Patents by Inventor Nasrollah S. Navid

Nasrollah S. Navid 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).

  • Patent number: 5808499
    Abstract: Self-oscillation of a prescalar circuit is avoided by including offset generators on the inputs of the prescalar circuit. This ensures that when the transistors in one differential pair in the prescalar circuit transition from ON to OFF, the other differential pair of transistors will not transition. As a result, spikes are prevented in the differential pair that does not have a transition. A quadrature signal generator constructed with such a prescalar circuit provides an accurate output despite weak or non-existent input signals.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: September 15, 1998
    Assignee: Philips Electronics North America Corporation
    Inventors: Farbod Behbahani, Ali Fotowat-Ahmady, Nasrollah S. Navid, Dan Linebarger
  • Patent number: 5606272
    Abstract: A comparator has a simple high frequency signal path from input to output formed by two differentially connected transistors with an output transistor connected to each. A current control circuit maintains a constant total current flowing through the differentially connected transistors. The ratio of currents flowing through the differentially connected transistors is initially set by a control circuit, so that the output of the comparator is predictable when powered up. The control circuit then gradually releases control, so that there is a smooth transfer to control by a reference signal input to the comparator.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: February 25, 1997
    Assignee: Philips Electronics North America Corporation
    Inventors: Farbod Behbahani, Ali Fotowat-Ahmady, Nasrollah S. Navid
  • Patent number: 5596299
    Abstract: An IF limiting amplifier uses localized positive feedback in each amplifier stage to provide additional small signal gain while maintaining the limiting gain. The extra small signal gain results in higher overall sensitivity for the receiver at less bias current. The reduction in the number of stages needed to perform the same signal response results in a significant decrease in power consumption by the circuit.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: January 21, 1997
    Assignee: Philips Electronics North America Corporation
    Inventors: Charles J. Persico, Nasrollah S. Navid, Ali Fotowat-Ahmady
  • Patent number: 5338985
    Abstract: An electronic circuit with a logarithmic detector performs the following operations: receiving an input voltage, generating a series of subsequently amplified versions of the input voltage, rectifying the versions, thereupon rescaling and converting the versions into currents, summing the currents and applying the summed current to a resistor. With regard to the prior art the order of rectification and rescaling has been interchanged. As a result, the design is simplified, the circuit's supply voltage is lower than that of the prior art, and the circuit is more accurate and easier to compensate for temperature dependence.
    Type: Grant
    Filed: April 28, 1993
    Date of Patent: August 16, 1994
    Assignee: North American Philips Corporation
    Inventors: Ali Fotowat-Ahmady, Nasrollah S. Navid
  • Patent number: 5296761
    Abstract: An IF amplifier/log detector with a modular architecture includes a plurality of voltage amplifiers, a plurality of rectifiers, a plurality of voltage-to-current converters and a current summing circuit. Each amplifier has a first differential transistor pair driven by a first current proportional to the temperature to fix the gain. Each converter includes a second differential transistor pair driven by a current proportional to the temperature and inversely proportional to a process parameter, and a third differential transistor pair driven by a third current inversely proportional to the process parameter. In this manner a circuit having improved performance with variations in temperature and process parameters is obtained.
    Type: Grant
    Filed: November 23, 1992
    Date of Patent: March 22, 1994
    Assignee: North American Philips Corporation
    Inventors: Ali Fotowat-Ahmady, Nasrollah S. Navid
  • Patent number: 5179361
    Abstract: A compandor system is provided that uses integrated circuitry in combination with fully external controlling devices for unity gain level adjustment without affecting the dynamic range. In addition, the system's stability is maintained. The external control is provided, for instance, by replaceable discrete resistors.
    Type: Grant
    Filed: May 15, 1991
    Date of Patent: January 12, 1993
    Assignee: North American Philips Corp.
    Inventors: Nasrollah S. Navid, Michael J. DeLurio