The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 01, 1994
Filed:
Dec. 22, 1992
Russ A Reisner, Redondo Beach, CA (US);
Wilbert Copeland, Los Angeles, CA (US);
Arnold Berman, Los Angeles, CA (US);
Charles C Curello, Torrance, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A predistortion linearizer (20) is operative with a microwave signal, as may be provided by signal source (62) to linearize the gain of a power amplifier, such as a traveling-wave-tube power amplifier (74), by introduction of an amplitude and/or a phase distortion to the microwave signal wherein the distortion is inverse to a distortion introduced by the power amplifier, thereby to compensate for the distortion of the power amplifier. The linearizer is constructed of two channels (22, 24) which are operated in parallel but approximately 180 degrees out of phase, with an additional phase increment provided by delay lines (46, 56) to offset one channel from the other channel by a phase difference in a range of approximately 160-200 degrees. Included within each channel is a diode circuit (40, 50) wherein the diode circuit (40) includes a set of PIN diodes operated in linear fashion in the channel (22), and the diode circuit (50) includes a set of Schottky diodes operated in nonlinear fashion in the channel (24). The limiter diode circuit (50) limits signal amplitude resulting in a gain expansion and a phase advance upon summation of signal vectors of the two channels to provide an output signal. These are adjusted to compensate for the gain compression and phase lag of the power amplifier. In each of the diode circuits, the diodes are mounted on components of a coplanar waveguide for symmetry in construction and avoidance of generation of parasitic reactances.