Electromagnetic field measuring apparatus and method therefor

• US 8,129,989 B2
• Filed: 05/26/2009
• Issued: 03/06/2012
• Est. Priority Date: 06/03/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ide, Takeshi
• Primary Examiner(s): Phan, Huy Q
• Assistant Examiner(s): Allgood, Alesa
• Application Number:
  US12/472,336
• Publication Number:
  US 20090295379A1
• Time in Patent Office: 1,015 Days
• Field of Search: 324/207, 324/207.2, 324/247, 324/72, 324/658
• US Class Current: 324/260
• CPC Class Codes: G01R 33/028 Electrodynamic magnetometers
• CPC Class Codes: G01R 33/04 using the flux-gate principle

Abstract

A plate conductor and at least three columnar conductors erected on the plate conductor are provided. At the same time when an electric field is measured by the plate conductor, two components of a magnetic field at the same measurement points as those at which the electric field is measured are measured by a loop formed by the plate conductor and the columnar conductors at the same time. As a result, three components of an electromagnetic field formed of one component of the electric field and two components of the magnetic field are measured at the same point, with high sensitivity, and at the same time.

Claims

1. An electromagnetic field measuring apparatus for measuring an electric field and a magnetic field radiated from an electronic device, comprising:

an electromagnetic field measuring sensor including a plate conductor and at least three columnar conductors on the plate conductor, wherein the at least three columnar conductors are electrically connected to the plate conductor;

measuring devices that detect currents induced in the at least three columnar conductors, independently; and

a calculator that calculates intensities of the electric field and the magnetic field with respective current values detected by the measuring devices,

wherein the calculator calculates a current excited by the plate conductor and a current excited by a loop formed by the plate conductor and an arbitrary two of the at least three columnar conductors, separately.

2. An electromagnetic field measuring apparatus according to claim 1, wherein the plate conductor is circular, and four of the columnar conductors are positioned at rotating symmetries with each other through 90 degrees.

3. An electromagnetic field measuring apparatus according to claim 1, wherein the at least three columnar conductors are erected perpendicular to the plate conductor.

4. An electromagnetic field measuring apparatus according to claim 1, wherein the at least three columnar conductors are erected at regular intervals on an outer peripheral portion of the plate conductor.

5. An electromagnetic field measuring apparatus according to claim 1, further comprising a display that displays results calculated by the calculator,

wherein the display displays an intensity distribution of the electric field and an intensity distribution of the magnetic field which are radiated from the electronic device with the calculated values at respective measurement points of the electronic device.

6. An electromagnetic field measuring apparatus according to claim 1, wherein the electric field and the magnetic field are detected simultaneously in a same position.

7. An electromagnetic field measuring method for measuring an electric field and a magnetic field radiated from an electronic device, comprising:

arranging an electromagnetic field measuring sensor including a plate conductor and at least three columnar conductors erected on the plate conductor in a vicinity of the electronic device, wherein the at least three columnar conductors are electrically connected to the plate conductor;

detecting currents induced in the at least three columnar conductors, independently; and

calculating a current excited by the plate conductor and a current excited by a loop formed by the plate conductor and an arbitrary two of the at least three columnar conductors with respective current values measured by a measuring device, separately, and calculating the electric field and the magnetic field radiated from the electronic device,

wherein the electric field and the magnetic field are detected simultaneously in a same position.

8. An electromagnetic field measuring method according to claim 7, wherein an intensity distribution of the electric field and an intensity distribution of the magnetic field which are radiated from the electronic device are calculated with the current excited by the plate conductor and the current excited by the loop formed by the plate conductor and the arbitrary two of the at least three columnar conductors, which are calculated at a plurality of positions of the electronic device.