multiple beamforming techniques for radar

Digital multiple beamforming techniques for radar are described. An efficient digital beamforming algorithm is derived for antenna elements arranged in a triangular grid pattern. Multibeam-phase-steering for the triangular grid can be implemented by first separating the elements into two overlapping rectangular grids. Corresponding beams are then combined in a phase-combiner network similar to a butterfly type of operation performed in a fast Fourier transform (FFT). Grating lobes are developed and related to the discrete Fourier transform (DFT) in an example. The example also describes hardware efficiencies possible for restricted angular coverages. Digital beamforming transforms are compared. A hybrid beamformer, analog scan-within-a-pulse (SWAP) beamforming in one dimension followed by digital beamforming in the second dimension, is then described.