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:
Dec. 15, 2009

Filed:

May. 25, 2007
Applicants:

Il-ku Nam, Anyang-si, KR;

Young-jin Kim, Yongin-si, KR;

Hyun-won Mun, Yongin-si, KR;

Inventors:

Il-Ku Nam, Anyang-si, KR;

Young-Jin Kim, Yongin-si, KR;

Hyun-Won Mun, Yongin-si, KR;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 1/36 (2006.01);
U.S. Cl.
CPC ...
Abstract

A feedback-type variable gain amplifier including a first field effect transistor, a feedback circuit, and a load circuit. The first field effect transistor receives an input voltage signal through an input node, amplifies the input voltage signal, and outputs the amplified input voltage signal through an output node. The feedback circuit is coupled between the input node and the output node, and generates feedback impedance that is changed in response to a control signal. The load circuit is coupled between the output node and a voltage source, and generates load impedance that is changed in response to the control signal to cancel a change of input impedance due to a change of the feedback impedance. Therefore, since the input impedance is not changed when the gain of the amplifier is changed, a voltage standing wave ratio is good, and a range of gain control is broad.


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