Patents by Inventor Aslamali A. Rafi

Aslamali A. Rafi 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).

  • Publication number: 20100130155
    Abstract: A receiver (400) includes a tracking bandpass filter (420), a tunable lowpass filter (434), a local oscillator (442), and a mixer (444). The tracking bandpass filter (420) has an input for receiving a radio frequency (RF) input signal, and an output. The tunable lowpass filter (434) has an input coupled to the output of the tracking bandpass filter (420), and an output. The local oscillator (422) has a first output for providing a local oscillator signal, which is characterized as being a square wave signal at the desired intermediate frequency (IF). The mixer (444) has a first input coupled to the output of the tunable lowpass filter (434), a second input coupled to the output of the local oscillator (442), and a first output for providing an IF signal at the desired IF. The tunable lowpass filter (434) is configured to substantially attenuate a third harmonic of the frequency of the local oscillator signal.
    Type: Application
    Filed: November 25, 2008
    Publication date: May 27, 2010
    Applicant: SILICON LABORATORIES, INC.
    Inventors: Ramin Khoini-Poorfard, Alessandro Piovaccari, Aslamali A. Rafi
  • Publication number: 20100130158
    Abstract: A receiver (400) includes a tracking bandpass filter (420) and a signal processing circuit (430-480). The tracking bandpass filter (420) has a first input for receiving a radio frequency (RF) signal, and an output, and includes a first portion (731) on a semiconductor die (730), and at least one inductor (721). The at least one inductor (721) is operatively coupled to the first portion of the tracking bandpass filter (420). The signal processing circuit (430-480) has an input coupled to the output of the tracking bandpass filter (420), and an output for providing a processed signal. The semiconductor die (730) and the at least one inductor (721) are integrated into a single multi-chip module (MCM) (710).
    Type: Application
    Filed: November 25, 2008
    Publication date: May 27, 2010
    Applicant: SILICON LABORATORIES, INC.
    Inventors: Ramin Khoini-Poorfard, Alessandro Piovaccari, Aslamali A. Rafi, Mustafa H. Koroglu, David S. Trager
  • Publication number: 20090004993
    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: Application
    Filed: June 29, 2007
    Publication date: January 1, 2009
    Inventors: Aslamali A. Rafi, Alessandro Piovaccari
  • Publication number: 20090004994
    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: Application
    Filed: June 29, 2007
    Publication date: January 1, 2009
    Inventors: Aslamali A. Rafi, Alessandro Piovaccari
  • Publication number: 20080076363
    Abstract: A system includes a cellular radio and an FM transmitter that are fabricated in the same semiconductor. The FM transmitter includes at least one mixer, a filter and an antenna tuning network. The mixer(s) translate an intermediate carrier frequency of an input signal to generate a second signal that has an FM carrier frequency. The filter removes spectral energy from the second signal to generate a third signal. The antenna tuning network is separate from the filter and produces a fourth signal to drive an antenna in response to the third signal.
    Type: Application
    Filed: September 27, 2006
    Publication date: March 27, 2008
    Inventors: Aslamali A. Rafi, Dan B. Kasha
  • Publication number: 20080076375
    Abstract: A technique includes providing a plurality of local oscillator signals such that each of the local oscillator signals has a different phase. The technique includes providing scaling units to scale the input signal pursuant to different scaling factors to generate scaled input signals. The scaling factors are selected on a periodic function of the phases. The technique also includes providing mixing circuits to mix the local oscillator signals with the scaled input signals to generate mixed signals and providing an adder to combine the mixed signals to generate an output signal.
    Type: Application
    Filed: September 27, 2006
    Publication date: March 27, 2008
    Inventors: Daniel J. Cooley, Aslamali A. Rafi
  • Publication number: 20070238421
    Abstract: A technique includes digitally generating orthogonal modulated signals, each of which has spectral energy that is generally centered at an intermediate frequency. The orthogonal modulated signals are frequency translated to produce translated signals, each of which has spectral energy that is generally centered about a second frequency that is higher than the intermediate frequency. The translated signals are combined to generate a modulated signal.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 11, 2007
    Inventors: Aslamali Rafi, George Tuttle, Lawrence Der
  • Publication number: 20070238423
    Abstract: A communications device is provided. The communications device includes a first antenna port coupled to a signal line, transmitter circuitry coupled to the signal line and configured to broadcast a radio frequency (RF) output signal across the first antenna port, tuning circuitry coupled to the signal line, and a controller configured to adjust a tuning of the tuning circuitry. The first antenna port, the transmitter circuitry, the tuning circuitry, and the controller are at least partially integrated on the same integrated circuit.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 11, 2007
    Inventors: Dan Kasha, Aslamali Rafi, Abhishek Kammula, Peter Vancorenland, George Tuttle
  • Publication number: 20070232248
    Abstract: A communications device is provided. The communications device includes first output stage circuitry configured to generate a first radio frequency (RF) output signal in response to receiving an RF input signal, a first antenna port configured to couple to a first antenna and configured receive the first RF output signal from the first output stage circuitry, second output stage circuitry configured to generate a second RF output signal in response to receiving the first RF output signal, and a second antenna port configured to couple to a second antenna and configured to receive the second RF output signal from the second output stage circuitry. The first output stage circuitry, the first antenna port, the second output stage circuitry, and the second antenna port are at least partially integrated on the same integrated circuit.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 4, 2007
    Inventors: Dan Kasha, Aslamali Rafi, Abhishek Kammula, Peter Vancorenland, George Tuttle
  • Publication number: 20070232236
    Abstract: A radio frequency (RF) communications device is provided. The RF communications device includes transmitter circuitry configured to generate a calibration signal on a signal line coupled to an antenna port in a calibration mode of operation and an RF output signal for broadcast across the antenna port subsequent to the calibration mode of operation, tuning circuitry coupled to the signal line and configured to receive the calibration signal, and a controller configured to adjust a signal level of the calibration signal generated by the transmitter circuitry and a tuning of the tuning circuitry during the calibration mode of operation. The transmitter circuitry, the tuning circuitry, and the controller are at least partially integrated on the same integrated circuit.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 4, 2007
    Inventors: Dan Kasha, Aslamali Rafi, Abhishek Kammula, Peter Vancorenland, George Tuttle
  • Publication number: 20070232367
    Abstract: A communications device is provided. The communications device includes an antenna port, transmitter circuitry configured to broadcast a radio frequency (RF) output signal across the antenna port, and a controller configured to adjust a signal level of the RF output signal in accordance with antenna compensation information. The antenna port, the transmitter circuitry, and the controller are at least partially integrated on the same integrated circuit.
    Type: Application
    Filed: March 31, 2006
    Publication date: October 4, 2007
    Inventors: Dan Kasha, Peter Vancorenland, Aslamali Rafi
  • Patent number: 7242912
    Abstract: Components of a radio-frequency (RF) apparatus including transceiver circuitry and frequency modification circuitry of a crystal oscillator circuit that generates a reference signal with adjustable frequency may be partitioned in a variety of ways, for example, as one or more separate integrated circuits. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator (“DCXO”) circuitry and a crystal. The frequency modification circuitry may include at least one variable capacitance device and may be employed to generate a reference signal with adjustable frequency. The adjustable reference signal may be provided to other components of the RF apparatus and/or the RF apparatus may be configured to provide the adjustable reference signal to baseband processor circuitry.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: July 10, 2007
    Assignee: Silicon Laboratories Inc.
    Inventors: James Maligeorgos, Augusto M. Marques, Lysander Lim, G. Tyson Tuttle, Aslamali A. Rafi, Tod Paulus, Gregory T. Uehara, Jeffrey W. Scott, Richard T. Behrens, Donald A. Kerth, G. Diwakar Vishakhadatta, Vishnu S. Srinivasan, Caiyi Wang
  • Patent number: 7221921
    Abstract: Components of a radio-frequency (RF) apparatus including transceiver circuitry and frequency modification circuitry of a crystal oscillator circuit that generates a reference signal with adjustable frequency may be partitioned in a variety of ways, for example, as one or more separate integrated circuits. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator (“DCXO”) circuitry and a crystal. The frequency modification circuitry may include at least one variable capacitance device and may be employed to generate a reference signal with adjustable frequency. The adjustable reference signal may be provided to other components of the RF apparatus and/or the RF apparatus may be configured to provide the adjustable reference signal to baseband processor circuitry.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: May 22, 2007
    Assignee: Silicon Laboratories
    Inventors: James Maligeorgos, Augusto M. Marques, Lysander Lim, G. Tyson Tuttle, Aslamali A. Rafi, Tod Paulus, Gregory T. Uehara, Jeffrey W. Scott, Richard T. Behrens, Donald A. Kerth, G. Diwakar Vishakhadatta, Vishnu S. Srinivasan, Caiyi Wang
  • Publication number: 20070054629
    Abstract: Components of a radio-frequency (RF) apparatus including transceiver circuitry and frequency modification circuitry of a crystal oscillator circuit that generates a reference signal with adjustable frequency may be partitioned in a variety of ways, for example, as one or more separate integrated circuits. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator (“DCXO”) circuitry and a crystal. The frequency modification circuitry may include at least one variable capacitance device and may be employed to generate a reference signal with adjustable frequency. The adjustable reference signal may be provided to other components of the RF apparatus and/or the RF apparatus may be configured to provide the adjustable reference signal to baseband processor circuitry.
    Type: Application
    Filed: December 8, 2003
    Publication date: March 8, 2007
    Inventors: James Maligeorgos, Augusto Marques, Lysander Lim, G. Tuttle, Aslamali Rafi, Tod Paulus, Gregory Uehara, Jeffrey Scott, Richard Behrens, Donald Kerth, G. Vishakhadatta, Vishnu Srinivasan, Caiyi Wang
  • Patent number: 7158574
    Abstract: Radio-frequency (RF) apparatus includes receiver analog circuitry that receives an RF signal and provides at least one digital signal to receiver digital circuitry that functions in cooperation with the receiver analog circuitry. The interface between the receiver analog circuitry and the receiver digital circuitry includes configurable signal lines that function as a serial interface, or as a data and clock signal interface, depending on the state of a control signal.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: January 2, 2007
    Assignee: Silicon Laboratories Inc.
    Inventors: G. Diwakar Vishakhadatta, Jeffrey W. Scott, G. Tyson Tuttle, Vishnu Shankar Srinivasan, Aslamali A. Rafi
  • Publication number: 20040166815
    Abstract: Components of a radio-frequency (RF) apparatus including transceiver circuitry and frequency modification circuitry of a crystal oscillator circuit that generates a reference signal with adjustable frequency may be partitioned in a variety of ways, for example, as one or more separate integrated circuits. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator (“DCXO”) circuitry and a crystal. The frequency modification circuitry may include at least one variable capacitance device and may be employed to generate a reference signal with adjustable frequency. The adjustable reference signal may be provided to other components of the RF apparatus and/or the RF apparatus may be configured to provide the adjustable reference signal to baseband processor circuitry.
    Type: Application
    Filed: July 31, 2003
    Publication date: August 26, 2004
    Inventors: James Maligeorgos, Augusto M. Marques, Lysander Lim, G. Tyson Tuttle, Aslamali A. Rafi, Tod Paulus, Gregory T. Uehara, Jeffery W. Scott, Richard T. Behrens, Donald A. Kerth, G. Diwakar Vishakhadatta, Vishnu S. Srinivasan, Caiyi Wang
  • Patent number: 6580575
    Abstract: An active damping circuit including an H-bridge circuit having an inductive load and a switching circuit, an impedance circuit responsive to a bias signal to damp the H-bridge circuit, and a bias circuit to generate the bias signal responsive to the voltage drop across the H-bridge circuit.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: June 17, 2003
    Assignee: Texas Instruments Incorporated
    Inventors: Aslamali A. Rafi, Bryan E. Bloodworth
  • Publication number: 20020141511
    Abstract: Radio-frequency (RF) apparatus includes receiver analog circuitry that receives an RF signal and provides at least one digital signal to receiver digital circuitry that functions in cooperation with the receiver analog circuitry. The interface between the receiver analog circuitry and the receiver digital circuitry includes configurable signal lines that function as a serial interface, or as a data and clock signal interface, depending on the state of a control signal.
    Type: Application
    Filed: March 29, 2001
    Publication date: October 3, 2002
    Inventors: G. Diwakar Vishakhadatta, Jeffrey W. Scott, G. Tyson Tuttle, Vishnu Shankar Srinivasan, Aslamali A. Rafi