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:
Jun. 28, 1994
Filed:
Mar. 23, 1993
Mishio Hayashi, Saitama, JP;
Kazuyoshi Chinoda, Fukaya, JP;
Advantest Corporation, Tokyo, JP;
Abstract
Based on a desired center frequency and a frequency resolution for a signal to be measured which are entered via an operator section, a micro-CPU calculates the frequency dividing number, a preset value and a center value for the signal to be measured. The frequency dividing number is set in a frequency divider, which frequency divides the signal to be measured and provides the frequency-divided output to a continuous period-to-voltage converter. The continuous period-to-voltage converter counts clock pulses occurring in each frequency-divided period, measures the difference between fractions of time from both the beginning and the end of the frequency-divided period to the generation of the next clock pulses, respectively, and outputs, as a voltage corresponding to the frequency-divided period, the sum of a voltage corresponding to a predetermined number of consecutive low-order bits of a binary value, obtained by adding the preset value to the pulse count value, and the fractional time difference. A subtractor is supplied with a voltage corresponding to the frequency-divided period and a voltage corresponding to the center value and outputs the voltage difference as a frequency-divided period deviation, and the micro-CPU calculates a frequency deviation of the measured signal from the center frequency on the basis of the frequency-divided period deviation.