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:
Feb. 18, 2003
Filed:
Oct. 04, 2001
Yoshiteru Hashimoto, Tokyo, JP;
Vertex Standard Co., Ltd., Tokyo, JP;
Abstract
In an SSB transmitter, a problem such that the central frequency of a BPF for extracting one of sideband signals from the modulated signals obtained by modulating a carrier frequency signal by an input sound signal is changed by temperatures, causing a drop in suppression ration and a deterioration in sound is solved. The microcomputer circuit determines the change of the central frequency (−&Dgr;&agr;) of the BPF from the compensation table related to the BPF stored in the ROM based on a temperature information of the BPF detected by the temperature sensor ; controls local oscillators and that output modulated signals and VHF band signals to the balanced modulator and the mixer ; and changes the frequency of each signal by −&Dgr;&agr; from the standard condition. By the accommodation control, in the BPF , the suppression of a carrier signal and the extraction of one sideband signal can always be executed under the same conditions as under the standard condition and the difference component signal by the mixer becomes a radio frequency signal with a prescribed frequency, and this is extracted by the BPF