Beamforming and array processing with active arrays

An experimental phased array radar (ELRA) has been developed as a basis for investigations of various kinds of new radar functions and signal processing techniques. Two separate active antenna arrays for transmitting (300 transistor power amplifiers) and receiving (768 channels) have been built. The antenna elements are printed dipoles that are distributed randomly thinned on a planar aperture. Multifunction operation is controlled by a network of microcomputers. Beamforming with active receiving arrays could be performed by digitizing all channel outputs, multiplying these with certain complex weights, and then summing up the products. Beam steering may be included in these weights. This approach achieves maximum flexibility, at the expense of maximum cost.<>