Abstract: Disclosed is a circular waveguide in which a slots are formed which are shaped and disposed such that they interrupt either the right hand or left hand circulating mode (RC and LC respectively) residing in the waveguide. Locating the slots in the waveguide wall is accomplished in accordance with the theory that for TE modes in circular waveguide with circumferential variation of e.sup..+-.jm.phi., current flow lines are produced that are helical. The slots are located so as to interrupt the helical current of the desired mode. In one embodiment, an ortho-polarization mode transducer and a circular polarizer are used to feed the slotted waveguide. By control of the amplitude and phase of the energy propagating in the waveguide, aximuthal pattern control can be effected. By dielectric loading the waveguide to make .lambda..sub.g in the loaded waveguide equal to .lambda.-free space, endfire radiation can be achieved.

Abstract: A telecommunications antenna is provided with a reflector having a semi-offset geometry, a feed mounted on a feed source rigidly fixed to the reflector, an antenna pedestal for supporting the reflector and the feed. Positioning of the feed is such that, in respect of a reflector illumination half-angle .beta. as seen from the feed such that 45.degree.<.beta.<55.degree., the offset angle .alpha. (angle between the focal axis .DELTA..sub.Foc and the median ray of the total beam which is emitted by the feed and illuminates the reflector) is 25.degree.<.alpha.<35.degree., the antenna mount being of the azimuth-elevation type known as an az-el mount.

Abstract: An automobile antenna system for receiving broadcast waves by means of a plurality of antennas, which are provided on a vehicle body, outputs the receiving signal from the antenna which enjoys the optimum reception by automatic changeover. The antenna system includes a pair of glass antennas disposed on the rear window or side windows of the vehicle body and a pair of high-frequency pickups disposed on both sides of the vehicle body apart from the glass antennas by a predetermined distance for effectively picking up high-frequency surface currents which are induced on a vehicle body by broadcast waves, these four antennas constituting a diversity antenna.

Abstract: An antenna pointing device capable of scanning in two orthogonal directions comprises a fixed source (20) emitting a radio beam (21) and associated with a main offset reflector (10) and a secondary offset reflector (11), together with a set of at least three mirrors (14, 15, and 17) including a first mirror (14) aligned with the secondary reflector (11), and in which the second and third mirrors (15 and 17) are fixed to respective rotary drive mechanisms (16 and 18) for rotating them about two axes (.DELTA., .DELTA.') extending in orthogonal directions. The main and the secondary reflectors (10, 11) and the first and the second mirrors (14, 15) are mechanically fixed to one another in order to constitute a moving assembly. The second mechanism (18) drives both the third mirror (17) and said moving assembly (10, 11, 14, and 15).

Abstract: A termination (20, 32) is placed in the opposing wall behind the center radiator (18c, 28c) of a multiple slot antenna array. The termination is inoperative when the array is excited for sum mode radiation patterns and is operative when the array is excited with difference mode radiation patterns. When the terminatrion is inoperative, the center slot radiator is excited along with the remaining slot radiators (18, 28) to produce the sum pattern. When the termination is operative, the center slot radiator is prevented from receiving excitation and a resultant difference pattern is produced by the remaining slot radiators (18, 28). Both E-plane and H-plane patterns can be achieved by the appropriate use of series slots and shunt slots. By eliminating the center slot (18c, 28c) in the difference pattern a reduction in side lobes results. This is an improvment over current practice where there are an even number of slots and no change of amplitude distribution--only a change of 180.degree.

Abstract: A mount for connecting a satellite television antenna to a pipe mast. The mount includes a support assembly of a linear upright member and a cross member which are adapted for attachment to a peripheral portion of a parabolic dish antenna and a fitting attached to a lower end of the upright member which connects with a pipe mast so as to enable or prevent rotation of the support assembly with respect to the mast axis and to enable or prevent varying the angle of inclination of the upright member with respect to vertical.

Abstract: A surface coil for use in conducting examinations in a nuclear magnetic resonance apparatus is formed by a coaxial conductor section arranged in a loop, the jacket shielding for the coaxial conductor having a gap at a selected location, and the inside conductor and the shielding of a free end of the coaxial conductor section being electrically connected to the shielding of the other end of the coaxial conductor section.

Abstract: An antenna having provision for mounting to a printed circuit board and method for making the antenna is described. The antenna includes a generally elongate, magnetically permeable core having a major axis and an insulating substrate affixed along an axis parallel to the major axis. The insulating substrate has a plurality of opposed pairs of spaced conductive runners positioned at generally regular intervals along the substrate normal to the major axis. A plurality of discrete capacitors are and perpendicular to secured between the opposed pairs of conductive runners. An electrically conductive split sleeve substantially surrounds the core and has pairs of opposed tabs on the edge portions in electrical connection with the opposed pairs of conductive runners. The sleeve further includes integral mounting tabs for securing the antenna assembly to the printed circuit board to establish electrical connection to the antenna without the use of wire leads.

Abstract: A multi-antenna element in the form of a narrow strip and including a dielectric substrate in the form of a narrow strip, a substantially continuous thin metallic layer coated onto one side of the dielectric substrate, at least one generally elongated discrete thin metallic layer coated onto the other side of the dielectric substrate and containing within its surface at least one void of predetermined location, size and shape, and each such void present in said discrete layer containing therewithin in noncontacting and in substantially coplanar relationship with the discrete layer at least one further discrete thin metallic coated layer of predetermined location, size and shape.

Abstract: The invention is a system for automatically controlling the surface contour of a deployable and restowable antenna 11 having a mesh reflector surface 26 supported by a circular, folding hoop 12 affixed to a central, telescoping column 14. The antenna 11, when deployed, forms a quad-aperture reflector with each quadrant A-D of the mesh surface 26 shaped to provide an offset parabolic RF reflector.The hoop 12 is supported and positioned by quartz support cords 12 attached to the top 22 of column 14 and by lower graphite hoop control cords 23 that extend between the hoop 12 and base 24 of the column 14. The antenna 11, an RF reflective surface 26, is a gold plated molybdenum wire mesh supported on a graphite cord truss structure that includes the hoop control cords and a plurality of surface control cords 27 attached at selected points on the surface 26 and to the base 24 of column 14.

Abstract: Phased array antennas are rapidly tested for performance degradation utilng a beam steering computer unit and built-in test equipment. The antenna includes a plurality of bays in a planar matrix, each bay having subarray modules containing pairs of dipoles. The beam steering unit controls scanning of driver cards having drivers which apply bias voltages to phase shifter diodes or bits of various fixed angular sizes in a main array and subarray. The bits are sequentially tested for current faults, with information obtained on number, size, and location of failed bits determining performance degradation of a predetermined threshold. Larger phase bits of the main array are given more weight than smaller subarray bits. The effect of the failures on sum beam gain and azimuth and elevation differences pattern null depths are computed and compared with the threshold to indicate whether performance is acceptable.

Abstract: A satellite transmission receiving antenna with unique mounting provisions for a recreational vehicle roof. A generally cylindrical collar extends upward from the vehicle roof and attaches to a load distributing panel under the collar and over the area of the vehicle roof for load distribution. A parabolic reflector is hinged along an edge to a generally horizontal turntable within the collar so that the reflector may be rotated to a concave downward position to act as a weather cover over the collar and also to provide smooth aerodynamic conditions during transport. Rotation of the turntable through a motor driven gear coupling to the turntable effects azimuth positioning of the antenna and elevation angle is set by a linear actuator.

Abstract: A plurality of small segments stowed in a compact stack are assembled, essentially automatically, into a large construction surface, such as a flat or parabolic reflector.

Abstract: A DBS antenna comprises a support arm (10) which at its front end supports a converter/feed unit (12) and at its rear end is secured to a mounting bracket. The antenna dish (14) is mounted on the support arm (10), so that the dish (14) is supported by the arm (10) without mechanical loading from the converter/feed unit (12). The converter feed unit (12) may have a tapering cover portion (74) of sufficient electrical thickness to produce focussing of the signal into the waveguide feed.

Abstract: An antenna assembly which comprises a first laminar structure which includes a sheet of dielectric material having on one side a contiguous metal sheet and on the other side a strip transmission line adapted to be coupled with signal feeding means, and a second laminar structure, one side of which is in contact with the transmission line, and having on the other side, at least one region but preferable at least two concentrically arranged regions of a coated or cladded metal which serves as a radiator, characterized in that the transmission line is non-symetrically disposed with respect to the radiator.

Abstract: An automobile TV antenna system for receiving TV broadcast waves includes high-frequency pickups which are accommodated in the interior of a vehicle body in a concealed state without any external exposure. A plurality of high-frequency pickup are provided on the vehicle body at positions spaced from each other and the pickup which has the best reception at a given time is automatically selected by a diversity circuit. Each of the high-frequency pickups is provided in proximity of a marginal edge portion of the vehicle body in order to pick up the high-frequency surface currents which are induced by the broadcast waves and flow concentratedly on the marginal edge portions of the vehicle body. The high-frequency pickup includes a loop antenna or an electrostatic electrode which is disposed in proximity to a marginal edge portion of the vehicle body.

Abstract: The invention relates to a matching network which may be serially inserted in the path between a transmitter power amplifier and/or a receiver low noise amplifier and an element of a steerable array antenna to compensate for mismatching occurring when the antenna is steered away from bore sight or tuned to off resonant frequencies. The invention permits computer controlled digital setting of the matching network in accordance with the known impedance characteristics of the antenna element, to restore VSWRs which in an exemplary case may have a maximum design value of 3.0 when uncompensated to a VSWR of 1.6 with a simple matching network, or to a VSWR of 1.22 with a more highly corrected matching network.

Abstract: The present invention provides a vehicle antenna system embedded in the vehicle body for efficiently detecting external waves and transmitting the detected signals to an onboard receiver. The antenna system includes a metallic armor member arranged extending along the vehicle body and electrically insulated from the vehicle frame and an antenna element disposed in close proximity to the metallic armor member without outwardly extending from the vehicle body. The metallic armor member is preferably a side molding on the vehicle body. The antenna element is in the form of an antenna wire or loop antenna disposed extending along the length of the side molding. The antenna element is intersected by an alternating field created by the surface currents on the metallic armor member to generate high frequency currents in the antenna element, the generated currents being then transmitted directly to the onboard receiver through a cable.

Abstract: A heavy duty aerial mounting base which is structurally resilient and electrically insulated. There is a solid inner core and a weathershielding outer core integrally formed with the inner core. The inner and outer cores are concentric and are formed with a space between them. The outer core tapers inwardly and upwardly at one end until it meets the inner core. There are reinforcing ribs in the space between the inner and outer cores.

Abstract: An antenna for receiving or transmitting electromagnetic waves with circular polarization or, in certain configurations, linear polarization. The antenna element is low-cost, wide-band and medium-gain broadside antenna element which may be used alone or in arrays. One embodiment disclosed comprises a wire or micro-strip conductor outlining a cruciform shaped loop parallel to a conductive plane from which it is separated by a dielectric layer. The lengths and widths of the branches of the cruciform loop are chosen to be .lambda.g/2 and .lambda.g/N respectively, where .lambda.g is the guide wavelength of the radiative transmission line formed by the conductor and plane. The antenna element is applicable to mobile earth-bound terminals for selective communications, for example.