Wireless power transmitter with a plurality of magnetic oscillators

Abstract

One aspect of the disclosure provides a power receiver configured to wirelessly transfer power from at least one power transmitter. The power receiver comprises a plurality of magnetic oscillators, each magnetic oscillator of the plurality of magnetic oscillators having a mechanical resonant frequency substantially equal to a first frequency, the plurality of magnetic oscillators configured to generate a first time-varying magnetic field in response to exposure to a second time-varying magnetic field. The power receiver further comprises at least one current circuit configured to generate a time-varying electric current in response to exposure to the first time-varying magnetic field. The first time-varying magnetic field has an operating frequency substantially equal to the first frequency.

What is claimed is: 
     
         1 . A power receiver configured to wirelessly receive power from at least one power transmitter, the power receiver comprising:
 a plurality of magnetic oscillators, each magnetic oscillator of the plurality of magnetic oscillators having a mechanical resonant frequency substantially equal to a first frequency, the plurality of magnetic oscillators configured to generate a first time-varying magnetic field in response to exposure to a second time-varying magnetic field; and   at least one current circuit configured to generate a time-varying electric current in response to exposure to the first time-varying magnetic field, the first time-varying magnetic field having an operating frequency substantially equal to the first frequency,   wherein the plurality of magnetic oscillators comprises:
 a first set of magnetic oscillators positioned to intersect a first plane, each magnetic oscillator of the first set of magnetic oscillators having a magnetic moment pointing in a first direction, the first set of magnetic oscillators having a first summed magnetic moment comprising a time-varying component and a time-invariant component; and 
 a second set of magnetic oscillators positioned to intersect a second plane different from the first plane, each magnetic oscillator of the second set of magnetic oscillators having a magnetic moment pointing in a second direction, the second set of magnetic oscillators having a second summed magnetic moment comprising a time-varying component and a time-invariant component, 
 wherein the time-invariant component of the first summed magnetic moment and the time-invariant component of the second summed magnetic moment have substantially equal magnitudes and point in substantially opposite directions. 
   
     
     
         2 . The power receiver of  claim 1 , wherein the plurality of magnetic oscillators is arranged in a three-dimensional array. 
     
     
         3 . The power receiver of  claim 1 , wherein the at least one current circuit comprises at least one coil surrounding at least a portion of the plurality of magnetic oscillators. 
     
     
         4 . The power receiver of  claim 1 , wherein an impedance of the at least one current circuit has an imaginary component that is equal to zero at a frequency substantially equal to the mechanical resonant frequency. 
     
     
         5 . The power receiver of  claim 1 , further comprising at least one substrate mechanically coupled to the plurality of magnetic oscillators. 
     
     
         6 . The power receiver of  claim 5 , wherein the at least one substrate comprises a silicon substrate. 
     
     
         7 . The power receiver of  claim 1 , wherein the plurality of magnetic oscillators is a micro-electro-mechanical system (MEMS) structure. 
     
     
         8 . The power receiver of  claim 1 , wherein each magnetic oscillator of the plurality of magnetic oscillators comprises a movable magnetic element configured to rotate about an axis in response to a torque applied to the movable magnetic element by the first magnetic field. 
     
     
         9 . The power receiver of  claim 8 , wherein the movable magnetic element comprises at least one spring configured to apply a restoring force to the movable magnetic element upon rotation of the movable magnetic element. 
     
     
         10 . A method of receiving wireless power from at least one power transmitter, the method comprising:
 generating, via a plurality of magnetic oscillators, a first time-varying magnetic field in response to exposure to a second time-varying second magnetic field, wherein each magnetic oscillator of the plurality of magnetic oscillators has a mechanical resonant frequency substantially equal to a first frequency; and   generating a time-varying electric current in response to exposure to the first time-varying magnetic field, the first time-varying magnetic field having the first frequency,   wherein the plurality of magnetic oscillators comprises:
 a first set of magnetic oscillators positioned to intersect a first plane, each magnetic oscillator of the first set of magnetic oscillators having a magnetic moment pointing in a first direction, the first set of magnetic oscillators having a first summed magnetic moment comprising a time-varying component and a time-invariant component; and 
 a second set of magnetic oscillators positioned to intersect a second plane different from the first plane, each magnetic oscillator of the second set of magnetic oscillators having a magnetic moment pointing in a second direction, the second set of magnetic oscillators having a second summed magnetic moment comprising a time-varying component and a time-invariant component, 
 wherein the time-invariant component of the first summed magnetic moment and the time-invariant component of the second summed magnetic moment have substantially equal magnitudes and point in substantially opposite directions. 
   
     
     
         11 . The method of  claim 10 , wherein an impedance of the at least one circuit has an imaginary component that is equal to zero at a frequency substantially equal to the mechanical resonant frequency. 
     
     
         12 . The method of  claim 10 , further comprising rotating a movable magnetic element of each magnetic oscillator of the plurality of magnetic oscillators about an axis in response to a torque applied to the movable magnetic element by the first magnetic field. 
     
     
         13 . The method of  claim 12 , further comprising applying a restoring force to the movable magnetic element upon rotation of the movable magnetic element. 
     
     
         14 . A power receiver configured to wirelessly receive power from at least one power transmitter, the power receiver comprising:
 a plurality of means for generating a first time-varying magnetic field in response to exposure to a second time-varying second magnetic field, wherein each means for generating has a mechanical resonant frequency substantially equal to a first frequency; and   at least one means for generating a time-varying electric current in response to exposure to the first time-varying magnetic field, the first time-varying magnetic field having the first frequency,   wherein the plurality of means for field generating comprises:
 a first set of means for field generating positioned to intersect a first plane, each means for field generating of the first set of means for field generating having a magnetic moment pointing in a first direction, the first set of means for field generating having a first summed magnetic moment comprising a time-varying component and a time-invariant component; and 
 a second set of means for field generating positioned to intersect a second plane different from the first plane, each means for field generating of the second set of means for field generating having a magnetic moment pointing in a second direction, the second set of means for field generating having a second summed magnetic moment comprising a time-varying component and a time-invariant component, 
 wherein the time-invariant component of the first summed magnetic moment and the time-invariant component of the second summed magnetic moment have substantially equal magnitudes and point in substantially opposite directions. 
   
     
     
         15 . The power receiver of  claim 14 , wherein the at least one means for current generating comprises at least one coil surrounding at least a portion of the plurality of means for field generating. 
     
     
         16 . The power receiver of  claim 14 , wherein an impedance of the at least one means for current generating has an imaginary component that is equal to zero at a frequency substantially equal to the mechanical resonant frequency. 
     
     
         17 . The power receiver of  claim 14 , wherein the plurality of means for field generating is a micro-electro-mechanical system (MEMS) structure. 
     
     
         18 . The power receiver of  claim 14 , further comprising at least one substrate mechanically coupled to the plurality of means for field generating. 
     
     
         19 . The power receiver of  claim 14 , wherein each means for field generating of the plurality of means for field generating comprises a movable magnetic element configured to rotate about an axis in response to a torque applied to the movable magnetic element by the first magnetic field. 
     
     
         20 . The power receiver of  claim 19 , wherein the movable magnetic element comprises at least one spring configured to apply a restoring force to the movable magnetic element upon rotation of the movable magnetic element.