Abstract: Ellipsoidal array antennas that include repeated, modular unit cells are disclosed. The ellipsoidal array antennas may be wide band array antennas with bandwidths exceeding one octave that are capable of handling high radio frequency (RF) power with high polarization purity and low-cost manufacturing for arrays with high element counts. The number of unit cells is given by (Element_Rows+1)*Element_Columns for single polarized arrays. For dual polarized arrays, the number of unit cells is given by (Element_Rows+1)*(Element_Columns+1).

Abstract: Embodiments of the invention provide high power waveguide polarizers with broad bandwidth and low loss, and methods of making and using the same. Under one aspect of the present invention, a waveguide polarizer includes a hollow waveguide body having an interior surface; a first ridge disposed on the interior surface of the hollow waveguide body and having an inward-facing surface; and a first plurality of projections disposed on the inward-facing surface of the first ridge. The projections may have a width that is narrower than that of the ridge, and a length that is tunable. The length of the projections may be selected to induce about a 90-degree phase delay in a first mode propagating in a plane parallel to the first ridge relative to a second mode propagating in a plane perpendicular to the first ridge.

Abstract: A compensating structure includes layers of non-uniform arrays of conductive patches configured to provide phase and/or amplitude distribution modification of feed primary patterns.

Abstract: Paraboloidal grid reflectors and antennas are provided which are lighter and have less wind loading because they efficiently realize selected front-to-back ratios by recognizing the angular distribution in typical differential path losses and feed gains. In particular, the reflectors are formed with adjacent pairs of parallel elongate members that are positioned at respective angles &thgr; from the paraboloidal vertex and spaced apart by respective spaces S that generally increase with increased angle &thgr;. In some reflector embodiments, the spaces S increase with increased angle &thgr; for a contiguous majority of adjacent pairs and may be constant for a contiguous minority that typically adjoins the vertex. In other reflector embodiments, the spaces S increase with increased angle &thgr; for all of the adjacent pairs.

Abstract: Antenna structures are shown that reduce fabrication and assembly time and cost, increase antenna reliability and enhance antenna performance. These structures include resilient flanges that are formed by a slotted ground plane and a rear ground plane which together surround a feed circuit. The ground planes are simply pressed together to engage the flanges in an overlapped and resiliently interlocked relationship. In other antenna structure, a capacitance probe forms a part of a coaxial transition. One end of the probe forms a capacitance face and the transition is configured to automatically space the capacitance face from a trunk end of the feed circuit. A second end of the probe is available for coupling signals to antenna-associated circuits (e.g., a downconverter). A pressed-together signal-transmission path through these circuits is formed with spring-loaded sockets. One socket receives the capacitance probe's second end and the other receives the center pin of an external coaxial connector.