Antenna Tuning With Frequency Shift Patents (Class 375/304)
  • Patent number: 10257625
    Abstract: The present disclosure relates to a head-wearable hearing device which comprises a magnetic inductance antenna having a predetermined resonance period for receipt of wireless data signals and a switched capacitor DC-DC converter configured for converting a DC input voltage into a higher or lower DC output voltage in accordance with a clock signal. The charge pump circuit is configured to charge an output capacitor by output current pulses where the output current pulses at least comprise first and second consecutive output current pulses having a mutual pulse delay corresponding to substantially one-half of the predetermined resonance period of the magnetic inductance antenna.
    Type: Grant
    Filed: November 17, 2017
    Date of Patent: April 9, 2019
    Assignee: GN HEARING A/S
    Inventors: Dennis Øland Larsen, Ivan Riis Nielsen
  • Patent number: 9231799
    Abstract: There is provided a Very Low Frequency (VLF) transmit antenna system, method, and apparatus for creating a magnetic field at low frequencies suitable for communications through the earth or other thick, solid barriers. At least two loop antennas are arranged such that a magnetic field of each one of the at least two loop antennas passes through each remaining one of the at least two loop antennas, thereby closely coupling the at least two loop antennas. A full bridge Pulse Width Modulated transmitter is directly connected to each loop antenna for driving the latter. When a loop of a given loop antenna is broken and its magnetic field collapses, the transmitters connected to the remaining loop antennas increase the current in the remaining loops to maintain a constant magnetic field.
    Type: Grant
    Filed: November 19, 2012
    Date of Patent: January 5, 2016
    Assignee: VITAL ALERT COMMUNICATION INC.
    Inventors: Michael James Roper, Vladimir Puzakov
  • Patent number: 8867655
    Abstract: Provided are an apparatus and method for transmitting data using multiple antennas and beamforming. The apparatus of the present invention comprises: a modulation unit which performs constellation mapping on input bits to generate modulated symbols; a pre-coding unit which multiplies a pre-coding matrix and the modulated symbols to generate pre-coded symbols; and a plurality of transmitting antennas for transmitting the pre-coded symbols. According to the present invention, a beam width is maintained constant, regardless of a radiation angle, thus preventing a loss of power caused by an angular spread and preventing the generation of shadow zone at a large radiation angle.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: October 21, 2014
    Assignee: Pantech Co., Ltd.
    Inventor: Kyoung Min Park
  • Patent number: 8831127
    Abstract: The MIMO method and apparatus disclosed herein improve throughput conditions limited by multiplicative noise by reducing the gain of the data streams associated with one or more dominant signal paths between MIMO communication nodes. As used herein, multiplicative noise refers to any noise dependent on or proportional to a signal strength at a transmitting node and/or a receiving node of a wireless communication network. An additional method and apparatus are included for determining that multiplicative noise limits the throughput conditions.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: September 9, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Andreas Nilsson, Henrik Asplund, Mikael Coldrey, Jonas Medbo, Mathias Riback, Karl Werner
  • Patent number: 8774315
    Abstract: An apparatus and method for generating a composite signal includes electronics configured to modulate a carrier utilizing a finite set of composite signal phases to generate a composite signal, the finite set of composite signal phases being determined through an optimization process that minimizes a constant envelope for the phase modulated carrier, subject to constraints on desired signal power levels of the signals to be combined and either zero or one or more relative phase relationships between the signals. The apparatus and method can be extended to generating an optimized composite signal of different frequencies.
    Type: Grant
    Filed: August 25, 2009
    Date of Patent: July 8, 2014
    Assignee: The Aerospace Corporation
    Inventors: Charles Robert Cahn, Philip A. Dafesh
  • Patent number: 8774196
    Abstract: The present disclosure relates to an active antenna array for a mobile communications network. The active antenna comprises a base band unit coupled to a base station, a plurality of transceiver units and at least one link. The plurality of transceiver units is terminated by at least one antenna element. The at least one link couples individual ones of the plurality of transceiver units to the base band unit 10. The at least one link is a digital link and is adapted to relay an individual transmit signal concurrently and in synchronisation with a transmit clock signal. The present disclosure further teaches a method for relaying radio signals in a mobile communications network. The present disclosure further relates to a computer program enabling a computer to manufacture the active antenna array of the present disclosure and to execute the method of relaying radio signal in a mobile communications system.
    Type: Grant
    Filed: June 3, 2010
    Date of Patent: July 8, 2014
    Assignee: Kathrein-Werke KG
    Inventors: Georg Schmidt, Johannes Schlee
  • Patent number: 8605823
    Abstract: Embodiments of a circuit are described. In this circuit, a modulation circuit provides a first modulated electrical signal and a second modulated electrical signal, where a given modulated electrical signal, which can be either the first modulated electrical signal or the second modulated electrical signal, includes minimum-shift keying (MSK) modulated data. Moreover, a first phase-adjustment element, which is coupled to the modulation circuit, sets a relative phase between the first modulated electrical signal and the second modulated electrical signal based on a phase value of the first phase-adjustment element. Additionally, an output interface, which is coupled to the first phase-adjustment element, is coupled to one or more antenna elements which output signals. These signals include a quadrature phase-shift-keying (QPSK) signal corresponding to the first modulated electrical signal and the second modulated electrical signal.
    Type: Grant
    Filed: April 29, 2008
    Date of Patent: December 10, 2013
    Assignee: Rambus Inc.
    Inventors: Aliazam Abbasfar, Farshid Aryanfar
  • Patent number: 8599861
    Abstract: The present disclosure teaches an active antenna array for a mobile communications network. The active antenna array comprises a base band unit, a plurality of transceiver units terminated by at least one antenna element; and at least one link. The link couples the individual ones of the plurality of transceiver units to the base band unit. The link is a digital link and is adapted to relay a payload signal at a selectable payload rate. The digital link is further adapted to relay a timing signal at a fixed timing rate, when the timing signal is embedded in the payload at a selectable payload rate. The present disclosure further teaches a method for relaying radio signals and a computer program for manufacturing the active antenna array and for executing the method.
    Type: Grant
    Filed: June 3, 2010
    Date of Patent: December 3, 2013
    Assignee: KATHREIN-Werke KG
    Inventors: Georg Schmidt, Johannes Schlee
  • Patent number: 8451934
    Abstract: A method and system for increasing the throughput of a wireless channel that sends different data on different multi-path components. The channel can be pre-mapped or dynamically mapped, and the different transmissions can be modulated by different complexity signals such as adaptive quadrature amplitude modulation (AQAM). Each multipath component is coded with a signature that will allow it to be separated at a receiver that has an omni-directional antenna. Common signature techniques can be offset PN codes, orthogonal spreading vectors, orthogonal alphabets and other signature techniques. The received channels can be combined for an overall increase in data-rate or used separate as multiplexed data.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: May 28, 2013
    Inventors: Clifford Kraft, Vasilios D. Dossas
  • Patent number: 8416879
    Abstract: A system and method providing signal combining to support multimode communication. Various aspects of the present invention may provide a first input adapted to receive a first baseband signal corresponding to a first communication protocol. A second input may be provided, which is adapted to receive a second baseband signal corresponding to a second communication protocol. A spectral placement module may, for example, be adapted to spectrally shift the first baseband signal. For example, the spectral placement module may be adapted to spectrally shift the first baseband signal to one or more frequency bands substantially distinct from one or more frequency bands associated with the second baseband signal. The spectrally shifted first baseband signal and the second baseband signal, which may also be spectrally shifted, may then be combined to form a composite signal.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: April 9, 2013
    Assignee: Broadcom Corporation
    Inventors: Ahmadreza Rofougaran, Arya Behzad
  • Patent number: 8259686
    Abstract: There is provided one exemplary array antenna system having a plurality of arrayed element antennas and transmit/receive modules that are respectively connected with those element antennas and that apply a predetermined phase shift amount to transmitting signals to be supplied to the element antennas and to received signals received by the element antennas, wherein the transmit/receive module has one transmitting path that is connected to first and second element antennas and that amplifies and distributes the transmitting signal to the first and second element antennas after applying a predetermined transmitting phase shift amount and two receiving paths that amplify and apply respectively a receiving phase shift amount to the received signals received from the first and second element antennas.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: September 4, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuhiro Kanto, Haruo Kojima, Tooru Tanaka
  • Patent number: 8254508
    Abstract: A system and method for obtaining a frequency error estimate representing the difference between a reference frequency and the frequency of a space-time transmit diversity signal is disclosed herein. The method includes taking the correlation of total sums, comprised of partial sums taken in defined first and second intervals, to represent the frequency error as the imaginary component of the correlation function.
    Type: Grant
    Filed: January 26, 2010
    Date of Patent: August 28, 2012
    Assignee: Research In Motion Limited
    Inventors: Xin Jin, Runbo Fu, Jorgen S. Nielsen
  • Patent number: 8170512
    Abstract: A wireless transmitter that includes a phase rotating unit which adds phase rotation to signals which are respectively input to antennas and adds first phase rotation for controlling the maximum delay time between the antennas and a second phase rotation for controlling the phases of arbitrary antennas among the antennas, wherein scheduling of users is performed on a per-chunk basis where a region defined in a frequency domain and in a time domain is divided into chunks in the frequency domain and in the time domain, and in the case in which the frequency bandwidth of the chunk is Fc, the phase rotating unit adds the first phase rotation so that the maximum delay time between the antennas is set to either a predetermined first value which is smaller than 1/Fc or a predetermined second value which is larger than 1/Fc.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: May 1, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Kimihiko Imamura
  • Patent number: 7904034
    Abstract: A system, a receiver apparatus, a transmitter apparatus and a method for inter-user interference cancellation when simultaneous transmissions from two wireless users to the same base station are repeated using the same time-frequency resource. The percentage of interference cancellation is pre-set and phase shifts of the first and repeated transmitted symbols for each mobile user are determined in accordance with this pre-set percentage. The receiver uses a pre-determined technique for estimating the received symbols in accordance with the pre-set percentage and phase shifts.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: March 8, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Farooq Khan, Cornelius Van Rensburg, Zhouyue Pi, Jiann-An Tsai, Yinong Ding
  • Patent number: 7826552
    Abstract: The present invention provides a structure in which an amplitude-modulation mode and a frequency-modulation mode are switched.
    Type: Grant
    Filed: August 4, 2006
    Date of Patent: November 2, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hidetomo Kobayashi, Tomoaki Atsumi
  • Patent number: 7796710
    Abstract: A digital demodulator includes a resonator having a resonance frequency same as a carrier frequency to store a charge corresponding to a digital signal modulated by phase shift keying, a capacitor to store the charge of the resonator, an amplifier including an input node and an output node between which the capacitor is connected to convert a stored charge of the capacitor into a voltage signal, and a controller configured to accumulate in the resonator the charge induced by the frequency signal modulated by phase shift keying in a first control mode and configured to transfer the charge of the resonator to the capacitor in a second control mode, to output the voltage signal corresponding to the stored charge of the capacitor from the output node of the amplifier.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: September 14, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuhide Abe, Michihiko Nishigaki, Toshihiko Nagano, Takashi Kawakubo
  • Patent number: 7792223
    Abstract: Method and system for demodulating data signals. According to an embodiment, the present invention provides a method for demodulating data signals. The method includes a step for receiving modulated data over a medium. The modulated data represents a plurality of bits, which includes at least a first bit. For example, the first bit is modulated by a number of modulation processes using a sequence of modulation symbols, and each of the sequence of modulation symbols is selected from a first plurality of modulation symbols. The method also includes a step for processing information associated with the first plurality of modulation symbols and the number of modulation processes. Also, the method includes a step for determining a plurality of sequences of modulation symbols based on at least information associated with the first plurality of modulation symbols and the number of modulation processes.
    Type: Grant
    Filed: March 24, 2007
    Date of Patent: September 7, 2010
    Assignee: Huawei Technologies Co., Ltd.
    Inventor: Shaoming Li
  • Patent number: 7769091
    Abstract: A communication system includes a first device and a second device connected to the first device by a single communication line. The first device includes a first transmitting portion which transmits to the second device a pulse signal set to a predetermined cycle that differs according to data, and a first receiving portion which reads data transmitted from the second device based on a voltage value of a transmission signal transmitted over the communication line. The second device includes a second transmitting portion which transmits to the first device a voltage signal set to a predetermined voltage value that differs according to the data, and a second receiving portion which reads data transmitted from the first device based on a pulse signal cycle of the transmission signal transmitted over the communication line.
    Type: Grant
    Filed: October 19, 2006
    Date of Patent: August 3, 2010
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Katsumi Tsuchida
  • Patent number: 7668258
    Abstract: Methods and systems for transmitter diversity expansion are provided. The methods and systems include steps and modules for applying a number of data streams (K) to a larger number of antennas (N). This is performed by applying each of the data streams to a single base antenna, such that K data streams are applied to K base antennas, and by shifting and combining the K data streams to produce N-K data streams to apply to N-K extension antennas.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: February 23, 2010
    Inventors: Mark Webster, Deniz Rende, Jim Petranovich
  • Patent number: 7606321
    Abstract: The system and method enable simpler analog processing in a transmitter by reducing the number of bits in a digital signal through delta sigma modulation. Selection of current sources in a digital to analog converter of the transmitter is done using a randomization circuit.
    Type: Grant
    Filed: June 29, 2004
    Date of Patent: October 20, 2009
    Assignee: Broadcom Corporation
    Inventor: Meng-An Pan
  • Patent number: 7583638
    Abstract: A device for processing a digital data signal in a CDMA radio transmitter includes a channelization device, a spectral shaping device and a frequency correction device. The channelization device adds a channel-individual CDMA code to the digital data signal, the spectral shaping device subjects the digital, channel-individualized data signal to a spectral shaping and the frequency correction device performs a spectral shift of the digital, spectrally shaped data signal.
    Type: Grant
    Filed: April 8, 2002
    Date of Patent: September 1, 2009
    Assignee: Infineon Technologies AG
    Inventors: Markus Doetsch, Tideya Kella, Peter Jung, Jörg Plechinger, Peter Schmidt, Michael Schneider
  • Patent number: 7502764
    Abstract: A method for determining an array space of an array antenna by using a genetic algorithm and an array antenna having a soft structure with irregular array spacing are disclosed. The array antenna having a sofa structure with irregular array spacing, includes: a plurality of radiation elements having an inclined angle based on a horizontal plane and arranged with irregular array spacing for radiating and receiving an radio wave; a plurality of phase shifters for amplifying radiation signals radiated from the plurality of radiation elements and receiving signals received from the plurality of radiation elements, and controlling phases of the radiation signals and the receiving signals; and a radio wave signal coupler for dividing a transmitting signal to the radiation signals, transferring the divided radiation signals to the plurality of phase shifters and coupling the receiving signals from the plurality of phase shifters.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: March 10, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seong-Ho Son, Ung-Hee Park, Soon-Ik Jeon, Chang-Joo Kim
  • Patent number: 7469021
    Abstract: The number of users and data capacity of wireless systems are increased by employing apparatus and method for increasing the number of spreading codes available in the system by providing a mechanism to reuse the already allocated spreading code or use the codes that may correlate to those already being used within the same sector/cell. This, in return, provides capacity improvement proportional to the number of added base station (BS) antennas for each cell. An antenna null steering technique for code allocation maintains the cross correlation properties of the codes only for the desired user and to obtain a gain in capacity improvement.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: December 23, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Nadar Bolourchi, Leonid Kazakevich, Rui Yang
  • Patent number: 7447277
    Abstract: An OFDM receiver (1) is provided which includes a clock-frequency error calculation circuit (41) to calculate a difference in clock frequency between a clock for a received signal and an operation clock used in the receiver (1), and a guard correlation/peak detection circuit (12) to determine an autocorrelation of a guard interval and detect a peak timing of the correlation signal. The guard correlation/peak detection circuit (12) incorporates a free-running counter, and outputs a count of the free-running counter at the peak timing to the clock-frequency error calculation circuit (41). The clock-frequency error calculation circuit (41) uses a plurality of time-change rate detection circuits provided at different time intervals to calculate a time-change rate of an input count. The clock-frequency error calculation circuit (41) plots the time-change rates to generate a histogram and calculates a clock-frequency error from the histogram.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: November 4, 2008
    Assignee: Sony Corporation
    Inventors: Atsushi Yajima, Kazuhisa Funamoto, Yasunari Ikeda
  • Patent number: 7421039
    Abstract: In the method and system, a transmitter demultiplexes an input data stream into M substreams, where each of the M substreams have a data rate lower than a data rate of the input data stream. The substreams are transmitted as signals from a transmit array of M antennas to be received by a receiver array at a receiver in the system, based on a set of transmission parameters. The transmitter adjusts at least one of the transmission parameters based on a condition experienced by the receiver so as to increase data throughput in the system. The adjustable parameters include the number of antennas to employ, the on/off patterns for the antennas, and eigenmode values for the antennas used in order to determine transmit power. Accordingly, system data throughput may be improved while maintaining transmit power and system bandwidth constant.
    Type: Grant
    Filed: June 4, 2002
    Date of Patent: September 2, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Laurence Eugene Malaender, Reinaldo A. Valenzuela
  • Patent number: 7379714
    Abstract: A method and apparatus for dynamically adjusting the impedance between a transmitter's power amplifier (PA) and antenna to efficiently transfer power from the PA to the antenna. The impedance between the PA and the antenna is adjusted based on power level measurements and/or PA direct current (DC) consumption measurements, depending on whether the PA is a linear PA or a switch-mode PA. In another embodiment, a hybrid PA including a first stage linear PA and a second stage switch-mode PA is implemented in a transmitter. The hybrid PA selectively connects the output of the first stage linear PA to one of the input of the second stage switch-mode PA and the output of the hybrid PA, depending on the output power level of the first stage linear PA, the output power level of the hybrid PA, or a requirement indicated by a transmit power control (TPC) command.
    Type: Grant
    Filed: December 27, 2004
    Date of Patent: May 27, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Tanbir Haque, Alpaslan Demir, Leonid Kazakevich, Gerard Klahn
  • Patent number: 7308240
    Abstract: A numerical control oscillator (NCO) for reducing a circuit size and power consumption while maintaining a desired frequency deviation, and suppressing generation of a spurious as much as possible. The NCO comprises a phase accumulator for accumulating input phase difference data to generate phase data, and a read only memory (ROM) for storing a phase/amplitude conversion table to output amplitude data corresponding to the phase data generated by the phase accumulator. The phase accumulator includes a phase register and a phase calculator. If a sampling frequency of an output signal from the NCO is Fs, the upper limit of a desired frequency setting interval of the output signal is FD and K and L are arbitrary integers, the phase calculator adds or subtracts the input phase difference data and phase data from the phase register to or from each other by a modulo operation taking the nearest integer of M as a modulus, where M=Fs/FD×K/L.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: December 11, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Takahiko Kishi
  • Patent number: 7218684
    Abstract: The number of users and data capacity of wireless systems are increased by employing apparatus and method for increasing the number of spreading codes available in the system by providing a mechanism to reuse the already allocated spreading code or use the codes that may correlate to those already being used within the same sector/cell. This, in return, provides capacity improvement proportional to the number of added base station (BS) antennas for each cell. An antenna null steering technique for code allocation maintains the cross correlation properties of the codes only for the desired user and to obtain a gain in capacity improvement.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: May 15, 2007
    Assignee: Interdigital Technology Corporation
    Inventors: Nader Bolourchi, Leonid Kazakevich, Rui Yang
  • Patent number: 7092685
    Abstract: The present invention relates to a method and a system for tuning a radio filter. The radio filter comprises at least one resonator module, each of said at least one resonator module having a tuning mechanism, a filter input connection, a filter output connection. High frequency broad band input and output signals of each of said at least one resonator module are sensed and processed to tune the radio filter. The processing of the sensed input and output signals includes processing in a low-frequency range.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: August 15, 2006
    Assignee: Allgon AB
    Inventors: Rolf Folkesson, Lennart Larsson
  • Patent number: 7079869
    Abstract: A radio frequency (RF) module for use in a communication device of a communication system includes integrated RF circuitry comprising at least one of a transmitter and a receiver, and an antenna element having at least one portion thereof arranged substantially adjacent to and operatively coupled to the integrated RF circuitry. For example, the antenna element may include at least first and second portions having opposing edges arranged immediately adjacent respective first and second sides of the integrated RF circuitry. A plurality of the modules can be used to implement a transceiver in a communication system base station or other communication device.
    Type: Grant
    Filed: February 12, 2003
    Date of Patent: July 18, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Turgut Sefket Aytur, Nathan R. Belk
  • Publication number: 20040097203
    Abstract: The present invention relates to a method and a system for tuning a radio filter. The radio filter comprises at least one resonator module, each of said at least one resonator module having a tuning mechanism, a filter input connection, a filter output connection. High frequency broad band input and output signals of each of said at least one resonator module are sensed and processed to tune the radio filter. The processing of the sensed input and output signals includes processing in a low-frequency range.
    Type: Application
    Filed: December 31, 2003
    Publication date: May 20, 2004
    Inventors: Rolf Folkesson, Lennart Larsson
  • Patent number: 6590945
    Abstract: A simplified method for frequency offset estimation in a TDMA cellular PCS environment using &pgr;/4-shifted DQPSK comprises the steps of multiplying a complex conjugate of a received complex-valued symbol and a succeeding symbol to produce a comparison vector having an angle equal to the phase angle between the received complex-valued symbol and the succeeding symbol, rotating the comparison vector so that the angle thereof is between 0° and 90°, and estimating the frequency offset by determining a constant deviation of the phase angle from an ideal phase angle value of 45° by calculating an average phase angle for a plurality of successive comparison vectors or correlating the rotated comparision vector against a bank of unit vectors to determine a maximum correlation.
    Type: Grant
    Filed: July 13, 1999
    Date of Patent: July 8, 2003
    Assignee: Lucent Technologies Inc.
    Inventors: Nima Brardjanian, Yong J. Lee, Walid E. Nabhane, Mohsen Sarraf, Sheng-Jen Tsai
  • Patent number: 6441804
    Abstract: A wireless cursor control system is provided that includes a pointing device and a receiver. The pointing device has a controller for receiving user input and for providing a control signal, and a transmitter that includes an antenna and a high frequency modulator coupled to the controller for receiving the control signal and for generating an output signal for transmission via the antenna. The high frequency modulator includes a variable frequency modulator circuit for selectively changing the frequency deviation of the control signal, and a high frequency circuit for increasing the frequency deviation of the control signal to produce the output signal. The receiver has an antenna that receives the output signal, and a demodulation circuit for demodulating the received output signal.
    Type: Grant
    Filed: February 1, 1999
    Date of Patent: August 27, 2002
    Assignee: KYE Systems Corp.
    Inventor: Po-Hsun Hsien
  • Patent number: 6434135
    Abstract: The invention reduces transient peaks in signals transmitted in CDMA communication systems. A plurality of spread spectrum data signals are combined into a combined signal having fluctuating power level corresponding to the combination of the data signals. The combined signal is modulated to produce an RF signal for transmission. The average power of the combined signal is measured over a selected time period. The combined signal power level is adaptively limited to a calculated power level based at least in part on the measured power.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: August 13, 2002
    Assignee: Interdigital Technology Corporation
    Inventors: Fatih M. Ozluturk, Brian Kiernan
  • Patent number: 6317009
    Abstract: The present invention teaches a system for selectably oscillating at a first or a second oscillating frequency. The system comprises an oscillator for providing an oscillating output. Moreover, the system comprises a switching device for selecting a first or a second impedance in response to a select signal having a voltage. Each of the first and second impedances are fixed independently of the select signal voltage such that the oscillating output oscillates at the first oscillating frequency when the first impedance is provided and oscillates at the second oscillating frequency when the second impedance is provided.
    Type: Grant
    Filed: April 16, 2001
    Date of Patent: November 13, 2001
    Assignee: Lear Automotive Dearborn, Inc.
    Inventor: John P. Hill
  • Publication number: 20010022540
    Abstract: The present invention teaches a system for selectably oscillating at a first or a second oscillating frequency. The system comprises an oscillator for providing an oscillating output. Moreover, the system comprises a switching device for selecting a first or a second impedance in response to a select signal having a voltage. Each of the first and second impedances are fixed independently of the select signal voltage such that the oscillating output oscillates at the first oscillating frequency when the first impedance is provided and oscillates at the second oscillating frequency when the second impedance is provided.
    Type: Application
    Filed: April 16, 2001
    Publication date: September 20, 2001
    Applicant: UT Automotive Dearborn, Inc.
    Inventor: John P. Hill
  • Patent number: 6275539
    Abstract: A radio frequency transmitter circuit including a user input switch for producing an input signal, an oscillator for producing a frequency signal having a first frequency, an antenna connected to the oscillator for broadcasting the frequency signal, a coupling circuit disposed a predetermined distance from the antenna, and a microprocessor for enabling the oscillator and activating the coupling circuit in response to the input signal. When the coupling circuit is activated, a reflected impedance, derived from a change in inductance, is reflected from the coupling circuit upon the antenna thereby shifting the frequency signal to a second frequency. Sequentially activating and deactivating the coupling circuit modulates the frequency signal.
    Type: Grant
    Filed: July 20, 1998
    Date of Patent: August 14, 2001
    Assignee: Lear Automotive Dearborn, Inc.
    Inventor: Steven P. Kulha
  • Patent number: 6246727
    Abstract: A method and a system for tuning a resonance module in e.g. a radio base station are disclosed. The resonance module has tuning means, a transmitter connection, and an antenna connection. First frequency input and output signals on the transmitter and antenna connection, respectively, are sensed and processed to tune the resonance module to a frequency of the input signal on the transmitter connection. The processing of the sensed input and output signals includes processing in a second frequency range. Prior art methods are improved by the invention through e.g. the use of a quadrature modulator to increase adjustment speed and overall applicability of the resonance module to be tuned.
    Type: Grant
    Filed: July 6, 1998
    Date of Patent: June 12, 2001
    Assignee: Allgon AB
    Inventors: Lennart Larsson, Rolf Folkesson, Björn Johansson
  • Patent number: 6225873
    Abstract: The present invention teaches a system for selectably oscillating at a first or a second oscillating frequency. The system comprises an oscillator for providing an oscillating output. Moreover, the system comprises a switching device for selecting a first or a second impedance in response to a select signal having a voltage. Each of the first and second impedances is fixed independently of the select signal voltage such that the oscillating output oscillates at the first oscillating frequency when the first impedance is provided and oscillates at the second oscillating frequency when the second impedance is provided.
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: May 1, 2001
    Assignee: Lear Automotive Dearborn, Inc.
    Inventor: John P. Hill
  • Patent number: 6041083
    Abstract: A method and a system for tuning a resonance module in a radio base station is disclosed. The resonance module has tuning means, a transmitter connection, and an antenna connection. High-frequency input and output signals on the transmitter and antenna connection, respectively, are sensed and processed to tune the resonance module to a frequency of the input signal on the transmitter connection. The processing of the sensed input and output signals includes processing in a low-frequency range. Prior art methods are improved by the invention through the use of a quadrature modulator to increase adjustment speed and overall applicability of the resonance module to be tuned.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: March 21, 2000
    Assignee: Allgon Ab
    Inventors: Lennart Larsson, Rolf Folkesson
  • Patent number: 5910968
    Abstract: A digital communication system having a transmitter and a receiver. The receiver transmits a radio-frequency (RF) signal that is continuous phase modulated by digital data. The receiver having a converter, a differential detector, and a sequential decoder. The receiver receives the RF signal. The RF signal is converted into a baseband signal by the converter. The baseband signal is received by the differential detector wherein the continuous phase modulation of the baseband signal is detected. The detected signal is received and the digital data is decoded by the sequential decoder. The sequential decoder has a Viterbi decoder to compensate for intersymbol interference caused by the differential detector. The Viterbi decoder performs reduced Viterbi decoding utilizing a feedback loop (FB) for reducing computing inaccuracies due to the reduction of the number of trellis states.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: June 8, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Antoine Chouly, Americo Brajal, Josep Casals Castane
  • Patent number: 5644598
    Abstract: A switching arrangement is provided for coupling a transmitting unit to a transmission line. According to the present invention, a transformer is provided, whose secondary winding is a portion of the transmission line and whose primary winding is connected with the transmitting unit and integrated into a parallel resonance circuit, whose resonant frequency is tuned, each time, to the carrier frequency of the transmitted signal. In addition, a tuning unit may be provided for the automatic tuning of the parallel resonance circuit.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: July 1, 1997
    Assignee: Siemens Schweiz AG
    Inventor: Werner Bidese
  • Patent number: 5491715
    Abstract: A method of matching the resonant frequency of an antenna resonant circuit (18, 46) to the output frequency of a transmitter output stage (26), the method includes the step of providing a powering signal from the transmitter output stage (26) to the antenna resonant circuit (18, 46). The method further includes the step of receiving at the antenna resonant circuit (18, 46) the powering signal, the antenna resonant circuit (18, 46) comprising a tuning circuit (48). The tuning circuit (48) is operable to variably modify the resonant frequency of the resonant circuit (18, 46). At its output the antenna resonant circuit (18, 46) provides a phase correlation signal having a known relationship to the frequency difference between the resonant frequency and the powering signal. A phase comparator (60) then receives the powering signal and the phase correlation signal and correspondingly adjusts the resonant frequency of the resonant circuit (18, 46) based upon the known phase relationship.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: February 13, 1996
    Assignee: Texas Instruments Deutschland GmbH
    Inventor: Thomas J. Flaxl
  • Patent number: 5448769
    Abstract: A method for tuning an RF bandpass filter, especially a combiner filter (10.sub.1, 10.sub.2. . . 10.sub.n) belonging to a GSM system, in which an RF signal having a certain nominal carrier frequency (f.sub.c) is inputted into the RF bandpass filter and a medium frequency of a pass band of the RF bandpass filter is tuned depending on an RF power propagating through the bandpass filter or on an RF power reflected from an input of the bandpass filter. For an easier tuning of the filter and for a tuning accuracy better than before, (a) a carrier is modulated by a signal causing a first predetermined offset (+.DELTA.f), of the carrier frequency, (b) a medium frequency, at which the power propagating through the filter is at the maximum or the power reflected from the input of the filter is at the minimum, is searched for for the bandpass filter, (c) the first medium frequency obtained at stage (b) is stored, (d) the carrier is modulated by a signal causing a second predetermined offset (-.DELTA.
    Type: Grant
    Filed: November 30, 1993
    Date of Patent: September 5, 1995
    Assignee: Nokia Telecommunication OY
    Inventor: Arto Jantti