Absorption power measuring device

• US 7,186,377 B2
• Filed: 08/08/2002
• Issued: 03/06/2007
• Est. Priority Date: 08/08/2001
• Status: Expired due to Fees

• Current Assignee: Google Inc. (Alphabet Inc.)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Uebayashi, Shinji, Nojima, Toshio, Iyama, Takahiro, Tarusawa, Yoshiaki
• Primary Examiner(s): SINES, BRIAN J
• Application Number:
  US10/398,205
• Publication Number:
  US 20040102694A1
• Time in Patent Office: 1,671 Days
• Field of Search: 422/82.01, 422/50, 422/68.1, 343/701, 343/703, 343/718, 436/149
• US Class Current: 422/50
• CPC Class Codes: G01R 29/08 Measuring electromagnetic field characteristics

Abstract

In an apparatus for measuring absorbed power including an electromagnetic field probe 1 fixedly mounted within a head simulation phantom 2 which simulates the configuration and the electromagnetic characteristics of a head of a human body, and wherein the strength of an electric field or a magnetic field of a radio wave externally irradiated upon the head simulation phantom 2 is measured by the electromagnetic field probe 1, and the power of the radio wave absorbed by the head is estimated on the basis of measured values, the head simulation phantom 2 comprises a solid dielectric 10′ which simulates the configuration and the electromagnetic characteristics of a head of a human body or a liquid dielectric 10 which simulates the electromagnetic characteristics of a head of a human body and which is filled in an enclosed vessel 10 which simulates the configuration of a head of a human body. The volume of the solid dielectric 10′ or the volume of the enclosed vessel 11 is equal to or less than 5×10⁵ mm³.

Claims

1. An apparatus for measuring absorbed power comprising:

a phantom which has a configuration that simulates a configuration of a head of a human body, and which is made of a material having electromagnetic characteristics that simulate those of a human body or formed of a container filled with said material, the phantom including an opening at a first side surface portion, the opening providing access to a second side surface portion opposite to the first side surface portion and interior to the phantom;

an electromagnetic field probe configured to measure a strength of an electric field or a magnetic field of a radio wave irradiated thereto, said probe being positioned in said phantom through the opening and retained in said phantom at or close to the second side surface portion of said phantom;

a radio wave radiation source positioned exterior of said phantom adjacent to said second side surface portion for irradiating a radio wave to said probe retained interior of said phantom; and

a calculation unit configured to estimate the power of the radio wave absorbed by the part of the human body on the basis of measured values from said probe;

wherein said phantom has a volume which is equal to or less than ⅛

times the volume of the head of the human body.

2. The apparatus for measuring absorbed power according to claim 1 in which the phantom and the electromagnetic field probe are integrally connected together by an adhesive filled in said opening.

3. The apparatus for measuring absorbed power according to claim 1, further comprising

a spacer having a predetermined thickness and made of a material of a low dielectric constant, said spacer being attached at one surface thereof to the second side surface portion of the phantom which is located adjacent to said radio wave radiation source so that said radio wave radiation source is movable on opposite surface of said spacer, whereby facilitating the measurement of the absorbed power under a state maintaining a constant spacing between said radio wave source and said probe.

4. The apparatus for measuring absorbed power according to claim 3 wherein the spacer has a thickness in a range from 1 to 20 mm.

5. The apparatus for measuring absorbed power according to claim 3 wherein the spacer is detachable.

6. The apparatus for measuring absorbed power according to claim 3 wherein the spacer comprises a plurality of spacer pieces stacked on above another and coupled together in a slidable manner and has a variable thickness by varying the number of spacer pieces positioned between said radio wave source and said second side surface portion of the phantom.

7. The apparatus for measuring absorbed power according to claim 1 wherein the phantom has a volume which is equal to or less than 5×

10⁵ mm³.

8. The apparatus for measuring absorbed power according to claim 1 wherein the electromagnetic field probe is disposed within 20 mm from the surface of the phantom which is disposed toward a radiation source of the irradiating radio wave.

9. The apparatus for measuring absorbed power according to claim 1 wherein the phantom is attached with a handle which is formed of a material having a low dielectric constant.

10. The apparatus for measuring absorbed power according to claim 1, further comprising:

a scan mechanism which causes a relative movement between the phantom and a radio transmitter acting as said radio wave radiation source.

11. The apparatus for measuring absorbed power according to claim 10, wherein a plurality of electromagnetic field probes are disposed within the phantom.

12. The apparatus for measuring absorbed power according to claim 10 wherein the phantom is in the form of a flat plate and has a size of substantially infinity relative to the size of the radio transmitter.

13. The apparatus for measuring absorbed power according to claim 10 wherein the scan mechanism comprises a belt conveyor, and the phantom is fixedly mounted in opposing relationship with the belt conveyor while the radio transmitter is placed on a surface of the belt conveyor which faces the phantom.

14. The apparatus for measuring absorbed power according to claim 13 wherein a plurality of electromagnetic field probes are disposed as an array in the crosswise direction of the belt conveyor.

15. The apparatus for measuring absorbed-power according to claim 13 wherein the phantom is in the form of a flat plate having a size of substantially infinity relative to the size of the radio transmitter, and a plurality of electromagnetic field probes are disposed as an oblique array relative to the crosswise direction of the belt conveyor.

16. The apparatus for measuring absorbed power according to claim 13 wherein a plurality of identical phantoms are fixedly mounted as an array in the running direction of the belt conveyor, and the electromagnetic field probes disposed within the respective phantoms assume a different position in each phantom.

17. The apparatus for measuring absorbed power according to claim 13 wherein a plurality of identical phantoms are fixedly mounted as an array in the running direction of the belt conveyor, and the electromagnetic field probes disposed within the respective phantoms assume an identical position.

18. The apparatus for measuring absorbed power according to claim 10, further comprising:

a position sensor disposed in the phantom for detecting the presence or absence of the radio transmitter.

19. The apparatus for measuring absorbed power according to claim 10, further comprising:

a radio wave dark box in which the phantom and the scan mechanism are contained.