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:
Sep. 19, 1995
Filed:
Jul. 07, 1993
Kiyoshi Tanaka, Chiba, JP;
Uniden Corporation, Ichikawa, JP;
Abstract
A radio communication receiving device performs prescribed operations upon detecting a frequency modulation preamble signal consisting of a series of alternating logical values. The device includes a low-pass filter that is connected to an output of a receiver that detects the frequency modulation signal and outputs an analog base band signal, and which has a numerical cutoff frequency value that does not exceed half the bit rate of the preamble, a comparison circuit that is connected to the output of the low-pass filter and compares an output voltage of the low-pass filter with prescribed threshold values, and a determining circuit that determines a preamble has been detected when the comparison by the comparison circuit indicates that an absolute value the low-pass filter output voltage does not exceed a prescribed threshold value for a prescribed time period.