Variable Automatic Gain Control Loop Gain Patents (Class 455/240.1)
  • Patent number: 8401507
    Abstract: A method of selecting an RF gain of an automatic gain control amplifier includes the steps of measuring a strength of a received signal, the signal reliable and consistent power characteristics, and then measuring an interference level of the received signal, and determining either a target output power level or a target output interference power level based on a ratio of the measured signal strength to the measured interference level. The method also includes determining a gain that, when applied to an incoming signal, will produce a corresponding one of the determined target output power level and the determined target output interference power level.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: March 19, 2013
    Assignee: Motorola Mobility LLC
    Inventors: William Hillery, James Kepler, Mickael Batariere
  • Patent number: 8391384
    Abstract: An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, a primary AGC loop controls an analog sub-receiver adapted to simultaneously receive multiple signals. Multiple digital demodulators, coupled to the sub-receiver, demodulate the multiple received signals. Multiple secondary AGC loops, one for each received signal, compensate for variations in demodulated signal strengths caused by the primary AGC loop. A feed-forward AGC compensation technique generates scalar control values for scaling the demodulated signals before the demodulated signals are processed by the secondary AGC loops. This at least partially compensates for gain variations caused by the primary AGC, reducing received signal drop-outs before the secondary AGC loops can compensate for the gain variations.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: March 5, 2013
    Assignee: Agere Systems LLC
    Inventors: Yhean-Sen Lai, Jie Song, Zhenyu Wang, Jinguo Yu
  • Patent number: 8320863
    Abstract: In one embodiment, the present invention includes a mixer circuit to receive and generate a mixed signal from a radio frequency (RF) signal and a master clock signal, a switch stage coupled to an output of the mixer circuit to rotatingly switch the mixed signal to multiple gain stages coupled to the switch stage, and a combiner to combine an output of the gain stages.
    Type: Grant
    Filed: June 4, 2010
    Date of Patent: November 27, 2012
    Assignee: Silicon Laboratories Inc.
    Inventors: Aslamali A. Rafi, Alessandro Piovaccari
  • Patent number: 8311501
    Abstract: A DC offset of a VGA is measured by selecting a ground contact of a switch. Then, the gain of the VGA is set at an appropriate value, monitoring contacts of the switch are successively selected, and the output values of an ADC for the respective cases are measured with the input to a DAC set at zero. Then, the DC offset of the VGA is removed, the DC offset value of each circuit block, such as DAC, in a transmitting part is calculated, and parameters are set so that the DC offset value of each circuit block is minimized.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: November 13, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kenichi Agawa
  • Patent number: 8306162
    Abstract: A method for use in a digital communications receiver for controlling an input signal level (200) into an analog-to-digital converter (ADC) initially receives a sample sequence (201) where a threshold crossing rate is measured as a percentage samples of an input signal that exceed the threshold (203). The error between the measured threshold crossing rate and a desired reference threshold crossing rate is calculated (205) and an error signal is then utilized in a feedback loop to control the receiver gain such that the error is reduced (207).
    Type: Grant
    Filed: November 28, 2007
    Date of Patent: November 6, 2012
    Assignee: Motorola Solutions, Inc.
    Inventors: Robert J. Corke, Daniel G. Prysby
  • Patent number: 8301096
    Abstract: Automatic gain control method and apparatus control a gain of a received signal. While the gain is adjusted and thus converges, a finding mode is entered to additionally change the gain at least once according to at least one characteristic value obtained from a relationship between the gain and time, such that the gain approaches a target level. In other embodiments, a tracking mode is further entered to periodically adjust the gain at a period greater than that before when signal strength is being tracked to reduce noise energy introduced. Hence, the embodiments can improve a gain converging speed and reduce the influence of the noise on the communication system in a dynamic receiving environment, and thus enhance the signal receiving performance.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: October 30, 2012
    Assignee: Industrial Technology Research Institute
    Inventor: Hsin-An Hou
  • Patent number: 8280340
    Abstract: Systems of clock generation for integrated radio frequency receiver. In an integrated radio frequency receiver, a mixer is often used to down convert the incoming radio frequency signal. The down converted signal is then digitized and digital signal processing circuitry is used for efficient and flexible implementation of various functions to receive the underlying audio and/or data information. The mixer requires clock generation circuitry to provide a proper local oscillator signal for a selected channel. On the other hand, the digital signal processing circuitry requires its separate digital clock for proper operations. The clock generation system utilizes single local oscillator generation circuitry to provide the local oscillator signals required by the mixer and the digital clock signals required by the digital signal processing circuitry.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: October 2, 2012
    Assignee: Quintic Holdings
    Inventors: Peiqi Xuan, Yifeng Zhang, Xuechu Li
  • Patent number: 8265581
    Abstract: Provided is a transceiver using a millimeter-wave (MM-wave). The transceiver determines output power of a transmitting signal according to a receiving signal of a receiving end in the same device so that a possible loss value occurring in the air may be predicted. By doing so, performance of a whole link budget may be enhanced, and the transmitting signal may be rapidly controlled.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: September 11, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bong-Su Kim, Woo-Jin Byun, Min-Soo Kang, Kwang-Seon Kim, Tae-Jin Chung, Myung-Sun Song
  • Patent number: 8259878
    Abstract: Provided are apparatus and method for receiving signals in a wireless communication system.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: September 4, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Chanho Yoon, Hun-Sik Kang, Eun-Young Choi, Sok-Kyu Lee
  • Patent number: 8260244
    Abstract: In one embodiment, the present invention includes a mixer circuit to receive and generate a mixed signal from a radio frequency (RF) signal and a master clock signal, a switch stage coupled to an output of the mixer circuit to rotatingly switch the mixed signal to multiple gain stages coupled to the switch stage, and a combiner to combine an output of the gain stages.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: September 4, 2012
    Assignee: Silicon Laboratories Inc.
    Inventors: Aslamali A. Rafi, Alessandro Piovaccari, Peter Vancorenland, Tyson Tuttle
  • Patent number: 8238861
    Abstract: Techniques for performing automatic gain control (AGC) at a terminal in a wireless communication network are described. In an aspect, the terminal may use different receiver gain settings to receive different types of signals in different time intervals. The terminal may determine a receiver gain setting for each signal type and may use the receiver gain setting to receive signals of that signal type. In another aspect, the terminal may determine a receiver gain setting for a future time interval based on received power levels for peer terminals expected to transmit in that time interval. The terminal may measure received power levels of signals received from a plurality of terminals. The terminal may determine a set of terminals expected to transmit in the future time interval and may determine the receiver gain setting for the future time interval based on the measured received power levels for the set of terminals.
    Type: Grant
    Filed: January 26, 2009
    Date of Patent: August 7, 2012
    Assignee: QUALCOMM Incorporated
    Inventors: Junyi Li, Ying Wang, Thomas Richardson, Aleksandar Jovicic
  • Patent number: 8233093
    Abstract: Disclosed is an automatic video gain control circuit, which includes an analog to digital converter, an envelope detector and an extreme value detector. The analog to digital converter converts an analog video signal to a digital video signal. The envelope detector detects a baseband amplitude signal according to the digital video signal. The extreme value detector generates an extreme value to control RF signal gain.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: July 31, 2012
    Assignee: MStar Semiconductor, Inc.
    Inventor: Shan-Tsung Wu
  • Patent number: 8229373
    Abstract: A high frequency power amplifier maintains an excellent linearity regardless of a fluctuation of a load impedance and is downsized. The high frequency power amplifier detects an AC voltage amplitude at an output terminal of a final amplification stage transistor, and suppresses an input signal amplitude of a power amplifier when the voltage amplitude exceeds a predetermined threshold value.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: July 24, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Tomonori Tanoue, Hidetoshi Matsumoto
  • Patent number: 8200179
    Abstract: In one embodiment, a combined VGA-and-equalizer (VGA-EQ) circuit for a communication link includes a current-mode logic (“CML”) amplifier with an inductive load circuit. The CML amplifier has a gain control terminal and is operable to amplify, with an adjustable gain, a signal received at an input terminal and provide the amplified signal at an output terminal. The CML amplifier has a first gain at frequencies below a predetermined frequency value and a second gain at frequencies in a predetermined frequency range above the predetermined frequency value, wherein the second gain is higher than the first gain. The higher second gain of the VGA-EQ circuit causes a reduction in inter-symbol interference in a signal received by the receiver.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: June 12, 2012
    Assignee: Lattice Semiconductor Corporation
    Inventors: Paulius Mosinskis, Richard Booth
  • Patent number: 8194804
    Abstract: An automatic gain control apparatus and method of a mobile station in an OFDM system are provided. The method includes identifying a preamble section and a data symbol section in a received frame signal; when a current symbol is the preamble section, measuring a power value of a preamble signal, comparing the measured power value of the preamble signal and a threshold value, and amplifying the received frame signal based on a predetermined gain; when a data symbol section includes a pilot carrier, measuring an average power value of the pilot carrier in the data symbol, comparing the measured average power value and the threshold value, and amplifying the received frame signal based on a predetermined gain; and when the data symbol section includes no pilot carrier, maintaining an existing gain, or performing an automatic gain control operation according to a gain estimated by using the pilot carrier during the data symbol section.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: June 5, 2012
    Assignees: Samsung Electronics Co., Ltd., Electronics and Telecommunications Research Institute, KT Corporation, SK Telecom Co., Ltd., Hanaro Telecom, Inc.
    Inventors: Ki-Seok Kim, Young-Il Kim
  • Patent number: 8145168
    Abstract: A DC offset of a VGA is measured by selecting a ground contact of a switch. Then, the gain of the VGA is set at an appropriate value, monitoring contacts of the switch are successively selected, and the output values of an ADC for the respective cases are measured with the input to a DAC set at zero. Then, the DC offset of the VGA is removed, the DC offset value of each circuit block, such as DAC, in a transmitting part is calculated, and parameters are set so that the DC offset value of each circuit block is minimized.
    Type: Grant
    Filed: October 1, 2008
    Date of Patent: March 27, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kenichi Agawa
  • Patent number: 8135375
    Abstract: A gain-controllable stage (CLN, A1, A2 . . . , A7, ACC) comprises a reactive signal divider (CLN) followed by an amplifier arrangement (A1, A2 . . . , A7, ACC). The reactive signal divider (CLN) may be in the form of, for example, a capacitive ladder network. The gain-controllable stage (CLN, A1, A2 . . . , A7, ACC) has a gain factor that depends on a signal division factor that the reactive signal divider (CLN) provides. The reactive signal divider (CLN) forms part of a filter (LC). The signal division factor is adjusted on the basis of a frequency (F) to which the receiver is tuned and a signal-strength indication (RS).
    Type: Grant
    Filed: August 23, 2006
    Date of Patent: March 13, 2012
    Assignee: NXP B.V.
    Inventor: Johannes Hubertus Antonius Brekelmans
  • Patent number: 8095101
    Abstract: A receiving device includes a mixer, an AC coupling circuit, a post-stage circuit, and a DC offset calibration circuit. The mixer is utilized for mixing an input signal with a local oscillating (LO) signal from an oscillator to generate a converted signal. The AC coupling circuit is coupled to the mixer and utilized for reducing at least one portion of DC offset of the converted signal to generate a filtered signal. The post-stage circuit is coupled to the AC coupling circuit and utilized for processing the filtered signal to generate an output signal. The DC offset calibration circuit is coupled to the post-stage circuit and utilized for providing at least a compensation current for the post-stage circuit to reduce DC offset of the output signal.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: January 10, 2012
    Assignee: Realtek Semiconductor Corp.
    Inventors: Pei-Ju Chiu, Chia-Jun Chang, Chao-Cheng Lee
  • Patent number: 8090334
    Abstract: A high accuracy programmable gain amplifier has reduced temperature dependency, reduced supply voltage dependency, and supports accurate amplifier gain and accurate amplifier gain steps. The high accuracy programmable gain amplifier allows requirements compliant electronic devices to be fabricated that are capable of providing improved operational performance with less power consumption, hence extended battery life and improved operational availability. Electronic devices that incorporate the high accuracy programmable gain amplifier described below, may experience reduced variations in operational performance resulting in a reduced need for post production calibration, reduced calibration data storage requirements, and reduced device control processor cycles for use in performing calibration operations, thereby allowing such devices to be produced at a lower cost and/or to provide users with increased operational performance and/or increased battery life and, hence, increased operational availability.
    Type: Grant
    Filed: August 25, 2008
    Date of Patent: January 3, 2012
    Assignee: Marvell International Ltd.
    Inventor: Nir Yahav
  • Patent number: 8078126
    Abstract: A communication apparatus and a low noise amplifying method. The communication apparatus includes a gain adjusting unit to adjust a gain of an input signal; a combiner to generate an output signal using the signal gain-adjusted at the gain adjusting unit; and a feedback unit which provides a feedback signal, which is generated using the output signal generated at the combiner, to an input stage. Accordingly, various frequency bands defined in the wireless standards can be supported. Since the load impedance is generated without resistance, the manufacturing cost and the product size can be reduced.
    Type: Grant
    Filed: April 10, 2007
    Date of Patent: December 13, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-woo Park, Chang-sik Yoo, Jin-soo Park, Heung-bae Lee, Young-eil Kim
  • Patent number: 8055231
    Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: November 8, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Khurram Muhammad, Meng-Chang Lee, Dirk Leipold
  • Patent number: 8041323
    Abstract: A portable electronic unit has a transmission-side section that transmits a signal and a receiving-side section that receives a signal from the transmission-side section. The receiving-side section includes a gain control amplification device that amplifies and outputs a signal from the transmission-side section. The gain control amplification device has a first amplification circuit that amplifies and outputs a signal from the transmission-side section, a detection circuit that detects and outputs a signal from the first amplification circuit, a gain control amplification circuit that amplifies and outputs a signal from the detection circuit, and a gain control circuit that controls a gain in the gain control amplification circuit in response to a level of a signal from the detection circuit.
    Type: Grant
    Filed: July 18, 2006
    Date of Patent: October 18, 2011
    Assignee: Seiko Instruments Inc.
    Inventor: Kazuo Kato
  • Patent number: 8000671
    Abstract: A method, algorithm, circuits, and/or systems for demodulation in an amplitude modulated (AM) radio receiver are disclosed. In one embodiment, a radio receiver can include an amplifier configured to receive a radio frequency (RF) input signal and a gain control signal, and provide an amplified signal, an automatic gain control (AGC) circuit configured to receive a high threshold comparator output and provide the gain control signal, a mixer configured to combine the amplified signal and a local oscillation signal and provide a mixed output, a high threshold comparator configured to compare the mixed output with a reference level and provide the high threshold comparator output, and a low threshold comparator configured to compare the mixed output with the reference level and provide an output of the radio receiver.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: August 16, 2011
    Assignee: Seiko Epson Corporation
    Inventors: David Meltzer, Gregory A. Blum, Muralikumar A. Padaparambil
  • Patent number: 7995684
    Abstract: A receiver operates to AGC a multi-carrier signal through a corresponding number of inner loops and an outer loop AGC processes. A first number of bits for representing the multi-carrier signal with a limited amount of interference is determined through a calibration mode process. The first number of bits provides for quantization of the multi-carrier signal at an outer loop AGC to a maximum quantization level. After the received signal power estimate is reached a predetermined “ON” threshold, the outer loop AGC is operated at a second number of bits higher than the first number of bits to allow a quantization of possible interference in accordance with a difference of the first and second number of bits. The outer loop AGC switches back to use the first number of bits when the received signal power estimate falls below a predetermined “OFF” threshold.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: August 9, 2011
    Assignee: QUALCOMM, Incorporated
    Inventors: Juan Montojo, Rohan Sudhakar Salvi, Peter J. Black
  • Patent number: 7983642
    Abstract: A system and method is provided for reducing signal distortion and saturation within an RF receiver which may be operated in an environment under the presence of interfering signals such as in a WiMAX environment. In an embodiment, a first gain stage and a second gain stage are selectively lowered to predetermined lower levels, assuring that if there is a blocker present, it would not cause signal distortion and saturation in the receiver. The loss of the gain in the first gain stage and second gain stage is compensated by a third gain stage which selectively amplifies the signals of interest. If a blocker is not detected, the maximum allowable gain of the first gain stage and the second gain stage is set to a predetermined upper limit allowing for maximum receiver sensitivity. Accordingly, with this system and method a direct conversional receiver can operate in the presence of interfering signals without signal distortion and saturation.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: July 19, 2011
    Assignee: Analog Devices, Inc.
    Inventors: Paul J. Da Graca, Alfred R. Mangino, Richard S. Camden
  • Patent number: 7978794
    Abstract: A method for automatic gain control of a front-end for a digital video receiver is provided. The method includes the following steps. First, a radio frequency signal is received and converted to an intermediate frequency signal. Then, the IF signal is amplified according to a gain. Next, the amplified IF signal is demodulated into a base-band signal, and the base-band signal is encoded into a transport stream. After that, a DC level of a pulse width modulation signal is controlled by at least one variable resistor to adjust the gain, the PWM signal being related to a setting of the gain. Afterwards, a BER measurement at each potential setting of the gain and the variable resistor under one or more power levels of the RF signal is read, and an optimum setting of the gain and the variable resistor is selected according to the BER measurements.
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: July 12, 2011
    Assignee: Himax Technologies Limited
    Inventors: Shin-Shiuan Cheng, Ming-Yeong Chen, Shyuan Liao
  • Patent number: 7978773
    Abstract: An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, a primary AGC loop controls an analog sub-receiver adapted to simultaneously receive multiple signals. Multiple digital demodulators, coupled to the sub-receiver, demodulate the multiple received signals. Multiple secondary AGC loops, one for each received signal, compensate for variations in demodulated signal strengths caused by the primary AGC loop. A feed-forward AGC compensation technique generates scalar control values for scaling the demodulated signals before the demodulated signals are processed by the secondary AGC loops. This at least partially compensates for gain variations caused by the primary AGC, reducing received signal drop-outs before the secondary AGC loops can compensate for the gain variations.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: July 12, 2011
    Assignee: Agere Systems Inc.
    Inventors: Yhean-Sen Lai, Jie Song, Zhenyu Wang, Jinguo Yu
  • Patent number: 7945226
    Abstract: A method for adaptive automatic gain control and an automatic gain control circuit are provided. A predetermined waveform is injected into the automatic gain control circuit. A signal is sampled at at least one point in the automatic gain control circuit in which the sampled signal includes the injected predetermined waveform. A small-signal control characteristic is calculated using the sampled at least one signal. A determination is made as to whether the calculated small-signal control characteristic is valid. In the case of a valid determination, the calculated small-signal control characteristic is used to adjust the gain of the automatic gain control circuit.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: May 17, 2011
    Assignee: Ciena Corporation
    Inventor: Gary Mak
  • Patent number: 7917114
    Abstract: The present invention relates to a DC offset canceling circuit. In one aspect of the invention, a DC offset canceling circuit with independently configurable gain and roll-off frequency is provided. In one embodiment of the present invention, the DC offset canceling circuit is used in the receive path of a down-conversion wireless receiver. In another aspect of the invention, a method for independently varying the gain and the roll-off frequency of the DC offset canceling circuit is provided. In one embodiment, the method is used to independently operate a gain control scheme and a DC offset cancellation strategy in a DC canceling circuit.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: March 29, 2011
    Inventors: Amit Bagchi, Rohit Gaikwad
  • Patent number: 7912436
    Abstract: A Radio Frequency (RF) receiver includes a low noise amplifier (LNA) and a mixer coupled to the output of the LNA. The gain of the LNA is adjusted to maximize signal-to-noise ratio of the mixer and to force the mixer to operate well within its linear region when an intermodulation interference component is present. The RF receiver includes a first received signal strength indicator (RSSI_A) coupled to the output of the mixer that measures the strength of the wideband signal at that point. A second received signal strength indicator (RSSI_B) couples after the BPF and measures the strength of the narrowband signal. The LNA gain is set based upon these signal strengths. By altering the gain of the LNA by one step and measuring the difference between a prior RSSI_B reading and a subsequent RSSI_B? reading will indicate whether intermodulation interference is present.
    Type: Grant
    Filed: April 9, 2008
    Date of Patent: March 22, 2011
    Assignee: Broadcom Corporation
    Inventor: Hong Shi
  • Patent number: 7899424
    Abstract: A method for reducing frequency glitches in a digital transceiver due to power amplifier input impedance variations. According to the method, the power amplifier is switched on after the end of a prior packet reception period and before a new packet transmission begins. Instead of ramping the power amplifier gain, the method ramps the modulation signals. As a consequence, any VCO frequency transients that may result from turning on the power amplifier have an opportunity to decay before the new packet transmission is initiated. This technique effectively isolates the transmitter power amplifier from the frequency synthesizer VCO to facilitate fast switching transceiver operation.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: March 1, 2011
    Assignee: ST-Ericsson SA
    Inventor: Rishi Mohindra
  • Patent number: 7894785
    Abstract: An amplifier assembly and also a receiver including such an amplifier assembly is disclosed, wherein the amplifier includes a programming input for setting the gain thereof. The signal level at the output of the amplifier is compared with a reference level and a counter is incremented in a step-by-step fashion such that the gain in the amplifier is reduced for as long as the output level lies above the reference level. The amplifier assembly enables frequency-dependent received field strength fluctuations that occur in frequency hopping methods to be corrected in a manner dependent on the conditions in the current time slot. The assembly is also suitable for modulation methods that use a modulation with phase and amplitude variation.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: February 22, 2011
    Assignee: Infineon Technologies AG
    Inventor: Elmar Wagner
  • Patent number: 7885625
    Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: February 8, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Khurram Muhammad, Meng-Chang Lee, Dirk Leipold
  • Patent number: 7881685
    Abstract: The present invention discloses an automatic gain controller with an amplifier (10) having an amplifier output connected to a mixer (20) and a receiver signal strength indicator (100) connected to the amplifier output and to a first counter (60). The first counter (60) is adapted to produce a signal to control gain of the amplifier (10) and receives its input from the receiver signal strength indicator (100) which causes the first counter (60) to count up or down depending on the strength of the signal output from the amplifier (10). The automatic gain controller also includes a second counter (70) which is connected to an applications circuit and is adapted to produce a signal to control gain of the mixer (20). The second counter (70) receives its input from a gain control signal from the applications circuit (50) and also from the first counter (60).
    Type: Grant
    Filed: December 31, 2007
    Date of Patent: February 1, 2011
    Assignee: Synopsys, Inc.
    Inventor: Ricardo dos Santos Reis
  • Patent number: 7860480
    Abstract: In one embodiment, the present invention includes a method for receiving a radio frequency (RF) signal and mixing the RF signal with a master clock to obtain a mixed signal, cyclically rotating the mixed signal to each of N gain stages for at least one cycle of the master clock, and summing the outputs of the N gain stages to provide an output signal.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: December 28, 2010
    Assignee: Silicon Laboratories Inc.
    Inventors: Aslamali A. Rafi, Alessandro Piovaccari
  • Patent number: 7830992
    Abstract: The present invention is directed to systems and methods for providing an AGC circuit for maintaining a constant output power level from an amplifier. More specifically, the AGC circuit includes a circuitry for determining whether an input signal is a QAM or a CW signal. A QAM/CW gain switch is then controlled depending upon the input signal. Depending upon the mode of the QAM/CW gain switch, the AGC circuit either attenuates the power level of the signal or bypasses the signal. The bypassed or attenuated signal is then compared to a reference signal so that the AGC circuit produces an adjusting voltage accordingly. The amplifier finally receives the adjusting voltage and attenuates the output power level of the signal.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: November 9, 2010
    Inventor: Jiening Ao
  • Patent number: 7809341
    Abstract: A received low-frequency standard radio wave, which is an amplitude modulation signal, is converted to an intermediate frequency signal Sa, and is output to a detection circuit and an AGC circuit. The detection circuit and AGC circuit generates an RF control signal Sf1 and IF control signal Sf2 from the input intermediate frequency signal Sa, and controls an RF control circuit and IF control circuit by outputting the generated RF control signal Sf1 and IF control signal Sf2 to the RF control circuit and IF control circuit. By this a radio wave reception device can speed up AGC operation.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: October 5, 2010
    Assignee: Casio Computer Co., Ltd.
    Inventor: Kaoru Someya
  • Publication number: 20100216418
    Abstract: An amplifier assembly and also a receiver including such an amplifier assembly is disclosed, wherein the amplifier includes a programming input for setting the gain thereof. The signal level at the output of the amplifier is compared with a reference level and a counter is incremented in a step-by-step fashion such that the gain in the amplifier is reduced for as long as the output level lies above the reference level. The amplifier assembly enables frequency-dependent received field strength fluctuations that occur in frequency hopping methods to be corrected in a manner dependent on the conditions in the current time slot. The assembly is also suitable for modulation methods that use a modulation with phase and amplitude variation.
    Type: Application
    Filed: May 11, 2010
    Publication date: August 26, 2010
    Inventor: Elmar WAGNER
  • Patent number: 7778223
    Abstract: Whether the reception electric field level of the antenna #1 is higher than the predetermined level is judged. If the reception electric field level of the antenna #1 is not higher than the predetermined level, the communication mode is to be set to the multi-slot mode, and then whether the reception electric field level of the antenna #1 is higher is judged by comparison of the reception electric field level of the antenna #1 and the reception electric field level of the antenna #2. If the reception electric field level of the antenna #1 is higher, the call mode is to be set to the antenna #1 for executing transmission and reception, or if the reception electric field level of the antenna #1 is not higher, the communication mode is to be set to the antenna #2 for executing transmission and reception.
    Type: Grant
    Filed: December 5, 2006
    Date of Patent: August 17, 2010
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Shinichi Sakakibara
  • Patent number: 7756504
    Abstract: In one embodiment, the present invention includes a mixer circuit to receive and generate a mixed signal from a radio frequency (RF) signal and a master clock signal, a switch stage coupled to an output of the mixer circuit to rotatingly switch the mixed signal to multiple gain stages coupled to the switch stage, and a combiner to combine an output of the gain stages.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: July 13, 2010
    Assignee: Silicon Laboratories Inc.
    Inventors: Aslamali A. Rafi, Alessandro Piovaccari
  • Patent number: 7746964
    Abstract: A signal processing apparatus includes a plurality of equalizer each used for a corresponding frequency band, controller for setting a gain value in each of the plurality of equalizer, and signal processor for processing an input signal by means of the plurality of equalizer. The controller determines a target gain value for each of the plurality of frequency bands, obtains a value of gain leakage from the first frequency band to a second frequency band adjacent to the first frequency band, updates a gain value set for the second frequency band, updates a gain value set for the first frequency band, repeats an update process for updating the gain value for each of the first frequency band and the second frequency band in an alternate manner until the gain value satisfies a predetermined condition, and sets the updated gain value for each of the frequency bands in the corresponding equalizer.
    Type: Grant
    Filed: December 4, 2006
    Date of Patent: June 29, 2010
    Assignee: Sony Corporation
    Inventor: Kenji Nakano
  • Patent number: 7738847
    Abstract: The circuit arrangement comprises a tuner with a control amplifier and a mixer connected downstream, and an automatic gain control. The automatic gain control contains a weighting filter, which is connected to the output of the mixer, upstream of an intermediate frequency filter, and which supplies the control signal for the control amplifier of the tuner via a detector. The weighting filter has, in particular, a passband, which corresponds to the passband of the intermediate frequency filter and at least partly encompasses at least one or two adjacent program channels. As a result of this, the control amplifier is better tuned under difficult reception conditions, since, by means of the weighting filter, adjacent channels, relative to the passband of the intermediate frequency filter, are also concomitantly included in the control signal.
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: June 15, 2010
    Assignee: Thomson Licensing
    Inventors: Stefan Stalf, Veit Armbruster
  • Patent number: 7734267
    Abstract: An amplifier assembly and also a receiver including such an amplifier assembly is disclosed, wherein the amplifier includes a programming input for setting the gain thereof. The signal level at the output of the amplifier is compared with a reference level and a counter is incremented in a step-by-step fashion such that the gain in the amplifier is reduced for as long as the output level lies above the reference level. The amplifier assembly enables frequency-dependent received field strength fluctuations that occur in frequency hopping methods to be corrected in a manner dependent on the conditions in the current time slot. The assembly is also suitable for modulation methods that use a modulation with phase and amplitude variation.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: June 8, 2010
    Assignee: Infineon Technologies AG
    Inventor: Elmar Wagner
  • Patent number: 7684772
    Abstract: A tuner down-converts a Radio Frequency (RF) wireless signal and outputs the converted signal. The tuner compensates for a TOP depending on a temperature and: detects a received signal strength depending on a RF output of the tuner and transmitting the detected strength to a gain control unit; measures an operating temperature of the tuner and transmits the measured temperature value; receives the measured temperature value to compare the received temperature value with a reference TOP value, compensating compensates for the TOP value depending on variation in temperature and outputting outputs the compensated value; and receives the compensated value to control the RF output based on the TOP value and the received signal strength.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: March 23, 2010
    Assignee: Integrant Technologies Inc.
    Inventors: Junghwan Lee, Bonkee Kim
  • Patent number: 7680476
    Abstract: A receiving device having an input receiving an input signal which includes a useful signal and an interference signal, a demodulator coupled to the input and generating a demodulated output signal from the input signal, which has an adjustable operating point, and a detector coupled to the demodulator and determining from the output signal a characteristic value representing a power level of the interference signal and setting the operating point of the demodulator as a function of the characteristic value.
    Type: Grant
    Filed: June 28, 2006
    Date of Patent: March 16, 2010
    Assignee: Infineon Technologies AG
    Inventor: Günther Tränkle
  • Patent number: 7676206
    Abstract: A radio receiver front-end includes a tunable antenna interface and a low noise amplifying section. The tunable antenna interface is operably coupled to receive a wide bandwidth signal from an antenna, wherein the wide bandwidth signal includes a plurality of channel signals, and wherein the tunable antenna interface is tuned to pass a selected one of the plurality of channel signals substantially unattenuated and to attenuate remaining ones of the plurality of channel signals to produce a filtered wide bandwidth signal. The low noise amplifying section is operably coupled to amplify the filtered wide bandwidth signal to produce a filtered and amplified wide bandwidth signal.
    Type: Grant
    Filed: December 5, 2005
    Date of Patent: March 9, 2010
    Assignee: Sigmatel, Inc.
    Inventors: Lawrence Henry Ragan, Matthew D. Felder, Jingyu Hu, Jamie Joseph Happ, Michael R. May
  • Patent number: 7647029
    Abstract: In a controller-assisted device for determining a characteristic of a compensation element in a level control circuit, the compensation element is serially mounted inside the level control circuit for a high-frequency signal (S<SB>HF</SB>) in a signal channel with respect to said signal channel. The characteristic of the compensation element has a characteristic which the inverse of the non-linear transmission characteristic of the signal channel in the event of ideal compensation. In the controller-assisted method for the determination of a characteristic of the compensation element in a level control circuit, each ordinate value of the characteristic of the compensation element arises, in the event of a bridged compensation element, from the corrective signal value (Pastel) which is adjusted at a signal level of the level reference signal (Pref) in the adjusted level control circuit, corresponding to the associated abscissa value of the characteristic of the compensation element.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: January 12, 2010
    Assignee: Rohde & Schwarz GmbH & Co. KG
    Inventors: Thomas Kuhwald, Werner Held
  • Patent number: 7634244
    Abstract: A multi-stage amplifier assembly configured to receive a terrestrial digital television (“DTV”) input signal including multiple frequency channels. The amplifier assembly optionally includes a PIN diode coupled across differential inputs to a first stage of the multi-stage amplifier assembly. The PIN diode is controlled to attenuate the input when an exceptionally large signal is present in a channel adjacent to a desired channel. The PIN diode, essentially a variable resistor, permits the multi-stage amplifier assembly to maintain dynamic range in such situations for reasonable tradeoffs. The amplifier assembly further optionally includes an out-of-band second stage LNA. The amplifier assembly further optionally includes a multi-band input filter. The multi-band filer insures that the AGC operates on the TV band of interest, thus improving the linearity of the system. The invention can be implemented in CMOS and/or SiGe.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: December 15, 2009
    Assignee: Broadcom Corporation
    Inventors: Lawrence M. Burns, Charles Brooks, Leonard Dauphinee
  • Patent number: 7627299
    Abstract: A signal processing device implemented in a semiconductor body includes a frequency conversion device and a converter connected to the frequency conversion device. The conversion device is coupled by a terminal to a terminal on the surface of the semiconductor body. One terminal of the converter is connected to a terminal node of the signal processing device. A signal generator, which is connected by its signal output to a local oscillator input of the frequency conversion device, has a control input for setting its operating point. Furthermore, a control circuit is provided. In this case, an output of the control circuit is connected to the control input of the signal generator. Depending on internal signals which identify an operating state of the signal processing device, the control circuit generates a regulating signal at the output.
    Type: Grant
    Filed: January 27, 2006
    Date of Patent: December 1, 2009
    Assignee: Infineon Technologies AG
    Inventors: Christian Münker, Bernd-Ulrich Klepser
  • Patent number: 7606550
    Abstract: In RF transceivers, a method and system for a dual mode receiver with low intermediate frequency (IF) and zero second IF are provided. An RF receivers may be adapted to operate in a low IF down conversion mode or a baseband down conversion mode. A control signal may be generated based on a local oscillator signal and may be utilized to configure a frequency mixer in accordance with the selected mode of operation. The frequency of the local oscillator may be based on the low IF value. When the low IF down conversion mode is selected, the frequency mixer operates in a pass through mode and the output may be transferred to a device with a low IF interface. When the baseband down conversion mode is selected, the output of the frequency mixer may be transferred to a baseband processor for further processing.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: October 20, 2009
    Assignee: Broadcom Corporation
    Inventors: Meng-An Pan, Hooman Darabi