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:
May. 13, 1997
Filed:
May. 24, 1993
Ryuji Yano, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A radio communication apparatus having a reception system having an automatic gain control circuit, which includes a first band-pass filter with a wide band inserted into a signal supplying passage to a digital demodulator located in the subsequent stage of a variable gain type intermediate frequency amplifier. The automatic gain control circuit further includes a second band-pass filter with a narrow-band set narrower than that of the first band-pass filter, inserted in a circuit that forms an automatic gain control (AGC) loop. Received analog signals are modulated and subjected to digital demodulation by the digital demodulator after passing through the first band-pass filter. Received intermediate-frequency signals which have passed through the second band-pass filter are supplied to a detector provided in the AGC loop. A gain control signal corresponding to the difference between the signal level value detected by the detector and a predetermined reference value is generated from an error amplifier, and is looped back to the intermediate frequency amplifier to control the gain thereof.