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.

Date of Patent:
Apr. 07, 1987

Filed:

Jul. 10, 1985
Applicant:
Inventors:

Tomohisa Yokogawa, Kawagoe, JP;

Nobuo Kanda, Kawagoe, JP;

Hideki Iwasaki, Kawagoe, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02J / ;
U.S. Cl.
CPC ...
307112 ; 307146 ; 333103 ;
Abstract

An antenna switching circuit which selectively transmits, to a receiver, RF signals from a plurality of antennas including RF signals of different frequency bands such as the VHF band and the MF band using a single output terminal. To prevent a level drop of RF signals of one of the frequency bands due to a common use of the output terminal, a unidirectional switching element is added to a switching circuit network by which the selection of RF signals from the different antennas is performed. A branching circuit for separating RF signals of different frequency bands is provided with an attenuation operation using a variable impedance characteristic of a semiconductor switching element which is basically on-off operated for the switching between the RF signals of the different frequency bands.


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