Patent ID: 8847825
Filing Date: 2014-09-30
Classification: H01Q

Abstract:
1. A circularly polarized patch antenna, comprising: a first patch radiator, comprising a substantially uniform, conductive surface having extents proportional to a wavelength of an electromagnetic signal of the antenna, wherein a positive direction along a first-patch reference axis, passing through a centroid of the first patch radiator perpendicular to the surface thereof, is parallel to a principal direction of propagation of signals emitted from the antenna; a first coaxial feed point and a second coaxial feed point on the first patch radiator; a first backing conductor, substantially parallel to and coextensive with the first patch radiator; a first parasitic radiator, substantially parallel to and aligned with the first patch radiator; a second patch radiator, substantially identical to and oriented equivalently to and coplanar with the first patch radiator is parallel to the principal direction of propagation of signals emitted from the antenna; a third coaxial feed point and a fourth coaxial feed point on the second patch radiator; a second backing conductor, substantially parallel to and coextensive with the second patch radiator; a second parasitic radiator, substantially parallel to and aligned with the second patch radiator; a power divider, configured to accept an applied broadcast signal on a coaxial input port and to provide a first two divider output signals on a first two divider coaxial output ports, and a second two divider output signals on a second two divider coaxial output ports; first two interconnecting coaxial signal lines between the first two coaxial output ports of the power divider and the radiator coaxial feed points of the first patch radiator; second two interconnecting signal lines between the second two coaxial output ports of the power divider and the radiator coaxial feed points of the second patch radiator; a conductive frame distal to the parasitic radiator and located further from the first patch radiator than is a backing conductor; and passage apertures through the frame for coaxial feed stems at prescribed locations, wherein the respective feed stem outer conductors are connected electrically and mechanically to the frame at the passage locations; wherein the respective interconnecting signal lines include: coaxial feed stems that pass through the first backing conductor, with electrical connections therebetween substantially coinciding with the first backing conductor passthrough locations, coaxial feed lines directed from the first two divider output ports to respective inputs of the coaxial feed stems, termination loci for respective coaxial feed stem outer conductors, located between the first backing conductor and the first patch radiator, and respective coaxial feed stem inner conductors that extend from the feed lines through the respective feed stem outer conductors, beyond the termination loci, and connect to the first patch radiator at the respective feed points, and wherein spacing along the principal propagation axis between the first backing conductor and the first patch radiator is less than one wavelength of a frequency in a range of the antenna, between the first patch radiator and the first parasitic radiator is less than one wavelength of a frequency in the range of the antenna, and between the first backing conductor and the frame is approximately one quarter of a wavelength of a frequency in the range of the antenna.