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:
Dec. 29, 1998
Filed:
Mar. 27, 1996
Yoshinori Nagoya, Yokohama, JP;
Takashi Sakai, Fujisawa, JP;
Yuji Ishida, Machida, JP;
Ken Takei, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an output-controlled power amplifier of a closed loop type, an input signal is inputted to a main path in which the input signal is power-attenuated by a variable attenuator and power-amplified by a power amplifier. A power divider distributes the amplified input signal between the main path and a feedback path diverging from the main path so that the signal distributed to the main path is outputted from the main path to the exterior while the input signal is controlled on the basis of the signal distributed to the feedback path. The feedback path includes a hold circuit for extracting the signal distributed to the feedback path and holding the value of the power of the extracted signal when the power reaches a predetermined value. A control signal for attenuating the power of the input signal inputted to the main path is generated by the hold circuit and is applied through the feedback path to the variable attenuator on the main path to control the power of the input signal. A transfer function of the closed loop has a Gaussian characteristic.