Planar antenna with patch elements

Claim 1

A planar antenna for concurrently receiving signals transmitted from a satellite in different polarization modes as carried on SHF band, comprising: a radiator circuit plate formed of a resin and carrying a radiator circuit of a conductive material and including a plurality of slots and a plurality of square-shaped patch elements disposed in respective ones of said slots, first and second power supply circuit plates formed of a resin and respectively carrying first and second power supply circuits of a conductive material, said first power supply circuit including a plurality of first terminals disposed to correspond to one of said polarization modes, there being a first terminal for each said patch element, said second power supply circuit including a plurality of second terminals disposed to correspond to another of said polarization modes, there being a second terminal for each said patch element, said first and second power supply circuits being separated from each other and from said radiator circuit to be independent of one another, with power supply terminals of each of said first and second power supply circuits being superposed relative to respective ones of said patch elements for electromagnetically coupling each of said patch elements with a power supply terminal of said first power supply circuit and with a power supply terminal of said second power supply circuit, and a ground conductor plate separated from said radiator circuit and said first and second power supply circuits to be independent thereof, said first terminals being arranged in a plurality of pairs, and said second terminals being arranged in a plurality of pairs, each pair of first terminals being arranged to bisect respective sides of two adjacent ones of said patch elements, each pair of second terminals being arranged to bisect respective sides of two adjacent ones of said patch elements, as said antenna is viewed in plan, such that the first and second terminals associated with each patch element are oriented perpendicularly to one another in such manner that said first and second power supply circuits correspond to horizontal and vertical polarization modes, respectively, said ground conductor plate being formed of a resin and carries a ground circuit of a conductive material, said ground conductor plate being disposed between said first and second power supply circuits and separated from them, said ground circuit including a plurality of slots at least as large as respective ones of said patch elements and disposed at positions superposed relative to said patch elements.