Patents by Inventor Raghbir S. Tahim

Raghbir S. Tahim 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: 6987488
    Abstract: An apparatus for introducing electromagnetic perturbation into a target device includes a piezoelectric transducer configured to deflect in response to an applied voltage and a perturber configured to deflect in response to deflection of the piezoelectric transducer. The deflection of the perturber causes electromagnetic perturbation, and in some cases a phase shift, in the target device. The electromagnetic perturbation may also be used to tune microwave devices such as filters, resonators, and oscillators.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: January 17, 2006
    Assignees: The Texas A&M University System, RST Scientific Research, Inc.
    Inventors: Kai Chang, Tae-Yeoul Yun, Raghbir S. Tahim
  • Patent number: 5617108
    Abstract: An antenna pointing detection system for use with circularly polarized electromagnetic radiation has a horn, a waveguide and at least one mode switching arm. The horn receives radiation in a primary mode from the radiation source. The waveguide receives radiation from the horn and supports only radiation in a primary mode, e.g. the TE.sub.11 mode and the next higher order TE mode, e.g. the TE.sub.21 mode at one or more rectangular mode switching arms extending from the circular waveguide for stimulating radiation of the-next order TE.sub.21 mode in the waveguide. The arm has a series of switchable pin diodes for changing the effective length of the mode switching arm to cause a phase alteration in the TE.sub.21 mode thereby causing a deflection of the effective pointing direction of the horn. The magnitude of the received signal is detected and compared with different deflections of the horn to operate conventional antenna pointing hardware.
    Type: Grant
    Filed: June 9, 1995
    Date of Patent: April 1, 1997
    Assignee: Hughes Electronics
    Inventors: Robert E. Silinsky, Frank Boldissar, Jr., Gary S. Campbell, Raghbir S. Tahim
  • Patent number: 5265268
    Abstract: A microwave mixer is formed of three orthogonally oriented waveguides, each having a rectangular cross-section defined by a pair of opposed broad walls and a pair of opposed sidewalls wherein the ratio of cross-sectional dimensions typically is 2 :1. The mixer includes an input coupling probe, a mixing region, and an output filter disposed serially along a first of the waveguides. A second of the waveguides applies a reference LO signal via the probe to the mixing region, the mixing region including at least one diode with two diodes being employed in the preferred embodiment of the invention. A section of dielectric board serves to support the diodes of the mixing region, components of the filter, and the probe in the first waveguide.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: November 23, 1993
    Assignee: Hughes Aircraft Company
    Inventor: Raghbir S. Tahim
  • Patent number: 4641369
    Abstract: A radio-frequency mixer and a local oscillator integrated into a single housing, and including a Gunn-type oscillator coupled to the mixer by a section of microstrip transmission line and a section of suspended stripline. A broadside coupler in the suspended stripline provides dc and intermediate-frequency isolation for the mixer, and a block of dielectric material on the microstrip provides improved temperature compensation for the diode oscillator. The entire compact assembly has good conversion loss performance over a relatively wide frequency band, and is relatively insensitive to temperature changes.
    Type: Grant
    Filed: November 29, 1984
    Date of Patent: February 3, 1987
    Assignee: TRW Inc.
    Inventors: Albert J. Grote, Raghbir S. Tahim, Kai Chang
  • Patent number: 4521747
    Abstract: Improved output power performance is obtained in a millimeter-wave integrated-circuit (MIC) voltage-controlled oscillator by forming an output circuit and a bias input circuit in a suspended stripline configuration, which is subject to relatively low losses compared with microstrip designs. A Gunn diode and a varactor diode are mounted in alignment and in close proximity to each other. The suspended microstrip configuration includes a suspended substrate with a Gunn diode output circuit and a bias input circuit on one side, and a varactor diode grounding pad on the other face of the substrate. A sliding short-circuit device aligned with the Gunn diode output circuit provides tuning of the oscillator over a relatively wide range, and avoids having to trim the Gunn diode circuit components for final adjustment of the frequency.
    Type: Grant
    Filed: October 11, 1983
    Date of Patent: June 4, 1985
    Assignee: TRW Inc.
    Inventors: Raghbir S. Tahim, George M. Hayashibara, Kai Chang