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. 16, 2009
Filed:
May. 24, 2007
Mitsuo Ariie, Kusatsu, JP;
Yasutaka Sugimoto, Omihachiman, JP;
Mitsuo Ariie, Kusatsu, JP;
Yasutaka Sugimoto, Omihachiman, JP;
Abstract
A semiconductor deviceincludes a plurality of amplifier circuitsconnected in parallel between an input terminal RFin and an output terminal RFout. Each of the amplifier circuitsincludes an HBT, an oscillation stabilizing circuitconnected between the input terminal RFin and a base B of the HBT, and a ballast resistorconnected between a bias terminal Bin and the base B of the HBT. The oscillation stabilizing circuitincludes a resistorand a capacitorconnected in parallel. Thus, thermorunaway of the HBTcan be prevented using the ballast resistor, and the stability against oscillation can be improved using the oscillation stabilizing circuiteven at low frequencies.