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:
Jul. 09, 1991
Filed:
May. 16, 1990
Tatsuo Hiramatsu, Higashiosaka, JP;
Hiroaki Takagi, Hirakata, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A spread spectrum signal demodulation circuit includes a multiplier which multiplies an input spread spectrum signal by a demodulation PN code, and a demodulation PN code generator generates the demodulation PN code by utilizing an oscillation signal from a VCO as a clock signal thereof. An output of the multiplier is given to a bandpass filter and an output of which is integrated by an integration circuit. A first integrated value for a first time is compared with a second integrated value for a second time later than the first time and, in accordance with a comparison result, a frequency of the oscillation signal of the VCO is changed so that the demodulation PN code is synchronized with a modulation PN code included in the input spread spectrum signal.