Patents by Inventor Richard J. Christensen

Richard J. Christensen 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: 5669068
    Abstract: A complimentary switched amplifier transceiver (10) is provided which offers performance advantages and reduces system complexity over conventional half-duplex transceivers by using complimentary switched amplifiers for eliminating switches. Power output to a channel transition (31) from a transmit amplifier (26) is not degraded by a switch insertion loss in a transmit mode. Receiver noise figure is not degraded due to the switch insertion loss from the channel transition (31) to a receive amplifier (27). Switch devices and their associated control lines are eliminated, reducing circuit complexity for complimentary switched amplifier circuits such as a combined amplifier switch (12) and a first bi-directional amplifier (22).
    Type: Grant
    Filed: July 3, 1995
    Date of Patent: September 16, 1997
    Assignee: Motorola, Inc.
    Inventors: Ronald F. Kielmeyer, Craig L. Fullerton, John D. Goshinska, Hugh R. Malone, Paul L. Brownlee, Richard J. Christensen, Michael L. Fraser
  • Patent number: 5583468
    Abstract: A high frequency transition (10) from a microstrip transmission line (57) to an MMIC coplanar waveguide (41) is provided. The microstrip transmission line (57) is representative of that typically encountered in a high frequency RF module on a first substrate (11). The MMIC coplanar waveguide (41) is representative of that encountered in low cost MMICs fabricated on a semiconductor substrate (56). An interface (15) couples the microstrip transmission line (57) to a mode converter (16). Mode converter (16) provides impedance mismatch compensation and coplanar waveguide propagation mode conditions for a connector coplanar waveguide (34) which connects from the first substrate (11) to the semiconductor substrate (56). An impedance transformer (40) provides additional impedance mismatch compensation on the semiconductor substrate (39) to complete the transition.
    Type: Grant
    Filed: April 3, 1995
    Date of Patent: December 10, 1996
    Assignee: Motorola, Inc.
    Inventors: Ronald F. Kielmeyer, Richard J. Christensen, Paul L. Brownlee, William M. Vassar