Patents by Inventor Apu Sivadas

Apu Sivadas 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: 20090289721
    Abstract: An electronic circuit comprising a transistor-based RF (radio frequency) power amplifier (112) having balanced outputs (172, 176), a transistor-based receiver RF amplifier (116) having balanced inputs (152, 156) ohmically connected to said balanced outputs (172, 176) respectively of said RF power amplifier (112), and a balun (114) having a primary (182, 186) and a secondary (188), said primary (182, 186) having primary connections and a supply connection (185) of said primary (182, 186) intermediate said primary connections and said primary connections ohmically connected both to said balanced outputs (172, 176) of said RF power amplifier (112) respectively and to said balanced inputs (152, 156) of said receiver RF amplifier, thereby to switchlessly couple RF between the balun (114) and the RF power amplifier (112) and switchlessly couple RF between the balun (114) and the receiver RF amplifier (116). Other electronic circuits, processes, devices and systems are disclosed.
    Type: Application
    Filed: May 5, 2009
    Publication date: November 26, 2009
    Applicant: Texas Instruments Incorporated
    Inventors: Gireesh Rajendran, Apu Sivadas, Subhashish Mukherjee
  • Publication number: 20090201088
    Abstract: According to an aspect of the present invention, the magnitude and phase angle of looking-in impedance driven by an amplifier are computed in digital domain during normal operation within a module containing the amplifier. In an embodiment, the computed magnitude and phase angle are used for impedance matching at a node driven by the amplifier. As a result, impedance matching may be obtained even in situations when the impedance changes during operation.
    Type: Application
    Filed: February 10, 2009
    Publication date: August 13, 2009
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Apu Sivadas, Gireesh Rajendran, Subhashish Mukherjee
  • Patent number: 7415064
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Grant
    Filed: July 22, 2005
    Date of Patent: August 19, 2008
    Assignee: Gennum Corporation
    Inventors: Apu Sivadas, Atul Krishna Gupta, Kenneth Steven Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Kumar Shukla, Bharat Tailor
  • Patent number: 7317757
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Grant
    Filed: July 22, 2005
    Date of Patent: January 8, 2008
    Assignee: Gennum Corporation
    Inventors: Apu Sivadas, Atul Krishna Gupta, Kenneth Steven Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Kumar Shukla, Bharat Tailor
  • Patent number: 7180941
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Grant
    Filed: July 22, 2005
    Date of Patent: February 20, 2007
    Assignee: Gennum Corporation
    Inventors: Apu Sivadas, Atul Krishna Gupta, Kenneth Steven Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Kumar Shukla, Bharat Tailor
  • Patent number: 7065134
    Abstract: An adaptive equalizer with a large data rate range is provided. The equalizer comprises an equalizer core, a slicer and an automatic gain control (AGC) loop. The equalizer core is coupled to an input signal from a transmission medium and applies a transfer function to the input signal to compensate for losses incurred in the transmission medium in order to generate a core output signal. The equalizer core is also coupled to a bandwidth control signal that controls a bandwidth of the transfer function. The slicer is coupled to the core output signal and converts the core output signal to a digital output signal having a fixed digital output swing that approximates a transmission swing of the input signal prior to transmission over the transmission medium. The AGC loop is coupled to the core output signal and the digital output signal and compares the core output signal with the digital output signal in order to generate the bandwidth control signal.
    Type: Grant
    Filed: August 27, 2001
    Date of Patent: June 20, 2006
    Assignee: Gennum Corporation
    Inventors: Vasilis Papanikolaou, Apu Sivadas, Atul Gupta, Hossein Shakiba
  • Publication number: 20050254566
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Application
    Filed: July 22, 2005
    Publication date: November 17, 2005
    Inventors: Apu Sivadas, Atul Gupta, Kenneth Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Shukla, Bharat Tailor
  • Publication number: 20050254565
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Application
    Filed: July 22, 2005
    Publication date: November 17, 2005
    Inventors: Apu Sivadas, Atul Gupta, Kenneth Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Shukla, Bharat Tailor
  • Publication number: 20050254567
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Application
    Filed: July 22, 2005
    Publication date: November 17, 2005
    Inventors: Apu Sivadas, Atul Gupta, Kenneth Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Shukla, Bharat Tailor
  • Patent number: 6956914
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: October 18, 2005
    Assignee: Gennum Corporation
    Inventors: Apu Sivadas, Atul Krishna Gupta, Kenneth Steven Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Kumar Shukla, Bharat Tailor
  • Publication number: 20030053534
    Abstract: Transmit amplitude independent adaptive equalizers are provided that compensate for transmission losses in an input signal when the transmit signal amplitude is unknown. Several embodiments are provided, including a first embodiment having an equalizer core, a controllable-swing slicer and an amplitude control loop, a second embodiment having an equalizer core, a fixed-swing slicer and a control loop, a third embodiment having an equalizer core, a variable gain amplifier, and a variable gain amplifier control loop, and a fourth embodiment having an equalizer core, a fixed-swing slicer, a variable gain amplifier, and a variable gain amplifier control loop.
    Type: Application
    Filed: September 19, 2001
    Publication date: March 20, 2003
    Inventors: Apu Sivadas, Atul Krishna Gupta, Kenneth Steven Lazaris-Brunner, Vasilis Papanikolaou, Rajiv Kumar Shukla, Bharat Tailor
  • Patent number: 6535087
    Abstract: An externally temperature-compensated microwave resonator comprises a microwave resonator and an external temperature compensator. The microwave resonator is a multi-cavity waveguide. The cavities are configured side-by-side and coupled through irises. The external temperature compensator is oriented and configured to effect a change in volume of the cavities when the resonator and compensator undergo a temperature gradient. The compensator deflects a wall portion of the resonator to accordingly counteract a change in volume of the cavity caused by a temperature gradient.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: March 18, 2003
    Assignee: COM DEV Limited
    Inventors: William Fitzpatrick, Ming Yu, David Smith, Apu Sivadas
  • Publication number: 20030043897
    Abstract: An adaptive equalizer with a large data rate range is provided. The equalizer comprises an equalizer core, a slicer and an automatic gain control (AGC) loop. The equalizer core is coupled to an input signal from a transmission medium and applies a transfer function to the input signal to compensate for losses incurred in the transmission medium in order to generate a core output signal. The equalizer core is also coupled to a bandwidth control signal that controls a bandwidth of the transfer function. The slicer is coupled to the core output signal and converts the core output signal to a digital output signal having a fixed digital output swing that approximates a transmission swing of the input signal prior to transmission over the transmission medium. The AGC loop is coupled to the core output signal and the digital output signal and compares the core output signal with the digital output signal in order to generate the bandwidth control signal.
    Type: Application
    Filed: August 27, 2001
    Publication date: March 6, 2003
    Inventors: Vasilis Papanikolaou, Apu Sivadas, Atul Gupta, Hossein Shakiba
  • Patent number: 6459346
    Abstract: A microwave filter has a set of irises to couple cavities within the filter. A trifurcated iris comprises a central iris and a pair of peripheral irises. The peripheral irises are configured and oriented to couple a primary mode having a magnetic field in the axial direction of a filter cavity. The central iris is configured and oriented to couple a secondary mode having a magnetic field in the azimuthal direction of the filter cavity. The configuration of the trifurcated iris is further oriented to minimize the influence of higher order signals such as the TE21X mode. The peripheral iris are oriented at null points of the primary TE21X mode and the central iris is also located at a null point. An input and an output iris are configured to receive electromagnetic energy in the axial direction of the filter. The input and output irises are oriented to minimize signals in the TE21X secondary mode and any TM modes.
    Type: Grant
    Filed: August 29, 2000
    Date of Patent: October 1, 2002
    Assignee: COM DEV Limited
    Inventors: Apu Sivadas, Ming Yu, David Smith, William Fitzpatrick