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:
May. 07, 2002
Filed:
Oct. 29, 1999
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
Conventional distortion compensation circuits have addressed the problem that their distortion compensation amount is greatly reduced at levels other than the designed power level. The present invention provides a distortion compensation circuit that comprises: a vector adjuster; a linearizer; a linear signal extraction path for extracting part of an input signal from the input side of the vector adjuster; a nonlinear signal extraction path for extracting part of an output signal from the output side of the amplifier; a level detector for detecting a combined power level of the signals from the linear signal extraction path and the nonlinear signal extraction path; and a control circuit for adjusting a bias of the linearizer in accordance with the detected combined power level, electrically adjusting the linearizer so that the power detected by the level detector is minimized, and adjusting the vector adjuster so that the power detected by the level detector is minimized every time the linearizer is adjusted. As a result, the distortion compensation circuit of the present invention can optimize distortion compensation at all times independently of the average power changes of the input signal, the secular changes of the amplifier and the state changes of the amplifier caused by temperature changes.