Electromagnetic field distribution measuring method, apparatus for the method, computer program and information recording medium

• US 8,073,641 B2
• Filed: 01/11/2006
• Issued: 12/06/2011
• 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: Kazama, Satoshi, Hori, Keigo, Tsutagaya, Hiroshi
• Primary Examiner(s): WACHSMAN, HAL D
• Application Number:
  US11/813,598
• Publication Number:
  US 20090006011A1
• Time in Patent Office: 2,155 Days
• Field of Search: 702/57, 702/60, 702/65, 702/76
• 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 a computed intensity, then mapped and displayed.

Claims

1. 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;

(b) computing an amplitude probability distribution during the measurement time period at each set of measurement coordinates based on the computed intensity; and

(c) mapping data about the electromagnetic field distribution on the object to be measured by using intensity values of the amplitude probability distribution when a probability is a predetermined value at the measurement coordinates, or by using probability values of the amplitude probability distribution when an intensity is a predetermined value at the measurement coordinates.

2. 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, 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

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

(b) computing an amplitude probability distribution during the measurement time period at each set of measurement coordinates based on the computed intensity; and

(c) mapping data about the electromagnetic field distribution on the object to be measured further including mapping according to information corresponding to the amplitude probability distribution at the measurement positions, wherein 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.

3. A non-transitory computer readable storage medium containing computer instructions stored therein 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 instructions 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;

a distribution computation step including computing an amplitude probability distribution during the measurement time period based on the intensity computation step; and

a step of mapping data about the electromagnetic field distribution on the object to be measured by using intensity values of the amplitude probability distribution when a probability is a predetermined value at the measurement coordinates or by using probability values of the amplitude probability distribution when an intensity is a predetermined value at the measurement coordinates.

4. The non-transitory computer readable storage medium containing computer instructions stored therein according to claim 3, 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 a probe for deriving the detected signal 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.

5. The non-transitory computer readable storage medium containing computer instructions stored therein according to claim 4, 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 amplitude probability distributions at sets of measurement coordinates.

6. 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;

a computation step including computing an amplitude probability distribution during the measurement time period; and

mapping data about the electromagnetic field distribution on the object to be measured by using intensity values of the amplitude probability distribution when a probability is a predetermined value at the measurement coordinates, or by using probability values of the amplitude probability distribution when an intensity is a predetermined value at the measurement coordinates.