METHOD AND DEVICE FOR MEASURING INTENSITY OF ELECTROMAGNETIC FIELD, METHOD AND DEVICE FOR MEASURING CURRENT-VOLTAGE DISTRIBUTION, AND METHOD FOR JUDGING QUALITY OF ELECTRONIC DEVICE, AND ELECTRONIC DEVICE THEREOF

• US 6,975,111 B2
• Filed: 09/10/2002
• Issued: 12/13/2005
• Est. Priority Date: 01/13/1999
• Status: Expired due to Term

• Current Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Original Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Inventors: Shimizu, Masayuki, Kazama, Satoshi, Fujita, Masakazu
• Primary Examiner(s): Deb, Anjan
• Assistant Examiner(s): Dole, Timothy J.
• Application Number:
  US10/237,719
• Publication Number:
  US 20030006786A1
• Time in Patent Office: 1,190 Days
• Field of Search: 324/260, 324/263, 324/632, 324/95, 324/750, 324/357, 324/371, 324/457, 324/529, 324/530, 324/167, 324/179, 324/144, 324/637, 324/258, 324/133, 324/72, 343/703, 343/743
• US Class Current: 324/260
• CPC Class Codes: G01R 29/0814 Field measurements related to measuring influence on or from apparatus, components or humans EMC, EMI and similar testing in general G01R31/001, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning
• 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 29/0878 Sensors; antennas; probes; detectors wave guide measuring sections G01R1/24
• CPC Class Codes: G01R 31/002 where the device under test is an electronic circuit
• CPC Class Codes: G01R 31/315 by inductive methods

Abstract

A conductor is disposed within an area where electric coupling and magnetic coupling take place between the conductor and a device-under-test (DUT) in at least a portion of frequency band width, and the value of composite currents that is outputted in a plurality of directions different from each other against the DUT, is measured. Based on the measured plurality of values of the composite currents, the first electric current due to electric coupling between the DUT and the conductor and the second electric current due to magnetic coupling between the DUT and the conductor are calculated. From these first and second electric current values, electric field intensity and magnetic field intensity are calculated.

Claims

1. Apparatus for deriving an indication of at least one of a magnetic and electric field component of an electromagnetic field from a device-under-test, the apparatus comprising an electromagnetic field detector probe including a conductor shaped as a loop and having opposite first and second ends, the loop having a portion adapted to be electromagnetically coupled with the device-under-test, the probe being arranged so that it does not include a shield that affects the electromagnetic field coupled between the device under test and the loop portion, the loop being arranged so that (a) in response to the magnetic field component a first current component I_m flows from the first end to the second end and (b) in response to the electric field component second and third equal amplitude current components I_e flow in the same direction through the first and second ends so that currents I₁ and I₂ flowing through the first and second ends respectively have values directly proportional to (I_e+I_m) and (I_e−

I_m), and circuitry connected to be response to the currents I₁ and I₂ for deriving at least one output signal having a value commensurate with the at least one of the magnetic and electric field components, and a scanner for moving the detector probe relative to the device-under-test in a region adjacent the device-under-test so that as the probe moves in the region, the loop portion is coupled with different electric and magnetic field components derived by the device under test, causing the currents I₁ and I₂ change, and the values of (I_e+I_m) and (I_e−

I_m) to change, the circuitry being arranged to respond to the values of I₁ and I₂ for deriving an indication of the distribution of the electromagnetic field of the device-under-test in the region.

2. The apparatus of claim 1 wherein the apparatus is arranged for deriving indications of both the magnetic and electric field components and the circuitry is arranged for deriving first and second output signals respectively having values commensurate with the magnetic and electric field components.

3. The apparatus of claim 2 wherein the circuitry is arranged for deriving the first and second output signals by combining I₁ and I₂ in accordance with I₁+I₂=(I_e+I_m)+(I_e−

I_m)=2I_e and I₁−

I₂=(I_e+I_m)−

(I_e−

I_m)=2I_m, respectively.

4. The apparatus of claim 1 wherein the at least one output signal has a value commensurate with the magnetic field component and the circuitry is arranged for deriving the output signal having a value commensurate with the magnetic field component by combining I₁ and I₂ in accordance with I₁−

I₂=(I_e+I_m)−

(I_e−

I_m)=2I_m.

5. The apparatus of claim 1 wherein the at least one output signal has a value commensurate with the electric field component and the circuitry is arranged for deriving the output signal having a value commensurate with the electric field component by combining I₁ and I₂ in accordance with I₁+I₂=(I_e+I_m)+(I_e−

I_m)=2I_e.

6. A method of deriving an indication of at least one of a magnetic and electric field component of an electromagnetic field from a device-under-test, the method comprising electromagnetically coupling an electromagnetic field detector probe including a conductor shaped as a loop and having opposite first and second ends with the device-under-test, the loop having a portion electromagnetically coupled with the device under test, the probe being arranged so that it does not include a shield that affects the electromagnetic field coupled between the device under test and the loop portion, the loop portion being arranged so that (a) in response to the magnetic field component coupled from the device-under-test to the loop portion, a first current component I_m flows from the first end to the second end and (b) in response to the electric field component second and third equal amplitude current components I_e flow in the same direction through the first and second ends so that currents I₁ and I₂ flowing through the first and second ends respectively have values directly proportional to (I_e+I_m) and (I_e−

I_m), responding to the currents I₁ and I₂ to derive at least one output signal having a value commensurate with the at least one of the magnetic and electric field components, and moving the detector probe relative to the device-under-test in a region adjacent the device-under-test so that as the probe moves in the region, the portion is coupled with different electric and magnetic field components derived by the device under test, causing the currents I₁ and I₂ change, and the values of (I_e+I_m) and (I_e−

I_m) to change, the circuitry responding to the values of I₁ and I₂ by deriving an indication of the distribution of the electromagnetic field of the device-under-test in the region.

7. The method of claim 6 wherein the method derives indications of both the magnetic and electric field components and the response to the currents I₁ and I₂ results in the derivation of first and second output signals respectively having values commensurate with the magnetic and electric field components.

8. The method of claim 7 wherein the first and second output signals are derived by combining I₁ and I₂ in accordance with I₁+I₂=(I_e+I_m)+(I_e−

I_m)=2I_e and I₁−

I₂=(I_e+I_m)−

(I_e−

I_m)=2I_m, respectively.

9. The method of claim 6 wherein the at least on output signal has a value commensurate with the magnetic field component and the output signal having a value commensurate with the magnetic field component is derived by combining I₁ and I₂ in accordance with I₁+I₂=(I_e+I_m)−

(I_e−

I_m)=2I_m.

10. The method of claim 6 wherein the at least one output signal has a value commensurate with the electric field component and the output signal having a value commensurate with the electric field component is derived by combining I₁ and I₂ accordance with I₁+I₂=(I_e+I_m)−

(I_e+I_m)=2I_e.

11. Apparatus for deriving an indication of at least one of a magnetic and electric field component of an electromagnetic field from a device-under-test, the apparatus comprising an electromagnetic field detector probe including a conductor shaped as a loop and having opposite first and second ends, the loop having a portion adapted to be electromagnetically coupled with the device-under-test, the probe being arranged so that it does not include a shield that affects the electromagnetic field coupled between the device under test and the loop portion, the loop being arranged so that (a) in response to the magnetic field component a first current component I_m flows from the first end to the second end and (b) in response to the electric field component second and third equal amplitude current components I_e flow in the same direction through the first and second ends so that currents I₁ and I₂ flowing through the first and second ends respectively have values directly proportional to (I_e+Im) and (I_e−

I_m), and circuitry connected to be responsive to the currents I₁ and I₂ for deriving at least one output signal having a value commensurate with at least one of the magnetic electric field components, the loop portion being arranged to be coupled with different electric and magnetic field components derived by the device under test for causing at least one of currents I₁ and I₂ to change and the values of (I_e+I_m) and (I_e−

I_m) to change as changes in at least one of the magnetic and electric field components coupled to the loop portion occur, the circuitry being arranged to respond to the values of I₁ and I₂ for deriving an indication of the distribution of the electromagnetic field of the device-under-test in the region.

12. A method of deriving an indication of at least one of a magnetic and electric field component of an electromagnetic field from a device-under-test, the method comprising electromagnetically coupling an electromagnetic field detector probe including a conductor shaped as a loop and having opposite first and second ends with the device-under-test, the loop having a portion electromagnetically coupled with the device under test, the probe being arranged so that it does not include a shield that affects the electromagnetic field coupled between the device under test and the loop portion, the loop portion being arranged so that (a) in response to the magnetic field component coupled from the device-under-test to the loop portion, a first current component I_m flows from the first end to the second end and (b) in response to the electric field component second and third equal amplitude current components I_e flow in the same direction through the first and second ends so that currents I₁ and I₂ flowing through the first and second ends respectively have values directly proportional to (I_e+I_m) and (I_e−

I_m) responding to the currents I₁ and I₂ derive at least one output signal having a value commensurate with at least one of the magnetic and electric field components, coupling at least one of different electric and magnetic field components derived by the device under test to the portion to cause at least one of the currents I₁ and I₂ to change and at least one of the values of (I_e+I_m) and (I_e−

I_m) to change, the circuitry responding to the values of I₁ and I₂ by deriving an indication of the distribution of the electromagnetic field of th device-under-test in the region.