Abstract: An integrated directional antenna includes a radome, a resonant cavity within the radome, a microstrip radiator and a patch re-radiator positioned within the resonant cavity to provide a directed or focused beam. A first radiator can be provided for signal transmission and a second radiator for signal reception. A chassis member is located within the radome and defines the resonant cavity/ies and a rear cavity for electronic components. A rear cover can incorporate an integral heat sink for dissipating heat from electronic components within the rear cavity. An antenna mounting bracket has first and second spaced mounting points to allow a large range of mounting angles with a compact construction. The chassis member, the radio transmission and/or receiving elements and the electronic circuit elements can be sandwiched together in a desired configuration by fixing the rear cover to the radome. The antenna finds particular application in the field of radio telephony systems.

Abstract: A dual-band octafilar helix antenna operational at two frequencies, while maintaining a relatively small package size. The dual-band octafilar antenna is manufactured by disposing radiators and a feed network onto a flexible substrate and forming the substrate into a cylindrical shape to obtain the helical configuration. The dual-band octafilar helix antenna includes four active radiators which are matched to a first frequency and disposed on a radiator portion of the flexible substrate. Four additional radiators, which may be either passive or active radiators, are matched to a second frequency, are also disposed on the radiator portion of the substrate and interleaved with the active radiators. At least one feed network is provided on a feed portion of the substrate that provides 0.degree., 90.degree., 180.degree., and 270.degree. signals to active radiators.

Abstract: A device for connecting the RF signal circuitry of a portable phone and a plurality of antennas utilized to transmit and receive signals is disclosed. The connector device includes a female portion electrically coupled to the RF signal circuitry, with the female portion providing a plurality of ports for electrical coupling with the RF signal circuitry. A complementary male portion is also provided which is electrically coupled to the antennas, the male portion including a separate pin member connected to each antenna. Each pin member of the male portion is received within a corresponding one of the ports in the female portion as the male and female portions of the connector device are mated together. In this way, the RF signal circuitry and the antennas are electrically coupled. The antennas of the portable phone are integrated with a flip cover rotatably mounted to a phone base containing the RF signal circuitry, where the flip cover may be either fixedly or detachably secured to the phone base.

Abstract: An antenna configuration includes a rod antenna and a helical antenna that are independently operable. The helical antenna is composed of a helical coil installed within an antenna housing mounted on a main body of a communication device. A feeding connector is electrically coupled to a bottom portion of the helical coil to thereby connect the helical antenna to a circuit of the communication device. The rod antenna is composed of a rod functioning as a conductive metal core wire. The rod is surrounded by the helical coil and the feeding connector and is extendable from and retractable into the main body of the communication device. When the rod is retracted into the main body, the helical coil operates as the exclusive radiating element and operation of the rod antenna is disabled. When the rod is extended from the main body, the rod electrically short-circuits and disables operation of the helical coil, and thereby operates as the exclusive radiating element.

Abstract: An antenna system utilizing an electrically conductive portion (16) of an aircraft structure to radiate and receive very-high-frequency (VHF) and ultra-high-frequency (UHF) radio signals over a wide frequency range without the need for an active tuner to accommodate frequency changes. An antenna element (22) is housed in a tail fin endcap section (20) and is positioned and shaped to form an elongated notch (26) between one edge (24) of the element itself and one adjacent edge (18) of an electrically conductive tail fin (16). The notch (26) is uniform over part of its length and is flared to a wider spacing over the remainder of its length. A feed point (30) along the notch (26) is selected for optimum performance. Matching electronics (14) couple the antenna system to a transceiver (15), which can operate either in a VHF/FM band, or in a UHF band, or in a VHF/AM band. The antenna system provides relatively good gain over the frequency range and provides a practically omnidirectional radiation pattern.

Abstract: A sheet antenna apparatus capable of favorably receiving vertically polarized electromagnetic waves is provided which includes an antenna element 11 comprising a main antenna portion 15 having a vertical segment 19, a pair of upper and lower lateral segments 20 and 21 respectively extending laterally from opposite ends of the vertical segment 19 and a pair of feeder segments 22 respectively extending inwardly from the terminating ends of the lateral segments 20 and 21, and a parasitic antenna element comprising an inner loop portion 16 and an outer loop portion 17 which form a double loop and are disposed as adjoining to one of the lateral segments 20 and 21. The vertical segment 19 of the antenna element 11 substantially coincides with the direction of vertically polarized electromagnetic waves and hence receives vertically polarized electromagnetic waves favorably.

Abstract: The invention provides a microstrip patch antenna for emitting backscatter-modulated signals in response to a received signal. The antenna has two segments that are connected together by a switch. When the switch is ON, the antenna is a full wave length antenna with its two segments out-of-phase with each other, thus producing minimal backscatter. When the switch is OFF, the two segments of the antenna act in concert with each other to produce a backscatter-modulated signal. Multiple pairs of such antennas can be connected together to make a single antenna with increased signal power.

Abstract: An antenna (20) including a continuous planar conductor (22) in a coaxial connector. The planar conductor (22) is made by stamping an array of slots (30) in a continuous sheet of metal with ends of adjacent slots (30) being offset from each other in an alternating pattern of long and short slot portions (32, 36) on each side of a centerline of the array; at least filling each slot (30) with a dielectric material (50), thereby defining a slot filled strip; and cutting along each side of the slot-filled strip intersecting each filled long slot portion (32) at a sufficient distance from the ends of adjacent ones of the filled short slot portions (36) to define a strap (42) of metal connecting the metal strips on each side of each slot (30).

Abstract: A method for measuring radiated emission using a GTEM cell is disclosed in which a DUT is placed inside the GTEM cell, and its power is measured by a power receiver. The direction of the DUT is changed, and then its transmission power is measured. Here, the arrangements of the DUT are fifteen, and their power measurement number is 15. These powers measured are transmitted to a computer system through a GPIB cable, in which the powers are accepted in the form of data in order to calculate emission in OATS. Accordingly, the maximum vertical/horizontal electric field emitted from the DUT in OATS is estimated over the whole band of radiated emission test. This enables a desired emission value to be measured for a short time only utilizing the GTEM cell.

Abstract: The invention relates to an antenna system which is capable of producing multiple, high-gain, independently steerable antenna beams from a single antenna aperture. The system accomplishes this, in part, by utilizing a separate phased array antenna as the feed element of a spherical lens for each desired beam. In this fashion, the beam(s) produced by the antenna system can each be electronically steered (independently of the other beams, if any) and physical movement of the feed element(s) is not required. The invention may also use multiple spherical lenses, wherein each lens includes at least one phased array feed.

Abstract: A folded dipole microstrip antenna is disclosed herein. The microstrip antenna includes a dielectric substrate for defining a first mounting surface and a second mounting surface substantially parallel thereto. A folded dipole radiative element is mounted on the second mounting surface. The microstrip antenna further includes a microstrip feed line, mounted on the first surface, for exciting the radiative element in response to an excitation signal. In a preferred implementation of the microstrip antenna an excitation signal is applied to the microstrip feed line through a coaxial cable. In such a preferred implementation the folded dipole radiative element includes a continuous dipole arm arranged parallel to first and second dipole arm segments separated by an excitation gap. The feed element is mounted in alignment with the excitation gap and is electrically connected to the continuous dipole arm.

Abstract: A rear feed source for a reflector antenna and an antenna using such a source. The source includes at least one horn connected to a waveguide. The horn has at least two inclined walls forming an aperture, each wall being extended by a wall with a different inclination. This invention can be applied to radars, notably surveillance radars.

Abstract: A radio telecommunications antenna includes a telescoping antenna portion for substantially receiving an electromagnetic signal. The telescoping portion is attached by an antenna mast for conducting the electromagnetic signal. A dielectric spacer and an inductor are in electrical contact with the antenna mast. An RF connector is in electrical contact with the dielectric spacer, opposite the antenna mast, so as to form a capacitor. The RF connector is also in electrical contact with the inductor so that the capacitor and the inductor form an LC circuit with values selected to provide a predetermined impedance match with the remainder of the antenna.

Abstract: An antenna for broadcasting omnidirectionally is disclosed. The antenna includes a cylindrical housing which has a lip which includes slots adapted to receive a patch antenna strip and a conductive ring. A GPS receiver and electronics package may be placed in the center of the housing. The patch antenna strip which includes a number of patch antennas broadcasts and receives radio signals. The conductive ring absorbs energy broadcast from the patch antennas and rebroadcasts the signal omnidirectionally. The resulting signal has a high gain and a wide bandwidth. A third embodiment in which the conductive ring is incorporated into a housing cover is also disclosed. The antenna is easily and inexpensively assembled and is more durable and reliable than prior art antennas.

Abstract: A surface mounting type antenna system 10 is formed by spirally winding a conductor 14 made of copper or copper alloy, with a power supply member 12 provided at one end of the conductor 14, the other end thereof being a free end 13, on the edge faces of a rectangular parallelepiped as a dielectric substrate 11 by printing, deposition, pasting or plating. The dielectric substrate 11 is prepared by stacking a plurality of layers of ceramics, resin or a combination of ceramics and resin. On the underside 111 of the dielectric substrate 11 lies a power supply terminal 15 to which the power supply member 12 of the conductor 14 is connected. The power supply terminal 15 is simultaneously used as a fixing terminal for securing the surface mounting type antenna system 10 to, for example, a mounting board. Moreover, the conductor 14 squarely intersecting the axis C of the conductor winding is rectangular in transverse cross section having a width of w and a length of l.

Abstract: In a mobile radio transceiver, an antenna has a fixed element and a movable element. When the movable element is in an extended state, the movable element functions. On the other hand, when the movable element is in a retracted state, the fixed element functions. An impedance matching circuit preferentially performs impedance matching relative to the fixed element. A reactance element is further provided which is connected to the movable element when the movable element is in the extended state. On the other hand, the reactance element is out of connection to the movable element when the movable element is in the retracted state. With this arrangement, the impedance matching circuit and the reactance element cooperatively achieve impedance matching relative to the movable element when the movable element functions.

Abstract: A circularly polarized antenna has an open reflector box, an array of crossed dipoles, and a single binary feed network. The open reflector box is formed of conductive material, has a ground plate and four side walls defining an opening, and has an input port for receiving an input signal. The single binary feed network is disposed within the open reflector box, is connected to the input port, and has a microstrip transmission line spaced from the ground plate. The microstrip transmission line has conductive bars mounted parallel to the ground plate and spaced therefrom forming an air dielectric low loss microstrip. Each pair of crossed dipoles has a first dipole comprising two downwardly bent radiating elements arranged at an angle with respect to the ground plate, and has a second dipole comprising two straight radiating elements arranged parallel to the ground plate.

Abstract: A slot spiral antenna with a planar integrated balun and feed. The slot spiral is produced using standard printed circuit techniques and comprises a dielectric substrate having a conductive layer which is etched to form the radiating slot spiral. An integrated microstrip feed is included to provide a balanced feed to the slot spiral. Impedance matching is performed between the microstrip feed and the slotline of the slot spiral to maximize energy transfer. A shallow reflecting cavity is included to limit the spiral radiation to one direction. The described antenna apparatus provides a simple, broadband spiral antenna suitable for incorporating into the skin of a moving vehicle.

Abstract: An innovative nonradioactive dielectric waveguide (NRD guide). Protrusions are separately formed on a surface of a dielectric strip. Recesses corresponding to the protrusions are formed on a parallel conductive plate. The dielectric strip is set between top and bottom parallel conductive plates such that the small protrusions on the dielectric strip are fitted into the recesses on the bottom parallel conductive plate.

Abstract: A method and apparatus for reading bar codes or other images while reducing or eliminating the need for self-generated illumination. An image reader is preferably embodied as a handheld unit and comprises an efficient optical collection system including an aperture with a high aspect ratio and/or a multi-focal lens or lenses. An optically transmissive spacer affixed to the front of the handheld unit allows ambient light to be collected at close range, and a diffuser may be used to reflect ambient light from the handheld unit to provide additional illumination at close range. A masked CCD detector with rectangular pixels receives collected light and is coupled to an adaptive exposure circuit for preventing saturation of the CCD detector at high illumination levels. A correlated double sampling circuit coupled to the adaptive exposure circuit rejects common mode noise and allows operation in lower light levels.