Selectivity Or Bandwidth Control Patents (Class 455/266)
  • Patent number: 8243864
    Abstract: A technique for noise reduction in a wireless communication system uses controllable bandwidth filters (120) to filter a received signal. In a typical implementation, the filters (120) are used at baseband frequencies. A measurement (RSSI) is indicative of the strength of the received signal. A control circuit (144) generates a control signal (146) to control the bandwidth of the filters (120). If the received signal strength is above a first threshold, a wider bandwidth may be used for the filters (120). If the received signal is below a second threshold, the control circuit (144) generates the control signal (146) to set the filters (120) to a more narrow bandwidth. The system (100) may also be used with digital filters (150, 152) following digitization by analog to digital converters (ADCs) (130, 132). The system (100) is particularly well-suited for operation with noise-shaped ADCs (130, 132), such as Delta-Sigma converters.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: August 14, 2012
    Assignee: QUALCOMM, Incorporated
    Inventors: Steven Ciccarelli, Arun Raghupathy, Brian C. Banister
  • Publication number: 20120202444
    Abstract: The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers.
    Type: Application
    Filed: April 17, 2012
    Publication date: August 9, 2012
    Applicant: UBIQUITI NETWORKS, INC.
    Inventors: Robert J. PERA, Lance D. LASCARI
  • Patent number: 8233870
    Abstract: A transceiver includes a receiver section and a transmitter section. The receiver section converts an inbound Multiple Frequency Bands Multiple Standards (MFBMS) signal into a down converted signal, wherein the inbound MFBMS signal includes a desired signal component and an undesired signal component. In addition, the receiver section determines spectral positioning of the undesired signal component with respect to the desired signal component and adjusts at least one of the MFBMS signal and the down converted signal based on the spectral positioning to substantially reduce adverse affects of the undesired signal component on the desired signal component to produce an adjusted signal. The transmitter section converts an outbound symbol stream into an outbound MFBMS signal.
    Type: Grant
    Filed: December 4, 2008
    Date of Patent: July 31, 2012
    Assignee: Broadcom Corporation
    Inventors: John Walley, Jeyhan Karaoguz, Brima B. Ibrahim, Arya Reza Behzad, Vinko Erceg, David Rosmann
  • Patent number: 8229380
    Abstract: A radio wave receiving apparatus includes: an antenna to receive a radio wave; a tuning member to allow a reception frequency of the antenna to be tuned to an intended frequency, in which tuning member a frequency characteristic is variable; a receiving member to receive a reception signal from the antenna to demodulate a modulation wave; a positive feedback member to perform a positive feedback in a signal path including the tuning member; and a switching member to turn on/off a feedback operation of the positive feedback member.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: July 24, 2012
    Assignee: Casio Computer Co., Ltd.
    Inventor: Kaoru Someya
  • Patent number: 8229384
    Abstract: A filter circuit includes first capacitors, second capacitors capable of altering a cutoff frequency by being connected in parallel with the first capacitors, first switches for connecting the second capacitors in parallel with the first capacitors, and charging circuits for the second capacitors. The charging circuits include second switches, and resistances for attenuating the amplitudes of input voltages to be fed to the second capacitors, by being connected in series with the second capacitors. The second capacitors are charged through the resistances in a state where the first switches are turned OFF and where the second switches are turned ON. Thus, a DC offset which is ascribable to the cutoff frequency switching of a filter is reduced.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: July 24, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Masaaki Yamada, Yusaku Katsube, Junichi Takahashi, Toshihito Habuka, Fumihito Yamaguchi
  • Patent number: 8219059
    Abstract: The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers. The high selectivity RF circuit comprises channel select filters, a down-converter, an up-converter and a programmable local oscillator.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: July 10, 2012
    Assignee: Ubiquiti Networks, Inc.
    Inventors: Robert J. Pera, Lance D. Lascari
  • Patent number: 8160526
    Abstract: A filter arrangement for a receiver for multiple broadcast signals includes a first filter for receiving a broadcast signal from a tuner, a second filter coupled to an output of said first filter, said second filter having a variable bandwidth response, said second filter providing an output for a demodulator; and a filter control responsive to said broadcast signal for controlling said variable bandwidth response of said second filter.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: April 17, 2012
    Assignee: Thomson Licensing
    Inventor: Clint Alan Ecoff
  • Patent number: 8150359
    Abstract: A multiple frequency band hybrid receiver includes a plurality of input terminals to which different frequency band signals are respectively inputted; a plurality of mixers connected to the plurality of input terminals sequentially, receiving the different frequency band signals respectively, and down-converting frequencies of the received frequency band signals to predetermined frequencies; an output terminal outputting baseband signals. Each mixer receives a signal from an input terminal connected thereto or another mixer. One of the plurality of mixers receives the lowest frequency band signal, converts a frequency of the received signal to a baseband frequency, and provides a signal having the baseband frequency to the output terminal. The other mixers each down-convert a frequency of a received signal to a frequency band of a signal which is inputted into another mixer.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: April 3, 2012
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Dong Ok Han, Jeong Hoon Kim
  • Patent number: 8150352
    Abstract: What is described herein is a technique that includes a clock generator configured to generate a clock signal having a frequency of |fbp+fi|. The technique further includes a mixer configured to input (1) an input signal that includes a desired signal at the frequency fi and (2) the clock signal and generate a mixed signal using the input signal and the clock signal. A filter, having a bandpass region that includes the frequency fbp, is configured to input the mixed signal and generate a filtered signal based at least in part on the bandpass region.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: April 3, 2012
    Assignee: Project FT, Inc.
    Inventors: Arshan Aga, Farbod Aram
  • Patent number: 8145172
    Abstract: A receiver (400) includes a tracking bandpass filter (420) and a signal processing circuit (430-480). The tracking bandpass filter (420) has a first input for receiving a radio frequency (RF) signal, and an output, and includes a first portion (731) on a semiconductor die (730), and at least one inductor (721). The at least one inductor (721) is operatively coupled to the first portion of the tracking bandpass filter (420). The signal processing circuit (430-480) has an input coupled to the output of the tracking bandpass filter (420), and an output for providing a processed signal. The semiconductor die (730) and the at least one inductor (721) are integrated into a single multi-chip module (MCM) (710).
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: March 27, 2012
    Assignee: Silicon Laboratories Inc.
    Inventors: Ramin Khoini-Poorfard, Alessandro Piovaccari, Aslamali A. Rafi, Mustafa H. Koroglu, David S. Trager
  • Patent number: 8145170
    Abstract: A receiver (400) includes a tracking bandpass filter (420), a tunable lowpass filter (434), a local oscillator (442), and a mixer (444). The tracking bandpass filter (420) has an input for receiving a radio frequency (RF) input signal, and an output. The tunable lowpass filter (434) has an input coupled to the output of the tracking bandpass filter (420), and an output. The local oscillator (422) has a first output for providing a local oscillator signal, which is characterized as being a square wave signal at the desired intermediate frequency (IF). The mixer (444) has a first input coupled to the output of the tunable lowpass filter (434), a second input coupled to the output of the local oscillator (442), and a first output for providing an IF signal at the desired IF. The tunable lowpass filter (434) is configured to substantially attenuate a third harmonic of the frequency of the local oscillator signal.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: March 27, 2012
    Assignee: Silicon Laboratories Inc.
    Inventors: Ramin Khoini-Poorfard, Alessandro Piovaccari, Aslamali A. Rafi, Abdulkerim L. Coban
  • Patent number: 8140034
    Abstract: A method and systems for a frequency locked feedback loop for wireless communications are provided. The method includes applying dither modulation from a harmonic modulator to modulated data at a transmit source, and mixing the dither modulation at a dither modulation frequency with the modulated data at a wireless carrier frequency to produce a modulated signal. The method also includes filtering and splitting the modulated signal using a bandpass filter to produce a wireless output signal and a feedback signal. The method further includes determining a frequency error in the feedback signal as a function of alignment of the wireless carrier frequency to a target frequency in a frequency response of the bandpass filter. The method additionally includes adjusting the wireless carrier frequency in response to the frequency error to establish a frequency lock between the wireless carrier frequency and the target frequency.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: March 20, 2012
    Assignee: International Business Machines Corporation
    Inventors: Casimer M. DeCusatis, Lawrence Jacobowitz
  • Patent number: 8140038
    Abstract: An adaptive receiver for receiving a radio frequency (RF) signal and converting the RF signal at an RF frequency FRF toward a low intermediate frequency FIF is disclosed. The adaptive receiver comprises a pair of band pass filters with a nominal center frequency Fc equal to FIF, a look-up table (LUT) configured to estimate a frequency offset ?f, representing the center frequency of the band pass filter due to an operating temperature change and/or process variation, a micro controller configured to estimate the operating center frequency of the band pass filter (=FIF+?f with the frequency offset included) and use this new center frequency as the adaptive intermediate frequency FIF,AD, and a local oscillator generates oscillating signals at a frequency FLO equal to FRF minus FIF,AD. A temperature sensing device may also be included in this adaptive receiver.
    Type: Grant
    Filed: October 14, 2009
    Date of Patent: March 20, 2012
    Assignee: ISSC Technologies Corp.
    Inventors: Peng-Sen Chen, Hsiang-Te Ho
  • Patent number: 8135370
    Abstract: Adjacent interference is reliably detected in an FM tuner. A receiving field strength judgment circuit (102) compares a reception field strength signal SM-DC input from an S-meter circuit (92) and a reference voltage Vref2, and outputs a receiving strength judgment signal SRE. An SD band judgment circuit (104) uses a window comparator to determine, based on an f-V conversion characteristic of a detection output SDET, whether or not a voltage ?V generated based on SDET is within a voltage range corresponding to a narrow band WN, and whether or not the voltage ?V is within a voltage range corresponding to a wide band WW; and outputs determination signals SBD-N, SBD-W corresponding respectively to WN, WW. An SD circuit (106) performs a station detection based on SRE and SBD-N, and determines the presence or absence of adjacent interference based on, e.g., SBD-N and SBD-W.
    Type: Grant
    Filed: September 2, 2008
    Date of Patent: March 13, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.
    Inventor: Keiji Kobayashi
  • Patent number: 8135367
    Abstract: Aspects of a method and system for on-demand linearity in a receiver are provided. In this regard, in a receiver such as on-chip receiver, a strength of a signal received by one or more antennas may be measured and linearity of the receiver may be controlled in response to the measured signal strength. The linearity may be controlled based on signal strength of in-band and/or out-of-band signals and by configuring component(s) of the receiver. Exemplary components may comprise one or more filter, amplifier, mixer, analog-to-digital converter, feedback loop, and equalizer and/or post corrector. Linearity may be increased, by switching one or more feedback loops and/or an equalizers and/or post correctors into a signal path of the receiver. Power consumption may be decreased, at the expense of reduced linearity, by switching one or more feedback loops and/or an equalizers and/or post correctors out of a signal path of the receiver.
    Type: Grant
    Filed: May 6, 2008
    Date of Patent: March 13, 2012
    Assignee: Broadcom Corporation
    Inventors: Ahmadreza Rofougaran, Maryam Rofougaran
  • Patent number: 8131247
    Abstract: An alternate adjacent channel interference (AACI) filter is integrated into an intermediate frequency (IF) channel select filter to filter received RF signals. The IF channel select filter is an IF staged structure comprising successive IF stages. Each of the successive IF stages is a 2-biquad integrator. The AACI filter is integrated into the first IF stage of the IF channel select filter by re-using circuit components such as an operational amplifier, an input resistor, and a shunt capacitor of the first IF stage. The shunt capacitor is coupled between a middle point of the input resistor and ground. The AACI filter is realized via different equivalent implementations of the re-used circuit components of the first IF stage. A value of the shunt capacitor of the AACI filter becomes a fixed-value when a value the input resistor is inversely proportional to the bandwidth of the AACI filter.
    Type: Grant
    Filed: May 20, 2009
    Date of Patent: March 6, 2012
    Assignee: Broadcom Corporation
    Inventor: Hung-Ming Chien
  • Patent number: 8131244
    Abstract: Certain aspects of a method and system for dynamically adjusting intermediate frequency (IF) and filtering in microwave circuits may include generating one or more intermediate frequency (IF) signals from one or more baseband signals and/or one or more radio frequency (RF) signals. The generated one or more IF signals may be filtered to avoid detected interference and/or detected noise from out-of-band radio sources. The frequency of the generated one or more IF signals may vary depending on the detected interference and/or detected noise. The filtering of the generated one or more IF signals may be adjusted based on the variation in the frequency of the generated one or more IF signals. The one or more RF signals may be down-converted to generate the one or more IF signals. The generated IF signals may be further down-converted and dynamically filtered to generate the desired baseband signals.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: March 6, 2012
    Assignee: Broadcom Corporation
    Inventors: Ahmadreza Rofougaran, Maryam Rofougaran
  • Patent number: 8116713
    Abstract: A signal processing system and methods for controlling a bandwidth of the signal processing system are disclosed. One method includes the steps of detecting a presence of an adjacent signal on at one adjacent channel relative to a desired channel, detecting a modulation characteristic of the desired channel, measuring a signal strength on the at least one adjacent channel, measuring a signal strength on the desired channel, and adjusting a bandwidth filter applied to the desired channel in response to the measurements and detection steps.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: February 14, 2012
    Assignee: Visteon Global Technologies, Inc.
    Inventors: J. William Whikehart, Robert Kelly Cadena
  • Patent number: 8107914
    Abstract: Radio-frequency (RF) circuits, methods and systems are implemented according to a variety of embodiments. According to one such embodiment, a radio-frequency (RF) receiver circuit is implemented with an adjustable RF filter circuit in a receive path of the RF receiver circuit. A local oscillator (LO) generates a LO signal and an RX_LO signal from the LO signal. A mixing circuit mixes a signal received from the adjustable RF filter circuit and the RX_LO signal. An intermediate-frequency (IF) circuit generates an IF_cal signal at the receiver circuit. A calibration circuit implements both a calibration mode and a receive mode. In the calibration mode, a calibration signal is injected into the receive path. A setting of the adjustable RF filter circuit is determined. In the receive mode, the calibration circuit disables the injection of the calibration signal into the receive path of the RF receiver circuit.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: January 31, 2012
    Inventors: Daniel Firoiu, Damian Costa, Mats Lindstrom, Kendal McNaught-Davis Hess, Weinen Gao
  • Patent number: 8103233
    Abstract: The present disclosure relates to a tuner capable of receiving a television broadcasting signal of a wide band having an operating frequency bandwidth of 48 MHz˜1 GHz, wherein the tuner filters a radio frequency (RF) signal outputted from the low noise amplifier using a tunable filter. The tunable filter includes according to an embodiment an inductor and a variable capacitor as passive elements to reject harmonics. The tuner includes a mixer which mixes an output signal of the tunable filter with a local oscillator signal and converts the mixed signal to an In-phase and Quadrature IF signal, where the converted IF signal of I channel and Q channel is processed through an IF signal processor and is converted to an appropriate signal by a demodulator.
    Type: Grant
    Filed: December 29, 2008
    Date of Patent: January 24, 2012
    Assignee: LG Electronics Inc.
    Inventors: Dong Gu Im, Jae Yup Lee, Hee Sub Lee, Hong Teuk Kim, Kwy Ro Lee
  • Patent number: 8095105
    Abstract: A single chip superhetrodyne AM receiver is disclosed herein. To compensate for process variations in the implementation of the IC, bias currents setting the operating conditions for various amplifiers and other components in the system are adjusted based on frequency control signals in a PLL circuit in the local oscillator. Since the magnitude of the control signal reflects the process variations, the bias currents are adjusted based on the control signal to offset these variations in other portions of the receiver. To further improve the signal to noise ratio of the receiver, the IF filter is tuned within a range so as not to include any integer multiple or integer divisor of the timing reference frequency. Various techniques are described for enabling a complete superhetrodyne AM receiver to be implemented on a single chip which receives an antenna input signal and outputs a digital data signal.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: January 10, 2012
    Assignee: Micrel, Incorporated
    Inventors: Joseph S. Elder, Joseph T. Yestrebsky, Mohammed D. Islam
  • Patent number: 8090888
    Abstract: A wireless USB hub for connecting a plurality of remote peripheral devices to a computer for communication therewith without the need to physically connect the peripheral devices to the hub via a cable connection. The wireless USB hub includes a receiver for receiving wireless data transmissions from one or more remote peripheral devices. The wireless USB hub further includes a hub controller for passing appropriate peripheral device information to a USB upstream port and then to a computer.
    Type: Grant
    Filed: April 29, 2010
    Date of Patent: January 3, 2012
    Assignee: Aalmason Two Data L.L.C.
    Inventors: Henry Milan, Rodney Haas
  • Patent number: 8078129
    Abstract: A method and apparatus for a tuner for adjusting the receiver bandwidth based on adjacent channel interference and group delay distortion.
    Type: Grant
    Filed: February 23, 2009
    Date of Patent: December 13, 2011
    Assignee: NXP B.V.
    Inventors: Mats Lindstrom, Abbolreza Shafie
  • Publication number: 20110294451
    Abstract: A receiver includes an input to receive data of a pilot channel having a carrier frequency associated therewith, and a first unit to obtain a quantity, wherein the quantity depends on a frequency broadening of the received data and a frequency shift of the received data with respect to the carrier frequency. The receiver also includes a second unit to adjust the bandwidth of a channel estimation unit, wherein the adjustment depends on the quantity.
    Type: Application
    Filed: May 26, 2010
    Publication date: December 1, 2011
    Applicant: Infineon Technologies AG
    Inventors: Edgar Bolinth, Herbert Dawid, Thorsten Clevorn
  • Patent number: 8068847
    Abstract: Disclosed herein is a system and method for notifying a person that they have become separated from their mobile communication device. A comparison between location information for the device and presence information for the person is used to determine whether or not a separation exists. Certain corrective actions are possible in order to mitigate the consequences of the separation. A separation may be allowed to exist within a certain maximum allowable distance of separation without the system or method notifying the person.
    Type: Grant
    Filed: August 9, 2006
    Date of Patent: November 29, 2011
    Assignee: Avaya Inc.
    Inventors: Chris Fegan, Katherine Hamilton, Neil Hepworth, Lawrence Ongud Opiyo
  • Patent number: 8068803
    Abstract: An booster/amplifier receives a plurality of RF signals, including a subject RF signal. A location-based signal spectrum is determined by performing either a frequency scan or an information lookup operation. An initial filter bandwidth for the booster/amplifier is set based at least in part on the determined signal spectrum and a target time delay interference. In one embodiment, the initial filter bandwidth is set such that both the TDI and ACI are optimized/minimized. The initial filter bandwidth subsequently may be adjusted from its initial value based on actual measured ACI and/or TDI values.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: November 29, 2011
    Assignee: Airorlite Communications, Inc.
    Inventor: Leon Michael Masoian
  • Publication number: 20110287730
    Abstract: A signal filtering system for a frequency reuse system. A first implementation may include a downlink baseband signal, coupled to a downlink bandwidth filter, including a composite received signal including at least an interfering signal and a signal of interest, each having a composite bandwidth, a first bandwidth, and a second bandwidth, respectively. An uplink baseband signal may be included, coupled to an uplink bandwidth filter, having a replica of the interfering signal corresponding with the interfering signal and having an interference bandwidth. A baseband processing module may be coupled with the downlink bandwidth filter and the uplink bandwidth filter and may be configured to cancel the interfering signal from the composite received signal using the replica of the interfering signal. The downlink bandwidth filter may be configured to reduce the composite bandwidth and the uplink bandwidth filter may be configured to reduce the interference bandwidth.
    Type: Application
    Filed: August 2, 2011
    Publication date: November 24, 2011
    Inventors: Richard M. Miller, Cris M. Mamaril
  • Patent number: 8027652
    Abstract: A radio front end utilizes at least one band pass filter to pass only the appropriate frequency band. Once the desired frequency band has been isolated it is converted to a digital format in an analog to digital converter and a digital signal processing device interprets the signal.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: September 27, 2011
    Assignee: Continental Automotive Systems US, Inc.
    Inventor: Stephen K. Gilbert
  • Patent number: 8005765
    Abstract: A method for scheduling and usage of bandwidth wherein data is transmitted to an artificial intelligence model for analysis and assigned a ranking. An event resource allocation model analyzes the ranking and determines how to compress the associated video. The event resource allocation model also determines when to compress the remotely stored video and transmit to a central data center where the video may be reviewed.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: August 23, 2011
    Assignee: STARSAT, LLC
    Inventors: Ken W. Anderson, Stephen A. Schwager
  • Patent number: 7991373
    Abstract: A signal filtering system for a frequency reuse system. A first implementation may include a downlink baseband signal, coupled to a downlink bandwidth filter, including a composite received signal including at least an interfering signal and a signal of interest, each having a composite bandwidth, a first bandwidth, and a second bandwidth, respectively. An uplink baseband signal may be included, coupled to an uplink bandwidth filter, having a replica of the interfering signal corresponding with the interfering signal and having an interference bandwidth. A baseband processing module may be coupled with the downlink bandwidth filter and the uplink bandwidth filter and may be configured to cancel the interfering signal from the composite received signal using the replica of the interfering signal. The downlink bandwidth filter may be configured to reduce the composite bandwidth and the uplink bandwidth filter may be configured to reduce the interference bandwidth.
    Type: Grant
    Filed: August 21, 2008
    Date of Patent: August 2, 2011
    Assignee: Comtech EF Data Corp.
    Inventors: Richard M. Miller, Cris M. Mamaril
  • Patent number: 7983643
    Abstract: A frequency demodulator comprises a frequency discriminator configured to generate a frequency modulation signal from frequency modulated signal, circuitry for generating a phase modulation signal from the frequency modulation signal, and a click reduction signal processing (CRSP) circuit operable to remove noise enhancements from the phase modulation signal caused by clicks. By first converting the frequency modulation signal to a phase modulation signal, noise enhancements caused by clicks are more readily distinguished from other noise in the phase modulation signal. After the noise enhancements have been removed by the CRSP, the frequency modulation is recovered substantially free of clicks. Removal of the clicks results in an improved output signal-to-noise ratio, thereby advantageously extending the onset of the threshold effect.
    Type: Grant
    Filed: July 3, 2008
    Date of Patent: July 19, 2011
    Assignee: Panasonic Corporation
    Inventors: Earl W. McCune, Jr., Richard W. D. Booth
  • Patent number: 7961827
    Abstract: A signal processing arrangement (REC) comprises a filter (PPF) with variable filter elements (FE). A switching circuit (SWCT) switches a filter element (FE1) and, subsequently, another filter element (FE3) from a filter state to an adjustment state and back again to the filter state. A filter element that is in the filter state contributes to a suppression of unwanted signals. A filter element that is in the adjustment state affects a characteristic of a measurement signal (Sm). An adjustment circuit (ADCT) adjusts the filter element that is in the adjustment state so that the characteristic of the measurement signal is substantially equal to a target value (TV).
    Type: Grant
    Filed: May 25, 2005
    Date of Patent: June 14, 2011
    Assignee: NXP B.V.
    Inventors: Jan Van Sinderen, Marc Godfriedus Marie Notten
  • Patent number: 7957412
    Abstract: An apparatus comprising a transmission line, a receiver circuit, and a high pass filter circuit coupled between the transmission line and a receiver circuit input. The receiver circuit is configured to receive a data signal over the transmission line at a first data rate. The high pass filter circuit is connected between the transmission line and a receiver circuit input and has a corner frequency that is less than approximately the first data rate and is greater or equal to than approximately one-half the second data rate. The second data rate is an effective data rate caused by an expected data pattern on the transmission line. Other devices, systems, and methods are disclosed.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: June 7, 2011
    Assignee: Cray Inc.
    Inventors: Michael Steinberger, Ricky J. Hakes, Christopher K. White
  • Patent number: 7953366
    Abstract: A receiver that can receive several initial signals modulated in a same initial frequency band and/or distinct initial frequency bands and generate a signal modulated in a transmission band to be transmitted on a coaxial cable, comprising a selector that can select several signals from among the received signals; for each selected signal, a mixer capable of transforming the selected signal into a signal at least partly in the transmission band, and a filter capable of extracting from the transformed signal a signal associated with a portion of the transmission band from among several at least partly distinct portions of the transmission band; and means for forming the signal modulated in the transmission band from signals associated with the transmission band portions.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: May 31, 2011
    Assignee: STMicroelectronics, SA
    Inventor: Jean-Yves Couet
  • Patent number: 7945004
    Abstract: A method and apparatus for detecting a frequency band and mode of operation using recursive sampling and narrowing down is disclosed. The method comprises sampling (215) by a multi-mode wireless communication device, a broad operational frequency spectrum at a first sampling rate to produce a first set of discrete signal samples. Then, the wireless communication device compares (230, 240) at least one of the energy graphs of the first set of discrete signal samples with at least one protocol-specific signature to confirm (245), if an approximate match is found. When one or more approximate matches are found, the wireless communication device narrows down (250) the broad frequency spectrum to a reduced set of frequency band(s) that correspond to the matched protocol-specific signature(s). Then the steps of sampling (215), comparing (230, 240), confirming (245), and narrowing down (250) are recursively followed till a frequency band and mode of operation is confirmed.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: May 17, 2011
    Assignee: Motorola Mobility, Inc.
    Inventors: Brian D. Storm, John R. Barr, Kevin J. Bush, Gregory W. Chance
  • Patent number: 7933230
    Abstract: A Dynamic Threshold Rule is provided for sharing of bandwidth of a shared medium between multiple devices. In one embodiment, a device determines a measure of available bandwidth of said medium; reserves bandwidth up to the available bandwidth; receives a request from a device for bandwidth of a specified amount; and honors the request when relinquishing the specified amount results in preserving an equal or greater percentage of bandwidth available at a time of reserving bandwidth. Different classes of devices may be distinguished, where the percentage for devices of a particular class is greater than for devices not of that particular class, or for which at least one class of device is exempt from the requirement to relinquish bandwidth.
    Type: Grant
    Filed: October 14, 2005
    Date of Patent: April 26, 2011
    Assignee: NXP B.V.
    Inventor: Takashi Sato
  • Patent number: 7899488
    Abstract: A method and apparatus for power conservation is provided for a multi-mode wireless communication device (100) capable of operating in a plurality of networks, each of the plurality of networks having a network signal with predetermined spectral characteristics. The wireless communication device (100) includes a variable bandwidth signal detector (140), a threshold detector (145), and a controller (120). The variable bandwidth signal detector (140) receives radio frequency (RF) signals and defines a detection bandwidth for signal detection. The threshold detector (145) is coupled to the variable bandwidth signal detector (140) and detects a network signal within the RF signals in response to determining whether a signal is present within the detection bandwidth having a signal strength greater than a predetermined signal strength.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: March 1, 2011
    Assignee: Motorola Mobility, Inc.
    Inventors: William E. Wangard, Timothy A. Dickinson, Robert M. Johnson, Arthur C. Leyh
  • Publication number: 20100330945
    Abstract: A radio receiver includes a down-converter 110 for receiving a radio multiplexed signal containing a first signal and a second signal, multiplying the first signal and the second signal by a mixer 104 to thereby down-convert the radio multiplexed signal and generate an intermediate frequency signal 5e. The mixer 104 has a control section for controlling an operating bias of the mixer 104 in response to a signal strength of at least either one of the first signal or the second signal. Thus, the dynamic range of the mixer can be widened so that stable image characteristics can be obtained over a wide range of transmission distance.
    Type: Application
    Filed: August 31, 2010
    Publication date: December 30, 2010
    Inventors: Shinichi HANDA, Eiji Suematsu, Atsushi Yamada, Keisuke Sato
  • Patent number: 7848726
    Abstract: A high-frequency receiver alleviates an influence of adjacent interference waves in a location where an identical set of broadcast channels can be received with different broadcast waves which are broadcast or relayed in frequency bands different from one another by satellites and ground repeater(s). The I and Q signals are passed to a pair of variable LPFs. A demodulation unit is provided for each of said different broadcast waves to demodulate the I and Q signals derived from the broadcast wave into a demodulated signal. One of the demodulated signals which has a better reception quality is selected for output. Based on a reception level and a noise evaluation information (e.g., the bit error rate) for a selected demodulated signal, a controller controls the bandwidths of the variable LPFs so as to optimize the reception level and the noise evaluation information for the selected demodulated signal.
    Type: Grant
    Filed: March 3, 2006
    Date of Patent: December 7, 2010
    Assignee: Pioneer Corporation
    Inventor: Sei Kato
  • Patent number: 7840196
    Abstract: In a filter circuit, resonators is connected in parallel between input and output terminal, an input signal is input through the input terminal and supplied to the resonators. Signal generators are connected to the resonators to control the resonators. The signal generators are controlled by a control unit so that the resonators are resonated to generate resonance signals at different resonant frequencies and at predetermined resonance phases. Thus, the output signal is set within a desired frequency range.
    Type: Grant
    Filed: September 21, 2006
    Date of Patent: November 23, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroyuki Kayano
  • Patent number: 7822385
    Abstract: Adjacent channel interference (ACI) suppression is achieved by selectively applying one or more pre-calculated fixed filters only when necessary, thereby preserving the sensitivity of the receiver. An energy detector accurately detects adjacent channel interference in the frequency band of the desired signal so that the likelihood of a false detection of ACI is very low. If the energy detector detects adjacent channel interference is present in the band of the desired signal, then the received signal is selected to be filtered by the pre-calculated filter, e.g., a low pass filter. Otherwise, the pre-calculated filter is bypassed. In either case, additional ACI suppression processing may be employed.
    Type: Grant
    Filed: February 26, 2007
    Date of Patent: October 26, 2010
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Miguel Lopez
  • Patent number: 7761067
    Abstract: Apparatus, systems, and methods implementing techniques for calibrating a filter circuit. A comparator generates an output based on a filter output amplitude signal and a reference amplitude signal. A calibration logic unit receives the comparator output and produces a component code that is used by the filter circuit to adjust one or more component values.
    Type: Grant
    Filed: April 21, 2004
    Date of Patent: July 20, 2010
    Assignee: Marvell International Ltd.
    Inventors: King Chun Tsai, Sang Won Son, Wayne A. Loeb
  • Patent number: 7756500
    Abstract: An integrated front-end filter for a tuner provides an array of from several to a multitude of passbands, each for passing at least one but less than all channels designated in a band of frequencies. Each passband is exclusively selectable. The integrated front end filter includes at least one active filter unit with an active reactance element in either of fixed and variable filter configurations and a decoder coupled to said at least one active filter unit and being responsive to a control signal for selecting a one of the passbands. In one example a multitude of active filter units of fixed filter configuration provide the multitude of passbands. Each data is stored at a predetermined location and reproduced in response to a corresponding control data signal from a tuner controller. Each data characterizes one of the plurality of passbands. The filter element is switchable from one passband to another in response to the control data signal.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: July 13, 2010
    Assignee: SiGe Semiconductor Inc.
    Inventors: Stefan Fulga, David Rahn
  • Patent number: 7756502
    Abstract: The high-frequency IC according to an embodiment of the invention includes a mixer down-converting the RF signal into an IF signal with a given center frequency lower than that of the RF signal, a first-order low-pass filter with a pass band set narrower than a bandwidth of the IF signal down-converted by the mixer, and an active low-pass filter removing a signal outside the bandwidth of the IF signal.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: July 13, 2010
    Assignee: NEC Electronics Corporation
    Inventor: Jianqin Wang
  • Patent number: 7747237
    Abstract: A highly agile low phase noise frequency synthesizer is provided for rapid generation of frequency specific signals. The frequency synthesizer is capable of rapidly generating signals at different output frequencies while maintaining low cross-coupling. Two or more signal generators utilize a reference frequency to generate two or more signals. These signals are limit processed to reduce cross-coupling prior to being presented to a switch. Responsive to a control signal, the switch outputs one of the signals to a frequency modification device, such as a frequency divider or multiplier. Responsive to a control signal, the frequency modification device scales the frequency of the switch output to convert the frequency of the switch output signal to a desired output frequency. By maintaining sufficient frequency separation between the switch input signals cross-coupling and phase noise is minimized and implementation on an integrated circuit may be achieved.
    Type: Grant
    Filed: April 9, 2004
    Date of Patent: June 29, 2010
    Assignee: Skyworks Solutions, Inc.
    Inventors: Akbar Ali, James P. Young
  • Patent number: 7729674
    Abstract: A multi-band communication device with a front end antenna switch module and shared bias circuit is disclosed. Control inputs determine signal routing and amplifier biasing in response to the communication device's mode or band of operation. A received signal is routed to an active path, which corresponds to the band of the received signal. A received signal is selectively switched to one or more switch outputs, which connect to one or more filters matched to the band of the received signal. After filtering, the signal is directly provided to an active amplifier. An amplifier is activated by a bias signal received from a shared bias circuit. The shared bias circuit generates a bias signal which is selectively switched to an amplifier associated with an active path.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: June 1, 2010
    Assignee: Skyworks Solutions, Inc.
    Inventors: Terrence John Shie, Russell David Wyse, Jinhua Zhong
  • Patent number: 7716402
    Abstract: A wireless USB hub for connecting a plurality of remote peripheral devices to a computer for communication therewith without the need to physically connect the peripheral devices to the hub via a cable connection. The wireless USB hub includes a receiver for receiving wireless data transmissions from one or more remote peripheral devices. The wireless USB hub further includes a hub controller for passing appropriate peripheral device information to a USB upstream port and then to a computer.
    Type: Grant
    Filed: May 12, 2008
    Date of Patent: May 11, 2010
    Inventors: Henry Milan, Rodney Haas
  • Patent number: 7684775
    Abstract: A radio frequency receiver 30, 32, includes a first component block 12, 16, 18, 20; a second compensating component block 22, 22a-22b, 34; and control circuitry 26 operable for controlling the state (e.g., load, bias, gain) of the first component block. When the control circuitry 26 causes a change in the state of the first component block that is expected to induce a DC offset in a signal, the control circuitry 26 changes the state of the second component block to compensate for an estimate of the DC offset. Preferably, the second component block is a filter 22, 22a-22b, 34, that temporarily changes from a nominal cutoff frequency to an elevated cutoff frequency so that voltage will settle quickly and accurately at an estimated voltage, the estimated voltage being predetermined and based on the state change to the first component block. A method is also described for practicing the invention.
    Type: Grant
    Filed: November 20, 2006
    Date of Patent: March 23, 2010
    Assignee: Nokia Corporation
    Inventors: Jussi Vepsäläinen, Aarno Pärssinen, Pauli Seppinen, Mikael Gustafsson
  • Patent number: 7668519
    Abstract: A system, apparatus and/or method provides frequency response adjustment of an RF input filter of an RF tuner based on impedance of an antenna system that is providing reception of RF signals to the RF tuner. The frequency response adjustment is preferably accomplished dynamically and/or with respect to each frequency tuned. Particularly, the system, method and/or apparatus provides compensation at the RF tuner level for mistuning effects produced on the RF tuner by antenna system impedance presented at the antenna input that is other than a designed for impedance. Frequency response of an RF input filter for the RF tuner is electronically adjustable with an independent or semi-independent control voltage signal based on one or more measured parameters of a tuning frequency. Frequency response adjustment may include adjustment of a center frequency of the RF input filter bandpass frequency range and/or altering the bandpass frequency range of the RF input filter.
    Type: Grant
    Filed: April 25, 2003
    Date of Patent: February 23, 2010
    Assignee: Thomson Licensing
    Inventors: Michael Anthony Pugel, Kumar Ramaswamy
  • Patent number: 7653368
    Abstract: Briefly, a radio receiver architecture and a method of measuring a power of a received signal to provide a first measurement, measuring a power of an assigned channel signal to provide a second measurement and adjusting a power of an input signal of an analog to digital converter according to a difference between the first and second power measurements.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: January 26, 2010
    Assignee: Intel Corporation
    Inventor: Rony Ashkenazi