Electromagnetic emission location and measurement apparatus and method

• US 6,144,341 A
• Filed: 08/18/1998
• Issued: 11/07/2000
• Est. Priority Date: 08/18/1997
• Status: Expired due to Term

• Current Assignee: Desco Industries Incorporated
• Original Assignee: Credence Technologies, Inc. (3M Company)
• Inventors: Kraz, Vladimir
• Primary Examiner(s): Ho, Tan
• Application Number:
  US09/135,912
• Time in Patent Office: 812 Days
• Field of Search: 343/703, 343/841, 343/789, 343/702, 455/89, 455/95, 455/226.1, 324/627, 324/628, 342/127, 342/131, 342/133
• US Class Current: 343/703
• 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

An apparatus for detecting, locating and measuring electromagnetic radiation is provided. The apparatus may be a self-contained, portable device which permits a user to detect, locate and measure electromagnetic radiation from distance away from the radiation source in presence of interference.

Claims

1. An apparatus for detecting and measuring electromagnetic radiation from a radiation source, the apparatus comprising:

means for receiving electromagnetic radiation from the radiation source;

means for determining a distance from the apparatus to the radiation source;

means for determining a value of one or more characteristics of the electromagnetic radiation; and

means for generating a value equal to the power of the radiation source based on the one or more characteristics of the electromagnetic radiation and the distance from the apparatus to the radiation source.

2. The apparatus of claim 1, wherein the value determining means comprises a detector that determines the magnitude of the electromagnetic radiation corresponding to the field strength of the electromagnetic radiation, and wherein said characteristic of said electromagnetic radiation comprises the field strength of said electromagnetic radiation.

3. The apparatus of claim 1, wherein said receiving means comprises a directional antenna having an axis of sensitivity pointed towards the radiation source.

4. The apparatus of claim 3, wherein the directional antenna is removable from the apparatus so that the directional antenna is independently directable towards the radiation source.

5. The apparatus of claim 3 further comprising a cable attached to the apparatus, and wherein the receiving means comprises an antenna attached to the apparatus via the cable so that the antenna is independently directable towards the radiation source.

6. The apparatus of claim 3 further comprising means for visually pointing the directional antenna towards the radiation source.

7. The apparatus of claim 6, wherein said visually pointing means comprises a laser pointer.

8. The apparatus of claim 3, wherein said directional antenna further comprises a shielded enclosure having an opening, the shielded enclosure surrounding an antenna element which is located in the shielded enclosure so that the antenna element receives electromagnetic radiation only through the opening in the shielded enclosure.

9. The apparatus of claim 8, wherein the directional antenna further comprises means for adjusting the directional sensitivity of the directional antenna.

10. The apparatus of claim 9, wherein the adjusting means comprises a cover slideably located adjacent the shielded enclosure to further enhance the directional sensitivity of the antenna.

11. The apparatus of claim 10, wherein the adjusting means further comprises means for adjusting the position of the antenna element relative to the shielded enclosure along the axis of directional sensitivity of the antenna element.

12. The apparatus of claim 1, wherein the distance determining means comprises a range finder.

13. The apparatus of claim 1, wherein the distance determining means comprises means for manually entering the distance into the apparatus.

14. The apparatus of claim 1, wherein the value determining means comprises means for determining a peak, average and quasi-peak magnitudes of the received electromagnetic radiation, means for determining the amplitude modulation of the received electromagnetic radiation and means for determining the frequency of the received electromagnetic radiation.

15. The apparatus of claim 1 further comprising a tuner for tuning the frequency response of the receiving means to a predetermined frequency.

16. An apparatus for detecting, locating and measuring electromagnetic radiation from a radiation source, the apparatus comprising:

a pointer for determining a location of the radiation source;

an antenna having a predetermined gain and a directional sensitivity along an axis, the directional sensitivity of the antenna being adjustable to be directed towards the radiation source to receive radiation from the radiation source but not interfering radiation sources; and

a detector for generating a value equal to a characteristic of the electromagnetic radiation.

17. The apparatus of claim 16 further comprising means for determining a distance from the apparatus to the radiation source and means for generating a value equal to the power of the radiation source based on the value of the characteristic of the electromagnetic radiation and the distance from the apparatus to the radiation source.

18. The apparatus of claim 17, wherein the distance determining means comprises a range finder.

19. The apparatus of claim 17, wherein the distance determining means comprises means for manually entering the distance into the apparatus.

20. The apparatus of claim 17, wherein the value generating means comprises means for determining a peak, average and quasi-peak magnitudes of the received electromagnetic radiation, means for determining the amplitude modulation of the received electromagnetic radiation and means for determining the frequency of the received electromagnetic radiation.

21. The apparatus of claim 16, wherein said antenna comprises an antenna element which is movable so that the antenna element is independently directable towards the radiation source.

22. The apparatus of claim 16 further comprising a cable attached to the apparatus, and wherein the antenna is attached to the apparatus via the cable so that the antenna is independently directable towards the radiation source.

23. The apparatus of claim 16, wherein the axis of directional sensitivity of said antenna is aligned with the axis of the pointer.

24. The apparatus of claim 16, wherein the pointer comprises a laser pointer.

25. The apparatus of claim 16 further comprising a tuner for tuning the frequency response of the receiving means to a predetermined frequency.

26. A method for detecting and measuring the power of an electromagnetic radiation from a radiation source, comprising:

receiving electromagnetic radiation from the radiation source;

determining a distance from the apparatus to the radiation source;

determining a value of one or more characteristics of the electromagnetic radiation; and

generating a value equal to the power of the radiation source based on the one or more characteristics of the electromagnetic radiation and the distance from the apparatus to the radiation source.

27. The method of claim 26, wherein the value generating comprises determining the magnitude of the electromagnetic radiation corresponding to the field strength of the electromagnetic radiation, and wherein said characteristic of said electromagnetic radiation comprises the field strength of said electromagnetic radiation.

28. The method of claim 26, wherein said receiving comprises using a directional antenna having an axis of sensitivity pointed towards the radiation source.

29. The method of claim 26, wherein receiving comprises using an antenna element removable from the apparatus so that the antenna is independently directable towards the radiation source.

30. The method of claim 26 further comprising attaching a cable to the apparatus, and wherein receiving comprises attaching an antenna to the apparatus via the cable so that the antenna is independently directable towards the radiation source.

31. The method of claim 26 further comprising means for visually pointing the directional antenna towards the radiation source.

32. The method of claim 26, wherein the distance determining comprises manually entering the distance into the apparatus.

33. The method of claim 26, wherein the value generating comprises determining a peak, average and quasi-peak magnitudes of the received electromagnetic radiation, determining the amplitude modulation of the received electromagnetic radiation and determining the frequency of the received electromagnetic radiation.

34. The method of claim 26 further comprising tuning the frequency response of the antenna to a predetermined frequency.

35. An apparatus for detecting and measuring electromagnetic radiation from a radiation source, the apparatus comprising:

an antenna that receives electromagnetic radiation from a radiation source;

a range finder that determines the distance between the apparatus and the radiation source;

detectors that determine a value of one or more characteristics of the electromagnetic radiation based on the received electromagnetic radiation; and

a processor that generates a value equal to the power of the radiation source based on the one or more characteristics of the electromagnetic radiation and the distance from the apparatus to the radiation source.