Wireless load modulation
Techniques of load modulation are described herein. A wireless power transmitting unit may include a resonator to periodically transmit a short beacon having a first time period. The wireless power transmitting unit also includes circuitry coupled to the resonator. The circuitry is configured to detect a load change in the resonator when transmitting the short beacon and cause the resonator to transmit a long beacon subsequent to said transmitting the short beacon if said load change is detected. The long beacon has a second time period longer than the first time period.
1. A wireless power transmitting unit, comprising:
a resonator to periodically transmit a short beacon having a first time period;
circuitry coupled to the resonator and configured to:
detect a load change in the resonator when transmitting the short beacon; and
cause the resonator to transmit a long beacon subsequent to said transmitting the short beacon if said load change is detected, the long beacon having a second time period longer than the first time period.
2. The wireless power transmitting unit of claim 1 , wherein the first time period is to be less than 30 milliseconds and the second time period is to be at least 100 milliseconds.
3. The wireless power transmitting unit of claim 1 , wherein the load change is to indicate a presence of a power receiving unit in a vicinity of the resonator.
4. The wireless power transmitting unit of claim 1 , further comprising a controller coupled to the resonator to control the resonator.
5. The wireless power transmitting unit of claim 1 , wherein the change in load is to be a comparison of a load determined in a current short beacon with a load determined in a previous short beacon.
6. A wireless power receiving unit, comprising
a resonator to:
periodically receive short beacons having a first time period; and
receive a long beacon, subsequent to receiving at least one of the short beacons, if the power receiving unit is placed into a charging area of a wireless power transmitting unit, the long beacon having a second time period longer than the first time period.
7. The wireless power receiving unit of claim 6 , wherein the first time period is to be less than 30 milliseconds and the second time period is to be at least 100 milliseconds.
8. The wireless power receiving unit of claim 6 , further comprising a controller coupled to the resonator.
9. A first device for wirelessly charging a second device, comprising:
means to periodically transmit, from a resonator, a series of short beacons having a first time period;
means to detect a load change in the resonator during at least one of the short beacons; and
means to transmit a long beacon from the resonator subsequent to said at least one of the short beacons, if said load change is detected, the long beacon having a second time period longer than the first time period.
10. The first device of claim 9 , wherein the first time period is to be less than 30 milliseconds and the second time period is to be at least 100 milliseconds.
11. The first device of claim 9 , wherein the load change is to indicate a presence of a power receiving unit in a vicinity of the resonator.
12. The first device of claim 9 , wherein the load change is to be a comparison of a load detected in a current short beacon with a load detected in a previous short beacon.
13. A wireless power receiving unit for being wirelessly charged by a wireless power transmitting unit, comprising
means to receive a series of short beacons having a first time period;
means to receive a long beacon, subsequent to said receiving at least one of the short beacons, if the power receiving unit is placed into a charging area of a wireless power transmitting unit, the long beacon having a second time period longer than the first time period.
14. The wireless power receiving unit of claim 13 , wherein the first time period is to be less than 30 milliseconds and the second time period is to be at least 100 milliseconds.