Planar Array Digital Beamforming Algorithm

The technology of digital beamforming (DBF) can dramatically increase array antenna performances. These performances include fast adaptive pattern nulling, ultra-low sidelobes, closely spaced multiple beams, adaptive space-time processing, high resolution direction fiding(DF) and increased capacity for band-limited communications systems. The application of DBF is limited by the high cost of digital receiver/transmitter elements. Over the years, as the technology of electronic components, microwave ICs and high speed digital processor continue to improve, DBF 's practical value for phased array radar is increasing rapidly, and the application of DBF is not limited in one-dimension or subarray level. The research of adaptive digital beamforming (ADBF) system for 2D planar array will be one of the emphases of digital radar.The DBF algorithms are essence of the DBF technology. DBF algorithms for 2D planar array based on the algorithms for 1D array are discussed in this paper. The author's main contributions include① Research of the adaptive digital beamforming algorithm, which control both amplitude and phase of each array element: diagonal loading QRD-SMI algorithm.② Research of two Phase-Only DBF algorithms: small phase perturbation restriction algorithm and maximum gain of the expected direction restriction algorithm.③ Research of multiple beams algorithm for planar array: 2D-FFT multiple beams. And the realization of FFT with CPLD.