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, 1998
Filed:
Nov. 06, 1995
Yoshiaki Kumagai, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
An AGC circuit used in radio transmitters for satellite communications and the like, which is intended to eliminate non-linearity compensators for detectors and reduce the radio transmitters in size and complexity. An RF input signal is amplified and output while passing through input splitting means, programmable attenuator, amplifier, and output splitting means. At the same time, a part of the RF input signal branches off at the input splitting means to input detecting means, where it is detected so as to obtain an input signal amplitude. In addition, a part of the amplifier output is split off at the output splitting means, then attenuated by attenuation means and finally reaches output detecting means, where the signal is detected so as to obtain an output signal amplitude after attenuation. Control means adjusts the attenuation factor of the programmable attenuator so that the input of the input detecting means will be equal to the input of the output detecting means. This structural arrangement allows both the input detecting means and output detecting means to work at the same operating point. Having well-matched detection characteristics for those two detecting means as well as the same operating point will eliminate non-linearity compensation.