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:
Jan. 25, 1983
Filed:
Nov. 28, 1980
Tadao Ogawa, Hino, JP;
Nobuhide Yamaguchi, Tokyo, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A low noise amplifier, comprising a grounded emitter transistor amplifier having a parallel impedance element connected between base and collector and a series impedance element connected between emitter and ground. The parallel impedance element is selected to have a pole near a zero of the series impedance element, and the parallel impedance element also has a zero near a pole of the series impedance element. The impedances of the series impedance element and of the parallel impedance element vary oppositely with respect to frequency, so that the input impedance of the amplifier is constant with respect to frequency. However, by selection of two impedances which are thus matched, the gain is increased at high frequencies and slightly reduced at low frequencies. Thus, the total noise figure is improved, due to the higher gain at the higher frequency range. In addition, frequency-selective attenuation imposed by a transmission line is compensated for, so that the amplifier has increased immunity to low-frequency overload.