Patent ID: 6407686
Filing Date: 2002-06-18
Classification: G01R

Abstract:
A waveform measuring apparatus having sampling signal generation means for generating a sampling signal having a cycle longer than the repetition cycle of a signal under test, a sampling portion for sampling the signal under test in synchronization with the sampling signal from the sampling signal from the sampling signal generation means and data processing portion for determining an envelope waveform of a signal under test which is sampled with the sampling portion, and determining a signal waveform of the signal under test from this envelope waveform; the apparatus comprising:reference signal generation means for generating a reference signal independently of a repetition cycle of the signal under test; frequency measuring means for measuring a repetition frequency of the signal under test by using a reference signal from the reference signal generation means; and sampling frequency setting means for computing and setting a value of a frequency of a sampling signal which can obtain a desired delay time with respect to a phase of the signal under test based on a value of a repetition cycle measured with the frequency measuring means; wherein the sampling frequency generation means uses a reference signal from the reference signal generation means and the value of the frequency set by the sampling frequency setting means to generate a sampling signal having a cycle corresponding to the frequency.