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:
Apr. 28, 1987
Filed:
Sep. 09, 1986
Toshihiro Kashiwagi, Ebina, JP;
Anritsu Electric Co., Limited, Tokyo, JP;
Abstract
A multi-superheterodyne receiver having a first local oscillator for generating a first local frequency signal, a first frequency converter for converting to a first intermediate frequency signal a received signal in response to the first local frequency signal, a second local oscillator for generating a second local frequency signal, a second frequency converter for converting to a second intermediate frequency signal the first intermediate frequency signal in response to the second local frequency signal, includes judging circuitry for judging if a residual spurious component is generated when harmonic waves of at least one of the local frequency signals are at certain frequencies. Control circuitry shifts the first local frequency signal by a first predetermined frequency to cause the first intermediate frequency signal to suppress the residual spurious component, and shifts the second local frequency signal by a second predetermined frequency to maintain the frequency of the second intermediate frequency signal constant, when the judging circuitry determines that a residual spurious component will be generated at a preset receiving frequency. Thus, intermodulation disturbances in the receiver are suppressed.