Antenna
AssigneeThorn EMI plc
InventorFrancis R. Trumble
Life of this patent
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Abstract
An antenna has a resonant cavity defined by electrically conducting plates and a sidewall, and has sixteen helical antenna elements each with five turns in the helical section and a probe at the opposite end, the stem of probe passing through an aperture in upper plate so that its end is within the resonant cavity common to all elements in that module. The cavity has a cross-section parallel to the plates essentially square in shape except for the presence of four inwardly-protruding buttresses, one situated mid-way along each side of the cavity to promote the formation of standing waves of different mode, and thereby enhance the frequency range of the array.
Claims8
An antenna module comprising a resonant cavity having a major cross-section formed by first and second spaced apart and juxtaposed plate members with sidewalls linking said members, a plurality of antenna elements supported externally of the cavity and to one side of one of said first and second plate members, each antenna element having a probe portion coupled into said cavity through a respective aperture in said one side of one of said first and second plate members, wherein the shape in plan of said cavity conforms to a parallelogram at least one sidewall of which has an identation formed thereon in the form of a buttress extending into the cavity to an extent sufficient to promote the formation of standing waves of differing modes to that defined by the aforesaid parallelogram, for each buttress located on one sidewall there is positioned an opposing buttress on the parallel sidewall, thereby enhancing the frequency range of the said module.
Dependencies are inferred from the claim text.