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:
Mar. 09, 1993
Filed:
Mar. 04, 1991
Applicant:
Inventor:
Norio Shimo, Kanagawa, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455 80 ; 455 81 ; 455 82 ; 455 83 ;
Abstract
A signal switching apparatus for switching between a 1/4 wavelength transmission line, which transmits a transmission signal, and a 1/4 wavelength reception line, which receives a reception signal, which share a common antenna. The apparatus sets the characteristic impedance of one of the 1/4 wavelength lines to be zero while the other 1/4 wavelength lines is set to infinity so that the switching operation can be effected without passing the transmission and reception signals through semiconductor switches.