Electromagnetic Field Distribution Measuring Method, Apparatus for the Method, Computer Program and Information Recording Medium

• US 20090006011A1
• Filed: 01/11/2006
• Published: 01/01/2009
• Est. Priority Date: 01/11/2005
• Status: Active Grant

• Current Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Original Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Inventors: Kazawa, Satoshi, Hori, Keigo, Tsutagaya, Hiroshi
• Granted Patent: US 8,073,641 B2
• Time in Patent Office: Days
• US Class Current: 702/57
• CPC Class Codes: G01R 29/0871 Complete apparatus or systems; circuits, e.g. receivers or amplifiers G01R29/0878, G01R29/0892 take precedence; dosimeters, warning devices G01R29/0857
• CPC Class Codes: G01R 29/10 Radiation diagrams of antennas
• CPC Class Codes: G01R 31/001 Measuring interference from external sources to, or emission from, the device under test, e.g. EMC, EMI, EMP or ESD testing measuring electromagnetic fields G01R29/08; circuits for generating HV pulses in dielectric strength testing G01R31/14

Abstract

Electromagnetic field distribution is measured by considering time variations of a measured electric and/or magnetic field value. In response to scanning performed with a probe at an arbitrary set of measurement coordinates in a predetermined measurement plane in the vicinity of an object to be measured, a signal is detected at each of plural sets of coordinates in a measurement plane. Electric and magnetic fields are computed during a measurement time period at each set of measurement coordinates in the measurement plane based on measurement coordinates where the probe is positioned and the signal is detected with the probe. Amplitude probability distribution during the time period at each set of measurement coordinates in the vicinity of the object is computed based on the computed intensity, then mapped and displayed.

Claims

1. An electromagnetic field distribution measuring method in which intensity of an electric field and/or a magnetic field in a space in the vicinity of an object being measured and that functions as an electromagnetic wave radiation source is detected with a probe that measures an electromagnetic field distribution in the vicinity of the object to be measured, the method including:

a detection step including scanning with the probe in an arbitrary measurement position in the space in the vicinity of the object being measured, and detecting the intensity sensed by the scanning with the probe during a predetermined measurement time period at a plurality of probe measurement positions; and

a distribution computation step including computing the distribution of the intensity on the object being measured, the intensity distribution including information about variations with time during the measurement time period.

2. The electromagnetic field distribution measuring method according to claim 1, wherein the distribution computation step includes computing the frequency of excess of the intensity over a predetermined reference value during the measurement time period.

27. The electromagnetic field distribution measuring method according to claim 1, further including mapping data about the electromagnetic field distribution on the object to be measured further including mapping according to information corresponding to the plurality of measurement positions and information corresponding to the intensities at the measurement positions.

3. An electromagnetic field distribution measuring method using a detector for detecting the intensity of an electric field and/or a magnetic field in a space in the vicinity of an object being measured, the object functioning as an electromagnetic wave radiation source, the method including:

a detection step of detecting the intensity in each of a plurality of frequency bands during a predetermined measurement time period at an arbitrary measurement position in the space in the vicinity of the object being measured; and

a distribution computation step including computing the distribution of the detected intensity with respect to time in each of the frequency bands.

4. The electromagnetic field distribution measuring method according to claim 3, wherein the distribution computation step includes computing the frequency of excess of the intensity over a predetermined reference value during the measurement time period.

5. The electromagnetic field distribution measuring method according to claim 3, wherein the plurality of frequency bands are communication channels of an electronic device in which the object being measured is mounted.

6. The electromagnetic field distribution measuring method according to claim 3, wherein the distribution computation step includes computing a distribution including a change in intensity on the object being measured, the distribution including information about variations with time during the measurement time period, and computing a distribution including a change in intensity on the object being measured corresponding to a change between frequency channels.

7. The electromagnetic field distribution measuring method according to claim 3, wherein the distribution computation step includes computing an amplitude probability of intensity during the measurement time period.

8. The electromagnetic field distribution measuring method according to claim 3, wherein the distribution computation step includes computing an average of intensity during the measurement time period.

9. An electromagnetic field distribution measuring method using a detector that detects the intensity of an electric field and/or a magnetic field in a space in the vicinity of an electronic device having first and second circuit blocks, the method including:

a detection step of detecting the intensity during a predetermined measurement time period in the vicinity of the first circuit block; and

a step of computing distribution of the detected intensity with respect to time during the predetermined measurement time period, and evaluating the influence of the first circuit block on the second circuit block on the basis of the value of the computed distribution.

10. The electromagnetic field distribution measuring method according to claim 9, wherein the distribution of intensity with respect to time includes the frequency of excess of the intensity over a predetermined reference value during the measurement time period and the evaluation step includes setting an allowable value of the frequency by considering distance between the first circuit block and the second circuit block.

11. The electromagnetic field distribution measuring method according to claim 9, wherein the distribution of intensity with respect to time includes the frequency of excess of intensity over a predetermined reference value during the measurement time period;

the second circuit block includes a communication function; and

the evaluation step includes evaluating the influence of an electromagnetic field radiated from the first circuit block on the communication function of the second circuit block on the basis of a correlation between the bit error rate of the communication function and the frequency of excess.

12. An electromagnetic field distribution measuring apparatus for measuring an electromagnetic field distribution in the vicinity of an object to be measured, the object being arranged to function as an electromagnetic wave radiation source, the apparatus comprising:

a probe for deriving a signal corresponding to intensity of an electric field and/or a magnetic field in a space in the vicinity of the object to be measured;

a scanner for scanning the probe at an arbitrary set of measurement coordinates;

a detector arrangement for detecting the signal during a predetermined measurement time period at each of sets of measurement coordinates at which the probe is positioned, and storing the results of measurements with the probe;

a computer arrangement for (a) computing the field intensity during the measurement time period based on the detected signals; and

(b) computing the distribution of the field intensity on the object to be measured including information on variations with time during the measurement time period at each set of measurement coordinates based on the computed intensity.

13. The electromagnetic field distribution measuring apparatus according to claim 12, wherein the detector arrangement is arranged for (a) detecting the signal in each of a plurality of frequency bands during the measurement time period with respect to each of the sets of measurement coordinates at which the probe is positioned, and (b) storing the results of the measurements with the probe, and the computer arrangement is arranged for computing the distribution of the intensity corresponding to variations with time during the measurement time period in each of a plurality of frequency bands.

14. The electromagnetic field distribution measuring apparatus according to claim 12, wherein the computer arrangement is arranged for computing a predetermined amplitude probability of the field intensity during the measurement time period at each set of measurement coordinates.

15. The electromagnetic field distribution measuring apparatus according to claim 12, wherein the computer arrangement is arranged for computing an average of the field intensity during the measurement time period.

16. A storage medium or storage device storing a computer program for causing a computer arrangement to compute an electromagnetic field distribution in the vicinity of an object to be measured, the object being arranged to function as an electromagnetic wave radiation source, the field distribution being computed from the intensity of an electric field and/or a magnetic field in a space in the vicinity of the object to be measured, the computer program causing the computer arrangement to perform:

a detection step including detecting a signal corresponding to the field intensity at an arbitrary set of measurement coordinates in the space in the vicinity of the object to be measured during a predetermined measurement time period, and storing the signal;

an intensity computation step including computing the field intensity at the set of measurement coordinates during the measurement time period based on the detection step; and

a distribution computation step including computing the distribution of the field intensity on the object to be measured including information on variations with time during the measurement time period based on the intensity computation step.

17. The storage medium or storage device according to claim 16, wherein the detection step includes detecting the signal in each of a plurality of frequency bands during the measurement time period with respect to each of the sets of measurement coordinates at which the probe is positioned, and storing the results of measurements made with the probe, and the distribution computation step includes computing the distribution of the field intensity corresponding to variations with time during the measurement time period in each of the plurality of frequency bands.

18. The storage medium or storage device according to claim 16, wherein the distribution computation step includes computing an amplitude probability of the field intensity during the measurement time period at each set of measurement coordinates.

19. The storage medium or storage device according to claim 16, wherein the distribution computation step includes computing an average of the field intensity during the measurement time period.

28. The storage medium or storage device according to claim 17, further including mapping data about the electromagnetic field distribution on the object to be measured further including mapping according to information corresponding to the arbitrary set of measurement coordinates and information corresponding to the field intensities at sets of measurement coordinates.

20-26. -26. (canceled)