Wireless charging platforms via three-dimensional phased coil arrays

Abstract

Methods, systems, and devices are disclosed for wirelessly charging electronic devices. In one aspect, a wireless charging transmitter device includes a three-dimensional coil array electrically coupled to a power source and structured to include two or more coils to produce an electromagnetic field that emanates from the three-dimensional coil array, in which the coils are arranged such that at least two coils are perpendicular to each other to direct the electromagnetic field. The wireless charging transmitter device is operable to wirelessly charge an electronic device by providing the electromagnetic field at a receiver coil of the electronic device to convert the electromagnetic energy to electrical energy to power the electronic device.

1 . A wireless charging transmitter device, comprising:
 a power source electrically coupled to a three-dimensional antenna array,   wherein the three-dimensional antenna array comprises a first surface spiral coil arranged on a x-axis plane, and a second surface spiral coil arranged on a y-axis plane perpendicular to the x-axis,
 wherein the first and second surface spiral coils each comprises a continuous conductor wound around a dielectric material at an angle to diminish a proximity effect at an operating frequency of the wireless charging transmitter device, and to maintain a high intrinsic quality factor (Q) of the first and second surface spiral coils at the operating frequency; and 
   a control circuit coupled to the power source and to the three-dimensional antenna array,   wherein the control circuit is configured to control the operating frequency of the wireless charging transmitter device as electrical power is delivered to the three-dimensional antenna array from the power source.   
     
     
         2 . The wireless charging transmitter device of  claim 1 , further comprising:
 a third surface spiral coil arranged on a z-axis plane perpendicular to the x-axis plane and perpendicular to the y-axis plane.   
     
     
         3 . The wireless charging transmitter device of  claim 1 , wherein the conductor has a thickness of approximately 40 um and has no breaks or radio frequency discontinuities. 
     
     
         4 . The wireless charging transmitter device of  claim 1 , wherein the conductor is wound around the dielectric material at an angle to maintain the high intrinsic quality factor (Q) of the surface spiral coil at approximately 700. 
     
     
         5 . The wireless charging transmitter device of  claim 1 , wherein the first and second surface spiral coils each have a maximum diameter of approximately 6 inches. 
     
     
         6 . The wireless charging transmitter device of  claim 1 , wherein the control circuit is disposed within the three-dimensional antenna array. 
     
     
         7 . The wireless charging transmitter device of  claim 1 , wherein the control circuit is configured to dynamically adjust an impedance of the wireless charging transmitter device without shifting a resonant frequency of the wireless charging transmitter device. 
     
     
         8 . The wireless charging transmitter device of  claim 7 , wherein dynamically adjusting the impedance of the wireless charging transmitter device is in response to at least one of a presence of an object close to the three-dimensional antenna array, an orientation of a receiver device inductively coupled to the wireless charging transmitter device, or a change in position of the receiver device relative to a position of the wireless charging transmitter device. 
     
     
         9 . The wireless charging transmitter device of  claim 1 , wherein the power source is a DC power source. 
     
     
         10 . The wireless charging transmitter device of  claim 9 , wherein the DC power source is a rechargeable battery. 
     
     
         11 . The wireless charging transmitter device of  claim 1 , wherein an AC/DC charger provides a DC signal to an input of an amplifier of the wireless charging transmitter device. 
     
     
         12 . A method for transmitting wireless power from a wireless charging transmitter device to a receiver device, the method comprising:
 supplying electrical power from a power source to a three-dimensional coil array,
 wherein the three-dimensional coil array comprises a first surface spiral coil arranged on a x-axis plane, and a second surface spiral coil arranged on a y-axis plane perpendicular to the x-axis plane,
 wherein the first and second surface spiral coils each comprises a continuous conductor wound around a dielectric material at an angle to diminish a proximity effect at an operating frequency of the wireless charging transmitter device, and to maintain a high intrinsic quality factor (Q) of the first and second surface spiral coils at the operating frequency; and 
 
   dynamically adjusting an impedance of the wireless charging transmitter device in response to a change in reflected impedance,
 wherein the change in the reflected impedance is based on at least one of a presence of an object close to the three-dimensional coil array, an orientation of the receiver device, or a change in position of the receiver device relative to a position of the wireless charging transmitter device. 
   
     
     
         13 . The method of  claim 12 , wherein the three-dimensional coil array further comprises a third surface spiral coil arranged on a z-axis plane perpendicular to x-axis plane and perpendicular to the z-axis plane. 
     
     
         14 . The method of  claim 12 , further comprising:
 controlling, by a control circuit, the operating frequency of the wireless charging transmitter device as the electrical power is supplied to the three-dimensional coil array from the power source.   
     
     
         15 . The method of  claim 12 , wherein the conductor has a thickness of approximately 40 um and has no breaks or radio frequency discontinuities. 
     
     
         16 . The method of  claim 12 , wherein the power source is a rechargeable battery. 
     
     
         17 . The method of  claim 12 , wherein an AC/DC charger provides a DC signal to an input of an amplifier of the wireless charging transmitter device. 
     
     
         18 . A three-dimensional coil array for a wireless charging transmitter device, comprising:
 a first surface spiral coil arranged on a x-axis plane;   a second surface spiral coil disposed inside the first surface spiral coil and arranged on a z-axis plane perpendicular to the x-axis plane; and,   a third surface spiral coil disposed inside the first surface spiral coil or the second surface spiral coils and arranged on a plane forming an acute angle with the x-axis plane and the z-axis plane,
 wherein the first, second, and third surface spiral coils each comprises a continuous conductor wound around a dielectric material at an angle to diminish a proximity effect at an operating frequency of the wireless charging transmitter device, and to maintain a high intrinsic quality factor (Q) of the first, second, and third surface spiral coils at the operating frequency. 
   
     
     
         19 . The three-dimensional coil array of  claim 18 , wherein the conductor has a thickness of approximately 40 um and has no breaks or radio frequency discontinuities.