Antenna coupling for sensing and dynamic transmission

• US 9,813,997 B2
• Filed: 01/10/2014
• Issued: 11/07/2017
• Est. Priority Date: 01/10/2014
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Mercer, Sean Russell, Khawand, Charbel
• Primary Examiner(s): TAYLOR, BARRY W
• Application Number:
  US14/152,529
• Publication Number:
  US 20150201385A1
• Time in Patent Office: 1,397 Days
• Field of Search: 4554521
• CPC Class Codes: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use
• CPC Class Codes: H04B 17/10 of transmitters
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 72/0473 the resource being transmission power

Abstract

A wireless transmission system disclosed herein includes a transmitter-receiver pair. When a dielectric object approaches the transmitter-receiver pair, a signal strength of a transmitted carrier wave increases at the receiver. In response, transmission power of the transmitter can be dynamically reduced. When the dielectric object moves away from the transmitter-receiver pair, a signal strength of the carrier wave decreases at the receiver. In response, the transmission power of the transmitter can be dynamically increased.

Claims

1. A method comprising:

detecting a change in signal strength of a carrier wave at an RF receiver of an electronic device, the RF receiver separated from an RF transmitter of the electronic device that communicates the carrier wave to the RF receiver, the change in the signal strength being influenced by proximity of a dielectric body positioned external to the electronic device relative to the RF transmitter; and

adjusting transmission power of the carrier wave transmitted from the RF transmitter based on the detected change in signal strength.

2. The method of claim 1 wherein the RF receiver includes a parasitic receiving antenna coupled to the electronic device.

3. The method of claim 1 further comprising:

determining the proximity of the dielectric body based on the detected change in the signal strength of the carrier wave received by the RF receiver from the RF transmitter.

4. The method of claim 1 wherein adjusting operation comprises:

adjusting the transmission power of the carrier wave transmitted from the RF transmitter if the detected change in the signal strength satisfies a threshold power change condition.

5. The method of claim 1 wherein the adjusting operation decreases the transmission power of the RF transmitter, responsive to detection of the change in the signal strength of the carrier wave received by the RF receiver.

6. The method of claim 1 wherein the adjusting operation increases the transmission power of the RF transmitter, responsive to detection of the change in the signal strength of the carrier wave received by the RF received.

7. The method of claim 1 wherein the carrier wave includes a mobile telephone RF transmission.

8. The method of claim 1 wherein the detecting operation further comprises:

measuring a correlation between the carrier wave and a stored wave signature to determine an object characteristic of the dielectric body.

9. The method of claim 8 wherein the object characteristic is an object type.

10. The method of claim 8 wherein the object characteristic is the proximity between the dielectric body and the RF transmitter.

11. A electronic device comprising:

a radiofrequency (RF) transmitter in the electronic device and being configured to transmit a carrier wave from the electronic device;

an RF receiver in the electronic device, the RF receiver separate from the RF transmitter and being configured to receive the carrier wave transmitted from the RF transmitter; and

a power detector coupled to the RF transmitter and the RF receiver, the power detector being configured to adjust transmission power of the RF transmitter responsive to detection of a change in signal strength of the carrier wave received by the RF receiver, the change in signal strength being influenced by proximity of a dielectric body to the RF transmitter.

12. The electronic device of claim 11 wherein the power detector adjusts transmission power of the carrier wave transmitted from the RF transmitter, if the detected change in signal strength satisfies a threshold power change condition.

13. The electronic device of claim 11 wherein the carrier wave includes a mobile telephone RF transmission.

14. The electronic device of claim 11 wherein the RF receiver includes a parasitic receiving antenna, and the parasitic receiving antenna and the RF transmitter are coupled within the electronic device.

15. The electronic device of claim 11 further comprising:

a comparator coupled to the power detector that identifies a proximity of the dielectric body based on the change in the signal strength of the carrier wave received by the RF receiver.

16. The electronic device of claim 11 further comprising:

a comparator coupled to the power detector that measures a correlation between the carrier wave transmitted by the RF transmitter and the carrier wave received by the RF receiver.

17. The electronic device of claim 16 wherein the comparator measures the correlation using at least one auto-correlation function.

18. The electronic device of claim 11 further comprising:

a comparator coupled to the power detector that measures a correlation between the carrier wave received by the RF receiver and a stored wave signature to determine an object characteristic of the dielectric body.

19. A processing circuit configured to perform steps comprising:

analyzing proximity sensing data received at an RF receiver of an electronic device by comparing the proximity sensing data with a pre-generated curve representing an object type in proximity to a radiofrequency (RF) transmitter in an electronic device, the proximity sensing data being based on a waveform of a carrier signal transmitted by the RF transmitter and received by the RF receiver, the RF transmitter separated from the RF receiver within the electronic device; and

adjusting transmission characteristics of a transmission signal transmitted by the RF transmitter based on the analyzed proximity sensing data.

20. The processing circuit of claim 19 wherein the object type is associated with a human being.