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, 1985
Filed:
Feb. 04, 1983
Applicant:
Inventors:
Masaki Yanagihara, Tokyo, JP;
Takashi Iimura, Tokyo, JP;
Assignee:
Trio Kabushiki Kaisha, , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ; H03H / ;
U.S. Cl.
CPC ...
328167 ; 455296 ; 455 26 ; 307540 ; 307543 ; 328138 ; 328165 ;
Abstract
A variable frequency passband circuit comprising two passband filters and three mixers (front, intermediate and output mixers) connected in a cascade fashion disposed in a signal path. Two VCOs inject frequency signals into the front mixer and the output mixer. The two VCOs are respectively controlled by control signals at two potentiometers through transfer switching means so that the synthetic passband of the filter may be varied. One potentiometer suppresses the higher frequency region of a baseband signal and the other potentiometer suppresses the lower frequency region of the base band signal, irrespective of USB or LSB receiving mode.