Spread spectrum digital beamforming virtual array and scalability to millimeter wavelength frequencies MMW-SSDBF virtual array

This paper describes a millimeter-wave spread spectrum digital beamforming (MMW-SSDBF) technique employing large-aperture 2D MIMO virtual arrays. The MIMO array utilizes truly shift-orthogonal (TSOC) radar waveforms in order to significantly reduce hardware complexity, thereby enabling implementation of the low-cost wafer array. The architecture utilizes simple branch-line coupler bi-phase modulators per element to implement the beamforming operations, with a single digital transceiver for the whole array.