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. 23, 1999
Filed:
May. 14, 1997
Masaharu Tanai, Tokyo, JP;
Masayasu Sugimori, Tokyo, JP;
Ando Electric Co., Ltd., Tokyo, JP;
Abstract
A method of adjusting modulation accuracy corrects an I modulation signal and a Q modulation signal without using special hardware when an accurate 90.degree. phase difference between the I modulation signal and the Q modulation signal is not present. The method comprises setting I component correction .DELTA.i for a plurality of phase differences in advance to an I component corrector in accordance with an I signal, which is converted from digital modulation data in a digital data train by a modulator and an IQ converter of a phase error corrector. The method also comprises setting a Q component correction .DELTA.q for a plurality of phase differences in advance to a Q component corrector in accordance with a Q signal, controlling the I component corrector and the Q component corrector by a phase error correction controller, thereby adding the I component correction .DELTA.i and the Q component correction .DELTA.q to the I signal and the Q signal so as to generate a corrected I signal and a corrected Q signal. Thus the phase difference between an I modulation signal and a Q modulation signal is accurately adjusted to 90.degree..