Abstract: A launching and/or receiving network is disclosed capable of coupling radio signals in a first frequency band, e.g., 2 GHz into and/or out of an existing antenna system without perturbing the signals being transmitted in other frequency bands, e.g., 4, 6 and/or 11 GHz. The first frequency band signal is launched through an evanescent mode waveguide filter which is both coupled to the flared sidewall of a feedhorn through an H-plane, T-junction, and provides a very broad stopband for the signals in the other frequency bands being launched in the feedhorn. To minimize mode conversion for the signals in the other frequency bands, a dummy evanescent mode waveguide filter is connected at one end thereof to the feedhorn facing the first frequency band launching network and at the other end thereof to a matched load through a waveguide section.

Abstract: A signal to be filtered is subjected to a known filter function a sufficient plurality of times and with appropriate processing to produce in a plot of the total filtering response versus the response of one such function at least one inflection in a portion of the plot corresponding to a transition band between a passband and a stopband of the filter function. Various embodiments of the overall filtering function are shown which are applicable to both recursive and nonrecursive filters and to filters having either single or multiple sets of passband and stopband combinations per filter function.

Abstract: Twin electric microstrip dipole antennas consisting of thin electrically ducting rectangular shape elements formed on both sides of a dielectric substrate. In these antennas the element on one side of the substrate is the mirror image of the element on the other side of the substrate. Each of the elements act, in effect, as a ground plane for the other. The thickness of the substrate to a large extent determines the bandwidth of the antenna and the length of the conducting elements on both sides of the substrate determines the resonant frequency.

Abstract: The present invention relates to thinned linear, planar and three-dimensional phased antenna array configurations which have the antenna or sensor elements positioned in a pseudorandom manner as prescribed by the equation based on difference sets. The present antenna array permit thinning factors well below one-half while retaining the sidelobe level characteristics of arrays with much higher thinning factors.

Abstract: A coupled fed magnetic microstrip dipole antenna consisting of a thin eleically conducting, rectangular-shaped radiating element (resonator) and a nonradiating coupler formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The radiating element has one end shorted to the ground plane. There is only a single mode of oscillation. Oscillation takes place along the length of the radiating element, and the length determines the resonant frequency. The feed point is normally located at the end of the coupler; energy is in turn coupled to the radiating element. However, the feed point can be located along the uncoupled edge of the coupler. Input impedance matching is determined by a combination of the coupler length and the separation between the coupler and the radiating element, and also the feed location when fed along the uncoupled edge of the coupler.

Abstract: Circularly polarized microstrip antennas consisting of thin electrically ducting, square-shaped radiating elements formed on one surface of a dielectric substrate and having a ground plane on the opposite surface of the substrate. Two feed points are used to provide a circular polarized radiation pattern. The feed points are located along the centerlines of the antenna length and width or along the diagonal lines of the element and the input impedances can be varied by moving the feed points along both centerlines or both diagonal lines from the centerpoint of the element. The antennas can be notched in from the edges of the radiating element along the centerlines of the element width and length, or along opposite diagonal lines of the element, to the optimum input impedance match feed point.

Abstract: A horn for radiating circularly polarized energy includes a rear launcher section commencing with a double-ridged cross section and ending at the horn flare with a square cross section with the plane of polarization so that the wave excited in the square cross section is along a diagonal of the square. The horn flare section opens up to a dimension of approximately 70% larger than the square throat dimension to narrow the elevation beam. A dielectric slab oriented in the horizontal plane is seated in the flare section for introducing a frequency-varying differential phase shift between orthogonal modes for effectively compensating for the inherent phase shift in the flare. Refracting lenses that are half-cylinders having a diameter of about 25% of the horizontal aperture dimension with their axes aligned vertically are located close to the vertical aperture edges for refracting the energy at the horn edges into the region between 30.degree. and 60.degree. from the horn axis.

Abstract: A compact arrangement having concentric loading element and coupling element with the latter forming a bearing support for a revolvable member mounting the former.

Abstract: Apparatus for automatically erecting a vehicle mounted antenna of the type utilized for citizens band radios. A p.m. motor provides drive to pivotally move the antenna and a logic circuit comprising only a double-pole-double-throw and two secondary switches provides fully automatic performance in conjunction with turning on the radio. LEDs are selectively illuminated to show antenna status by utilizing a circuit logic path incorporating the winding of the motor. A friction coupling override arrangement protects the erecting mechanism while retaining drive logic.

Abstract: A microwave element is disclosed that is fabricated from a dielectric material wherein the antenna, the iris, and a microwave cavity portion are formed generally from a single piece of relatively high dielectric constant material. The microwave cavity portion is converted into an actual microwave resonant cavity by covering the microwave cavity portion with a conductive material.