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:
May. 14, 1991
Filed:
Jun. 15, 1989
Tomokazu Komazaki, Tokyo, JP;
Katsuhiko Gunji, Tokyo, JP;
Norio Onishi, Tokyo, JP;
Akira Mashimo, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
An isolating circuit, which isolates a first frequency signal in a first frequency range and a second frequency signal in a second frequency range which is higher than the first frequency range, has as antenna terminal, a first filter and a second filter. The first filter, having a first input terminal and a first output terminal, receives a first input signal including the first frequency signal at the first input terminal and attenuates first frequency component of the first input signal below the first frequency range at a first attenuation rate and second frequency components of the first input signal above the first frequency range at a second attenuation rate. One of the first input and output terminals of the first filter is coupled to the antenna terminal. The first filter further has a first setting terminal setting the first attenuation rate and the second attenuation rate so that the second attenuation rate is greater than the first attenuation rate. The second filter, having second input and output terminals, receives a second input signal including the second frequency signal at the second input terminal and attenuataes third frequency components of the second input signal below the second frequency range at a third attenuation rate and fourth frequency components of the second input signal above the second frequency range at a fourth attenuation rate. One of the second input and output terminals of the second filter is coupled to the antenna terminal. The second filter further has a second setting terminal setting the third attenuation rate and fourth attenuation rate so that the third attenuation rate is greater than the fourth attenuation rate.