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:
Dec. 16, 2003
Filed:
Nov. 16, 2000
Masaki Yamamoto, Fukushima-ken, JP;
Toshiro Furuta, Miyagi-ken, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
It is an object of the present invention to provide an input circuit of a TV tuner without causing unnecessary attenuation within a VHF high band bandwidth and without worsening performance such as NF, input sensitivity, and S/N when receiving a VHF high band signal. The input circuit of a TV tuner is provided with a parallel resonance circuit and an input tuning circuit connected to an output of the resonance circuit, a varactor diode is provided in parallel with the parallel resonance circuit, and a resonance frequency of a parallel connecting circuit connecting in parallel the parallel resonance circuit with the varactor diode in a nonconductive state is set to a frequency of an FM broadcasting band. Further, a capacitance value of a capacitor is set such that a resonance frequency of a parallel connecting circuit connecting in parallel a second inductor in a conductive state of the varactor diode with the parallel resonance circuit constitutes a frequency higher than the VHF high band bandwidth.