Waveform measuring apparatus wherein the peak-to-peak amplitude is measured

• US 8,120,349 B2
• Filed: 05/29/2008
• Issued: 02/21/2012
• Est. Priority Date: 12/05/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kimura, Tomoaki, Okada, Tadayuki
• Primary Examiner(s): NATALINI, JEFF WILLIAM
• Application Number:
  US12/129,035
• Publication Number:
  US 20080228448A1
• Time in Patent Office: 1,363 Days
• Field of Search: 324/76.12, 709/191
• US Class Current: 324/76.12
• CPC Class Codes: G01R 13/0272 for sampling
• CPC Class Codes: G01R 19/04 Measuring peak values or amplitude or envelope of ac or of pulses

Abstract

A waveform measuring apparatus includes: a digital filter for removing a large-amplitude changing component from an input signal and for outputting a resultant output signal with a small-amplitude noise component left therein; a window generating section for receiving a differential signal between this input signal and the resultant output signal of the digital filter and for generating a window indicating a position of an edge portion of the differential signal; and a ringing measurement section for extracting, from the resultant output signal of the digital filter, a portion of waveform which is indicated by the window generated by the window generating section and for measuring at least a peak-to-peak amplitude of the portion of waveform.

Claims

1. A waveform measuring apparatus comprising:

a first digital filter that removes a large-amplitude changing component from an input signal and outputs a resultant output signal with a remaining small-amplitude noise component left therein;

a second digital filter that removes the small-amplitude noise component from the input signal and outputs a resultant output signal with a remaining large-amplitude changing component left therein;

a window generating a section that inputs the output signal of the first digital signal and that generates a window which indicates a position of an edge portion of said signal of the second digital filter; and

a ringing measurement section that extracts, from the output signal of the first digital filter, a portion indicated by the window generated by the window generating section, and that measures at least a peak-to-peak amplitude of an extracted waveform.

2. The waveform measuring apparatus according to claim 1, wherein

the first digital filter is an ε

filter that removes a component, which has amplitude larger than a fixed value, from a signal including waveform components having different amplitudes, and that outputs a remaining component having amplitude not larger than the fixed value;

the second digital filter is an ε

filter that removes a component, which has amplitude not larger than the fixed value, from a signal including waveform components having different amplitudes, and for outputting a remaining component having amplitude larger than the fixed value.

3. The waveform measuring apparatus according to claim 1, wherein the window generating section generates the window by differentiating the output signal of the second digital filter twice and by sectioning an obtained waveform at a predetermined threshold.

4. A program for causing an internal computer of a measuring apparatus for measuring a waveform of a signal to function as:

means for extracting a small-amplitude noise component from an input signal inputted by input means of the measuring apparatus;

means for removing the small-amplitude noise component from the input signal;

means for generating a window, which indicates a position of an edge portion of a signal wherein the small-amplitude noise component has been removed; and

means for extracting a portion, which is indicated by the window, from the small-amplitude noise component extracted from the signal to be processed, and for measuring at least a peak-to-peak amplitude of the extracted waveform.