Patents by Inventor Amir Amirkhany
Amir Amirkhany 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: 20120147944Abstract: High resolution output drivers having a relatively small number of sub-driver branches or slices each having nominal impedances substantially larger than a quantization step and that incrementally differ from one another by an impedance step substantially smaller than a quantization step. In one implementation, such “differential” or “non-uniform” sub-driver slices implement respective elements of an n choose k equalizer, with each such differential sub-driver slice being implemented by a uniform-element impedance calibration DAC. In another implementation, each component of a uniform-slice equalizer is implemented by a differential-slice impedance calibration DAC, and in yet another implementation, each component of a differential-slice equalizer is implemented by a differential-slice impedance calibration DAC.Type: ApplicationFiled: September 14, 2010Publication date: June 14, 2012Inventors: Amir Amirkhany, Chaofeng Huang, Kambiz Kaviani, Wayne D. Dettloof, Kun-Yung Chang
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Publication number: 20120139638Abstract: A receiver includes an amplifier and a transconductance bias circuit. The amplifier gain is largely determined by transconductance and load impedance. The transconductance bias circuit varies the transconductance in inverse proportion to the load impedance to maintain the gain over process, voltage, and temperature. Differential amplifiers can use separate transconductance bias circuits for each amplifier leg, and the bias circuits can be independently controlled to minimize common-mode gain and voltage offsets.Type: ApplicationFiled: December 2, 2011Publication date: June 7, 2012Applicant: Rambus Inc.Inventors: Kambiz Kaviani, Amir Amirkhany, Aliazam Abbasfar
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Patent number: 8149972Abstract: A data receiver circuit includes an interface to receive an input signal that includes a data signal and a clock signal superimposed on the data signal. The data signal has an associated symbol rate and an associated symbol period equal to the reciprocal of the associated symbol rate. The clock signal has a frequency N times the associated symbol rate, where N is an integer. A phase-locked loop (PLL) coupled to the interface extracts the clock signal from the input signal to provide an extracted clock signal. A phase interpolator adjusts the phase of the extracted clock signal to provide a phase-adjusted extracted clock signal. A sampling circuit samples the data signal at a sampling point. The sampling circuit is synchronized to the phase-adjusted extracted clock signal.Type: GrantFiled: May 28, 2008Date of Patent: April 3, 2012Assignee: Rambus Inc.Inventors: Aliazam Abbasfar, Amir Amirkhany, Bruno W. Garlepp
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Patent number: 8139675Abstract: A multi-tone system includes a data transmission circuit with an interface for receiving a data stream for transmission, a data steam splitter that splits the data stream to produce multiple substreams and a plurality of parallel data preparation circuits. Each data preparation circuit prepares a respective substream for transmission and generates a respective sub-channel signal. At least a first data preparation circuit of the plurality of parallel data preparation circuits includes a first analog filter for filtering a first substream. The first analog filter operates at a sample rate greater than the respective symbol rate of the first substream. The first analog filter provides pre-emphasis of the respective sub-channel signal and attenuation of signals outside of a respective band of frequencies corresponding to the respective sub-channel signal. The data transmission circuit also includes a combiner for combining respective sub-channel signals to generate a data transmission signal.Type: GrantFiled: October 19, 2010Date of Patent: March 20, 2012Assignee: Rambus Inc.Inventors: Vladimir M. Stojanovic, Amir Amirkhany, Jared L. Zerbe
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Patent number: 8031802Abstract: A data transmission circuit comprises a plurality of data preparation circuits and a combiner. Each data preparation circuit receives a respective data stream and generates a respective sub-channel signal. Each respective data stream has a respective symbol rate and a respective Nyquist bandwidth. The combiner combines the respective sub-channel signals to generate a data transmission signal having an associated bandwidth. The bandwidth associated with the data transmission signal is greater than or equal to the sum of the Nyquist bandwidths for the respective data streams. Each data preparation circuit comprises a programmable linear equalizer that equalizes the respective sub-channel signal across the bandwidth of the data transmission signal.Type: GrantFiled: November 9, 2007Date of Patent: October 4, 2011Assignee: Rambus Inc.Inventors: Aliazam Abbasfar, Amir Amirkhany
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Publication number: 20110228864Abstract: The frequency response of a first component signal path of a differential signaling link is adjusted to off-set a notch in the frequency response from a corresponding notch in the frequency response of a second component signal path of the differential signaling link.Type: ApplicationFiled: December 3, 2009Publication date: September 22, 2011Inventors: Farshid Aryanfar, Aliazam Abbasfar, Amir Amirkhany
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Publication number: 20110184999Abstract: A first device includes a linear transformation circuit to implement multiplication by a matrix D. The linear transformation circuit as an input to receive a vector having N digital values and an output to output N first output signals. The linear transformation circuit optionally includes a sign-adjustment circuit to adjust signs of a subset including at least M of the N first output signals in accordance with a set of coefficients H. The linear transformation circuit includes a digital-to-analog conversion (DAC) circuit coupled to the output of the sign-adjustment circuit. Outputs from the DAC circuit are summed to produce an output.Type: ApplicationFiled: April 8, 2011Publication date: July 28, 2011Inventors: Aliazam Abbasfar, Amir Amirkhany, Vladimir Stojanovic, Mark A. Horowitz
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Publication number: 20110150051Abstract: A multi-tone system includes a data transmission circuit with an interface for receiving a data stream for transmission, a data steam splitter that splits the data stream to produce multiple substreams and a plurality of parallel data preparation circuits. Each data preparation circuit prepares a respective substream for transmission and generates a respective sub-channel signal. At least a first data preparation circuit of the plurality of parallel data preparation circuits includes a first analog filter for filtering a first substream. The first analog filter operates at a sample rate greater than the respective symbol rate of the first substream. The first analog filter provides pre-emphasis of the respective sub-channel signal and attenuation of signals outside of a respective band of frequencies corresponding to the respective sub-channel signal. The data transmission circuit also includes a combiner for combining respective sub-channel signals to generate a data transmission signal.Type: ApplicationFiled: October 19, 2010Publication date: June 23, 2011Inventors: Vladimir M. Stojanovic, Amir Amirkhany, Jared L. Zerbe
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Patent number: 7925686Abstract: A first device is described. The first device may include a linear transformation circuit to implement multiplication by a matrix D. The linear transformation circuit may have an input to receive a vector having N digital values and an output to output N first output signals, a sign-adjustment circuit to adjust signs of a subset including at least M of the N first output signals in accordance with a set of coefficients H, and a conversion (DAC) circuit coupled to the sign-adjustment circuit. Outputs from the DAC circuit may be summed to produce an output.Type: GrantFiled: December 19, 2005Date of Patent: April 12, 2011Assignee: Rambus Inc.Inventors: Aliazam Abbasfar, Amir Amirkhany, Vladimir Stojanovic, Mark A. Horowitz
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Patent number: 7907676Abstract: A communication system utilizing an adjustable link has at least a first data transmission circuit including at least a first communication link circuit. The first communication link circuit has a baseband circuit and at least a passband circuit. The baseband circuit corresponds to a baseband sub-channel and the passband circuit corresponds to a passband sub-channel. The first communication link circuit also includes a circuit that distributes a first subset of a data stream having a first symbol rate to the baseband circuit and a second subset of the data stream having a second symbol rate to the passband circuit. The baseband sub-channel and the passband sub-channel are separated by an adjacent guardband of frequencies. The passband carrier frequency is adjusted to define the guardband and the guardband corresponds to a first notch in a channel response of a first communications channel.Type: GrantFiled: October 6, 2009Date of Patent: March 15, 2011Assignee: Rambus Inc.Inventors: Vladimir M. Stojanovic, Amir Amirkhany, Jared L. Zerbe
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Publication number: 20110019722Abstract: A data transmission circuit has an interface for receiving a data stream for transmission, a data stream splitter, a plurality of parallel data preparation circuits, and a combiner. The data stream splitter splits the data stream to produce multiple substreams, the plurality of parallel data preparation circuits prepare a respective substream for transmission and generate a respective sub-channel signal, and the combiner combines the respective sub-channel signals to generate a data transmission signal. At least two of the plurality of data preparation circuits each include a programmable element for delaying the corresponding substream.Type: ApplicationFiled: July 16, 2010Publication date: January 27, 2011Inventor: Amir Amirkhany
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Patent number: 7817743Abstract: A multi-tone system includes a data transmission circuit with an interface for receiving a data stream for transmission, a data steam splitter that splits the data stream to produce multiple substreams and a plurality of parallel data preparation circuits. Each data preparation circuit prepares a respective substream for transmission and generates a respective sub-channel signal. At least a first data preparation circuit of the plurality of parallel data preparation circuits includes a first analog filter for filtering a first substream. The first analog filter operates at a sample rate greater than the respective symbol rate of the first substream. The first analog filter provides pre-emphasis of the respective sub-channel signal and attenuation of signals outside of a respective band of frequencies corresponding to the respective sub-channel signal. The data transmission circuit also includes a combiner for combining respective sub-channel signals to generate a data transmission signal.Type: GrantFiled: December 22, 2004Date of Patent: October 19, 2010Assignee: Rambus Inc.Inventors: Vladimir M. Stojanovic, Amir Amirkhany, Jared L. Zerbe
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Publication number: 20100128813Abstract: A data transmission circuit comprises a plurality of data preparation circuits and a combiner. Each data preparation circuit receives a respective data stream and generates a respective sub-channel signal. Each respective data stream has a respective symbol rate and a respective Nyquist bandwidth. The combiner combines the respective sub-channel signals to generate a data transmission signal having an associated bandwidth. The bandwidth associated with the data transmission signal is greater than or equal to the sum of the Nyquist bandwidths for the respective data streams. Each data preparation circuit comprises a programmable linear equalizer that equalizes the respective sub-channel signal across the bandwidth of the data transmission signal.Type: ApplicationFiled: November 9, 2007Publication date: May 27, 2010Inventors: Aliazam Abbasfar, Amir Amirkhany
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Patent number: 7711063Abstract: A transmitter with data stream transformation circuitry is described. The transmitter has a first driver and a second driver. Each driver has an output for a respective analog signal. A summation circuit combines respective analog signals from the first driver and the second driver. A data selection circuit processes at least two data streams. Each data stream corresponds to a time sequence of digital data symbols. The data selection circuit selectively couples at least one of the data streams to at least one of the drivers during each time interval of a sequence of time intervals, thereby applying a linear transformation to the data streams. A finite state machine controls the data selection circuit during each time interval of the sequence of time intervals.Type: GrantFiled: August 25, 2005Date of Patent: May 4, 2010Assignees: Rambus, Inc., The Board of Trustees of the Leland Stanford Junior UniversityInventors: Elad Alon, Vladimir Stojanovic, Amir Amirkhany
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Publication number: 20100020898Abstract: A communication system utilizing an adjustable link has at least a first data transmission circuit including at least a first communication link circuit. The first communication link circuit has a baseband circuit and at least a passband circuit. The baseband circuit corresponds to a baseband sub-channel and the passband circuit corresponds to a passband sub-channel. The first communication link circuit also includes a circuit that distributes a first subset of a data stream having a first symbol rate to the baseband circuit and a second subset of the data stream having a second symbol rate to the passband circuit. The baseband sub-channel and the passband sub-channel are separated by an adjacent guardband of frequencies. The passband carrier frequency is adjusted to define the guardband and the guardband corresponds to a first notch in a channel response of a first communications channel.Type: ApplicationFiled: October 6, 2009Publication date: January 28, 2010Inventors: Vladimir M. Stojanovic, Amir Amirkhany, Jared L. Zerbe
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Patent number: 7599422Abstract: A communication system utilizing an adjustable link has at least a first data transmission circuit including at least a first communication link circuit. The first communication link circuit has a baseband circuit and at least a passband circuit. The baseband circuit corresponds to a baseband sub-channel and the passband circuit corresponds to a passband sub-channel. The first communication link circuit also includes a circuit that distributes a first subset of a data stream having a first symbol rate to the baseband circuit and a second subset of the data stream having a second symbol rate to the passband circuit. The baseband sub-channel and the passband sub-channel are separated by an adjacent guardband of frequencies. The passband carrier frequency is adjusted to define the guardband and the guardband corresponds to a first notch in a channel response of a first communications channel.Type: GrantFiled: November 11, 2008Date of Patent: October 6, 2009Assignee: Rambus Inc.Inventors: Vladimir M. Stojanovic, Amir Amirkhany, Jared L. Zerbe
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Publication number: 20090202004Abstract: An analog multi-tone receiver includes an interface for receiving a data transmission signal containing N sub-channel signals corresponding to N active sub-channels. The receiver includes a plurality of samplers to sample, during each time interval of a sequence of time intervals, the received signal in parallel to produce a plurality of data sets, each sampler having a distinct threshold level. The receiver includes a decoder to jointly decode the plurality of data sets to determine a plurality of data symbols including at least one data symbol for each of the N active sub-channels.Type: ApplicationFiled: February 11, 2009Publication date: August 13, 2009Inventor: Amir Amirkhany
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Publication number: 20090067537Abstract: A communication system utilizing an adjustable link has at least a first data transmission circuit including at least a first communication link circuit. The first communication link circuit has a baseband circuit and at least a passband circuit. The baseband circuit corresponds to a baseband sub-channel and the passband circuit corresponds to a passband sub-channel. The first communication link circuit also includes a circuit that distributes a first subset of a data stream having a first symbol rate to the baseband circuit and a second subset of the data stream having a second symbol rate to the passband circuit. The baseband sub-channel and the passband sub-channel are separated by an adjacent guardband of frequencies. The passband carrier frequency is adjusted to define the guardband and the guardband corresponds to a first notch in a channel response of a first communications channel.Type: ApplicationFiled: November 11, 2008Publication date: March 12, 2009Inventors: Vladimir M. Stojanovic, Amir Amirkhany, Jared L. Zerbe
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Patent number: 7483491Abstract: A transform circuit includes a first circuit and a second circuit. The first circuit and the second circuit implement first and second mappings that together generate a pre-defined transform of N digital data symbols. The first circuit maps a set of N digital data symbols from N parallel data streams to N analog data symbols by generating N sets of first weighted sums of the N digital data symbols. Each respective first weighted sum is defined by a respective set of pre-determined first weighting values in a first matrix. The second circuit maps the N analog data symbols to a sequence of N output signals over N time intervals. Each of the N output signals corresponds to a respective second weighted sum of the N analog data symbols. Each respective second weighted sum is defined by a respective set of pre-determined second weighting values in a second matrix.Type: GrantFiled: November 6, 2006Date of Patent: January 27, 2009Assignee: Rambus Inc.Inventors: Amir Amirkhany, Vladimir Stojanovic, Elad Alon, Jared LeVan Zerbe, Mark A. Horowitz
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Publication number: 20080310491Abstract: A multi-mode transmitter within an integrated circuit device. The multi-mode transmitter transmits a first data sequence in a baseband signal when a first transmission mode is enabled, and transmits the first data sequence in a multi-band signal when a second transmission mode is enabled.Type: ApplicationFiled: May 8, 2008Publication date: December 18, 2008Inventors: Aliazam Abbasfar, Amir Amirkhany