With Frequency Control Patents (Class 455/113)
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Patent number: 7174139Abstract: A relative delay between analog R.F. output signals of a plurality of digital radio transmitters in a digital radio transmitter system is controlled. At least one interface receives delay information for each transmitter. A processing unit determines the relative delay between the output signals based on the received delay information. An adjuster adjusts in the digital domain the absolute delay of at least one of the radio transmitters in accordance with the determined relative delay.Type: GrantFiled: October 11, 2001Date of Patent: February 6, 2007Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Dietmar Lipka, Bojidar Hadjiski
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Patent number: 7123890Abstract: A sample acquisition apparatus for sampling first and second signals within a signal processing arrangement, includes a sampler for capturing sections of the waveforms of both the first and second signals, a switch for alternating correction of the sampler to a point in the arrangement where said first signal can be sampled and a point in said arrangement where said second signal can be sampled. A timer for timing the operation of the switch to causes the sampler to capture a first waveform section of the first signal and a second waveform section of the second signal, wherein the second signal is responsive to the first signal and the timing of the switch is such that the second section includes a portion that has been generated in response to the first section.Type: GrantFiled: February 20, 2004Date of Patent: October 17, 2006Assignee: Andrew CorporationInventors: Peter Blakeborough Kenington, Jonathan Paul Rogers, John Bishop, Antony James Smithson
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Patent number: 7123666Abstract: A method and apparatus for generating a burst FSK signal having precisely shaped transitions between modulation states. The apparatus uses feedforward compensation of phase gain and phase preemphasis coefficients for compensating the frequency conversion gain of the apparatus, and the phase gain coefficient is used for stabilizing a frequency synthesis loop. The phase gain and preemphasis coefficients are determined in a calibration within the time constraints of on-line signal bursts based upon measured phase errors and accelerated predicted phase gain and preemphasis phase errors.Type: GrantFiled: May 9, 2003Date of Patent: October 17, 2006Assignee: Texas Instruments IncorporatedInventors: James E. C. Brown, Bret Rothenberg, Chienkuo Vincent Tien
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Patent number: 7123665Abstract: A method and apparatus for generating a burst FSK signal having precisely shaped transitions between modulation states. The apparatus uses feedforward compensation of phase gain and phase preemphasis coefficients for compensating the frequency conversion gain of the apparatus, and the phase gain coefficient is used for stabilizing a frequency synthesis loop. The phase gain and preemphasis coefficients are determined in a calibration within the time constraints of on-line signal bursts based upon measured phase errors and accelerated predicted phase gain and preemphasis phase errors.Type: GrantFiled: May 9, 2003Date of Patent: October 17, 2006Assignee: Texas Instruments IncorporatedInventors: James E. C. Brown, Bret Rothenberg
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Patent number: 7120390Abstract: An offset history table is implemented and maintained in a BLUETOOTH device and is used to pre-seed an expected frequency offset of a received signal from another BLUETOOTH device. The disclosed offset history table includes one entry for each piconet device in a particular piconet, each entry including a best guess of the relevant piconet device's frequency offset with respect to the receiving BLUETOOTH device. Using a frequency offset history table and a pre-seeded frequency offset corresponding to an expected frequency offset based on the offset value maintained in the frequency offset history table, the performance of a BLUETOOTH device can be increased in a steady state piconet scenario.Type: GrantFiled: March 21, 2001Date of Patent: October 10, 2006Assignee: Agere Systems Inc.Inventors: Jeffrey P. Grundvig, Carl R. Stevenson
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Patent number: 7054606Abstract: An apparatus comprising a first circuit, a second circuit and a third circuit. The first circuit may be configured to filter an analog input signal in an analog domain in response to one or more control signals. The second circuit may be configured to convert the analog input signal to a digital signal. The third circuit may be configured to generate the control signals in response to the digital signal. The third circuit may also be configured to control skewing of the analog input signal within the first circuit to partially compensate for frequency dependent effects associated with a transmission medium.Type: GrantFiled: September 21, 2001Date of Patent: May 30, 2006Assignee: LSI Logic CorporationInventors: Samuel W. Sheng, Lapoe E. Lynn, Ivan C-Y Eng
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Patent number: 7031675Abstract: An FM transmitter that can control start/idle of each of such devices as a buffer amplifier without using a sample-and-hold circuit for moving a PLL into open loop control, wherein a controller that controls a charging pump in the PLL to start/idle the FM modulation is controlled with use of a closed/open loop select signal of the PLL, a start/idle signal of the buffer amplifier, and a preamble detection signal. The power consumption of the FM transmission can be reduced, since both the buffer amplifier and the PLL in the FM transmitter can be started/idled together in a ganged manner.Type: GrantFiled: February 7, 2002Date of Patent: April 18, 2006Assignee: Renesas Technology Corp.Inventor: Masaru Kokubo
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Patent number: 7031672Abstract: A system and method are provided for communicating a radio frequency (RF) signal. In use, a baseband signal is mixed with a plurality of oscillator signals with different phases in an interleaving manner. The mixed baseband signal is then communicated as an RF signal.Type: GrantFiled: March 22, 2004Date of Patent: April 18, 2006Assignee: Quorum Systems, inc.Inventors: Lawrence J. Malone, Lon W. Christensen
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Patent number: 7003273Abstract: A temperature compensating circuit is provided in a radio unit, an ambient temperature is detected by a temperature sensor of the temperature compensating circuit, the detected temperature value is supplied to a correction address storage section as an address after it is converted to a digital value, and thus a correction address corresponding to a correct temperature value obtained by correcting the detected temperature value is read out. Then, the correction address is supplied to a frequency correction data storage section to read out frequency correction data corresponding to the corrected temperature value, and the frequency correction data is converted to an analog control voltage by a D/A converter and then supplied to a variable capacitance element of a reference oscillator, thereby making it possible to correct the reference oscillation frequency according to the temperature.Type: GrantFiled: June 21, 2000Date of Patent: February 21, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Masanobu Shimanuki, Taku Hatsukano
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Patent number: 7003270Abstract: An electronic apparatus comprising a radio transmitter is disclosed. In a computer system (1) having a radio transmission circuit (3) of a phase modulation type supplied with power from a power supply (4) of a switching type, the switching frequency of the power supply (4) is determined based on the comparison frequency for the sampling operation of a PLL circuit (10) of the radio transmitter, thereby removing the power noises generated from the switching regulator of the radio transmitter of a phase modulation type.Type: GrantFiled: February 5, 2002Date of Patent: February 21, 2006Assignee: Fujitsu LimitedInventors: Nobuhide Maruo, Makoto Saotome, Makoto Kotani
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Patent number: 6985703Abstract: A direct synthesis transmitter. A very efficient and highly linear direct synthesis transmitter is provided that can be used to directly synthesize and transmit any type of modulated signal. The direct synthesis transmitter includes a phase-locked loop (PLL) with controls phase modulation plus an accompanying variable gain amplifier for amplitude modulation. Also included is a system to align the phase and amplitude modulation signals. A transmitter constructed in accordance with the present invention is very efficient and suitable for use in portable radio equipment.Type: GrantFiled: October 4, 2002Date of Patent: January 10, 2006Assignee: Sequoia CorporationInventors: John B. Groe, Joseph Austin, Naone Farias, Carrie Lo
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Patent number: 6983131Abstract: A circuit configuration for direction modulation contains an oscillator, whose output signal is split into quadrature components for modulation with a useful signal. A frequency shifting circuit has the effect that that the output frequency and the frequency of the oscillator are fractional rational multiples with respect to one another. The circuit contains a phase shifter for generating first further quadrature components and also a divider for generating second further quadrature components. The quadrature components are mixed with one another. As a result of the frequency offset, the oscillation frequency of the oscillator is shifted to outside the useful frequency band. Remodulation effects do not influence the adjacent channels. The circuit can be realized simply and cost-effectively and, in particular, requires only one oscillator.Type: GrantFiled: June 7, 2002Date of Patent: January 3, 2006Assignee: Infineon Technologies AGInventor: Werner Veit
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Patent number: 6933798Abstract: In the case of a trimming method for a PLL circuit operating based on the principle of a two-point modulation, the PLL circuit is locked without any modulation being impressed and then an analog and a digital modulation signal are impressed into the locked PLL circuit. A signal that is characteristic of the PLL control error is tapped from the PLL circuit, and the modulation swing in the analog modulation signal is changed such that the characteristic signal has the same value as before the analog and digital modulation signals were impressed.Type: GrantFiled: August 22, 2003Date of Patent: August 23, 2005Assignee: Infineon Technologies AGInventors: Markus Hammes, Stefan Van Waasen
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Patent number: 6915117Abstract: In a multiple stage transmitter, and analog signal is modulated and mixed to produce a radio frequency output. A separate mixing frequency signal is provided to each stage. A single frequency synthesizer is used rather than a plurality of frequency synthesizers. In a two-stage system, first and second dividers each receive the output of the frequency synthesizer and deliver a mixing signal to the first and second stages respectively. The modulus of each divider may be selected to minimize spurious signals.Type: GrantFiled: May 3, 2001Date of Patent: July 5, 2005Assignee: International Business Machines CorporationInventors: Paul P. Chominski, Jonathan L. Kennedy, Lawrence E. Larson, Joshua C. Park
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Patent number: 6882851Abstract: Systems and methods to enable different types of radio communication devices to communicate using a common language in order to enable the devices to regulate their use of the spectrum. Each device participating in the ad hoc control channel (ACC) protocol transmits information using a common signal format that each of the other participant devices is capable of recognizing, in order to share information about how it uses the radio frequency band. Each device receives the information transmitted by other participant devices and based on that information, controls one or more of its operational parameters that impact usage of the radio frequency band. The ACC protocol enables devices of the same or different type to harmonize (instead of alienate) themselves with each other by allowing them to communicate about their usage of the radio frequency band using a common signaling framework.Type: GrantFiled: March 20, 2003Date of Patent: April 19, 2005Assignee: Cognio, Inc.Inventors: Gary L. Sugar, Neil R. Diener
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Patent number: 6873831Abstract: An apparatus according to one embodiment of the invention includes a transmitter. The transmitter receives an RF signal and produces at least two modulated signals based on the RF signal. Each of the modulated signals is coupled to a respective antenna. The combined radiation pattern of the antennas varies in an angular direction over time. In a system according to one embodiment of the invention, a base station including such an apparatus receives channel quality indications from mobile units and schedules data transmissions to the mobile units accordingly.Type: GrantFiled: April 1, 2002Date of Patent: March 29, 2005Assignee: Qualcomm IncorporatedInventors: Rashid A. Attar, Charles E. Wheatley, III
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Patent number: 6873836Abstract: A communication system comprising a multi-protocol, multi-bearer sub-system is described herein. The sub-system is a universal platform module that can transmit and receive one or more information signals in one or more protocols using one or more bearer services. In one embodiment, the sub-system may form a portion of a transceiver that is composed of a transmitter and a receiver, and which is a gateway server between a personal area network (PAN) and the global wireless network.Type: GrantFiled: May 10, 2000Date of Patent: March 29, 2005Assignee: ParkerVision, Inc.Inventors: David F. Sorrells, Michael J. Bultman, Robert W. Cook, Richard C. Looke, Charley D. Moses, Jr.
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Patent number: 6868135Abstract: A method and apparatus for correcting for a phase shift between a transmitter and receiver comprising the steps of: a) transmitting a signal from a transmitter (14); b) receiving the transmitted signal (16) at a receiver (20); c) comparing the received signal (17) to a reference signal; d) if a difference between the reference signal and the received signal (17) is greater than a predetermined value go to step e), if not go to step g); e) adjusting a frequency of the transmitted signal (16); f) go to step a); and g) calibration complete.Type: GrantFiled: May 18, 2000Date of Patent: March 15, 2005Assignees: Eastman Kodak Company, Rochester Institute of TechnologyInventors: Daniel P. Phinney, Albert H. Titus
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Patent number: 6865399Abstract: In a mobile telephone apparatus corresponding to dual-band provided with an RF power module to operate in two kinds of different frequencies, a common harmonics control circuit is provided to the output circuit of such RF power module to realize higher efficiency in view of controlling respective harmonics power for both band frequencies. Moreover, a means for selectively setting the bias is also provided so that the maximum efficiency can be attained depending on the output power required with respective communication systems with the bias control signal output from the CPU of the control unit interlocking with selection of frequency of the mobile telephone apparatus body.Type: GrantFiled: February 5, 2002Date of Patent: March 8, 2005Assignee: Renesas Technology Corp.Inventors: Toru Fujioka, Isao Yoshida, Mineo Katsueda, Masatoshi Morikawa, Yoshikuni Matsunaga, Kenji Sekine, Osamu Kagaya
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Patent number: 6856791Abstract: An Automatic Frequency Control (AFC) circuit for a mobile terminal employs a fractional-N Phase Locked Loop (PLL) to directly reduce errors in the synthesized frequency, such as due to component tolerances, temperature drift, and the like. The frequency error is detected by the average speed of rotation of the I,Q constellation. A corresponding offset is added to the tuning frequency selection word prior to encoding, such as in a ?? modulator, to generate an effective non-integer PLL frequency division factor over a specified duration. The ?? modulator may include dithering the different integer values by a pseudo-random number to minimize noise in the output frequency spectrum introduced by the fractional-N division. Component and parameter selection allow a high degree of resolution in frequency control of the fractional-N PLL. By directly controlling for the frequency error, a DAC and XTAL oscillator tuning circuit may be eliminated from the AFC circuit.Type: GrantFiled: March 14, 2002Date of Patent: February 15, 2005Assignee: Ericsson Inc.Inventor: Nikolaus Klemmer
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Patent number: 6839548Abstract: A radio communication device modulates a received audio signal with an intermediate frequency (IF) signal before mixing with the radio frequency (RF) waveform for transmission by an antenna. A voltage controlled oscillator is utilized, which is tuned to N times the desired IF frequency. This voltage controlled oscillator is frequency modulated with the inputted audio signal to a deviation N times the desired IF source deviation. The voltage controlled oscillator is locked in a phase locked loop with a system reference frequency so that the output frequency is N times the desired IF frequency. The output of the voltage controlled oscillator is supplied to a “divide-by-N” frequency prescaler for generating a signal at precisely the right IF frequency and deviation.Type: GrantFiled: March 1, 1996Date of Patent: January 4, 2005Assignee: International Business Machines CorporationInventor: Daniel Paul Homiller
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Patent number: 6834187Abstract: A frequency plan for a signal analysis circuit includes operational parameters that are selected on the basis of first intermediate frequency (IF) filtering characteristics that are uniquely identified for the circuit. That is, rather than selecting a frequency plan based upon an original design of the circuit and circuit layout, actual IF filtering characteristics are considered. The center frequency of the passband of the first. IF filter may be measured and then used as an important factor, along with inhibiting spurious responses, in a devising the frequency plan for the specific circuit.Type: GrantFiled: September 5, 2002Date of Patent: December 21, 2004Assignee: Agilent Technologies, Inc.Inventors: Leonard Weber, Neus Padros
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Patent number: 6829469Abstract: A method for producing an output signal (42) with a specific frequency from an input signal (40) received, the frequency of which changes quickly in steps of the size of an input frequency resolution or a multiple of the input frequency resolution, on the input frequency band. Furthermore, a method is presented for producing an output signal (72) from an input signal (70) with a specific frequency, and for changing the frequency of the output signal (72) quickly in steps of the size of an output frequency resolution or a multiple of the output frequency resolution, on the output frequency band. Methods, as well as a receiver and a transmitter that implement the methods are based on the setting of an intermediate frequency from an intermediate frequency band, which comprises at least two different values. The difference between the values, i.e. the intermediate frequency resolution, is higher than the input or output frequency resolutions.Type: GrantFiled: February 4, 2002Date of Patent: December 7, 2004Assignee: Nokia CorporationInventor: Markku Henriksson
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Publication number: 20040192231Abstract: A two-point modulator includes a PLL circuit and a simplified digital pre-filtering system. The two-point modulator includes a first circuit path for impressing an analog modulation signal into a first point in the PLL circuit, and a second circuit path for impressing a digital modulation signal into a second point in the PLL circuit. The second circuit path actuates a frequency divider in the feedback path in the PLL circuit and contains a digital filter which has a square-wave pulse response.Type: ApplicationFiled: May 27, 2004Publication date: September 30, 2004Inventors: Christian Grewing, Markus Hammes, Stefan Van Waasen
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Publication number: 20040180635Abstract: An apparatus and method for compensating for the frequency offset of a received signal in a receiving apparatus of a mobile communication system. In the present invention, a sine component is calculated by adding I and Q channel signals resulting from downconverting a training sequence inserted between data symbols, and a cosine component is calculated by subtracting the Q channel signal from the I channel signal. Using the cosine and sine components at two time points, tangent components for the two time points are computed and thus first and second phase values are obtained. The frequency offset is estimated by determining the slope of a second-order line derived from the first and second phase values. The frequency offset of the received signal is compensated for based on the estimated frequency offset.Type: ApplicationFiled: March 12, 2004Publication date: September 16, 2004Applicants: SAMSUNG ELECTRONICS CO., LTD., KOREAN ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGInventors: Pil-Soon Choi, Mi-Hyun Son, Seong-Soo Lee, Kwy-Ro Lee
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Publication number: 20040180634Abstract: Sample acquisition apparatus for sampling first and second signals within a signal processing arrangement, said apparatus comprising a sampler for capturing sections of the waveforms of both the first and second signals, a switch for alternating correction of the sampler to a point in the arrangement where said first signal can be sampled and a point in said arrangement where said second signal can be sampled and a timer for timing the operation of the switch to cause the sampler to capture a first waveform section of said first signal and a second waveform section of said second signal, wherein said second signal is responsive to said first signal and the timing of said switch is such that said second section comprises a portion that has been generated in response to said first section.Type: ApplicationFiled: March 11, 2003Publication date: September 16, 2004Applicant: Andrew CorporationInventors: Peter Blakeborough Kenington, Jonathan Paul Rogers, John Bishop, Antony James Smithson
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Patent number: 6760571Abstract: An RF carrier signal is frequency modulated by a modulating signal, as a function of the amplitude of the modulating signal. The number of cycles in the frequency modulated carrier is counted in a first counter during the positive half cycle of the modulating signal and in a second counter during the negative half cycle of the modulating signal. A microprocessor obtains the difference of the counts in the counters, and from the difference computes the deviation of the modulated carrier from the center frequency of the carrier. This is compared with a desired deviation and the microprocessor calculates and generates a correction signal to vary the amplitude of the modulating signal when the difference between the computed and desired deviation exceeds a predetermined value. An arrangement is also provided whereby, after a calibration procedure, an external source may provide the modulation signal.Type: GrantFiled: December 18, 2001Date of Patent: July 6, 2004Assignee: The United States of America as represented by the Secretary of the NavyInventor: Kenneth M. Prockup
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Patent number: 6754474Abstract: In a transmission system, a modulator and a fractional frequency divider are introduced into the control loop of a voltage-controlled oscillator. It is shown that the benefit of this is a reduction in noise associated with the reduction of noise due to using a divider with a lower division coefficient. In one embodiment, the fractional divider is obtained by selecting different dividers in turn in accordance with temporal proportions corresponding to a required division fraction.Type: GrantFiled: July 21, 2000Date of Patent: June 22, 2004Assignee: AlcatelInventors: Patrick Savelli, Vassiliki Nikolopoulou
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Patent number: 6748203Abstract: A three port structure for the down conversion demodulation of a digitally modulated RF signal is proposed, wherein no RF switches are provided. The three port structure (1) has a first input (2) for the RF signal to be down converted and a second input (3) for a RF signal originating from a local oscillator (8). An output (4) of the three port structure (1) is supplied to a power sensor unit (5). The RF signal from the local oscillator (8) is modulated (7) before it is supplied to the three port structure (1).Type: GrantFiled: September 28, 2000Date of Patent: June 8, 2004Assignees: Sony International (Europe) GmbH, Sony CorporationInventors: Veselin Brankovic, Dragan Krupezevic, Gerald Oberschmidt, Tino Konschak, Thomas Dölle, Hamid Amir-Alikhani, Masayoshi Abe
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Patent number: 6671500Abstract: A system is disclosed for transmitting and receiving signals. The system includes the use of a frequency plan table a system for creating the frequency plan table. The frequency plan table relates carrier frequency channels to the operation of a synthesizer and a plurality of programmable frequency dividers in a locked loop. In a transmitter, a first programmable frequency divider accepts a reference signal and produces a comparison signal. A mixer accepts the reference signal and a transmission signal and produces a loop signal. A second programmable frequency divider accepts the loop signal and produces a loop signal having a divided intermediate frequency signal. A phase detector compares the comparison signal and the loop signal having a divided intermediate frequency and produces an output that controls a variable controlled oscillator. The variable controlled oscillator produces a modulated transmission signal.Type: GrantFiled: March 30, 2001Date of Patent: December 30, 2003Assignee: Skyworks Solutions, Inc.Inventors: Morten Damgaard, Alyosha C. Molnar, Rahul Magoon, William J. Domino, Andrew Zhang
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Publication number: 20030083025Abstract: An electronic apparatus comprising a radio transmitter is disclosed. In a computer system (1) having a radio transmission circuit (3) of a phase modulation type supplied with power from a power supply (4) of a switching type, the switching frequency of the power supply (4) is determined based on the comparison frequency for the sampling operation of a PLL circuit (10) of the radio transmitter, thereby removing the power noises generated from the switching regulator of the radio transmitter of a phase modulation type.Type: ApplicationFiled: February 5, 2002Publication date: May 1, 2003Applicant: Fujitsu LimitedInventors: Nobuhide Maruo, Makoto Saotome, Makoto Kotani
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Patent number: 6549078Abstract: A method for generating a plurality of frequencies having predetermined frequency deviations from a phase lock loop device including a VCO having a main voltage input, a modulation voltage input and a frequency output, a first and second feedback loop digital divider, each having an input and an output, a phase frequency detector having a first and second input and an output, a reference frequency generator such as a crystal oscillator having an output, a first and second reference frequency digital divider, each having an input and an output, a loop filter having an input and an output, a switch having an input and a first and a second switched output, a hold circuit having an input and an output, a memory circuit for storing the a lock voltage and the corresponding loop output frequency, the steps including; setting a first initial predetermined value of the first feedback loop digital divider, connecting a switch output to the main input of the VCO, supplying a first predetermined reference frequency to thType: GrantFiled: November 18, 2000Date of Patent: April 15, 2003Assignee: Ashvattha Semiconductor Inc.Inventors: Guruswami M. Sridharan, Kartik M. Sridharan
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Patent number: 6542722Abstract: A method and system is described wherein a signal with a lower frequency is up-converted to a higher frequency. In one embodiment, the higher frequency signal is used as a stable frequency and phase reference. In another embodiment, the invention is used as a transmitter. The up-conversion is accomplished by controlling a switch with an oscillating signal, the frequency of the oscillating signal being selected as a sub-harmonic of the desired output frequency. When the invention is being used as a frequency or phase reference, the oscillating signal is not modulated, and controls a switch that is connected to a bias signal. When the invention is being used in the frequency modulation (FM) or phase modulation (PM) implementations, the oscillating signal is modulated by an information signal before it causes the switch to gate the bias signal.Type: GrantFiled: April 16, 1999Date of Patent: April 1, 2003Assignee: ParkerVision, Inc.Inventors: David F. Sorrells, Michael J. Bultman, Robert W. Cook, Richard C. Looke, Charley D. Moses, Jr., Gregory S. Rawlins, Michael W. Rawlins
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Publication number: 20030027527Abstract: Frequency modulation switching apparatus for rapidly increasing and decreasing the frequency within radio-frequency pulses of radio wave pulse trains transmitted by an antenna having series inductance and capacitance, the apparatus having, in combination, a solid state four-terminal rectifier bridge circuit with opposing pairs of bridge terminals connected with one pair of opposing terminals shunting said inductance and said capacitance; and series-connected staturable and linear inductors and an SCR switch connected between the other pair of opposing terminals of the bridge circuit, whereby the high-speed triggering of the SCR on effects corresponding high-speed frequency increasing or decreasing of the frequency within the radio-frequency pulse to provide the desired frequency modulation thereinType: ApplicationFiled: August 3, 2001Publication date: February 6, 2003Applicant: Megapulse, Inc.Inventor: Paul R. Johannessen
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Publication number: 20020180548Abstract: Direct frequency modulation of a phase-locked loop (PLL) output signal is achieved by means of a modulation signal comprising a digital sequence. The digital modulation signal is coupled to the input of the VCO of the PLL, and is also coupled to drive an up-down counter. The output of the counter is coupled to a D/A converter to provide a compensation signal for the PLL. When the counter output reaches values representing modulation-induced phase errors of +360 degrees and −360 degrees, the counter generates signals respectively corresponding thereto to adjust the PLL frequency divider.Type: ApplicationFiled: May 29, 2001Publication date: December 5, 2002Inventors: Sven Mattisson, Hakan Eriksson
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Publication number: 20020111147Abstract: A circuit arrangement for a mobile radio system has a base station and a non-adaptive antenna device. The base station has n outputs for n carrier-frequency signals which have essential the same frequency and amplitude. These n signals are adapted to the operation of a non-adaptive antenna device using devices for dividing and combining signals, if appropriate which perform phase correction.Type: ApplicationFiled: February 14, 2002Publication date: August 15, 2002Applicant: Siemens AktiengesellschaftInventors: Leo RaDemacher, Mohamed Shaalan, Hans Rudolf
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Patent number: 6433830Abstract: The proposed phase lock technique uses various feedback loops to lock the frequency and phase of a CATV modulator output signal to that of an off-air signal without directly measuring the output frequency. One embodiment includes a tuner for receiving the off-air signal and generating an intermediate frequency signal and a phase-frequency detector for comparing the frequency and phase of the intermediate frequency signal generated by the tuner with the frequency and phase of an intermediate frequency signal generated by the modulator based on a reference input signal. The output of the phase-frequency detector is used to control the reference input signal into the modulator and the reference input signal to the tuner such that the frequency and phase of the modulator output signal is locked to the frequency and phase of the received off-air signal.Type: GrantFiled: June 14, 1999Date of Patent: August 13, 2002Assignee: General Instrument CorporationInventors: Donald Groff, Edgar Rhodes
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Publication number: 20020072338Abstract: A frequency tracking and locking system of a wireless microphone has a frequency selection unit selecting a predetermined frequency and outputting the predetermined frequency to the frequency data storage unit, a frequency data storage unit storing a predetermined frequency data and outputting the predetermined frequency data to the data encoding unit, the data encoding unit encoding the predetermined frequency data and outputting the predetermined frequency data to the infrared modulation transmitter, an infrared modulation transmitter transforming the predetermined frequency data to the infrared frequency data and transmitting the infrared frequency data to the data decoding unit, a data decoding unit decoding the infrared frequency data to a first radio frequency and outputting the first radio frequency to the frequency transformation unit, a frequency transformation unit transforming the first radio frequency to a second radio frequency and outputting the second radio frequency to the radio emission unit,Type: ApplicationFiled: December 11, 2000Publication date: June 13, 2002Inventor: Jen-Cheng Chang
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Publication number: 20020044025Abstract: A frequency modulator having variable carrier frequency is provided. A VCO frequency-modulates an oscillator input signal using an oscillation frequency set by a set signal as the carrier frequency. A phase/frequency detector outputs phase and frequency differences between a VCO output signal and a reference signal. A filter receives a phase/frequency detector output and generates the set signal. An amplifier generates a pair of output signals whose voltage levels change in opposite directions. A compensation circuit changes the voltage levels of the output signal pair and provides resulting signals to the VCO as the oscillator input signal.Type: ApplicationFiled: April 3, 2001Publication date: April 18, 2002Applicant: Samsung Electronics Co., Ltd.Inventor: Jae-Ho Park
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Patent number: 6345173Abstract: A frequency modulator (50, 150) for modulating a carrier signal according to a modulation data signal to provide a modulated output signal (RFout), comprises a reference signal generator (54, 154) coupled to receive the modulation data signal for performing a low frequency modulation process and for generating a reference signal modulated according to the modulation data signal, and a main synthesizer (52, 152) coupled to receive the modulated reference signal and the modulation data signal for performing a high frequency modulation process and for providing the modulated output signal at an output. Preferably, the modulated reference signal has a first modulation gain (Kr) and the modulated output signal has a modulation gain (KV) which is substantially proportional to the first modulation gain (Kr).Type: GrantFiled: May 6, 1999Date of Patent: February 5, 2002Assignee: Motorola, Inc.Inventors: Christophe Fourtet, Jacques Trichet
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Patent number: 6304748Abstract: A cellular phone for a mobile communications system includes a dual band transmitter which operates at a first radio frequency band and a second radio frequency band. The dual band transmitter includes two amplifiers. The first amplifier has a first input for a first signal at the first radio frequency band, and a first output for an amplified first signal. The first output is connectable to the antenna via a first signal path. The second amplifier has a second input for a second signal at the second radio frequency band and a second output for an amplified second signal. The second output is connectable to the antenna via a second signal path. A filter module is associated with the first and second signal paths and configured to receive a control signal which controls the filter module to have one of a first and second cut-off frequencies.Type: GrantFiled: September 23, 1998Date of Patent: October 16, 2001Assignee: Conexant Systems, Inc.Inventors: Leo L. Li, Christopher M. Chorey
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Publication number: 20010014590Abstract: A reference frequency generating section 10 capable of suitably changing frequency accuracy of an output signal in accordance with an input control voltage, and a high-accurate reference frequency generating section 13 having accuracy for a temperature change extremely higher than that of the reference frequency generating section 10 and in which output frequency accuracy thereof changes only within a range of prescribed values (frequency accuracy within a range where transmission and reception of a portable telephone can be conducted) are provided. A reference frequency after an AFC operation, which is output from the reference frequency generating section 10, is compared with an output signal from the high-accurate reference frequency generating section 13, and whether or not frequency accuracy of an output signal from the reference frequency generating section 10 meets a prescribed value is determined.Type: ApplicationFiled: January 19, 2001Publication date: August 16, 2001Inventor: Akihiro Nakano
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Patent number: 6266518Abstract: Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal are described herein. Briefly stated, such methods, systems, and apparatuses operate by receiving an EM signal and an aliasing signal having an aliasing rate. The EM signal is aliased according to the aliasing signal to down-convert the EM signal. The term aliasing, as used herein, refers to both down-converting an EM signal by under-sampling the EM signal at an aliasing rate, and down-converting an EM signal by transferring energy from the EM signal at the aliasing rate. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a demodulated baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.Type: GrantFiled: August 18, 1999Date of Patent: July 24, 2001Assignee: ParkerVision, Inc.Inventors: David F. Sorrells, Michael J. Bultman, Robert W. Cook, Richard C. Looke, Charley D. Moses, Jr.
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Patent number: 6246297Abstract: This device includes a frequency synthesizer (12) comprising two phase-locked loops (L1 and L2). The one comprises a low-pass filter (68) and the other a high-pass filter (49). The loop with the low-pass filter fixes the basic frequency of the synthesizer and the other corrects the phase noise. With this arrangement it is easy to apply a modulation frequency to the terminal (11) that is not disturbed by said loops if this modulation frequency is found to be higher than the cut-off frequency of the low-pass filter.Type: GrantFiled: December 6, 1999Date of Patent: June 12, 2001Assignee: U.S. Philips CorporationInventor: Jean A. Chabas
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Patent number: 6211747Abstract: A direct modulation multi-accumulator fractional-N frequency synthesizer 1 for generating a carrier signal 150 modulated by a modulation signal 170, 121 is disclosed. The frequency synthesizer includes a Voltage Controlled Oscillator, VCO 50, having a tuning port for controlling the frequency of the signal 110 output by the VCO, a variable divider 20 and a multi-accumulator sequence generator 21 for controlling the variable divider, a reference signal generator 50, a phase detector 30 and a low pass filter 40. These elements are arranged to form a Phase Locked Loop arrangement, the directly modulated output signal of which is taken from the output of the VCO, wherein in-band modulation is performed by varying the variable divider and out-of-band modulation is performed by directly applying the modulating signal to the VCO tuning port.Type: GrantFiled: May 28, 1999Date of Patent: April 3, 2001Assignee: Motorola, Inc.Inventors: Jacques Trichet, Christophe Fourtet
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Patent number: 6204750Abstract: Interrogator for an electronic identification system having a first oscillator arranged to vary in frequency in accordance with the frequency of a received signal, a second oscillator arranged to vary in accordance with the frequency of the first oscillator after a delay of a number of cycles of the received signal, a phase discriminator for detecting the phase difference between respective output signals of the first and second oscillators and a phase-change detector arranged to determine the frequency at which the phase changes occur. In this way, a modulation frequency of the received signal can be determined.Type: GrantFiled: October 27, 1997Date of Patent: March 20, 2001Assignee: British Technology Group Inter-Corporate Licensing LimitedInventor: Jos Scheelen
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Patent number: 6144846Abstract: A frequency translation circuit (10) translates an incoming reference signal (RF.sub.IN) to a lower frequency using a compound mixer circuit (42). The compound mixer circuit (42) has a first mixer circuit (14A) that receives both the incoming reference signal (RF.sub.IN) and a signal generated by a first counter (28A). A second mixer circuit (14X) of the compound mixer circuit (42) receives a signal generated by a second counter (28X) and further translates the signal received from the first mixer circuit (14A) to a lower frequency. Both the first mixer circuit (14A) and the second mixer circuit (14X) generate output signals having a carrier frequency that is lower in frequency by the difference of the two input signals.Type: GrantFiled: December 31, 1997Date of Patent: November 7, 2000Assignee: Motorola, Inc.Inventor: Jeffrey C. Durec
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Patent number: 6115586Abstract: A radio frequency synthesizer receives a relatively low frequency input signal and synthesizes from it a high frequency output signal whose frequency can be programmed to change in fine steps, for use e.g. in cordless telephone. The frequency synthesizer includes three linked phase locked loops with a single side band mixer in one embodiment coupling two of the phase locked loops together. This provides an output signal free of in-band frequency spurs within the spacing of two channels. The synthesizer can be integrated in a single chip with a narrowband FM modulation circuit. In spite of using a novel synthesizer to achieve monolithic integration, the user programming interface and control value equations are the industry standard format.Type: GrantFiled: December 18, 1997Date of Patent: September 5, 2000Assignee: Integrated Circuit Systems, Inc.Inventors: Ignatius Bezzam, Herbe Q. H Chun, Gregory Richmond
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Patent number: 6018275Abstract: A transmitter and a phase locked loop (30) for a transmitter are disclosed. The phase locked loop (30) upconverts the frequency of a baseband signal to a frequency for radio transmission. As well as the usual components, the phase locked loop (30) comprises a modulator (39) for modulating a baseband signal (f.sub.bb) onto a carrier (f.sub.ref /R) and forwarding the resultant modulated signal (f.sub.c) to one of the inputs of the phase detector (33). It also comprises a low pass filter (38) in its forward path between the phase detector (33) and the voltage controlled oscillator (34) for passing signals having baseband signal frequencies. A mixer (35) and main frequency divider (36) are provided in the feedback path to downconvert the transmit signal (f.sub.tx). This low division eliminates large amounts of multiplicative noise within the loop bandwidth, and therefore enables a large loop bandwidth to be used. Consequently, the settling time of the phase locked loop is improved.Type: GrantFiled: December 18, 1997Date of Patent: January 25, 2000Assignee: Nokia Mobile Phones LimitedInventors: Alan Christopher Perrett, Kenneth Peter Mason
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Patent number: 6008704Abstract: A method and apparatus are provided for modulating a frequency synthesizer with an adjusted frequency control word determined by adjusting a carrier frequency control word based upon a bit content of a unsigned modulation control word. The method includes the steps of inverting a most significant bit of the unsigned modulation control word to produce an adjusted modulation control word and replicating the inverted most significant bit and appending the replicated bits to a most significant bit side of the adjusted modulation control word to increase a width of the adjusted modulation control word to a width of the carrier frequency control word. The method further includes the step of adjusting the carrier frequency control word by adding the replicated bits and the adjusted modulation control word to corresponding bits of the carrier frequency control word.Type: GrantFiled: June 9, 1998Date of Patent: December 28, 1999Assignee: Rockwell Collins, Inc.Inventors: Paul L. Opsahl, Dennis J. Hrncirik