Adjustable magnetic probe for efficient near field scanning

• US 9,335,384 B2
• Filed: 09/25/2013
• Issued: 05/10/2016
• Est. Priority Date: 09/25/2013
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Hwang, Kyu-Pyung, Song, Young K., Kim, Dong Wook, Yun, Changhan Hobie
• Primary Examiner(s): LEDYNH, BOT L
• Application Number:
  US14/037,142
• Publication Number:
  US 20150084623A1
• Time in Patent Office: 958 Days
• Field of Search: 324/244
• US Class Current: 1/1
• 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 33/02 Measuring direction or magnitude of magnetic fields or magnetic flux G01R33/20 takes precedence

Abstract

A method and apparatus for testing near field magnetic fields of electronic devices. The method comprises measuring a magnetic field using a loop antenna that is oriented in a first direction. The loop antenna is swept through a desired range of azimuth angles while measuring the magnetic field. Once the first direction testing is completed, the loop antenna is changed to a second orientation direction. The magnetic field is then measured in the second orientation direction and is swept through a desired range of orientation angles in the second direction. The apparatus provides a loop antenna connected to a coaxial probe, with the coaxial cable serving as the center conductor, and two outer conductors. An axle is mounted to the loop antenna and connected to a step motor. A servo motor is also provided for moving the arm assembly.

Claims

1. A method for testing near field magnetic fields of electronic devices, comprising:

measuring a magnetic field using a loop antenna in a first orientation direction with respect to a conductor connected to the loop antenna;

sweeping the loop antenna, around a first axis, through a desired range of azimuth angles in the first orientation direction;

changing the loop antenna orientation, around a second axis, from the first orientation direction to a second orientation direction with respect to the conductor;

measuring a magnetic field using the loop antenna in the second orientation direction; and

sweeping the loop antenna through a desired range of azimuth angles in the second orientation direction.

2. The method of claim 1, further comprising increasing a probe spot size.

3. The method of claim 1, further comprising decreasing a probe spot size.

4. The method of claim 1, further comprising testing multiple devices using multiple probe arms controlled by a controller.

5. The method of claim 4, wherein the multiple probe arms use the same probe spot size.

6. The method of claim 4, wherein the multiple probe arms use at least two probe spot sizes.

7. An apparatus for testing near field magnetic fields of electronic devices, comprising:

means for measuring a magnetic field using a loop antenna in a first orientation direction with respect to a conductor connected to the loop antenna;

means for sweeping the loop antenna, around a first axis, through a desired range of azimuth angles in the first orientation direction;

means for changing the loop antenna orientation, around a second axis, from the first orientation direction to a second orientation direction with respect to the conductor;

means for measuring a magnetic field using the loop antenna in the second orientation direction; and

means for sweeping the loop antenna through a desired range of azimuth angles in the second orientation direction.

8. The apparatus of claim 7 further comprising means for increasing probe spot size.

9. The apparatus of claim 7, further comprising means for decreasing probe spot size.

10. The apparatus of claim 7, further comprising means for testing multiple devices using multiple probe arms controlled by a controller.

11. A computer-readable non-transitory storage medium, containing instructions, which when executed cause a processor to perform the steps of:

measuring a magnetic field using a loop antenna in a first orientation direction with respect to a conductor connected to the loop antenna;

sweeping the loop antenna, around a first axis through a desired range of azimuth angles in the first orientation direction;

changing the loop antenna orientation, around a second axis, from the first orientation direction to a second orientation direction with respect to the conductor;

measuring a magnetic field using the loop antenna in the second orientation direction; and

sweeping the loop antenna through a desired range of azimuth angles in the second orientation direction.

12. The computer-readable non-transitory storage medium of claim 11, further comprising instructions for controlling multiple adjustable magnetic probes controlled using one controller.

13. The computer-readable non-transitory storage medium of claim 11, further comprising instructions for adjusting a loop antenna to increase a probe spot size and to rotate the loop antenna around a z-axis.

14. The computer-readable non-transitory storage medium of claim 11, further comprising instructions for increasing a probe spot size.

15. The computer-readable non-transitory storage medium of claim 11, further comprising instructions for decreasing a probe spot size.

16. The computer-readable non-transitory storage medium of claim 11, further comprising instructions for controlling multiple probe arms.

17. The computer-readable non-transitory storage medium of claim 16, further comprising instructions for controlling multiple probe arms having at least two different probe spot sizes.

18. An apparatus for near field magnetic probe testing, comprising:

a loop antenna connected to a conductor, wherein the loop antenna is configured to

measure a magnetic field with the loop antenna in a first orientation direction with respect to the conductor,

sweep, around a first axis, through a desired range of azimuth angles in the first orientation direction,

change orientation, around a second axis, from the first orientation direction to a second orientation direction with respect to the conductor;

measure a magnetic field using the loop antenna in the second orientation direction; and

sweep through a desired range of azimuth angles in the second orientation direction.

19. The apparatus of claim 18, wherein the loop antenna is further configured to rotate around the first axis to adjust a probe spot.

20. The apparatus of claim 19, wherein the conductor extends alone the first axis.