Abstract: An antenna for providing a broadband omnidirectional circumferential radion pattern is formed by an array of arcuate waveguide radiators arranged to form a cylindrical antenna. Each waveguide radiator has a ridged waveguide cavity and a plurality of longitudinally-oriented slots communicating with the waveguide cavity. The slots are arranged in two parallel rows on either side of the longitudinal centerline in a staggered relationship along the outside surface of the radiator. Each radiator is fed from the interior of the cylindrical array at a feed point located at the center of the radiator.

Abstract: The present invention provides within three particular aspects thereof an isolating and matching device operable to enable an electrically heatable window of a motor vehicle to be used as an efficient VHF communications aerial or antenna; wherein isolating and matching circuitry is provided for Series VHF Matching, Shunt VHF Matching and Split Passband Matching of an electrically heatable window heating element to an aerial input impedance of an aerial feeder circuit of a radio frequency receiver or transmit/receiver device.

Abstract: There is provided an electric antenna apparatus which is mounted on a vehicle such as an automobile, and in which the rotation of a DC motor drives and rotates a pinion through a reducing mechanism, and a cable coupled to the base end portion of an antenna rod is coupled to this pinion so as to come into engagement therewith. The cable is driven in its longitudinal direction due to the pinion, rotated in response to the rotation of the motor, and the antenna rod coupled to this cable is driven, thereby allowing the antenna rod to be extended or retracted. In this case, a magnetic disk, formed with a plurality of magnetic poles in its outer peripheral portion, is mounted to a worm wheel constituting the reducing mechanism so that the magnetic disk is rotated coaxially with the worm wheel. Also, a reed switch is attached to a circuit board set adjacent to the motor, thereby allowing a pulse-like signal from the reed switch to be detected in response to the rotation of the magnetic disk.

Abstract: A phased array lens antenna which includes a lens having two faces disposed ubstantially at a right angle to each other. Transmit-receive modules which include phase-shifters are shared between the two lens faces. Two lens antennas positioned in back-to-back relationship about a ship superstructure scan 360.degree..

Abstract: An adjustable transceiver antenna mount in which the force required for adjustment is such as to facilitate one-hand operation, enabling the driver to adjust the antenna position from the driver's seat. With internal controls, the driver is able to do so without even opening the window. The mount has a releasable positive locking action and also a serially arranged fail-safe friction connection. The mount provides for connection of the coax cable to a fixed component of the mount to eliminate cable flexing. The mount provides a sealed housing for the connection. The mount provides embracing electrical contact elements for a main shaft. These are pressed against the shaft by a compression spring arrangement which also urge releasable antenna locking members to remain in engagement. The mount has other features recited in the body of the specification.

Abstract: An improved ground-plane antenna with a quarterwave resonant radiating rod (1) made of a hollow tube in which a central earthing rod (7) is arranged to form with the internal cylindrical wall of the radiating rod a line section short-circuited at the upper end, and a further line section (16) open at the lower end is arranged in the extension of the short-circuited line section to form a combined tapped line section therewith having an electrical length substantially equal to the quarterwavelength, in which the combined line section is coupled with its tapping points in parallel to the input terminals of the antenna, whereby the susceptance represented by the combined line section is capable of compensating the changes of the antenna reactance within a fairly wide band.

Abstract: A low profile antenna is provided which includes a counterpoise above which are situated three parallel oriented L-shaped elements. Each of the elements includes leg and foot portions. One common end of the leg portions of the elements are electrically coupled together and to an antenna trimming stub. The remaining end of the middle element constitutes the feedpoint of the antenna together with the remaining ends of the other two elements. The dimensions of the counterpoise top surface are selected to be substantially less than one wavelength at the desired operating frequency of the antenna. In this manner, the antenna generates or is responsive to radio frequency waves exhibiting two polarizations.

Abstract: A relatively short broad band monopole coaxial antenna is provided with a center conductor and an outer radiator. The antenna is mounted above a ground plane and comprises a bare outer radiator portion adjacent the ground plane and a portion remote from the ground plane which is covered with a variable thickness microwave absorbent material. The signal to be transmitted is applied to the base of the monopole antenna adjacent the ground plane. Non-radiated signals propagate up the antenna. The high frequency components are absorbed by the microwave absorbing material. A tip matching network and a base matching network are coupled between the outer conductor and the ground plane for attenuating and matching the low frequency components of the non-radiated signals. The resulting monopole coaxial antenna has no undesirable reflections and has the appearance of infinite effective length antenna.

Abstract: A terminated, end-fed inverted V antenna provides continuous coverage over the 1.8 to 30 MHz frequency range. A special matching transformer is an integral part of the antenna system.

Abstract: This invention relates to an improvement in a collapsible antenna reflector with rigid, collapsible elements for high accuracy of contour, composed of a central panel and collapsible segments mounted thereto by means of joints, the improvement comprising means mounting the individual collapsible segments (5) so that in their collapsed state their contour curvature is equidirectional, with the individual collapsible segments being mounted perpendicularly to the central panel and being arranged from its periphery obliquely to the antenna axis.

Abstract: An active antenna system for an airborne high frequency single sideband receiver comprised of a shorted loop type antenna having an inductive characteristic over the frequency range of 2.0 to 10.0 MHz and which is tuned to resonance at a selected operating frequency by shunting the antenna at its feedpoint by selectively switched sets of voltage variable capacitors. Also coupled to the feedpoint is a field effect transistor which is adapted to provide radio frequency amplification. Impedance matching between the output of the field effect transistor and the input of a radio frequency receiver is further provided by a transistor configured as an emitter follower.

Abstract: A mirror antenna employing a continuous mirror without a hole. A feed horn nd an electromagnetic lens, located behind a rotatable twist reflector (the mirror), collimates a beam toward a polarized reflector located near the twist reflector and tilted to aim energy toward the twist reflector. Energy reflected back toward the polarized reflector from the twist reflector passes through the polarized reflector to free space.

Abstract: A broadband radiating element design is disclosed which provides a smooth, continuous transition from a microstrip feed configuration to a flared notch antenna for transmitting or receiving radio frequency signals.

Abstract: A passive platform stabilization system is disclosed which is suitable for antenna stabilization in maritime communication systems. The stabilization system of the present invention comprises a platform rotatable in a horizontal plane. At least two gyros are suspended from the platform by suspension means which are rotatable about a vertical axis independent of the rotation of the platform in order to avoid undesirable torque components which would result from precession of the gyros. The platform pivots about axes which are parallel to the pitch and roll axes of a vessel on which it is mounted.

Abstract: A radar antenna includes a box horn radiator which is capable of simultaneously transmitting X band and S band signals. The S band signals are transmitted as a resultant of the TE.sub.01 and TE.sub.03 mode, which is generated within the box horn. Additionally, the X band frequencies are fed into an off-set input port, which launches the X band signal as a surface wave. By positioning the box horn at the focus of a reflector, azimuth pointing errors are prevented but different elevation patterns are produced.

Abstract: A broadband antenna for electromagnetic interference testing within a test chamber of limited dimensions includes a triangular array of tuned, quarter-wavelength monopole antenna elements with a common feed point in a plane parallel to elements defining a ground plane. The tuned elements transmit electromagnetic signals down to a low limiting resonant frequency determined by the longest element and further comprise, with the ground plane elements, a capacitor to transmit longer wavelength signals by a varying electric field between the triangular array and ground plane.

Abstract: An omnidirectional, vertically polarized antenna having a lower, 1/4 wavelength skirt made up of circumferentially-spaced arms which extend down from the lower end of a vertical, 1/4 wavelength, upper radiator at an angle between 12 degrees and 25 degrees, and preferably 17 degrees. The upper radiator carries a multi-spoke capacity "hat" to increase its electrical length.