RADIATED POWER CONTROL SYSTEMS AND METHODS IN WIRELESS COMMUNICATION DEVICES

• US 20110117973A1
• Filed: 11/13/2009
• Published: 05/19/2011
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Biggerstaff, Matthew, Napoles, Adrian, White, Ben, Nanni, Pete, Leyh, Arthur Christopher, Asrani, Vijay, Black, Greg
• Granted Patent: US 8,483,632 B2
• Time in Patent Office: Days
• US Class Current: 455/571
• CPC Class Codes: H04W 52/245 taking into account received signal strength

Abstract

Embodiments include systems and methods for controlling radiation of radio frequency (RF) energy by a wireless communication device that includes a transmitter, an antenna, a vector field sensor, and a processing system. The transmitter produces an analog RF signal, and the antenna radiates the analog RF signal into an environment. The vector field sensor senses an intensity of a vector field resulting from the analog RF signal radiated by at least the antenna (and possibly other portions of the device). The processing system determines whether a value representing the intensity is greater than a first threshold, and when the value is greater than the first threshold, the processing system causes the radiated RF energy produced by the wireless communication device to be decreased.

Claims

1. A method for controlling radiation of radio frequency (RF) energy by a wireless communication device that includes a transmitter and an antenna, the method performed by the wireless communication device and comprising the steps of:

producing radiated RF energy by the wireless communication device;

sensing, by a vector field sensor of the wireless communication device, an intensity of a vector field resulting from the radiated RF energy;

determining whether a value representing the intensity is greater than a first threshold; and

when the value is greater than the first threshold, decreasing the radiated RF energy produced by the wireless communication device.

2. The method of claim 1, wherein decreasing the radiated RF energy comprises adjusting one or more values of one or more impedance matching components to cause a decrease in the radiated RF energy.

3. The method of claim 1, wherein decreasing the radiated RF energy comprises adjusting power control parameters of the transmitter to cause a decrease in the radiated RF energy.

4. The method of claim 1, further comprising the steps of:

determining whether the value is less than a second threshold, wherein the second threshold has a lower value than the first threshold; and

when the value is less than the second threshold, increasing the radiated RF energy produced by the wireless communication device.

5. The method of claim 4, wherein increasing the radiated RF energy comprises adjusting one or more values of one or more impedance matching components to cause an increase in the radiated RF energy.

6. The method of claim 4, wherein increasing the radiated RF energy comprises adjusting power control parameters of the transmitter to cause an increase in the radiated RF energy.

7. The method of claim 1, wherein the wireless communication device further comprises one or more circuits that include one or more impedance matching components, and wherein the one or more impedance matching components includes one or more capacitors, and wherein decreasing the radiated RF energy is performed by adjusting the one or more values of the one or more capacitors.

8. The method of claim 1, wherein the first threshold is less than or equal to an applicable Hearing Aid Compatibility (HAC) Act upper limit.

9. The method of claim 1, wherein sensing the intensity of the vector field comprises sensing the intensity of an electric field.

10. The method of claim 1, wherein sensing the intensity of the vector field comprises sensing the intensity of a magnetic field.

11. The method of claim 1, wherein the vector field sensor is positioned within a portion of the device that corresponds to a Hearing Aid Compatibility (HAC) grid, and wherein sensing the intensity of the vector field comprises sensing the intensity within the portion of the device that corresponds to the HAC grid.

12. The method of claim 11, wherein the HAC grid includes a three-by-three array of measurement areas, and wherein sensing the intensity of the vector field comprises sensing the intensity within a portion of the device that corresponds to a particular measurement area of the HAC grid within which an intensity measurement taken during device testing was highest, when compared with intensity measurements taken during the device testing within measurement areas other than the particular measurement area.

13. A wireless communication device comprising:

a transmitter configured to produce an analog radio frequency (RF) signal;

an antenna, operably coupled with the transmitter, and configured to radiate the analog RF signal into an environment;

a vector field sensor configured to sense an intensity of a vector field resulting from the analog RF signal radiated by at least the antenna; and

a processing system operably coupled with vector field sensor, and configured to determine whether a value representing the intensity is greater than a first threshold, and when the value is greater than the first threshold, to cause radiated RF energy produced by the wireless communication device to be decreased.

14. The device of claim 13, wherein the processing system is further configured to determine whether the value is less than a second threshold, wherein the second threshold has a lower value than the first threshold, and when the value is less than the second threshold, to cause RF energy produced by the wireless communication device to be increased.

15. The device of claim 13, further comprising:

an impedance matching circuit, operably coupled between the antenna and the transmitter, wherein the impedance matching circuit includes one or more impedance matching components, and wherein the processing system is configured to cause the radiated RF energy to be decreased by causing one or more values of the one or more impedance matching components to be adjusted.

16. The device of claim 13, further comprising:

an antenna tuning circuit, operably coupled to the antenna and to the processing system, wherein the antenna tuning circuit includes one or more impedance matching components, and wherein the processing system is configured to cause the radiated RF energy to be decreased by causing one or more values of the one or more impedance matching components to be adjusted.

17. The device of claim 13, further comprising:

a first ground plane;

a second ground plane; and

an impedance matching circuit, operably coupled between the first ground plane and the second ground plane, wherein the impedance matching circuit includes one or more impedance matching components, and wherein the processing system is configured to cause the radiated RF energy to be decreased by causing one or more values of the one or more impedance matching components to be adjusted.

18. The device of claim 13, wherein the processing system is configured to cause the radiated RF energy to be decreased by adjusting power control parameters of the transmitter to cause a decrease in the radiated RF energy.

19. The device of claim 13, wherein the vector field sensor is positioned within a portion of the device that corresponds to a Hearing Aid Compatibility (HAC) grid.

20. The device of claim 19, wherein the HAC grid includes a three-by-three array of measurement areas, and wherein the vector field sensor is positioned within a portion of the device that corresponds to a particular measurement area of the HAC grid within which an intensity measurement taken during device testing was highest, when compared with intensity measurements taken during the device testing within measurement areas other than the particular measurement area.