Patents by Inventor Rajasekhar Pullela
Rajasekhar Pullela has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20200052730Abstract: A wireless communication device includes a radio frequency antenna and a transceiver. The transceiver includes a receiver having a switching architecture configured to generate a plurality of output phases within a local oscillator period based on the filtered RF signal and a respective plurality of local oscillator signals. The plurality of output phases can be organized into at least K groups where K is an integer of four or greater, and each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases. The receiver can difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases.Type: ApplicationFiled: July 19, 2019Publication date: February 13, 2020Inventors: Rajasekhar Pullela, William J. Domino
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Patent number: 10404302Abstract: A wireless communication device includes a radio frequency antenna and a transceiver. The transceiver includes a receiver having a switching architecture configured to generate a plurality of output phases within a local oscillator period based on the filtered RF signal and a respective plurality of local oscillator signals. The plurality of output phases can be organized into at least K groups where K is an integer of four or greater, and each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases. The receiver can difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases.Type: GrantFiled: April 26, 2017Date of Patent: September 3, 2019Assignee: Skyworks Solutions, Inc.Inventors: Rajasekhar Pullela, William J. Domino
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Patent number: 10135573Abstract: Methods and systems for improved cross polarization rejection and tolerating of coupling between satellite signals may comprise receiving radio frequency (RF) signals on a chip, where the RF signals comprising a desired signal and at least one crosstalk signal. The received RF signals may be down-converted to baseband frequencies, and the down-converted signals are converted to digital signals. Crosstalk may be determined by estimating complex coupling coefficients between the received RF signals utilizing a de-correlation algorithm across a frequency bandwidth comprising the desired and crosstalk signals. The down-converted signals may be low-pass filtered and summed with an output signal from a cancellation filter. The complex coupling coefficients may be determined utilizing the de-correlation algorithm on the summed signals, and may be used to configure the cancellation filter.Type: GrantFiled: January 25, 2018Date of Patent: November 20, 2018Assignee: Maxlinear, Inc.Inventors: Rajasekhar Pullela, Timothy Gallagher, Glenn Chang
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Patent number: 10063343Abstract: Apparatus and methods for transmit power control in wireless communication systems are provided. In one aspect, a wireless communication system includes a transmit chain that generates a transmit signal based on a data signal having a time-varying signal envelope, a power amplifier that amplifies the transmit signal, and a transmit chain controller that generates a first power control signal and a second power control signal that control an adjustable power level of the transmit chain. The transmit chain controller includes an error extractor that generates an error signal based on comparing an output signal power of the power amplifier to the time-varying signal envelope. The transmit chain controller further includes a control signal generator that generates the first power control signal and an adjustment signal based on estimating the error signal, and that generates the second power control signal based on the error signal and the adjustment signal.Type: GrantFiled: December 13, 2016Date of Patent: August 28, 2018Assignee: Skyworks Solutions, Inc.Inventors: Dmitriy Rozenblit, Rajasekhar Pullela, Jaleh Komaili, Masoud Kahrizi, Shahrzad Tadjpour
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Publication number: 20180152265Abstract: Methods and systems for improved cross polarization rejection and tolerating of coupling between satellite signals may comprise receiving radio frequency (RF) signals on a chip, where the RF signals comprising a desired signal and at least one crosstalk signal. The received RF signals may be down-converted to baseband frequencies, and the down-converted signals are converted to digital signals. Crosstalk may be determined by estimating complex coupling coefficients between the received RF signals utilizing a de-correlation algorithm across a frequency bandwidth comprising the desired and crosstalk signals. The down-converted signals may be low-pass filtered and summed with an output signal from a cancellation filter. The complex coupling coefficients may be determined utilizing the de-correlation algorithm on the summed signals, and may be used to configure the cancellation filter.Type: ApplicationFiled: January 25, 2018Publication date: May 31, 2018Inventors: Rajasekhar Pullela, Timothy Gallagher, Glenn Chang
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Publication number: 20170331504Abstract: A wireless communication device includes a radio frequency antenna a transceiver. The transceiver includes a receiver having a switching architecture configured to generate a plurality of output phases within a local oscillator period based on the filtered RF signal and a respective plurality of local oscillator signals. The plurality of output phases can be organized into at least K groups where K is an integer of four or greater, and each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases. The receiver can difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases.Type: ApplicationFiled: April 26, 2017Publication date: November 16, 2017Inventors: Rajasekhar Pullela, William J. Domino
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Patent number: 9667293Abstract: A low noise receiver includes a downconverter configured to receive a radio frequency (RF) signal, the downconverter comprising a switching architecture configured to generate a plurality of output phases based on a respective plurality of local oscillator (LO) signals, a differencing circuit configured to combine the plurality of output phases such that an nth output phase is differenced with an (n+K)th output phase, resulting in gain-added output phases, and a summation filter configured to receive the gain-added output phases and configured to combine the gain-added output phases such that a response of the receiver effectively reduces odd harmonics of the RF signal.Type: GrantFiled: May 21, 2015Date of Patent: May 30, 2017Assignee: SKYWORKS SOLUTIONS, INC.Inventors: Rajasekhar Pullela, William J. Domino
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Publication number: 20170093524Abstract: Apparatus and methods for transmit power control in wireless communication systems are provided. In one aspect, a wireless communication system includes a transmit chain that generates a transmit signal based on a data signal having a time-varying signal envelope, a power amplifier that amplifies the transmit signal, and a transmit chain controller that generates a first power control signal and a second power control signal that control an adjustable power level of the transmit chain. The transmit chain controller includes an error extractor that generates an error signal based on comparing an output signal power of the power amplifier to the time-varying signal envelope. The transmit chain controller further includes a control signal generator that generates the first power control signal and an adjustment signal based on estimating the error signal, and that generates the second power control signal based on the error signal and the adjustment signal.Type: ApplicationFiled: December 13, 2016Publication date: March 30, 2017Inventors: Dmitriy Rozenblit, Rajasekhar Pullela, Jaleh Komaili, Masoud Kahrizi, Shahrzad Tadjpour
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Patent number: 9559808Abstract: Apparatus and methods for power control in mobile communication devices are provided. In one aspect, a wireless communication device includes a transmit chain that receives a digital in-phase (I) signal and a digital quadrature-phase (Q) signal and that generates a transmit signal. The wireless communication device further includes a power amplifier that amplifies the transmit signal, and a transmit chain controller including a reference generator that combines the digital I signal and the digital Q signal and generates a reference signal corresponding to an instantaneous value of an envelope of the combined signal. The transmit chain controller further includes an error extractor that generates an error signal based on the reference signal and an output power of the power amplifier, and a control signal generator that uses the error signal to generate one or more power control signals for controlling an adjustable power level of the transmit chain.Type: GrantFiled: October 30, 2015Date of Patent: January 31, 2017Assignee: SKYWORKS SOLUTIONS, INC.Inventors: Dmitriy Rozenblit, Rajasekhar Pullela, Jaleh Komaili, Masoud Kahrizi, Shahrzad Tadjpour
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Publication number: 20160056917Abstract: Apparatus and methods for power control in mobile communication devices are provided. In one aspect, a wireless communication device includes a transmit chain that receives a digital in-phase (I) signal and a digital quadrature-phase (Q) signal and that generates a transmit signal. The wireless communication device further includes a power amplifier that amplifies the transmit signal, and a transmit chain controller including a reference generator that combines the digital I signal and the digital Q signal and generates a reference signal corresponding to an instantaneous value of an envelope of the combined signal. The transmit chain controller further includes an error extractor that generates an error signal based on the reference signal and an output power of the power amplifier, and a control signal generator that uses the error signal to generate one or more power control signals for controlling an adjustable power level of the transmit chain.Type: ApplicationFiled: October 30, 2015Publication date: February 25, 2016Inventors: Dmitriy Rozenblit, Rajasekhar Pullela, Jaleh Komaili, Masoud Kahrizi, Shahrzad Tadjpour
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Patent number: 9209770Abstract: Apparatus and methods for power control in mobile communication devices are provided. In one aspect, a method for accurately controlling an adjustable power level of a data signal in a transmit chain of a transmitter is provided. The method includes adjusting a controllable gain level of a digital-to-analog converter based on a desired peak-to-average ratio of a transmit signal envelope, adjusting a digitally controlled discrete gain-step amplifier, the amount of gain per step based on an initial estimate of the transmitter gain and a target power, applying a factor to a gain adjuster responsive to the gain step change in the transmit chain, and repeating the adjusting and applying steps until a feedback signal level exceeds a reference signal level.Type: GrantFiled: October 10, 2014Date of Patent: December 8, 2015Assignee: SKYWORKS SOLUTIONS, INC.Inventors: Dmitriy Rozenblit, Rajasekhar Pullela, Jaleh Komaili, Masoud Kahrizi, Shahrzad Tadjpour
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Publication number: 20150333785Abstract: A low noise receiver includes a downconverter configured to receive a radio frequency (RF) signal, the downconverter comprising a switching architecture configured to generate a plurality of output phases based on a respective plurality of local oscillator (LO) signals, a differencing circuit configured to combine the plurality of output phases such that an nth output phase is differenced with an (n+K)th output phase, resulting in gain-added output phases, and a summation filter configured to receive the gain-added output phases and configured to combine the gain-added output phases such that a response of the receiver effectively reduces odd harmonics of the RF signal.Type: ApplicationFiled: May 21, 2015Publication date: November 19, 2015Inventors: Rajasekhar Pullela, William J. Domino
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Patent number: 9071325Abstract: A low noise receiver includes a downconverter configured to receive a radio frequency (RF) signal, the downconverter comprising a switching architecture configured to generate a plurality of output phases based on a respective plurality of local oscillator (LO) signals, a differencing circuit configured to combine the plurality of output phases such that an nth output phase is differenced with an (n+K)th output phase, resulting in gain-added output phases, and a summation filter configured to receive the gain-added output phases and configured to combine the gain-added output phases such that a response of the receiver effectively reduces odd harmonics of the RF signal.Type: GrantFiled: September 14, 2011Date of Patent: June 30, 2015Assignee: Skyworks Solutions, Inc.Inventors: Rajasekhar Pullela, William J. Domino
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Publication number: 20150023450Abstract: Apparatus and methods for power control in mobile communication devices are provided. In one aspect, a method for accurately controlling an adjustable power level of a data signal in a transmit chain of a transmitter is provided. The method includes adjusting a controllable gain level of a digital-to-analog converter based on a desired peak-to-average ratio of a transmit signal envelope, adjusting a digitally controlled discrete gain-step amplifier, the amount of gain per step based on an initial estimate of the transmitter gain and a target power, applying a factor to a gain adjuster responsive to the gain step change in the transmit chain, and repeating the adjusting and applying steps until a feedback signal level exceeds a reference signal level.Type: ApplicationFiled: October 10, 2014Publication date: January 22, 2015Inventors: Dmitriy Rozenblit, Rajasekhar Pullela, Jaleh Komaili, Masoud Kahrizi, Shahrzad Tadjpour
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Patent number: 8874051Abstract: A transmitter adjusts a transmitted power level by modifying a control input of a variable gain amplifier. A power amplifier control system includes an envelope extractor, an error extractor, and a feed-forward multiplier. The envelope extractor receives data signal inputs and computes the envelope of the combined signal. The error extractor generates an error signal as a function of the combined signal and the output power generated by the power amplifier. The feed-forward multiplier generates a modified error signal that is responsive to a function of the gain in a feedback path. A corresponding method for controlling a power level is also disclosed. In some embodiments, a transmit chain with a power control loop is used to adjust the transmit signal power applied at an input of a variable gain amplifier. A corresponding method for adjusting the transmit signal power level is also included.Type: GrantFiled: December 2, 2011Date of Patent: October 28, 2014Assignee: Skyworks Solutions, Inc.Inventors: Dmitriy Rozenblit, Masoud Kahrizi, Jaleh Komaili, Rajasekhar Pullela, Shahrzad Tadjpour
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Publication number: 20140198835Abstract: A multi-standard receiver may comprise in an electronic device, receiving an input radio frequency (RF) signal comprising at least two RF signals of different communication standards. The input RF signal may be separated into two signals based on their different communication standard sand configurable gain levels may be applied to equalize their magnitudes. The amplified signals may be combined, and the combined signals may be converted to a digital signal. The configurable gain may be applied to the two signals using variable gain amplifiers. A null may be generated at the input of at least one of the variable gain amplifiers utilizing a mixer and a filter, both configured to a desired frequency. The desired frequency may correspond to an interferer signal. The input RF signal may be separated into two signals utilizing a diplexer. The input RF signal may be received from a wired connection and/or an antenna.Type: ApplicationFiled: January 14, 2014Publication date: July 17, 2014Inventors: Curtis Ling, Rajasekhar Pullela
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Patent number: 8406707Abstract: Various embodiments of systems and methods for generating local oscillator (LO) signals for a harmonic rejection mixer are provided. One embodiment is a system for generating local oscillator (LO) signals for a harmonic rejection mixer. One such system comprises a local oscillator, a divide-by-N frequency divider, a divide-by-three frequency divider, and a harmonic rejection mixer. The local oscillator is configured to provide a reference frequency signal. The divide-by-N frequency divider is configured to divide the reference frequency signal by a value N and provide an output signal. The divide-by-three frequency divider is configured to receive the output signal of the divide-by-N frequency divider and divide the output signal into three phase-offset signals. The harmonic rejection mixer is configured to receive the three phase-offset signals and eliminate third frequency harmonics.Type: GrantFiled: March 14, 2012Date of Patent: March 26, 2013Assignee: Skyworks Solutions, Inc.Inventors: Rajasekhar Pullela, Dmitriy Rozenblit, Hamid Firouzkouhi
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Patent number: 8396436Abstract: A system for calibrating a closed power control loop includes an adder configured to inject a test signal into an adjustable element, a first peak detector configured to determine an amplitude of the injected test signal, a second peak detector configured to determine an amplitude of a return test signal, a comparator configured to determine the difference between the injected test signal and the return test signal, and a calibration engine configured to adjust the adjustable element so that the return test signal is offset from the injected test signal by a predetermined amount.Type: GrantFiled: December 5, 2011Date of Patent: March 12, 2013Assignee: Skyworks Solutions, Inc.Inventors: Dmitriy Rozenblit, Tirdad Sowlati, Dongsoo Daniel Koh, Rajasekhar Pullela
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Patent number: 8275326Abstract: A low noise divider includes a voltage controlled oscillator (VCO) having a first frequency output, a frequency divider configured to receive the first frequency output and configured to provide a second frequency output; and a buffer circuit configured to receive the first frequency output and the second frequency output, the buffer circuit configured to provide the second frequency output as an output of the low noise divider, where a phase noise of the second frequency output is dependent only on a phase noise of the first frequency output.Type: GrantFiled: August 10, 2007Date of Patent: September 25, 2012Assignee: Skyworks Solutions, Inc.Inventors: Rajasekhar Pullela, Sohrab Samadian
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Publication number: 20120170624Abstract: A transmitter adjusts a transmitted power level by modifying a control input of a variable gain amplifier. A power amplifier control system includes an envelope extractor, an error extractor, and a feed-forward multiplier. The envelope extractor receives data signal inputs and computes the envelope of the combined signal. The error extractor generates an error signal as a function of the combined signal and the output power generated by the power amplifier. The feed-forward multiplier generates a modified error signal that is responsive to a function of the gain in a feedback path. A corresponding method for controlling a power level is also disclosed. In some embodiments, a transmit chain with a power control loop is used to adjust the transmit signal power applied at an input of a variable gain amplifier. A corresponding method for adjusting the transmit signal power level is also included.Type: ApplicationFiled: December 2, 2011Publication date: July 5, 2012Applicant: SKYWORKS SOLUTIONS, INC.Inventors: Dmitriy Rozenblit, Masoud Kahrizi, Jaleh Komaili, Rajasekhar Pullela, Shahrzad Tadjpour