NON-LINEAR PARAMETER MEASURING METHOD AND SYSTEM STRONG TO NOISE

• US 20140358489A1
• Filed: 06/04/2014
• Published: 12/04/2014
• Est. Priority Date: 06/04/2013
• Status: Abandoned Application

• Current Assignee: SungKyunKwan University's Research & Business Foundation (SungKyunKwan University)
• Original Assignee: SungKyunKwan University's Research & Business Foundation (SungKyunKwan University)
• Inventors: KANG, To, KIM, Hunhee, KIM, Hak Joon, LEE, Taek Gyu, SONG, Sungjin
• Application Number:
  US14/295,416
• Publication Number:
  US 20140358489A1
• Time in Patent Office: Days
• US Class Current: 702/191
• CPC Class Codes: G01N 2291/02491 Materials with nonlinear acoustic properties
• CPC Class Codes: G01N 2291/048 Transmission, i.e. analysed material between transmitter and receiver
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/2437 Piezoelectric probes
• CPC Class Codes: G01N 29/32 Arrangements for suppressing undesired influences, e.g. temperature or pressure variations , compensating for signal noise
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency
• CPC Class Codes: G01N 29/4463 Signal correction, e.g. distance amplitude correction [DAC], distance gain size [DGS], noise filtering

Abstract

A nonlinearity parameter measuring method and system is configured to separately process a signal of a fundamental wave and second harmonic wave that went through a probe attached to a specimen using a circuit including an analogue band pass filter and intermediate frequency amplifier, and minimize the effects caused by noise, thereby measuring an exact nonlinearity parameter.

Claims

1. A nonlinearity parameter measuring method comprising:

inputting a signal into a first probe that is connected to one end of a specimen;

filtering a signal being output from a second probe connected to another end of the specimen using a first band pass filter for filtering a fundamental wave and a second band pass filter for filtering a second harmonic wave, the first band pass filter and second band pass filter made of analogue filters;

amplifying the signal that went through the filtering using a first amplifier connected to an output end of the first band pass filter and configured to amplify the fundamental wave and a second amplifier connected to an output end of the second band pass filter and configured to amplify a second harmonic wave;

measuring a voltage of the signal that went through the amplifying;

calculating a correction function for the second probe;

calculating an amplitude of the fundamental wave and second harmonic wave using the correction function for the second probe calculated at the calculating of a correction function and the voltage calculated at the measuring of a voltage; and

calculating a nonlinearity parameter of the specimen using the amplitude of the fundamental wave and second harmonic wave calculated at the calculating of an amplitude.

2. The method according to claim 1,

wherein the inputting of a signal involves passing a signal generated in a signal generator through an electric amplifier and low pass filter, successively, and inputting the signal into the specimen through the first probe.

3. The method according to claim 1,

wherein the first amplifier and second amplifier are intermediate frequency amplifiers.

4. The method according to claim 1,

wherein the calculating of an amplitude involves calculating an absolute displace amplitude of a fundamental wave component and an absolute displace amplitude of a second harmonic wave component using math formula

5. The method according to claim 4,

wherein the correction function for the second probe is calculated using math formula

6. The method according to claim 1,

wherein the calculating of a nonlinearity parameter involves calculating a nonlinearity parameter of the specimen using math formula

7. The method according to claim 2,

wherein the calculating of a nonlinearity parameter involves calculating a nonlinearity parameter of the specimen using math formula

8. The method according to claim 3,

wherein the calculating of a nonlinearity parameter involves calculating a nonlinearity parameter of the specimen using math formula

9. The method according to claim 4,

wherein the calculating of a nonlinearity parameter involves calculating a nonlinearity parameter of the specimen using math formula

10. The method according to claim 5,

wherein the calculating of a nonlinearity parameter involves calculating a nonlinearity parameter of the specimen using math formula

11. A nonlinearity parameter measuring system comprising:

a signal inputter configured to input a signal into a first probe that is connected to one end of a specimen;

a filter configured to filter a signal being output from a second probe connected to another end of the specimen using a first band pass filter for filtering a fundamental wave and a second band pass filter for filtering a second harmonic wave, the first band pass filter and second band pass filter made of analogue filters;

a signal amplifier configured to amplify the signal that went through the filter using a first amplifier connected to an output end of the first band pass filter and configured to amplify the fundamental wave and a second amplifier connected to an output end of the second band pass filter and configured to amplify the second harmonic wave;

a voltage measurer configured to measure a voltage of the signal that went through the signal amplifier;

a correction function calculator configured to calculate a correction function for the second probe;

an amplitude calculator configured to calculate an amplitude of the fundamental wave and second harmonic wave using the correction function for the second probe calculated by the correction function calculator and the voltage calculated by the voltage measurer; and

a nonlinearity parameter calculator configured to calculate a nonlinearity parameter of the specimen using the amplitude of the fundamental wave and second harmonic wave calculated at the calculating of an amplitude.

12. The system according to claim 11,

wherein the signal inputter passes a signal generated in a signal generator through an electric amplifier and low pass filter, successively, and inputs the signal into the specimen through the first probe.

13. The system according to claim 11,

wherein the first amplifier and second amplifier are intermediate frequency amplifiers.

14. The system according to claim 11,

wherein the correction function calculator calculates the correction function for the second probe using math formula