A comparison of quadrature and single-channel receiver processing in adaptive beamforming

A performance comparison is made between single-channel and quadrature receivers in an HF adaptive beamforming array application. Results obtained with a bistatic HF radar, with digitized data recorded simultaneously at eight receiver outputs processed adaptively off-line, were compared with data obtained using quadrature receivers at the subarray outputs. A quantitative assessment of the frequency-independent gain and phase shift across the received bandwidth attainable in quadrature reception when a single real multiplying weight is applied at two receiver outputs is made for adaptive beamforming arrays. Differences less than 5 dB in the processed outputs are reported, provided the same number of adaptive degrees of freedom are used in the two distinct processors.