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:
Feb. 04, 1992
Filed:
Jun. 13, 1990
Hideho Tomita, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In an automatic gain control device which is connected to an output circuit (21, 22) supplied with a gain controlled signal to produce a timing signal in a receiver of a direct conversion type and which includes an amplifier (23, 24) for amplifying a received baseband signal into an amplified signal with a controllable gain, a d.c. blocking circuit (25, 26) for producing a variable level signal with the amplified signal exempted from a d.c. component, and a level detector (27, 28) for producing a level value signal by detecting level values of the variable level signal, a timing controller (31) is supplied with the timing signal to produce a first control signal in each of predetermined time slots in which a receiver input signal comprises bursts representative of an information signal. A second control signal is produced in an interval between two consecutive ones of the predetermined time slots. Controlled by the first control signal, a sample holding circuit (35, 36) supplies the level value signal to the amplifier to control the gain. Controlled by the second control signal, a clamping switch (33, 34) produces the gain controlled signal by removing a d.c. offset from the variable level signal. The receiver input signal may be orthogonally modulated.