Quarter-wave Transformer Patents (Class 343/864)
  • Patent number: 8294631
    Abstract: An exemplary antenna system for an electromagnetic wave includes a conductor having a first portion and a second bent portion. The exemplary antenna system includes a first transformer connected to the second bent portion and configured to invert current of the second bent portion relative to current received from the first portion. An exemplary method for conducting an electromagnetic signal includes conducting an electromagnetic signal through a first portion and a second bent portion of a conductor. The exemplary method includes inverting current of the signal of the second bent portion relative to current received from the first portion. A wave created by current of the first portion can be added to a wave created by current of the second bent portion.
    Type: Grant
    Filed: July 8, 2009
    Date of Patent: October 23, 2012
    Assignee: Lockheed Martin Corporation
    Inventor: Roy Phillip Croston
  • Patent number: 7277677
    Abstract: A control device for an antenna matching circuit is configured to output an adjusting signal for changing impedance of an element in the antenna matching circuit based on change over time in signal power ratio of a reflected signal from the antenna matching circuit to an incident signal to the antenna matching circuit.
    Type: Grant
    Filed: June 22, 2004
    Date of Patent: October 2, 2007
    Assignee: Fujitsu Limited
    Inventors: Ichirou Ida, Jun-ichi Takada, Takeshi Toda, Yasuyuki Oishi
  • Patent number: 7133810
    Abstract: A method for applying an algorithm to facilitate the design of wideband omnidirectional antennas, and the design of sleeve cage monopole and sleeve helix units includes rapid resolution of a complex relationship among antenna components to yield an optimal system. A genetic algorithm is used with fitness values for design factors expressed in terms to yield optimum combinations. Cage antennas are optimized via a genetic algorithm for operation over a wide band with low VSWR. Genetic algorithms and an integral equation solver are employed to determine the position and lengths of parasitic wires around a cage antenna in order to minimize VSWR over a band. The cage may be replaced by a normal mode quadrifilar helix for height reduction and with re-optimized parasites.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: November 7, 2006
    Assignee: Clemson University
    Inventors: Chalmers M. Butler, Shawn D. Rogers
  • Patent number: 7072690
    Abstract: A multi-band antenna and a notebook computer with a built-in multi-band antenna are disclosed. Since the multi-band antenna is installed at the inner side of a upper and a lower case, it is much favored for a radio communication when a computer is in use by standing up a display device. The multi-band antenna includes at least two transmitting and receiving parts formed with different lengths to fit frequency bands, so that a remote communication of at least two or more bands can be made. The multi-band antenna is positioned between liquid crystal and a side wall of the lower case, and a grounding unit is installed to contact a liquid crystal frame. That is, since the grounding unit is grounded to the liquid crystal frame and the bracket, substantially, the liquid crystal frame and the bracket are wholly grounded to ensure a stable radio frequency communication.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: July 4, 2006
    Assignee: LG Electronics Inc.
    Inventors: Hyo Sik Shin, Kwang Seog Bang, Eung Bok Kim
  • Patent number: 7015870
    Abstract: A multi-band inductive circuit in an integrated circuit, including at least two parallel branches respectively including a first inductance and a second inductance in series with a capacitor, the two inductances being coupled to each other.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: March 21, 2006
    Assignee: STMicroelectronics S.A.
    Inventors: Fabrice Guitton, François Dupont
  • Patent number: 6856211
    Abstract: A coaxial type impedance matching device includes a matching device body including an external conductor and an internal conductor arranged in the external conductor, an input side dielectric disposed in the matching device body and including a first dielectric and a second dielectric, and an output side dielectric disposed in the matching device body and including a third dielectric and a fourth dielectric. Distance between opposed surfaces of the first dielectric and the second dielectric is a predetermined distance, which is in a range of N?/4??/6 to N?/4??/6, where ? represents a guide wavelength of an input signal in the matching device body and N represents odd number. Distance between opposed surfaces of the third dielectric and the fourth dielectric is the predetermined distance.
    Type: Grant
    Filed: May 20, 2003
    Date of Patent: February 15, 2005
    Assignees: Nagano Japan Radio Co., Ltd., Tokyo Electron Limited
    Inventors: Fumio Yamada, Toshiaki Kitamura, Hiroyuki Kobayashi, Koichi Rokuyama, Akihiro Kubota, Shigeru Kasai, Takashi Ogino, Yuki Osada
  • Patent number: 6718157
    Abstract: Disclosed is an apparatus for commonly using an antenna for a call signal and a television (TV) broadcasting signal in a radio communication terminal including an antenna, a phone duplexer, a TV tuner, an LC parallel circuit, connected between the antenna and the phone duplexer, for forming an LC resonance circuit for a call signal frequency band, an LC series circuit connected to a connected point of the LC parallel circuit and the antenna and to a DC power supply terminal, a stub for impedance matching one terminal of which is connected between a capacitor and an inductor of the LC series circuit and the other terminal of which is connected to the TV tuner, and a path providing section for providing a path between a connected point of the stub and the TV tuner and a ground terminal in accordance with a switching control signal provided according to a TV or call operating mode.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: April 6, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Teak-Kyun Choi
  • Publication number: 20030234748
    Abstract: The present invention provides a support for an antenna. In particular, the present invention provides a substrate with conductive transition pads for a co-linear coaxial antenna array. The transition pads are constructed and arranged to properly provide power and phase shifting to the antenna array.
    Type: Application
    Filed: January 15, 2003
    Publication date: December 25, 2003
    Inventors: Blaine R. Bateman, Randy Bancroft, Gary Cumro
  • Patent number: 6664935
    Abstract: A broadband impedance matching integrated circuit apparatus comprising an alternating current ground plane, a direct current ground plane positioned proximate to the alternating current ground plane, a first conductive transmission line positioned a distance from the alternating current and direct current ground planes, a dielectric material layer with a thickness positioned on the first conductive transmission line, a second conductive transmission line positioned on the dielectric material layer wherein the first and second conductive transmission lines are electrically interconnected to behave as an electromagnetically coupled tapped autotransformer.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: December 16, 2003
    Assignee: Motorola, Inc.
    Inventors: William John Thompson, Anthony M. Pavio, Lei Zhao, John C. Estes
  • Patent number: 6624794
    Abstract: In an antenna having at least one vertical radiator, preferably a vehicle mobile radiotelephone antenna, the at least one vertical radiator is connected to the ground on one end and to a vertical conductor fed against the ground on the other end by means of an impedance transforming device having an electrical length which is approximately one fourth the mean operating wavelength or an uneven multiple thereof. Said structure makes it possible for the at least one vertical radiator to have a uniform current occupancy over its entire length. By cooperating with the vertical conductor fed in a co-radiating manner, said occupancy exhibits high radiation power comparable to that of a &lgr;/4 monopole antenna despite the fact that the at least one vertical radiator has a smaller length which is approximately {fraction (1/10)} of the mean operating wavelength. The invention also describes advantageous embodiments or configurations of said antenna and practical arrangements of said antenna in vehicles.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: September 23, 2003
    Assignee: Hirschmann Electronics GmbH & Co. KG
    Inventors: Dirk Wendt, Martin Kuhn, Markus Pfletschinger, Peter Riedhofer
  • Patent number: 6222500
    Abstract: The present invention relates to an impedance-matching device of antenna units, and in particular to antenna-matching in small radio units. An impedance-matching device is arranged in a radio equipment having an antenna, between said antenna and a feeding unit, e.g. an output power unit, the impedance quotient of which units exceeding a factor 3. The invented impedance-matching includes at least two quarter-wave transformers connected in series, which consist of a dielectric material having a dielectric coefficient ∈, the value of which is exceeding a factor 10. The device may be made with dimensions so small that it may be integrated with the antenna to an antenna unit and despite the small dimensions, good frequency characteristics are achieved, such as good precision, easy tuning and sufficiently broad bandwidth.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: April 24, 2001
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Evald Arvid Koitsalu, Lars Wallin
  • Patent number: 6020852
    Abstract: An antenna element intended for transmission and reception of orthogonal polarizations having a good polarization purity of electomagnetic radiation is described. It comprises a ground plane (2) and at least one radiation disc (1) connected to two ports (4, 5) for the supply of a desired electromagnetic radiation, preferably in the microwave range. The distance between the ground plane (2) and the radiation disc (1) is a fraction of the wavelength .lambda. of the radiation. The antenna element is in particular characterized in that the ports (4, 5) are located at an electric distance of 90.degree. from each other and that a quarterwave transformer (6) is added between the ground plane (2) and the radiation disc (1) that is shaped so that the transmission line impedance between the ports (4, 5) is reduced in order to make the ports radiationally independent of each other.
    Type: Grant
    Filed: November 5, 1997
    Date of Patent: February 1, 2000
    Assignee: Saab Ericsson Space AB
    Inventor: Ulf Jostell
  • Patent number: 5936584
    Abstract: A radio frequency (RF) local area network (LAN) adapter card for a personal computer conforms to the Personal Computer Memory Card International Association (PCMCIA) standard 2.0 (extended), providing a credit-card sized RF LAN communications terminal that plugs into the side of a personal computer, a laptop computer, a palmtop computer, and the like. The RF LAN adapter card includes a minimum height, broadband integrated antenna that provides a vertically polarized RF signal with good horizontal range. The combination of the antenna and its surrounding radome provide a high gain, omnidirectional radiation pattern that overcomes the parasitic distortions imposed by the close proximity of the personal computer housing. The adapter card housing includes internal RF shielding structures that shield the antenna from noise radiated by radio frequency signal circuits within the housing.
    Type: Grant
    Filed: March 17, 1998
    Date of Patent: August 10, 1999
    Assignee: International Business Machines Corporation
    Inventors: Mark John Lawrence, William B. Nunnery
  • Patent number: 5565881
    Abstract: An electrical connection between a balanced circuit, such as a radio receiver and an unbalanced circuit, such as an antenna requires a balun. In a small electronic device such as a radiotelephone, a traditional balun is impractical because of the physical constraints. The balun function is performed by using a transmission line of minimum transverse dimensions and a predetermined length between the receiver and the antenna.
    Type: Grant
    Filed: March 11, 1994
    Date of Patent: October 15, 1996
    Assignee: Motorola, Inc.
    Inventors: James P. Phillips, Louis J. Vannatta
  • Patent number: 5457468
    Abstract: An antenna is mounted on a window of a vehicle and includes an antenna rod (6) fastened to an electrically conductive base (1) mounted on the outside of the window, and a connection member on the inside of the window directly opposite the base. An antenna lead from the vehicle's radio is connected to the connection member, which comprises a box (8) with an earth plane and is mounted on the window with a conductive plate (12). A connection conductor (13) between the plate (12) and the antenna lead (15) has an electrical length of (1/4+n.times.1/2) times the wavelength of operation, where n=0 or a whole number. The surface exposed by the conductor (13) is spaced from the earth plane (16) so as to define a characteristic impedance for the conductor (13), so that the impedance at the antenna feed point together with the capacitive coupling through the window is transformed into an impedance equal to that of the antenna lead.
    Type: Grant
    Filed: January 6, 1993
    Date of Patent: October 10, 1995
    Assignee: Allgon AB
    Inventor: Ulf Saldell
  • Patent number: 5369413
    Abstract: Mutual coupling effects, which would tend to degrade operation of a two-element end-fire array over a frequency band, are overcome by provision of an inter-element coupling impedance which is effective to equalize the Q at the inputs to the quadrature-excited elements. A quarter-wave transmission line section is coupled between the inputs to provide such impedance, which has a value selected to offset the effect of mutual coupling on Q. For a pair of monopoles, the inter-element coupling line is connected to the respective monopoles by quarter-wave sections having impedances selected in order to provide desired input impedances. The performance of dual-element end-fire slot or dipole array antennas may similarly be improved. Linear array antennas of four or more elements are provided by forced feeding of the additional elements from the basic dual-element configuration in accordance with the invention.
    Type: Grant
    Filed: July 2, 1993
    Date of Patent: November 29, 1994
    Assignee: Hazeltine Corp.
    Inventor: Peter W. Hannan
  • Patent number: 5068670
    Abstract: A broadband microwave antenna exhibiting high radiation efficiency over a broad frequency band in which the VSWR is less than 2.5:1 over at least 15% of the frequency band, includes a ground plane at one side of a dielectric substrate and formed with at least one slot, and a feed strip at the other side of the substrate. The feed strip is of uniform width for substantially its complete length, but includes a change in width at the feed end of the slot to produce a first impedance matching network effective to bring the slot impedance to the level of the feed line over the broad frequency band, and another change in width at the load end of the slot to produce a second impedance matching network which reduces the slot reactance to match the reactive impedance of the load to the reactive part of the slot impedance over the broad frequency band.
    Type: Grant
    Filed: January 25, 1990
    Date of Patent: November 26, 1991
    Inventor: Joseph Maoz
  • Patent number: 4983985
    Abstract: A cellular antenna including a matching transformer section connected to a substantially rectangular member of braid. An off-center feed provides for an omni-polar radiation.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: January 8, 1991
    Inventor: Steve Beatty
  • Patent number: 4875051
    Abstract: An on-glass antenna for a vehicle is provided having a radiator for location on the outside of the vehicle window and a cable for location on the inside of the vehicle window for coupling the radiator to a transmitter/receiver. The cable comprises a first cable portion, a second cable portion, and an impedance matching member at the intersection of the first and second cable portions. The first cable portion and the impedance matching member together have a combined electrical length of about 1/4 wavelength.
    Type: Grant
    Filed: May 4, 1988
    Date of Patent: October 17, 1989
    Inventor: Herbert R. Blaese
  • Patent number: 4829316
    Abstract: A small size broad-band ultra high frequency antenna including a dielectric substance in the sleeve of an antenna body whereby approximating resonance frequency of the sleeve portion to resonance frequency of the body of the antenna so that a double-tuning circuit is formed thereby causing the impedance characteristics of the antenna to have double-peak characteristics within the working frequency band. The antenna further includes an impedance matching transformer for matching the impedance of the antenna to the characteristic impedance of a feeder line connected to the antenna, the matching transformer being composed of a coaxial type impedance transducer which has an opposite reactance component sufficient to offset the reactance component of the antenna and has the characteristic impedance convertible to the feeder line impedance.
    Type: Grant
    Filed: May 4, 1988
    Date of Patent: May 9, 1989
    Assignee: Harada Kogyo Kabushiki Kaisha
    Inventors: Kazuhiko Nakasa, Yoshiimi Egashira
  • Patent number: 4760400
    Abstract: The antenna is adapted to be connected to a coaxial cable and includes a dielectric carrier board and a radiating element undulating longitudinally of the carrier board. The carrier board and radiating element are disposed in a conductive channel which has side walls adjacent the side edges of the carrier board. An input transition means is provided between the center conductor of the coaxial connector and the undulating track to provide a transition from the impedance of the coaxial cable to the impedance of the radiating element of the sandwich-wire antenna. When the antenna may, or may not, be connected to a coaxial cable, the side walls extend above the carrier board for such a height that the radiating aperture, which comprises the gap between the top edges of the side walls, presents a resistive load in the plane of the radiating element.
    Type: Grant
    Filed: July 15, 1986
    Date of Patent: July 26, 1988
    Assignee: Canadian Marconi Company
    Inventor: Andrew J. Lait
  • Patent number: 4713670
    Abstract: A microwave plane antenna comprises a plurality of pairs of antenna elements connected at their one end to a power supply circuit and respectively including at the other terminating end an impedance-matched patch antenna means, whereby signal energy remaining at the terminating ends of the antenna elements is caused to be effectively utilized as radiation energy, and any power loss is restrained for a high antenna gain and improved aperture efficiency.
    Type: Grant
    Filed: January 17, 1986
    Date of Patent: December 15, 1987
    Assignees: Toshio Makimoto, Sadahiko Nishimura, Matsushita Electric Works, Ltd.
    Inventors: Toshio Makimoto, Sadahiko Nishimura, Masayuki Matsuo, Toshio Abiko, Hirohumi Ishizaki, Minoru Kanda, Hidetsugu Nunoya, Mikio Komatsu
  • Patent number: 4673949
    Abstract: A radio antenna which operates over a broad frequency band, comprising a half-wave antenna tuned to a frequency beyond one cut-off frequency of the desired frequency band and a quarter-wave transformer tuned to a frequency beyond the other cut-off frequency at the other end of said band. The quarter-wave transformer acts as an impedance compensation device by canceling the reactive components of the half-wave antenna such novel reactive cancellation technique provides broadband performance while maintaining the antenna's gain and impedance characteristics.
    Type: Grant
    Filed: September 24, 1984
    Date of Patent: June 16, 1987
    Assignee: Modublox & Co., Inc.
    Inventor: Jack W. Sheriff
  • Patent number: 4644364
    Abstract: Impedance matching between two conductor transmission lines and conventional antenna designs including a straight antenna element having an effective length of at least one-quarter wavelength in the operating frequency range and a zero impedance at one end is disclosed in which a straight coupling conductor having a length of about one-quarter wavelength in the operating frequency range is mounted in close spaced co-planar relation to such antenna element with one end electrically connected to the zero impedance end of the antenna element. The two conductors of the transmission line are coupled to the antenna element and coupling conductor, respectively, at the interconnected ends thereof and the spacing between the antenna element and the coupling conductor is adjusted along their coextensive lengths to achieve an impedance match at each frequency in the operating frequency range.
    Type: Grant
    Filed: December 7, 1984
    Date of Patent: February 17, 1987
    Inventor: Malcolm G. Parks
  • Patent number: 4262250
    Abstract: A device for measuring the power in a microwave transmission and for providing a measuring port at the output of a microwave signal generator or transmitter. First and second quarter wavelength transmission line sections, coupled in series with one another and having characteristic impedances Z.sub.2 and Z.sub.1 respectively, where Z.sub.2 >>Z.sub.1, are coupled at the first section to a predetermined point on a transmission line to be monitored. A port at the free end of the second section allows for the connection of two independent measuring circuits to the transmission line.
    Type: Grant
    Filed: January 10, 1979
    Date of Patent: April 14, 1981
    Assignee: Thomson-CSF
    Inventors: Philippe Legendre, Claude Van Kerrebroeck
  • Patent number: 4259673
    Abstract: An antenna having a unique method of feed is comprised of a vertical radiator and a driven element. The driven element is defined by an integral, substantially straight part. RF energy is fed into or extracted from the antenna by a coil perimetrically wound around the straight part of the driven element. Preferably, this coil is comprised of the exposed, insulated inner conductor of a coaxial cable. The coil covers a relatively large segment along the periphery of the driven element giving rise to unique electrical properties. With this method of feed, the antenna exhibits good bandwidth and requires no metal-to-metal contact between feedline and antenna.
    Type: Grant
    Filed: June 5, 1979
    Date of Patent: March 31, 1981
    Inventor: Harold Guretzky
  • Patent number: 4254420
    Abstract: A VHF whip antenna of reduced physical length comprising a whiplike electrical conductor mounted atop a hollow, plastic, sealed cylindrical housing having a coaxially mounted circuit support tube mounted therein, with a highly resonant circuit attached thereto. Resonance is achieved in the circuit from a U-shaped inductance of a predetermined length mounted on the inside support tube, the inductance being coupled in series electrically with a variable capacitor. The whip conductor is designed to be three half-wave lengths long and when in combination with the resonant circuit, radiates power in perfect phase relationship that accounts for a power gain in the order of ten DB.
    Type: Grant
    Filed: January 7, 1980
    Date of Patent: March 3, 1981
    Inventor: John C. Peoples
  • Patent number: 4152704
    Abstract: A portable transceiver antenna is provided with a base suitable for retention by a fishing rodholder or for hand held use and is pretuned to facilitate its use without a ground plane. The antenna includes an electrically conductive rod which may be covered by a dielectric and segmented, and would then include couplings fabricated from ferrules closely fitted over nipples to produce reliable electrical contact through the coupling. The antenna may be used with citizens band, very high frequency - frequency modulated, and similar applications.
    Type: Grant
    Filed: October 19, 1977
    Date of Patent: May 1, 1979
    Assignees: Gerald Buckwald, Susan Buckwald
    Inventor: Donald E. Burg