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:
Sep. 07, 2010
Filed:
Feb. 15, 2007
Kiyoshi Yanagisawa, Tokyo, JP;
Noriaki Matsuno, Tokyo, JP;
Kiyoshi Yanagisawa, Tokyo, JP;
Noriaki Matsuno, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A signal generator generates a test signal including a positive signal and a negative signal which have the same amplitude. The signal generator corrects a DC level of the test signal based on a DC offset correcting signal supplied thereto, and supplies the corrected test signal to a frequency converter. An amplitude detector detects the amplitudes of the positive and negative signals of the test signal processed by the frequency converter. A level compressor converts in level the amplitudes of the positive and negative signals which are detected by the amplitude detector, with a gain variable depending on an input level thereto. A comparator compares the amplitudes of the positive and negative signals which are converted in level by the level compressor, with each other. An offset adjuster supplies the DC offset correcting signal depending on a compared result from the comparator to the signal generator.