Geometrically derived beam circular antenna array

Claim 1

An antenna for scanning a spherical sector comprising: a plurality in excess of 2N + 1 where N is an integer valve, of antenna elements oriented normal to said spherical sector and spaced tangentially along an arc within said spherical sector; a radio frequency device for processing a signal having a characteristic wavelength; conductive means electrically coupled to said signal processing means for providing a plurality equal to the number of said antenna elements, of non-cophasal radio frequency paths differing in length by multiples of one said wavelength; a plurality of networks equal in number to said antenna elements, each network providing a minor path and a major path one-half of a wavelength longer than the minor path, for radio frequency energy passing between one of said non-cophasal paths and a corresponding one of said antenna elements; a source of bias energy; a plurality equal to the sum of the number of said major and minor paths, of electronic devices, each device providing a shorted circuit between a ground potential and a point on a corresponding said network path one quarter of said wavelength from the junction of that network and the corresponding said non-cophasal path in response to reception of said bias energy; and switching means for electrically coupling each of said electronic devices to said source of bias energy according to a selected sequence; whereby said antenna scans said spherical sector in successive overlapping sectorates of that part of said sector having an arcuate width in conformance with said arc by sequentially exciting each stepped groups of 2N + 1 said elements symmetrical about a normal bisecting the successive corresponding sectorates wherein for each sectorate all of said plurality of electronic devices except those electronic devices providing shorted circuits to the minor paths of those networks corresponding to the N adjoining said elements symmetric about said normal and those networks corresponding to those elements next adjoining but one from said N adjoining elements are coupled via said switching means to said source of bias energy.