Patents by Inventor Stephen T. Valentine

Stephen T. Valentine 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).

  • Power amplifier linearization in a TDMA mobile radio system
    Patent number: 5559807
    Abstract: This invention relates to a time division multiple access (TDMA) trunked radio system and it relates to a frame structure for communication between fixed, mobile and portable radios in such a system. The radio system comprises: a base station and a plurality of remote radio units for communicating over time slots of a time divided radio channel, the base station having means for transmitting a synchronization signal for defining the timing of the time slots, and each of the remote units having a power amplifier with linearization means, characterized in that the channel comprises predetermined linearization time slots (120, FIG. 2) for transmission of training signals, interspersed between other time slots and each remote radio unit comprises means for generating a training signal during a linearization time slot and linearizing its power amplifier during that time slot in advance of and independent of transmission of signals during one of said other time slots.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: September 24, 1996
    Assignee: Motorola, Inc.
    Inventors: Anthony P. van den Heuvel, Stephen T. Valentine, Dragan Boscovich
  • Radio transmitter with power amplifier and linearization
    Patent number: 5524285
    Abstract: A radio transmitter includes a power amplifier (12); a linearizer (10) for maintaining linearity in the power amplifier; and a feedback path (13) for feeding a signal from an output of the power amplifier to the linearizer. The amplifier, linearizer and feedback path cooperate to form a feedback loop having adjustable loop linearization parameters (for example phase and gain). Further, a look-up table (19) is used to store predetermined loop linearization parameters and cooperates with a microprocessor having an operating condition input.
    Type: Grant
    Filed: November 2, 1993
    Date of Patent: June 4, 1996
    Inventors: Anthony J. Wray, Stephen T. Valentine, Matthew Q. Bridle
  • Radio transmitter circuit with time dependant inhibited transmissions
    Patent number: 5507014
    Abstract: A radio transmitter circuit is provided comprising: a power amplifier coupled to an antenna for transmission of radio signals; linearizer means, such as a Cartesian feedback linearizer or a predistortion equalizer, for compensating for non-linearity in the power amplifier; means for inputting a training sequence to the linearizer means and outputting a training signal from the power amplifier resulting from the training sequence; and a feedback circuit for feeding the training signal output from the power amplifier back to the linearizer means to adjust the linearizer means and/or feedback circuit. Means are provided for inhibiting transmission of radio signals through the antenna while the training signal is being output from the power amplifier.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: April 9, 1996
    Assignee: Motorola, Inc.
    Inventors: Anthony J. Wray, Stephen T. Valentine