Abstract: A planar microwave beamforming lens system achieves wide-angle scanning using a planar lens by using a design in two degrees of freedom. One degree of freedom is provided by varying lengths of transmission lines between aperture side elements and feed side elements as a function of radius. A second degree of freedom results from the distribution of feed side elements so that they are displaced radially from their corresponding aperture elements as a function of the radius of the planar lens. All aperture antenna elements are regularly distributed over the aperture side of the planar lens.

Abstract: An antenna for a transceiver which does not require a transmit/receive switch, typically a cordless telephone, is formed by a printed circuit board (10) which is subdivided by two separating slits, located in respective separating planes (A, B) into three adjacent regions, defining a first end region (F2) adjacent a first slit, a second end region (F3) adjacent a second slit, and an intermediate or central region (F1) between the slits. Electrical surfaces or conductive tracks are connected across the slits (18, 19) by high-frequency impedance elements, such as high-resistance resistors or chokes, (20, 21).

Abstract: An antenna reflector having a parabolically curved reflecting surface is formed of a cellular ceramic material having ceramic fibers fused together in a rigid cellular structure. The body is formed by bonding or fusing a mass of silicon dioxide fibers together at their points of intersection with a fusing agent such as boron nitride in a sintering process, resulting in a fused array of fibers with cellular porosity intentionally distributed through the body to reduce its density. Other types of ceramic fibers can be used either alone or in combination with the silicon dioxide fibers. The antenna reflector finds particular utility in parabolic antennas for satellite microwave communications systems.

Abstract: An FM antenna utilizes a generally rigid conductive element, as a dipole segment, that is connected in electrical communication with a capacitive segment. The capacitive segment can be manufactured from a preselected length of coaxial cable with the central conductor of the coaxial cable being connected in electrical communication with the dipole segment and with the cylindrical conductor, or braided shield, of the coaxial cable being connected to an electrical ground. A variable inductor is connected in electrical communication with the central conductor of the coaxial cable between the capacitive segment and an FM receiver. The central conductor of the capacitive element is connected serially between the dipole segment and the variable inductor. This configuration provides an omnidirectional antenna for use with FM receivers that is relatively small in size and inexpensive to manufacture.

Abstract: The invention is a miniature antenna useful for portable radios, pocket pager receivers, etc. A plurality of sequentially wound windings is located on a ferrite core, each winding being connected in series with a capacitor. The resulting series circuits are connected in parallel with each other. Preferably the resonant frequency of each series circuit is approximately 80% to 90% of a receive frequency. An external tuning capacitance resonates with the net inductance of the antenna at the receive frequency. The antenna exhibits low hand effect while maintaining output EMF.

Abstract: A circularly polarizing antenna feed comprises a feed waveguide having a short circuit reflecting plate at one end and a radiating horn at the other, a wave exciter for launching linearly polarized plane waves axially along the feed waveguide in opposite directions, and a grid of parallel reflector strips disposed in a plane which is perpendicular to the waveguide axis and which is located between the wave exciter and the reflecting termination at a distance of approximately .lambda.g/8 from the exciter and approximately .lambda.g/4 from the termination. The reflecting strips of the grid are inclined at an angle of 45.degree. to the direction of polarization of the waves propagated by the exciter, the grid and the reflecting termination together forming a twist reflector which effectively reflects and rotates through 90.degree. the waves incident upon the grid. These reflected waves together with the forwardly propagated waves from the exciter represent circularly polarized waves.

Abstract: An antenna is adapted to be connected to a coaxial cable having a central conductor and a conductive sheath. The antenna is adapted for operation at a wavelength .lambda. and comprises two loops disposed in substantially parallel planes the distance between which is .lambda./8.+-.20%. At least one connecting element connects the loops, having a length substantially equal to the distance between them. Each loop is adapted to be connected to a respective conductor of the coaxial cable and is either closed with an approximate length of 3.lambda./8 or open with a length of .lambda./4.

Abstract: A microwave antenna formed with a conductive patch supported over and facing a ground plate beneath a support sheet overlapping the ground plate and spaced therefrom. An electrical lead to the patch is passed up through the ground plate to a hole through the patch and support sheet through which a solder joint is formed.

Abstract: A flat antenna particularly suited for mounting to a briefcase as part of a cellular telephone. The antenna has a radiator conductor and ground-plane conductor spaced from each other and mounted at right angles on an insulating support, preferably cardboard. The cardboard also serves as a mounting structure for a cable having two conductors, one soldered to the ground-plane conductor and a second soldered to the radiator. The flat structure is mounted in a panel of a carrying case and the cable is routed to a suitable transceiver.

Abstract: A radome shutter structure for preventing the transmission of electromagnetic energy within a selected frequency range and for permitting the transmission of energy outside such frequency range during a first mode of operation and for permitting the transmission of electromagnetic energy over a relatively wide frequency range which includes such selected frequency range during a second mode of operation. The structure includes an insulative substrate having a symmetrical array of metallized regions, each region preferably in the form of a Jerusalem Cross having discontinuous arms interconnected by diode elements which are placed in a conductive state in the first mode of operation and in a non-conductive state in the second mode of operation.