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:
Sep. 24, 2002
Filed:
Jul. 20, 1999
Wasuke Yanagisawa, Machida, JP;
Shozaburo Kameda, Yokohama, JP;
Ryo Horie, Saitama, JP;
Haruhisa Uchida, Takasakishi, JP;
Junichi Imai, Annaka, JP;
Yuichi Kagoshima, Takasaki, JP;
Yokowo Co., Ltd., Tokyo, JP;
Abstract
An antenna circuit which is improved the deterioration of amplitude characteristic in a strong electric field, an antenna circuit for AM broadcasting which can surely inhibit and damp FM-band signals in the strong electric field and amplifies to output AM-band signals, and an antenna circuit for AM/FM broadcasting in which AM-band signals are not damped by means of an FM-band filter. In the first antenna circuit, the output signal of an antenna ( ) is supplied to the base of a transistor Tr forming a current amplification type amplifier having a high-input and low-output impedance and the emitter of the transistor Tr is grounded through a coil L and connected to an FM receiver ( ) through a band-pass filter ( ). In the second antenna circuit for receiving AM broadcasting, an input terminal is connected to an AM amplifier circuit ( ) through coils (L ) and L in series and to the gate G of a field effect transistor FET. The source S of the transistor FET is grounded and the connecting point of the coils L and L is grounded through a capacitor C and a coil L in series. The second antenna circuit inhibits and damps FM-band signals in a plurality of steps. In the third antenna circuit for AM/FM broadcasting, the output signal of an antenna is divided into two parts and one part is supplied to an FM-band filter ( ) through a serial FM resonance circuit ( ) composed of capacitors and coils. The other part of the output signal is supplied to an AM-band filter ( ).