Power efficient feed network for TACAN antenna arrays

Claim 1

An antenna feed for a circular array of antenna elements which generate a TACAN radiation envelope comprising: a source of radio frequency signals; a power divider for providing first and second pairs of radio frequency signals from said source, and one additional signal larger in amplitude than each of said signals of each pair; a first pair of phase shifters connected to receive said first pair of signals, and phase shifting said first pair of signals at a first periodic frequency; a second pair of phase shifters connected to receive said second pair of signals and phase shifting said signals at a second periodic frequency; a feed matrix connected to each element of said circular array, including a plurality of hybrid networks equal to one half the number of said elements, each having a pair of output ports connected to a pair of said and a pair of inputs; a second power divider for dividing said one additional signal into a plurality of signals equal in number to said number of hybrid networks, and supplying each of said plurality of said signals to one input of each hybrid network; a phase shift network having first and second pairs of inputs connected to each pair of phase shifters, and providing a plurality of outputs for the remaining inputs of said hybrid networks, whereby a combined signal proportional to the sum of said phase shifted signals is applied to each hybrid; and, said circular array forming a pattern of radiation having an omni-directional component produced by said additional output signal and first and second modulation components from said first and second pairs of phase shifters.