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.

Date of Patent:
Oct. 15, 2013

Filed:

Nov. 08, 2010
Applicants:

Kazuya Yamamoto, Tokyo, JP;

Tomoyuki Asada, Tokyo, JP;

Miyo Miyashita, Tokyo, JP;

Inventors:

Kazuya Yamamoto, Tokyo, JP;

Tomoyuki Asada, Tokyo, JP;

Miyo Miyashita, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R 31/00 (2006.01); G01R 25/02 (2006.01);
U.S. Cl.
CPC ...
Abstract

A detector circuit for detecting degradation in the distortion characteristics of a power amplifier based on signals from both ends of a coupled line of a directional coupler. The detector circuit includes a phase shifter/attenuator for phase shifting and attenuating a signal from a coupled terminal of the coupled line, a differential amplifier for outputting difference between an output signal from the phase shifter/attenuator and a signal from the isolated terminal of the coupled line, a wave detector circuit for converting the difference into a DC signal, and a comparing circuit for determining whether the voltage level of the DC signal exceeds a predetermined level. When degradation in the distortion characteristics of the power amplifier arises, the phase shifter/attenuator phase shifts the signal from the coupled terminal and outputs a signal 180° out of phase with the signal from the isolated terminal.


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