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. 18, 2014
Filed:
Sep. 20, 2011
Toyokazu Kitano, Osaka, JP;
Toyokazu Kitano, Osaka, JP;
Daihen Corporation, Osaka, JP;
Abstract
A signal detection apparatus detects the frequency of an input signal without using a PLL. The detection apparatus includes a first and a second orthogonalizer, a phase difference calculator and an integrator, to control the variable coefficient aof a band-pass filter. Information e[k]=M·sin(φ) representing the phase difference φ between the input data x[k] and the output data y[k] is calculated with the first and second orthogonalizers and the phase difference calculator. The sign of e[k] is inverted and a predetermined integral calculation is performed with the integrator, and the calculated integral value is set as the coefficient aof the band-pass filter. Every time input data x[k] is input, the coefficient ais changed by reducing it when e[k]>0 and increasing it when e[k]<0. Thus, the frequency of the output signal of the band-pass filter is matched to the input signal.