Cylindrical phased array antenna system to produce wide open coverage of a wide angular sector with high directive gain and strong capability to resolve multiple signals

An apparatus capable of adding the features of separating multiple signals and for eliminating sampling loss of signal energy in antenna systems having an azimuth coverage sector through which the antenna system scans at a rate that is faster than the rate at which information is being received, comprising:

• (a) a cylindrical phased array antenna comprising a plurality of radiator elements evenly spaced around a circular arc;
• (b) means for decomposing the current distribution on the radiator elements caused by electromagnetic wave incidence into component signals being Fourier spatial harmonics of the distribution wherein said component signals have amplitudes corresponding to the incident electromagnetic wave;
• (c) means for forming a plurality of beams of sensitivity from said component signals, said plurality of beams of sensitivity being equal in number to said plurality of radiator elements in said circular arc, the beams being contiguous and considered as lying in the azimuth plane of an emitter for reference purposes, with each beam being generally evenly spaced from adjacent beams in .theta. spaced, where .theta. is the angle away from broadside in the azimuthal plane, wherein the spacing between beam center directions in .theta. space is generally proportional to the reciprocal of the number of antenna elements, and the beams, taken together to form a larger composite beam, span the entire azimuth coverage sector of said antenna system;
• (d) means to differentially weight said amplitude of said component signals to achieve a desired time invariant relative weighing of the signals for beam shape control;
• (e) means to differentially delay and phase shift said component signals to achieve a desired time invariant relative phasing of the signals for beam focusing;
• (f) means to differentially phase shift these component signals at rates exceeding 4.pi. radians per cycle of the highest frequency present in the information content of said incident electromagnetic wave for synchronously scanning each of the beams over the entire coverage sector, the beams maintaining their relative positions adjacent one another in 0 space during scanning, the scanning being carried out periodically at a rate that is at least twice as fast as the highest information rate being received;
• (g) means for accepting signals received by each beam and differentially delaying said signals to cause their modulation envelopes to respond in unison to a single emitting source at a particular azimuth angle;
• (h) means for coherently combining said signals after said signals have been differentially delayed, said means for combining being arranged to cause coherent addition selectively at different signal frequencies;
• and
• (i) means for separating multiple signals at a single output port of said combiner when said signals have frequencies corresponding to grating lobe response.