With Specified Local Oscillator Structure Or Coupling Patents (Class 455/318)
  • Patent number: 7319849
    Abstract: A system for tuning a radio-frequency signal includes a first input path, a second input path, a common reference generator, a selector, a mixer, and a filter. The first input path and the second input path propagate a first single-ended input signal and a second single-ended input signal, respectively, to the selector. The selector converts the first single-ended input signal and the second single-ended input signal into a first differential input signal and a second differential input signal, respectively, using a reference signal generated by the common reference generator. The selector selectively couples one of the first and the second input path to an input of the mixer. The mixer downconverts a selected on of the differential input signals received from the selector. The filter attenuates a portion of the downconverted input signal outside a passband associated with the filter.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: January 15, 2008
    Assignee: Microtune (Texas), L.P.
    Inventor: Michael D. Womac
  • Patent number: 7319366
    Abstract: A local oscillator without a frequency divider is provided. The local oscillator includes a quadrature voltage controlled oscillator generating I and Q signals having a frequency which is one-third of a local oscillation frequency, and a differential second-harmonic signal having a frequency which is two-thirds of the local oscillation frequency, a poly-phase filter converting the differential second-harmonic signal input from the quadrature voltage controlled oscillator into I and Q signals, and a single side band (SSB) mixer receiving the I and Q signals having the frequency which is one-third of the local oscillation frequency from the quadrature voltage controlled oscillator as an input and receiving the I and Q signals having the frequency which is two-thirds of the local oscillation frequency from the poly-phase filter as an input, and outputting the I and Q signals having the local oscillation frequency.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: January 15, 2008
    Assignee: Research and Industrial Cooperation Group
    Inventors: Nam-Jin Oh, Sang-Gug Lee
  • Publication number: 20080009259
    Abstract: A frequency-converting circuit and a down converter with the frequency-converting circuit are disclosed. The above-mentioned frequency-converting circuit is used for converting an RF signal into a first baseband signal according to a poly-phase LO signal. The frequency-converting circuit includes a coupler, a first transduction unit and a first switching unit. The coupler is for receiving and splitting the RF signal and delivering a first RF signal via the first output terminal thereof. The first transduction unit is for amplifying the first RF signal. The first switching unit is for performing switching operations on the output signal of the first transduction unit and producing the first baseband signal.
    Type: Application
    Filed: July 10, 2006
    Publication date: January 10, 2008
    Inventors: Jen-Chung Chang, Chia-Jung Hsu, Shey-Shi Lu, Hsiao-Chin Chen, Yu-Yee Liow
  • Patent number: 7312669
    Abstract: An oscillation circuit for generating two oscillation signals having a phase difference of 90° by using an LC oscillator has a disadvantage for integration. Therefore, a differential type ring oscillator comprising interpolation type delay circuits of four stages is used as an original oscillator without using any LC oscillator. The oscillation frequency of the original oscillator is set to f/2. Intermediate signals S(k) having a phase difference of 45(k?1)° with respect to a reference phase are obtained as the outputs of the respective stages of the original oscillator. A multiplying circuit 22 generates the product signal of S(2) and S(4) in mixers. This product signal is vibrated at cos (ft/2), and the output signal Vout1 is generated on the basis of the product signal. A multiplying circuit generates the product signal of S(1) and S(3) in mixers. This product signal is vibrated at cos(ft/2+?/2), and the output signal Vout2 is generated on the basis of the product signal.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: December 25, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masaki Kinoshita, Takashi Kamimura
  • Patent number: 7302248
    Abstract: A signal generator for generating signals that are spaced ?/X rad apart, where X is an integer. The signal generator includes at least one delay cell with a delay that approximately corresponds to a phase shift ?/X rad for a given signal. The signal generator also includes at least one phase detection system receiving at least two signals with a phase difference of approximately ?/2 rad with respect to one another from said at least one delay cell and generating a feedback signal that is communicated to the at least one delay cell to adjust the phase relationship of the at least two signals. Such signal generators are used in radio frequency up-converters or down-converters.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: November 27, 2007
    Assignee: Interuniversitair Microelektronica Centrum (IMEC)
    Inventor: Jan Craninckx
  • Patent number: 7299028
    Abstract: A latch driver circuit is provided as a local oscillator driver for driving a passive mixer of an RF receiver. The driver circuit includes a differential amplifier stage coupled to a supply and a biasing circuit. The amplifier stage is operative to receive and process first and second input signals from a local oscillator for providing first and second amplified signals. The driver circuit further includes a latch stage coupled to the differential amplifier stage, which is operative to receive and process the first and second amplified signals for providing latched versions thereof. A filtering stage of the latch driver circuit is operative to receive and filter the latched versions of the first and second amplified signals for providing first and second mixer signals. Each of the first and second mixer signals includes signal content associated with a fundamental frequency particularly tuned for driving the passive mixer circuit.
    Type: Grant
    Filed: January 21, 2005
    Date of Patent: November 20, 2007
    Assignee: United States of America as represented by the Secretary of the Air Force
    Inventor: Helen Kim
  • Patent number: 7277683
    Abstract: The present invention relates generally to communications, and more specifically to a method and apparatus for generating local oscillator signals used for up- and down-conversion of RF (radio frequency) signals. A major problem in the design of modulators and demodulators, if the leakage of local oscillator (LO) signals into the received signal path. The invention presents a number of highly integratable circuits which resolve the LO leakage problem, using regenerative divider circuits acting on oscillator signals which are running at a multiple or fraction of the frequency of the desired LO signal, to generate in-phase (I) and quadrature (Q) mixing signals. Embodiments of these circuits also use harmonic subtraction and polyphase mixers, as well as virtual local oscillator TM (VLO) mixing signals. VLO mixing signals are signal pairs which emulate local oscillator signals by means of complementary mono-tonal and multi-tonal mixing signals.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: October 2, 2007
    Assignee: Sirific Wireless Corporation
    Inventors: Sathwant Dosanjh, William Kung, Tajinder Manku
  • Patent number: 7272170
    Abstract: A frequency plan is provided for particular use in a transceiver. Advantageously, a single oscillator may be used to generate desired frequency signal. One or more power splitters receive the signal and equally divide the signal into first and second signals having a frequency substantially equal to the original. Multipliers on each arm of the transceiver receive a signal and increase the frequency of the signal. Ultimately, multiple signals having different frequencies may be transmitted over the same cable due in part to the generated frequency separation between the signals. In one particular aspect, the frequency plan provides a two-thirds relationship between the frequencies of the multiple signals.
    Type: Grant
    Filed: February 6, 2006
    Date of Patent: September 18, 2007
    Assignee: U.S. Monolithics, L.L.C.
    Inventor: Dean Lawrence Cook
  • Patent number: 7266352
    Abstract: Multistage RF transmitter and receiver circuits may use independently variable RF and IF local oscillators, allowing the RF and IF local oscillator frequencies for a given RF channel to be selected to have a large common factor with respect to the reference oscillator used by the local oscillator circuits, thus allowing the use of small divisor numbers in the local oscillator circuits and reducing phase noise. Independent high-side and low-side RF local oscillators may be provided and selectively used depending on the RF channel to be transmitted or received.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: September 4, 2007
    Assignee: Wionics Research
    Inventors: Zaw Min Soe, Tony Yang, Jackie Cheng, Sining Zhou, Kuangyu Li, Fei-Ran Yang, Shoufang Chen, Tom Baker
  • Patent number: 7248850
    Abstract: A mixer design is described that permits greater integration on standard silicon chips with an improvement in power and linearity compared to previous mixer designs, enabling low-power, high performance RF reception.
    Type: Grant
    Filed: December 5, 2003
    Date of Patent: July 24, 2007
    Assignee: NanoAmp Solutions, Inc.
    Inventor: David H. Shen
  • Patent number: 7231192
    Abstract: A high frequency receiver of the present invention has a mixer of which one input part is connected to an output part of a filter and the other input part is connected to an output part of a frequency-variable local oscillator, and an output terminal connected to an output part of the mixer. The mixer is an image rejection mixer. The filter has a moderated damping characteristic in a frequency where the image rejection mixer reduces an image. Therefore, a high performance filter is not required, and hence a low price is realized.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: June 12, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masanori Suzuki, Koji Nakatsuji, Sanae Asayama, Atsuhito Terao, Kazutoshi Sato
  • Patent number: 7224951
    Abstract: A device and a method for processing high data rate serial data includes circuitry for recovering a clock based on the high data rate input data stream. A transceiver includes a coarse loop of a phase-locked loop that selectively provides a clock having accuracy that is within a specified amount. In a sample mode of operation, only the coarse loop PLL is coupled to provide an error signal from which an oscillation signal and clock may be derived. In a second mode (lock) of operation, the transceiver may lock to the received serial data stream by coupling the fine loop PLL to provide an adjusted error signal. In a third mode of operation, (automatic) the transceiver initially performs coarse loop calibration by de-coupling the fine loop PLL and coupling the coarse loop PLL until a steady state has been reached.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: May 29, 2007
    Assignee: Xilinx, Inc.
    Inventors: Jerry Chuang, William C. Black, Scott A. Irwin
  • Patent number: 7224235
    Abstract: A local oscillator (LO) generator for driving a bank of mixers that provides precise phase relationship between multi-phase LO outputs comprises a shift register using slave-master-slave flip-flop elements. The LO generator can be used over a wide operating frequency range. The LO generator is suitable for driving a multi-phase LO clock input to a harmonic suppression mixer. A pattern generator produces a pattern signal and a reclocking signal that determines the frequency of the LO signals and the phase delay between the LO output phases.
    Type: Grant
    Filed: September 6, 2005
    Date of Patent: May 29, 2007
    Assignee: RF Magic, Inc.
    Inventors: Carl De Ranter, Peter Jivan Shah
  • Patent number: 7218179
    Abstract: In one embodiment of the present invention, an apparatus includes a plurality of gain stages each having a gain greater than one, and which are coupled to create a positive feedback at an oscillation frequency. The gain stages may be formed of transconductance gain stages which may be coupled together as a ring oscillator or a latch type circuit. Such circuits may be used as calibration circuits in which small signal parameters of the gain stages are directly calibrated, and are used in turn to directly calibrate small signal parameters of a target circuit.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: May 15, 2007
    Assignee: Silicon Laboratories Inc.
    Inventor: Philip Crawley
  • Patent number: 7205857
    Abstract: An oscillator that provides a quadrature output and has a cross-coupled configuration is disclosed. The oscillator generates an output signal having a frequency. Two phase shift circuits, or stages, are activated by a control signal to provide phase shifts within the oscillator. Each phase shift circuit includes poles to provide the phase shift. A pole includes a varactor to tune, adjust or vary the phase shift accordingly.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: April 17, 2007
    Assignee: Broadcom Corporation
    Inventor: Hung-Ming Chien
  • Patent number: 7206565
    Abstract: The present invention relate to a wideband frequency generating apparatus using a frequency dividing method of dividing a frequency signal of a voltage control oscillator to expand a frequency generating range.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: April 17, 2007
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Seung Min Oh, Hyo Seok Kwon, Yoo Sam Na, Gi Won Choi
  • Patent number: 7203457
    Abstract: A method and apparatus for compensating for frequency drift in an LNB by storing the frequency offset of each LNB with respect to each channel. When a channel is selected, a particular LNB is activated and the table of offset values is consulted. The offset value for the LNB and channel is used to tune the LNB to a frequency that is appropriate for receiving the selected channel.
    Type: Grant
    Filed: July 19, 2000
    Date of Patent: April 10, 2007
    Assignee: Thomson Licensing
    Inventor: Daniel Thomas Wetzel
  • Patent number: 7203475
    Abstract: A local oscillation generator includes a clock circuit, a first divide module, a first mixing module, a second divide module, and a second mixing module. The clock circuit is operably coupled to generate a first clock signal. The first divide module is operably coupled to divide rate of the first clock signal by a first factor to produce a second clock signal. The first mixing module is operably coupled to mix the first clock signal and the second clock signal to produce a first local oscillation. The second divide module is operably coupled to divide rate of the second clock signal by a second factor to produce a third clock signal. The second mixing module is operably coupled to mix the first clock signal and the third clock signal to produce a second local oscillation.
    Type: Grant
    Filed: October 5, 2004
    Date of Patent: April 10, 2007
    Assignee: Broadcom Corporation
    Inventor: Seema B. Anand
  • Patent number: 7194245
    Abstract: A high-frequency signal receiver includes a mixer having one port for receiving an input signal and another port for receiving an output from a local oscillator, a filter for receiving an output from the mixer, and an output terminal to which an output from the filter is supplied. At least the mixer and the filter are formed of balanced circuits, so that they have high capability of eliminating interference. Distances between the circuits thus can be short. Further, partition plates for shielding the interference are not needed, thus allowing the receiver to be small.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: March 20, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshihiro Furusawa, Akira Fujishima, Hirotoshi Takeuchi
  • Patent number: 7190942
    Abstract: Disclosed are systems and methods which provide phase shifting of signals while minimizing signal attenuation associated with providing such phase shifting. Preferred embodiments provide a compact polyphase filter structure in which the geometry of the polyphase filter both minimizes parasitic capacitance and signal transmission paths therein. A polyphase filter of a preferred embodiment utilizes a radial pinwheel structure providing a geometry in which successive circuit components are disposed very near one another and in an orientation to accommodate very short connections therebetween. Embodiments may include the use of a buffer at the outputs of the polyphase filter circuit to reduce the amount of parasitics associated with the polyphase filter.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: March 13, 2007
    Assignee: Microtune (Texas) L.P.
    Inventor: Benjamin E. Nise
  • Patent number: 7187917
    Abstract: A circuit provides a reduced harmonic content output signal OUTA and/or OUTB that is modulated according to an input signal 231. The circuit has an oscillator circuit 210 and a harmonic rejection mixer (HRM) 230. The oscillator circuit 210 includes at least one “circuit portion” (FIG. 2A) configured to receive first and second orthogonal oscillator input signals (two of I, I?, Q, Q?) having respective first and second phases, and to provide an arbitrarily large number of oscillator output signals (?M) having respective mutually distinct phases that are interpolated between the first and second phases. Harmonic rejection mixer 230 is configured to use the input signal to modulate a combination of the oscillator output signals, the oscillator output signals being respectively weighted so as to provide an emulated sinusoidal signal constituting the reduced harmonic content output signal.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: March 6, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Heng-Chih Lin, Ranjit Gharpurey
  • Patent number: 7177618
    Abstract: A low noise block down converter accommodates two local oscillators within one shielding chamber in a metal shielding box and has a conductive bar provided between two dielectric resonators included in the local oscillators respectively. The conductive bar prevents electromagnetic coupling between the two dielectric resonators. Therefore, the device dimension can be made small compared to the conventional case in which two local oscillators are completely separated from each other by a metal wall.
    Type: Grant
    Filed: August 18, 2003
    Date of Patent: February 13, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Koji Motoyama
  • Patent number: 7177591
    Abstract: In a frequency converter, a phase-locked loop generates a local-oscillation signal having a low frequency, of a plurality of local-oscillation signals having different frequencies, based on an intermediate frequency beacon signal that results from mixing a predetermined beacon signal with the local-oscillation frequency signal. Even if the phase-locked loop is used to generate the low frequency local-oscillation signal only, a frequency offset and a phase noise taking place in remaining high frequency local-oscillation signals are compensated for or canceled out. The frequency converter thus results in a high frequency accuracy. This arrangement reduces the number of bulky, costly and power-consuming phase-locked oscillators, typically used in the quasi millimeter band or the millimeter band. A simplified, compact frequency converter is thus provided, reducing both installation and operating costs.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: February 13, 2007
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Koyo Kegasa, Chitaka Manabe, Takuya Kusaka, Yuichiro Goto, Koji Inoue
  • Patent number: 7171173
    Abstract: With a redundant GPS antenna splitter two GPS antennas are connected through an amplifier to a passive antenna splitter in parallel feeding mode, whereby the direct current supply of the antennas is provided by a DC driver stage, whose inputs (DC1 to DC8) are coupled with outputs of the antenna splitter of the connected transmitters in order to control the power supply with current measuring stages depending on the operating condition of the GPS antennas and to deliver a supply voltage both to the GPS antenna and HF-amplifier, if the antenna is active.
    Type: Grant
    Filed: July 1, 2002
    Date of Patent: January 30, 2007
    Assignee: Harris Communications Austria GmbH
    Inventor: Bernhard Zangerl
  • Patent number: 7164895
    Abstract: A multi-band receiver in which characteristics including a tracking error are improved is provided with a variable frequency oscillator circuit, a variable divider circuit (39) for dividing an oscillation signal (SVCO) of the variable frequency oscillator circuit, and mixer circuits (15I) and (15Q) for subjecting a received signal SRX to frequency conversion into an intermediate frequency signal (SIF) by a local oscillation signal (SLO). A divided output of the variable divider circuit (39) is supplied as the local oscillation signal (SLO) to each of the mixer circuits (15I) and (15Q). When a signal in a first frequency band is received, the division ratio n of the variable divider circuit (39) and the oscillation frequency of the variable frequency oscillator are changed to change the reception frequency in the first frequency band.
    Type: Grant
    Filed: June 4, 2002
    Date of Patent: January 16, 2007
    Assignee: Sony Corporation
    Inventor: Taiwa Okanobu
  • Patent number: 7164900
    Abstract: An impulse waveform generating apparatus comprises an oscillator for generating a reference signal having a center frequency in a frequency band of an impulse to generate, a timing matching circuit for shifting a phase of the reference signal by 90 degrees, a frequency demuultiplier for dividing a frequency of the phase shift signal and obtaining a timing signal having a frequency component having a frequency width of an impulse to generate, a memory storing a waveform shape table, a waveform forming section for forming a waveform in synchronism with the timing signal, according to information of a shape table having a predetermined waveform, a low-pass filter for obtaining an envelope signal from an output signal of the waveform forming section, and a waveform generating section for changing an amplitude of the reference signal according to a value of the envelope signal.
    Type: Grant
    Filed: May 7, 2004
    Date of Patent: January 16, 2007
    Inventors: Masahiro Mimura, Suguru Fujita, Kazuaki Takahashi
  • Patent number: 7164329
    Abstract: The present invention provides a phase shifting filter and a phase compensating direct downconversion receiver. A DC offset detector detects a DC offset in a received baseband signal and provides a feedback signal. A tunable filter phase shifts a local oscillator signal responsive to the feedback signal. The phase-shifted local oscillator signal is used to directly downconvert a received RF signal, whereby DC offset in the resulting baseband signal is reduced.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: January 16, 2007
    Assignee: Kyocera Wireless Corp.
    Inventors: Stanley S. Toncich, Raymond Curtis Wallace
  • Patent number: 7155176
    Abstract: A system for synchronizing a portable transceiver to a network is disclosed. Embodiments of the system for synchronizing a portable transceiver to a network include a crystal oscillator, a frequency synthesizer adapted to receive an output of the crystal oscillator, logic coupled to the crystal oscillator, the logic configured to estimate a frequency error of a received signal; and a first control signal supplied from the logic to the frequency synthesizer, the first control signal configured to adjust the frequency synthesizer to compensate for the error.
    Type: Grant
    Filed: April 8, 2004
    Date of Patent: December 26, 2006
    Assignee: Skyworks Solutions, Inc.
    Inventors: Jaleh Komaili, Darioush Agahi, Ricke W. Clark
  • Patent number: 7155194
    Abstract: A frequency conversion apparatus for converting an input signal having an input frequency into an output signal having an output frequency. The frequency conversion apparatus includes a first multiplier and a gm stage. The first multiplier multiplies a first local signal having a first frequency with a second local signal having a second frequency to generate a differential current signal having a third frequency. The third frequency is substantially the same as the input frequency or the output frequency, and the first frequency and the second frequency are different from the input frequency or the output frequency. The gm stage is electrically connected to the first multiplier and receives the differential current signal and the input signal to generate the output signal.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: December 26, 2006
    Assignee: Mediatek Incorporation
    Inventors: Chinq-Shiun Chiu, Kuang-Kai Teng
  • Patent number: 7146149
    Abstract: A local oscillator (LO) circuit is disclosed which provides improved isolation between the unselected LO source and a mixer. The LO circuit includes a first LO source to generate a first periodic signal cycling at a first frequency, a second LO source to generate a second periodic signal cycling at a second frequency different than the first frequency, a limiter, a first switching element to selectively couple the first LO source to the limiter, and a second switching element to selectively couple the second LO source to the limiter. The limiter improves the isolation of the leakage LO signal (i.e. the unselected LO signal) with respect to the selected LO signal. The improved isolation comes about because the limiter gain associated with the selected LO signal is greater than the gain associated with the leakage LO signal. A receiver and transmitter using the LO circuit are also disclosed.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: December 5, 2006
    Assignee: Maxim Integrated Products, Inc.
    Inventor: Kathiravan Krishnamurthi
  • Patent number: 7139548
    Abstract: A semiconductor integrated circuit device has an oscillation circuit using either an oscillator or an oscillation module, as an external part of a reference oscillation circuit. Two external terminals are provided in correspondence with the oscillation circuit. A control terminal (base terminal) of a transistor of the oscillation circuit is connected to one external terminal, and part of an output of the transistor is fed back to the control terminal. The other external terminal is connected to a power source voltage terminal via a resistive element of a high resistance value. Capacitor elements are connected between the two external terminals. When an oscillator is connected to the one of the external terminals, the other external terminal is fixed to a constant potential. When an electronic part for oscillation (oscillation module) is connected, the other external terminal is set into an open state.
    Type: Grant
    Filed: October 23, 2003
    Date of Patent: November 21, 2006
    Assignee: Renesas Technology Corp.
    Inventors: Norio Hayashi, Jiro Shinbo
  • Patent number: 7133690
    Abstract: A method and corresponding equipment for communicating from a Node B (10) to a UE device (11) a data rate pointer (11a) value indicating a new maximum allowed data rate in case of a current low value for the data rate pointer (11a), based on predetermined rules governing signaling to change the data rate pointer and used by the Node B (10) in responding to a change request from the UE device (11), rules that differ for different current values of the data rate pointer (11a), and in particular rules that allow for a fast ramp up in case of a current value of zero or less than a threshold.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: November 7, 2006
    Assignee: Nokia Corporation
    Inventors: Karri Ranta-Aho, Tero Henttonen
  • Patent number: 7130599
    Abstract: In an exemplary application, an apparatus according to a disclosed embodiment receives a radio frequency signal and outputs an intermediate frequency signal. Rejection of image components in the intermediate frequency signal is obtained without the need to preprocess the radio frequency signal with an image reject filter. Such an apparatus may also exhibit an image rejection performance that is robust to frequency deviation of a local oscillator.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: October 31, 2006
    Assignee: Qualcomm Inc.
    Inventors: Charles J. Persico, James Jaffee, Steven C. Ciccarelli
  • Patent number: 7130604
    Abstract: A radio frequency (RF) demodulation circuit comprising a harmonic rejection mixing stage capable of receiving and mixing an incoming radio frequency (RF) signal having a frequency RF and a reference local oscillator (LO) signal having a frequency LO and generating an output signal in which out-of-band harmonic signals are suppressed. The harmonic rejection mixing stage comprises 1) a multiphase local oscillator (LO) generator for receiving the reference LO signal and generating M phase-shifted local oscillator signals having frequencies LO and 2) M mixers, each of the M mixers receiving the incoming radio frequency signal and one of the M phase-shifted local oscillator signals. Each of the M mixers generates a subcomponent signal. The subcomponent signals are then scaled and combined to produce the output signal.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: October 31, 2006
    Assignee: National Semiconductor Corporation
    Inventors: Hee Wong, Shu-Ing Ju, Michael Schwartz, Robert K. Butler
  • Patent number: 7123891
    Abstract: A wireless communications device includes an antenna that receives a first signal at a first frequency and a second signal at a second frequency and converts the first and second signals into a composite signal. A first oscillator outputs a first oscillator signal at a first frequency and a second oscillator outputs a second oscillator signal at a second frequency. A demodulator receives the composite signal and the first and second oscillator signals. The oscillator signals are selected so that the demodulator generates a low frequency signal with components of the first and second signals occupying a common frequency band. The wireless communications device allows executing a “Soft Handoff” even when the first and second frequencies are different.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: October 17, 2006
    Assignee: Skyworks Solutions, Inc.
    Inventor: Aravind Loke
  • Patent number: 7120414
    Abstract: A frequency mixing circuit and a frequency mixing method. The frequency mixing circuit includes first and second differential amplifiers, a subtracter and a mixer. The first differential amplifier amplifies a first pair of input signals having a first frequency to generate a first differential signal. The second differential amplifier amplifies a second pair of input signals having the first frequency orthogonal to the first pair input signals to generate a second differential signal. The subtracter subtracts the second differential signal from the first differential signal. The mixer mixes the subtracted signal with a first and second pairs of drive signals having a second frequency orthogonal to each other, in a sub-harmonic double balanced mixing mode, so that the mixer generates a pair of output signals orthogonal to each other without secondary harmonics.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: October 10, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young-Jin Kim, In-Chul Hwang
  • Patent number: 7099646
    Abstract: A single-ended-to-differential mixer includes a differential input circuit having a single-ended input. The differential input circuit is responsive to a single-ended input signal to generate first and second signals. The single-ended-to-differential mixer includes a passive tank circuit in communication between a reference voltage and the differential input circuit. The single-ended-to-differential mixer includes a mixer circuit in communication with the differential input circuit and responsive to the first and second signals and a second input signal to generate a differential mixer output signal.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: August 29, 2006
    Assignee: Marvell International Ltd.
    Inventors: Xiaodong Jin, Lawrence Tse
  • Patent number: 7095989
    Abstract: A frequency translating device (FTD) includes at least one mixer diode connected to down-convert a radio frequency (RF) to an intermediate frequency (IF) and to up-convert an IF to an RF and a source of direct current (DC) bias that is connected to the mixer diode. The source of DC bias provides DC bias to the mixer diode that moves the voltage applied to the mixer diode closer to the threshold voltage of the mixer diode. The mixer diode is turned on in response to the DC bias and a local oscillator (LO) drive. Because DC bias is applied to the mixer diode, the peak to peak voltage range of the LO drive can be reduced, thereby reducing the voltage-dependent capacitance of the mixer diode, causing the FTD to exhibit improved reciprocity. The FTD can be used in a three-pair measurement system to determine the conversion response of another FTD.
    Type: Grant
    Filed: August 28, 2001
    Date of Patent: August 22, 2006
    Assignee: Agilent Technologies, Inc.
    Inventor: Richard K. Karlquist
  • Patent number: 7092687
    Abstract: An apparatus for a direct down-conversion of modulated RF signals, the device including: a first power detector connected between an input port for the modulated RF signal and ground, which outputs a first DC signal, a second power detector connected between an input port for a local oscillator signal and ground, which outputs a second DC signal, the local oscillator signal having the same center frequency as the modulated RF signal, and a third power detector connected between the input port for the modulated RF signal and the input port for the local oscillator signal, which outputs a third DC signal.
    Type: Grant
    Filed: January 17, 2003
    Date of Patent: August 15, 2006
    Assignee: SONY International (Europe) GmbH
    Inventors: Dragan Krupezevic, Mohamed Ratni, Veselin Brankovic
  • Patent number: 7088981
    Abstract: A differential mixer includes DC currents that reduce flicker noise in the mixer circuit without increasing local oscillator drive requirements. The differential mixer circuit includes an RF transconductance circuit and a local oscillator (LO) switching circuit. The RF transconductance circuit converts a differential RF input signal to a differential RF current. The LO switching circuit commutates the differential RF input signal according to a local oscillator signal to frequency translate the RF input signal. The DC currents or bleeder currents are added directly to the field effect transistors in the RF transconductance circuit, which reduces the flicker noise produced by the mixer. The DC currents do not pass through the FETs in the LO switching circuit so there is no increase in the LO drive requirements.
    Type: Grant
    Filed: November 29, 2001
    Date of Patent: August 8, 2006
    Assignee: Broadcom Corporation
    Inventor: James Y. C. Chang
  • Patent number: 7088973
    Abstract: A wireless communications device includes an antenna that receives a first signal at a first frequency and a second signal at a second frequency and converts the first and second signals into a composite signal. A first oscillator outputs a first oscillator signal at a first frequency and a second oscillator outputs a second oscillator signal at a second frequency. A demodulator receives the composite signal and the first and second oscillator signals. The oscillator signals are selected so that the demodulator generates a low frequency signal with components of the first and second signals occupying a common frequency band. The wireless communications device allows executing a “Soft Handoff” even when the first and second frequencies are different.
    Type: Grant
    Filed: April 22, 2004
    Date of Patent: August 8, 2006
    Assignee: Skyworks Solutions, Inc.
    Inventor: Aravind Loke
  • Patent number: 7065329
    Abstract: A half duplex radio transceiver comprises a transmitter (100) and a low IF receiver (200). The difference between the transmit frequency and the receive frequency is equal to the low IF. A common frequency generator (300) is shared between the transmitter and receiver without needing to be retuned. An upconversion signal at the transmit frequency is used for down conversion in the receiver. Transceivers at opposite ends of a communication link, such as in a master/slave network, have their transmit and receive frequencies interchanged. Optionally a transceiver may be configurable to either form e.g. as either a master of a slave station. Channel sensing for Carrier Sense Multiple Access (CSMA) may be performed on the transmit frequency without retuning the receiver.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: June 20, 2006
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Christopher B. Marshall
  • Patent number: 7046122
    Abstract: A detector receiver circuit for use as a wake-up detector for detecting an amplitude modulated carrier signal includes an antenna for receiving the modulated carrier signal; and a transistor, such as an FET, which is connected to the antenna and configured to operate as a detector of modulation of the carrier frequency. The circuit further comprises a resonator circuit which is also connected to the transistor and configured such that the transistor can simultaneously oscillate at substantially the modulation frequency; and an oscillator quenching circuit for periodically quenching oscillation of the transistor. The characteristics of the build-up of oscillation are sensed to indicate the presence of a modulated carrier signal. How quickly the magnitude of oscillation of the transistor builds up is dependent on whether the antenna is receiving a carrier signal which is modulated at the frequency of self-oscillation of the transistor, which is utilized to detect for the presence of a valid wake-up signal.
    Type: Grant
    Filed: November 4, 1999
    Date of Patent: May 16, 2006
    Inventor: Ian J Forster
  • Patent number: 7039129
    Abstract: The present invention relates to an I/Q demodulator (21) comprising a n-port structure (1,16) is provided, wherein n is an integer value of 4,5 or 6. The demodulator (21) is supplied at a first input (3) with a RF signal (2) which has to be demodulated. At a second input (5) it is supplied with a second RF signal (4). The n?2 output signals (6) are detected by power sensors (7). After low pass filtering (14) the output signals of the power sensors (7) are multiplexed by a multiplexing means (8).
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: May 2, 2006
    Assignees: Sony International (Europe) GmbH, Sony Corporation
    Inventors: Mohamed Ratni, Dragan Krupezevic, Veselin Brankovic, Masayoshi Abe, Noboru Sasho
  • Patent number: 7039383
    Abstract: In a quadrature mixer circuit for receiving a radio frequency signal to generate first and second quadrature output signals, a first three-input mixer receives the radio frequency signal, a first local signal having a first frequency and a second local signal having a second frequency to generate the first quadrature output signal, and a second three-input mixer receives the radio frequency signal, the first local signal and the second local signal to generate the second quadrature output signal. The second local signal received by the first three-input mixer and the second local signal received by the second three-input mixer being out of phase by ?/2 from each other.
    Type: Grant
    Filed: December 3, 2002
    Date of Patent: May 2, 2006
    Assignee: NEC Electronics Corporation
    Inventor: Katsuji Kimura
  • Patent number: 7039384
    Abstract: A low power supply band-gap current reference includes a 1st P-N junction device, a 2nd and P-N junction device, a 1st current source, a 2nd current source, a 1st resistor, a 2nd resistor, a 3rd resistor, an operational amplifier, and a current mirror. The 1st and 2nd P-N junction devices are operably coupled to the 1st and 2nd current sources, respectively. The 2nd P-N junction device is a larger device than the 1st P-N junction device. The 2nd resistor is operably coupled in parallel with the 1st P-N junction device and the 2nd resistor is coupled in series with the 2nd P-N junction device. The 3rd resistor is coupled in parallel with the series combination of the 2nd resistor and 2nd P-N junction device. The operational amplifier is coupled to control the 1st and 2nd current sources based on the voltage imposed across the 1st and 2nd resistors. The current mirror is operably coupled to mirror the current of the 1st and/or 2nd current source to provide a band-gap reference current.
    Type: Grant
    Filed: June 12, 2003
    Date of Patent: May 2, 2006
    Assignee: Broadcom Corporation
    Inventor: Meng-An (Michael) Pan
  • Patent number: 7031688
    Abstract: A system and method are provided for direct-conversion of a modulated radio-frequency (RF) signal. After receiving an RF signal, the RF signal is mixed with a plurality of oscillator signals with different phases in an interleaving manner.
    Type: Grant
    Filed: March 22, 2004
    Date of Patent: April 18, 2006
    Assignee: Quorum Systems, Inc.
    Inventors: Lawrence J. Malone, Lon W. Christensen
  • Patent number: 7027833
    Abstract: A MMIC based superheterodyne receiver for converting at RF energy in an upper and a lower frequency band includes at least one attenuator for the RF energy input, a mixer for mixing the lower band input with a LO1 signal, another mixer for mixing the upper band input with the LO1 signal signal, a switch to direct the LO1 signal to the first mixer or to the second mixer, and a third mixer for mixing a LO2 signal with the first stage mixer output to produce a signal at the output frequency. Passband filters at the outputs of the mixers can reject interfering mixer-generated frequencies. Input frequency range can span 0.1 to 18 GHz with a 160 MHz or 1 GHz output. A modular receiver can have two or more converter modules for each LO module. The receiver can receive antenna input directly, without pre-mixing filtering or attenuating.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: April 11, 2006
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Daniel J. Goodman
  • Patent number: 7027793
    Abstract: Techniques to reduce LO leakage by controlling the amplitude of LO signal based on the level of output signal after the frequency conversion process. An LO generator receives a VCO signal and generates an LO signal having a variable amplitude and a frequency that is related to the frequency of the VCO signal. A variable gain amplifier receives a control signal and adjusts the amplitude of the LO signal based on the control signal. The variable amplitude LO signal is used for frequency upconversion (e.g., direction upconversion) of an input signal (e.g., at baseband) to obtain an output signal (e.g., at RF). The relationship between LO signal amplitude and output signal level may be defined by a particular transfer function. In general, the LO signal is set higher for higher output signal level and is reduced proportionally for lower output signal level.
    Type: Grant
    Filed: November 15, 2002
    Date of Patent: April 11, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Kevin Gard, Anthony Segoria, Gurkanwal (Kamal) Sahota, Charles Persico
  • Patent number: 7024220
    Abstract: GPS functionality is added to a wireless communication device in an efficient and cost effective manner. Briefly, the present invention has a common mixer constructed to be used for a GPS signal and another signal or a common IF filter constructed to be used for a GPS signal and another signal. In one embodiment, a common mixer and IF filter are used for both PCS and GPS signals. In another embodiment, a band select switch may be used to select either the PCS signal or the GPS signal. Alternatively, a duplexer or diplexer may couple the GPS signal and the PCS signal to the common mixer. In this way, a common mixer is enabled to be used for both GPS and PCS. A dual band local oscillator may be configured to output a local oscillator signal facilitating selection of a GPS IF signal, a PCS IF signal or a cellular CDMA IF signal, using a common IF filter.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: April 4, 2006
    Assignee: Kyocera Wireless Corp.
    Inventor: Tim Forrester