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:
Apr. 06, 2010
Filed:
Apr. 14, 2008
Hirokazu Makihara, Osaka, JP;
Haruhiko Koizumi, Osaka, JP;
Kazuki Tateoka, Kyoto, JP;
Masahiko Inamori, Osaka, JP;
Shingo Matsuda, Kyoto, JP;
Hirokazu Makihara, Osaka, JP;
Haruhiko Koizumi, Osaka, JP;
Kazuki Tateoka, Kyoto, JP;
Masahiko Inamori, Osaka, JP;
Shingo Matsuda, Kyoto, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A radio-frequency power amplifier for preventing a final-stage HBT from being destroyed is provided. To this end, a radio-frequency multistage power amplifier of the present invention includes: a first amplification stage having a first hetero bipolar transistor of which collector output is detected; a second amplification stage which is prior to the first amplification stage and which has a second hetero bipolar transistor in which the detection result is reflected; a first resistor provided between a collector of the second hetero bipolar transistor and a power supply; and a protection circuit which is connected between a collector of the first hetero bipolar transistor and the collector of the second hetero bipolar transistor, detects output from the collector of the first hetero bipolar transistor, and reduces a voltage of the collector of the second hetero bipolar transistor in accordance with the detected output.