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:
Oct. 24, 1995
Filed:
Apr. 30, 1993
Taketo Kunihisa, Osaka, JP;
Tadayoshi Nakatsuka, Osaka, JP;
Abstract
A variable impedance element suitable for controlling a high-frequency signal is formed of a pair of FETs of identical conduction type, and functions to prevent variations in degree of channel opening of the FETs in response to positive and negative-going changes of the controlled signal voltage, to thereby achieve high linearity of impedance characteristics. Each FET has the drain and gate electrodes mutually coupled by a capacitor, the source electrodes of the FETs are mutually coupled, the gate electrodes are mutually isolated with respect to the high-frequency signal and coupled in common to receive an impedance control voltage, and the variable impedance appears between the drain electrodes.