Advanced design of phased-array beam-forming networks

Recent, very general and fundamental results in the theory of electrically large microwave networks lead to new, advanced designs of high-efficiency beam-forming networks, for high-directivity electronically-steered phased arrays. On the basis of the rigorous new results, the beam-forming networks of electronically-steered phased arrays can be simultaneously impedance matched to any given set of radiating elements on one side, and to any given set of mutually-coherent, phase- and amplitude-controlled microwave sources on the other. Further, the impedance match attained in transmission also holds in reception, as long as the set of mutually-coherent receivers used has the same internal impedances as the set of sources used. The impedance match attained accounts simultaneously for both the electromagnetic proximity coupling between all the radiating array elements, and for any given internal cross-coupling of the set of sources, in transmission, or of the set of receivers, in reception. The resulting impedance match is totally independent from the amplitude and phase settings of the sources, in transmission, and from the direction of the incoming beam, in reception, completely suppressing the notorious array-blindness effect for all beam directions. Further, beam-forming networks can also be designed with prescribed transmission responses-besides a prescribed impedance match-in both the transmission and reception modes, and with a number of beam-steering control components that is much smaller than the number of array elements.