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:
Jun. 19, 1979
Filed:
Sep. 08, 1977
Kazuyoshi Imazeki, Tokyo, JP;
Koichi Kazami, Tokyo, JP;
General Research of Electronics, Inc., Tokyo, JP;
Abstract
A variable impedance circuit is included between the antenna and the RF amplifier stage of a radio receiver portion of a transceiver and is responsive to a phase-inverted and amplified AGC signal to automatically protect the receiver from breaking down or otherwise malfunctioning when it receives an over-input or excessive input signal level. When the input signal level to the receiver is at the typical operating level, the circuit provides a substantially infinite impedance to ground so as not to interfere with signal transmission from the antenna to the input stage and the successive stages. The impedance to ground of the circuit decreases as the input signal level increases and, when an excessive input signal level sufficient to cause receiver breakdown or malfunction is applied to the circuit, the impedance to ground of the variable impedance reaches an almost zero level, thereby shunting to ground and thus harmlessly dissipating the excessive signal level input to the receiver before it can burn out or otherwise damage the input or subsequent circuitry or cause a malfunction thereof.