Patent•
Impedance matching arrangement
24 Jun 1986-
TL;DR: In this article, an impedance matching arrangement is proposed for frequency hopping radio communications system which is operable over a wide frequency band, so as to match the operating impedance of the antenna at each of the frequencies used.
Abstract: An impedance matching arrangement is suitable for use with a frequency hopping radio communications system which is operable over a wide frequency band, so as to match the operating impedance of the antenna at each of the frequencies used. As the frequency of the radio system hops from one frequency to another, a note of any impedance mismatch is noted and data derived therefrom is stored for future use when that frequency is next selected so as to reduce any impedance mismatch.
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Patent•
04 Mar 2009TL;DR: In this article, a wireless power system includes a power source, power receiver, and components thereof, and a parasitic antenna that can improve the coupling to the power source in various modes.
Abstract: A wireless power system includes a power source, power receiver, and components thereof. The system can also include a parasitic antenna that can improve the coupling to the power source in various modes. The antenna can have both a variable capacitor and a variable inductor, and both of those can be changed in order to change characteristics of the matching.
611 citations
Patent•
14 Jun 2013TL;DR: In this paper, a transmit antenna generates an electromagnetic field having a region for wirelessly transferring power from the transmit antenna to a plurality of receiver devices, and a controller determines a power allocation for a particular one of the plurality of receivers disposed within the region, and adjusts the power allocation based at least in part on a power requirement received from the particular receiver devices.
Abstract: Exemplary embodiments are directed to wireless power transfer. A transmit antenna generates an electromagnetic field having a region for wirelessly transferring power from the transmit antenna to a plurality of receiver devices. A controller is operably coupled to the transmit antenna. The controller determines a power allocation for a particular one of the plurality of receiver devices disposed within the region, and adjusts the power allocation based at least in part on a power requirement received from the particular one of the plurality of receiver devices.
280 citations
Patent•
22 Jan 2010TL;DR: In this paper, a transmitter (202) generates an electromagnetic field at a resonant frequency with a transmit antenna to create a coupling-mode region within a near field of the transmit antenna (204), and defines a beginning of a recurring period by on-off keying the electromagnetic field during a synchronization portion of the recurring period.
Abstract: Exemplary embodiments are directed to wireless power transfer. A transmitter (202) generates an electromagnetic field at a resonant frequency with a transmit antenna to create a coupling -mode region within a near field of the transmit antenna (204). The transmitter defines a beginning of a recurring period by on-off keying the electromagnetic field during a synchronization portion of the recurring period. During a power transmission portion of the recurring period, the transmitter couples portions of the electromagnetic field to different receive antennas of various receiver devices within the coupling -mode region. The transmitter also determines a power allocation within the recurring period for the various receiver devices disposed within the coupling -mode region and adjusts a power level of the near field radiation responsive to power requirements received from the receiver devices.
266 citations
Patent•
26 Jul 2004TL;DR: In this paper, a dual-band antenna matching system and a method for dualband impedance matching are presented, which consists of accepting a frequency-dependent impedance from an antenna; and selectively supplying a conjugate impedance match for the antenna at either a first and a second communication band, or a third and a fourth communication band.
Abstract: A dual-band antenna matching system and a method for dual-band impedance matching are provided. The method comprises: accepting a frequency-dependent impedance from an antenna; and, selectively supplying a conjugate impedance match for the antenna at either a first and a second communication band, or a third and a fourth communication band. More specifically, the method comprises: tuning a first tuning circuit to a first frequency; and, simultaneously tuning a second tuning circuit to a second frequency. In response, a conjugate match is supplied to the antenna in the first communication band in response to the first frequency. Simultaneously, the antenna is matched in the second communication band in response to the second frequency. When the first tuning circuit is tuned to a third frequency, and the second tuning circuit is tuned to a fourth frequency, then conjugate matches are supplied for the third and fourth communication bands, responsive to the third and fourth frequencies, respectively.
259 citations
Patent•
17 Mar 2008
TL;DR: In this article, an impedance matching circuit includes a conductor line having an input port and an output port, a ground conductor, a tunable dielectric material positioned between a first section of the conductor line and the ground conductor and means for applying a DC voltage between the ground and the strip conductor.
Abstract: An impedance matching circuit includes a conductor line having an input port and an output port, a ground conductor, a tunable dielectric material positioned between a first section of the conductor line and the ground conductor, a non-tunable dielectric material positioned between a second section of the conductor line and the ground conductor, and means for applying a DC voltage between the conductor line and the ground conductor. The impedance matching circuit may alternatively include a first planar ground conductor, a second planar ground conductor, a strip conductor having an input port and an output port, and positioned between the first and second planar ground conductors to define first and second gaps, the first gap being positioned between the strip conductor and the first planar ground conductor and the second gap being positioned between the strip conductor and the second planar ground conductor. A non-tunable dielectric material supports the first and second planar ground conductors and the strip conductor in the same plane. A connection is provided for applying a DC voltage between the strip conductor and the first and second planar ground conductors. A plurality of tunable dielectric layer sections are positioned between the strip conductor and the first and second planar ground conductors so as to bridge the gaps between the said first and second planar ground conductors and the strip conductor at a plurality of locations, leaving non-bridged sections in between, defining a plurality of alternating bridged and non-bridged co-planar waveguide sections.
245 citations
References
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Patent•
19 Nov 1981TL;DR: In this paper, a simple technique and circuit is disclosed to replace prior Z-θ type discriminators in supplying the loading and phasing control signals to the impedance matching network in an automatic antenna tuner.
Abstract: A simple technique and circuit is disclosed to replace prior Z-θ type discriminators in supplying the loading and phasing control signals to the impedance matching network in an automatic antenna tuner. The new circuit samples forward and reflected voltage V f and V r (or equivalently I f and I r ) in the RF input. The loading control signal is supplied according to the in-phase component of V r relative to V f . The phasing control signal is supplied according to the quadrature component of V r relative to V f . The magnitude of each of the in-phase and quadrature V r components is reduced to zero by the matching network to thus reduce the phasor amplitude of V r to zero and hence eliminate reflected voltage.
100 citations
Patent•
21 Jan 1976
TL;DR: An antenna matching device comprises a directional coupler and, respectively connected, in a prior art manner, to two conjugate ports of the coupler, one of which is a high-power port, and the other of which a low power port, a matching circuit in series with the antenna, and a matched load as mentioned in this paper.
Abstract: An antenna matching device comprises a directional coupler and, respectively connected, in a prior art manner, to two conjugate ports of the directional coupler, one of which is a high-power port, and the other of which a low-power port, a matching circuit in series with the antenna to be matched, and a matched load A switching device makes it possible, during the matching phase, to reverse the connections of the aforementioned ports and thus to substitute the directional coupler low-power path for the high-power path in the link between the transmitter and the antenna
36 citations
Patent•
30 Apr 1985TL;DR: In this paper, an adaptive interference cancellation (AIC) system is proposed to adjust the antenna matching network of a radio system in the presence of an interfering signal in the matching network being adjusted comprises a loop from which the interfering signal is cancelled by an AIC system.
Abstract: A system for adjusting the antenna matching network of a radio system in the presence of an interfering signal in the matching network being adjusted comprises a loop from which the interfering signal is cancelled by an adaptive interference cancellation (AIC) system. The AIC system receives an interference sensor signal having the frequency of the interfering signal. Means responsive to the interference sensor signal and phase and amplitude control signals provides a modified interference sensor signal having a phase and amplitude determined by the control signals. This modified interference sensor signal is combined with a mismatch signal which is derived from the signal in the matching network to produce a modified mismatch signal. An adaptive interference cancellation processor is responsive to the modified mismatch signal for providing the phase and amplitude control signals of values to reduce the amplitude of the interfering signal frequency in the modified mismatch signal relative to its amplitude in the mismatch signal. An adjustment processor responds to the modified mismatch signal to control an impedance adjuster for adjusting the impedance of the matching network.
36 citations
Patent•
09 Nov 1976
TL;DR: In this article, an antenna matching network for matching a citizens band radio transceiver to a standard automotive whip or windshield antenna utilizes a matching section for matching the nominal 50 ohm output of the transceivers to the generally lower impedance of the automotive antenna.
Abstract: An antenna matching network for matching a citizens band radio transceiver to a standard automotive whip or windshield antenna utilizes a matching section for matching the nominal 50 ohm output of the citizens band transceiver to the generally lower impedance of the automotive antenna. A trap tuned to the citizens band prevents the output of the citizens band transmitter from damaging the automotive broadcast receiver when transmitting. The matching section is tunable over a sufficient range to match the citizens band transceiver to most automotive antennas, and a dual sensitivity indicator is utilized to aid the operator in tuning the matching network to provide optimum matching without the use of specialized equipment.
27 citations