Loop antennas with selectively-activated feeds to control propagation patterns of wireless power signals

Abstract

An example wireless power transmitter includes a ground plate, a conductive wire offset from the ground plate, and a signal-conveyance member. The conductive wire of the wireless power transmitter forms a loop antenna that is configured to radiate a radio frequency (RF) signal for wirelessly powering a receiver device. And the signal-conveyance member of the wireless power transmitter is configured to selectively feed a waveform to a connection point of a plurality of connection points along the conductive wire, wherein the waveform, when provided to the conductive wire, causes the loop antenna to radiate the RF signal.

1 . (canceled) 
     
     
         2 . A wireless power transmitter, comprising:
 a ground plate;   a conductive wire offset from the ground plate, the conductive wire forming:
 a loop antenna that is configured to radiate a radio frequency (RF) signal for wirelessly powering a receiver device; 
   a signal-conveyance member configured to:
 selectively feed a waveform to a connection point of a plurality of connection points along the conductive wire; 
 wherein the waveform, when provided to the conductive wire, causes the loop antenna to radiate the RF signal. 
   
     
     
         3 . The wireless power transmitter of  claim 2 , wherein the signal-conveyance member includes a power amplifier. 
     
     
         4 . The wireless power transmitter of  claim 2 , further comprising a controller configured to:
 select a respective connection point from the plurality of connection points based on a location of the receiver device relative to the plurality of connection points; and   send an instruction to the signal-conveyance member that causes the signal-conveyance member to feed the waveform to the respective connection point.   
     
     
         5 . The wireless power transmitter of  claim 4 , further comprising a communications radio configured to receive a communications signal from a communications radio of the receiver device,
 wherein the controller is further configured to determine the location of the receiver device relative to the plurality of connection points based on the communications signal.   
     
     
         6 . The wireless power transmitter of  claim 4 , further comprising a sensor configured to detect a presence of the receiver device,
 wherein the controller is further configured to determine the location of the receiver device relative to the plurality of connection points based on information generated by the sensor.   
     
     
         7 . The wireless power transmitter of  claim 4 , wherein the loop antenna is configured to radiate the RF signal with different propagation patterns depending on which of the plurality of connection points is fed by the signal-conveyance member. 
     
     
         8 . The wireless power transmitter of  claim 7 , wherein the loop antenna is configured to radiate the RF signal with the different propagation patterns based on a plurality of physical dimensions, including:
 a width of the conductive wire;   a length of the conductive wire;   a height of the conductive wire;   a thickness of the conductive wire;   a shape of the loop antenna; and   a magnitude of an offset between the ground plate and the conductive wire.   
     
     
         9 . The wireless power transmitter of  claim 7 , wherein:
 the signal-conveyance member is further configured to feed the waveform to the connection point when the location of the receiver device is within a threshold distance from the connection point.   
     
     
         10 . The wireless power transmitter of  claim 9 , wherein:
 the loop antenna is configured to radiate the RF signal in a respective propagation pattern of the different propagation patterns when the connection point of the plurality of connection points is fed by the signal-conveyance member,   wherein a high concentration of RF energy in the respective propagation pattern is steered to travel towards the location of the receiver device.   
     
     
         11 . The wireless power transmitter of  claim 10 , wherein:
 when the respective connection point is a different connection point, distinct from the connection point, of the plurality of connection points, the signal-conveyance member is further configured to feed an additional waveform to the different connection point when the receiver device is located at a different location, distinct from the location, the different location being within a second threshold distance from the different connection point.   
     
     
         12 . The wireless power transmitter of  claim 11 , wherein:
 the loop antenna is configured, when the additional waveform is fed to the conductive wire, to radiate an additional RF signal in an additional propagation pattern of the different propagation patterns when the different connection point of the plurality of connection points is fed by the signal-conveyance member,   wherein a high concentration of RF energy in the additional propagation pattern is steered to travel towards the different location of the receiver device.   
     
     
         13 . The wireless power transmitter of  claim 12 , wherein the wireless power transmitter is configured such that in use:
 the RF signal radiated in the respective propagation pattern propagates in a first direction towards the location of the receiver device;   the additional RF signal radiated in the additional propagation pattern propagates in a second direction towards the different location of the receiver device; and   the second direction is different from the first direction.   
     
     
         14 . The wireless power transmitter of  claim 13 , wherein the wireless power transmitter is configured such that in use:
 the propagation pattern has a first polarization;   the additional propagation pattern has a second polarization; and   the second polarization differs from the first polarization.   
     
     
         15 . The wireless power transmitter of  claim 2 , wherein:
 the ground plate is disposed in a first plane;   the conductive wire is disposed in a second plane; and   the second plane is substantially parallel to the first plane.   
     
     
         16 . The wireless power transmitter of  claim 15 , wherein the second plane is offset from the first plane by a distance. 
     
     
         17 . The wireless power transmitter of  claim 15 , wherein a portion of the signal-conveyance member is positioned substantially perpendicular to the first and second planes. 
     
     
         18 . The wireless power transmitter of  claim 2 , wherein:
 the conductive wire comprises a plurality of contiguous segments; and   each of the plurality of connection points is positioned between a respective pair of segments of the plurality of contiguous segments.   
     
     
         19 . The wireless power transmitter of  claim 18 , wherein:
 one or more first segments of the plurality of contiguous segments have a first shape;   one or more second segments of the plurality of contiguous segments have a second shape different from the first shape; and   each of the plurality of contiguous segments is configured to radiate the RF signal when one of the plurality of connection points is fed by the signal-conveyance member.   
     
     
         20 . A non-transitory, computer-readable storage medium storing instructions that, when executed by a processor associated with a wireless power transmitter, cause the wireless power transmitter to:
 selectively feed, by a signal-conveyance member, a waveform to a connection point of a plurality of connection points along a conductive wire, wherein the wireless power transmitter includes:
 a ground plate; 
 the conductive wire being offset from the ground plate, the conductive wire forming a loop antenna that is configured to radiate a radio frequency (RF) signal for wirelessly powering a receiver device; 
   wherein the waveform, when provided to the conductive wire, causes the conductive wire to radiate the RF signal.   
     
     
         21 . A method of manufacturing a wireless power transmitter, the method comprising:
 providing a ground plate;   coupling a conductive wire to the ground plate, wherein the conductive wire forms a loop antenna and is configured to radiate a radio frequency (RF) signal for wirelessly powering a receiver device;   providing a signal-conveyance member, wherein:
 the signal-conveyance member is configured to selectively feed a waveform to a connection point of a plurality of connection points along the conductive wire, and 
 the waveform, when provided to the conductive wire, causes the conductive wire to radiate the RF signal.