Abstract: A dual polarized printed circuit antenna operating in dual frequency bands. A first array of radiating elements radiates at a first frequency, and a second array of radiating elements radiates at a second, different frequency. Separate power divider arrays are provided for each array of radiating elements, and the overall structure is provided in a stacked configuration.

Abstract: In a flat plate antenna, insertion loss is reduced significantly by providing an extensive waveguide structure at the back of the ground plane of the antenna. Depending on antenna size, the waveguide may feed the antenna at one or a plurality of points. According to a preferred embodiment, the transition from waveguide to stripline is made via a coaxial connection, with a quarter-wave transformation, including mode suppression walls to direct the energy more efficiently. Alternatively, a direct waveguide to stripline transition may be provided. The technique has wide applicability to a number of antenna designs, including single- and dual-polarization structures, and linear and circular polarization operation.

Abstract: A printed-circuit antenna array having broadband linear polarization, and circular polarization with high polarization purity, feedlines of the array being capacitively coupled to feeding elements at a single feedpoint or at multiple feedpoints, the feeding elements in turn being electromagnetically coupled to corresponding radiating elements. The radiating elements may be patches, disposed on a dielectric board which is contactlessly coupled to another board containing the feeding elements, in accordance with a first embodiment of the invention. Alternatively, the radiating elements may be slots, formed by an absence of material in ground planes which are formed on the same dielectric board as the feeding elements. Still further, both radiating patches and radiating slots may be used. The exclusively contactless coupling enables simple, inexpensive multilayer manufacture.

Abstract: A printed-circuit antenna enabling two signals to be received simultaneously. Two layers of radiating elements and corresponding power dividers are provided, one set of power dividers being disposed orthogonally with respect to the other, so as to enable reception of two signals with orthogonal senses of polarization. Either dual linear or dual circular polarization may be achieved through suitable selection of radiating elements. Alternatively, a quadrature hybrid may be coupled, either externally or as an integral part of the antenna, to enable dual circular polarization.

Abstract: A gridded radiating element for printed circuit antennas employing capacitive coupling of radiating elements to feedlines. The radiating element is formed of a grid wherein a metallization region is etched selectively to yield a plurality of metal strips disposed parallel to each other with a predetermined separation. This element, in contrast to known elements which employ solid metallization regions, finds particular application in dual polarization geometries, and enables improved performance over a wide bandwidth.