Patent Publication Number: US-2016241044-A1

Title: Methodology for multiple pocket-forming

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     The present disclosure is related to U.S. Non-Provisional patent application Ser. No. 13/891,340 filed May 10, 2013, entitled Methodology for Pocket-Forming, the entire content of which is incorporated herein by this reference. 
    
    
     FIELD OF INVENTION 
     The present disclosure relates to wireless sound power transmission, and more particularly to a method utilizing transducer arrangements for wireless sound power transmission based on pocket-forming. 
     BACKGROUND OF THE INVENTION 
     Portable electronic devices such as smart phones, tablets, notebooks and others have become an everyday need in the way we communicate and interact with others. The frequent use of these devices may require a significant amount of power, which may easily deplete the batteries attached to these devices. Therefore, a user is frequently needed to plug in the device to a power source, and recharge such device. This may be inconvenient and troublesome if the user forgets to plug in or otherwise charge a device, the device may run out of power and be of no use to the user until the user is again able to charge the device. 
     For the foregoing reasons, there is a need for a sound wireless power transmission system where electronic devices may be powered without requiring extra chargers or plugs, and where the mobility and portability of electronic devices may not be compromised. 
     SUMMARY OF THE INVENTION 
     The present disclosure provides a methodology for multiple pocket-forming. The methodology includes at least one transmitter and two or more receivers. A transmitter may include a housing having at least two transducer elements, at least one sound wave integrated circuit (SWIC), and at least one digital signal processor or micro-controller which may be connected to a power source. The housing may also include a communications component. A receiver may include a housing having at least one sensor element, one rectifier, one power converter, and one or more communications component. 
     The method for multiple pocket-forming may start when receivers generate short signals (e.g., Sound Frequency) through one or more transducer elements. The transmitter, which may have two or more transducer elements, intercepts these signals and sends them to a micro-controller. The micro-controller decodes the signals and identifies the gain and phase from the signals sent by each receiver, and hence determining the direction of the pocket of energy. The latter may form channels or paths between the transmitter and receivers. Once the channels are established, the transmitter may transmit controlled Sound Waves (SW), which may converge in 3-d space. These SW waves may be controlled through phase and/or relative amplitude adjustments to form constructive and destructive interference patterns (multiple pocket-forming). A receiver may then utilize pockets of energy produced by multiple-pocket-forming for charging or powering multiple electronic devices and thus effectively providing wireless sound power transmission. 
     In addition, an adaptive power focusing technique is disclosed. This technique may be implemented when there may be obstacles interfering the signals between the receivers and the transmitter or for regulating power at two or more receivers. In an embodiment, receivers and transmitter may use the advantage of having omni-directional transducer, hence allowing the signal to bounce over the walls or ceilings inside a room until establishing a path among them. 
     The methodology described in the present disclosure may provide wireless sound power transmission while eliminating the use of wires or pads for charging devices which may require tedious procedures such as plugging to a wall, and may turn devices unusable during charging. These and other advantages of the present disclosure may be evident to those skilled in the art, or may become evident upon reading the detailed. description of the prefer embodiment, as shown in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present disclosure are described by way of example with reference to the accompanying figures, which are schematic and may not he drawn to scale. Unless indicated as representing prior art, the figures represent aspects of the present disclosure. 
         FIG. 1  shows an example of a transmitter that can be used for multiple pocket-forming, according to an embodiment. 
         FIG. 2  shows an example of a receiver that can be used for multiple pocket-forming, according to an embodiment. 
         FIG. 3  is an exemplary illustration of a method for multiple pocket-forming, according to an embodiment. 
         FIG. 4  is an exemplary illustration of an adaptive power focusing technique for multiple pocket-forming, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     “Pocket-forming” may refer to generating two or more SW waves which converge in 3-d space, forming controlled constructive and destructive interference patterns. 
     “Pockets of energy” may refer to areas or regions of space where energy or power may accumulate in the form of constructive interference patterns of SW waves. 
     “Null-space” may refer to areas or regions of space where pockets of energy do not form because of destructive interference patterns of SW waves. 
     “Transmitter” may refer to a device, including a chip which may generate two or more SW signals, at least one SW signal being phase shifted and gain adjusted with respect to other SW signals, substantially all of which pass through one or more SW transducer such that focused SW signals are directed to a target. 
     “Receiver” may refer to a device including at least one transducer element, at least one rectifying circuit and at least one power converter, which may utilize pockets of energy for powering, or charging an electronic device. 
     “Adaptive pocket-forming” may refer to dynamically adjusting pocket-forming to regulate power on one or more targeted receivers. 
     DESCRIPTION OF THE DRAWINGS 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, which may not be to scale or to proportion, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings and claims, are not meant to be limiting. Other embodiments may he used and/or and other changes may be made without departing from the spirit or scope of the present disclosure. 
       FIG. 1  shows an example of a transmitter  100  that can he used for multiple pocket-forming. In this embodiment, transmitter  100  may be used to provide wireless sound power transmission. Transmitter  100  may include a housing  102  having at least two or more transducer elements  104 , at least one SW integrated circuit (SWIC  106 ), at least one digital signal processor (DSP) or micro-controller  108 , and one communications component  110 . Housing  102  may be made of any suitable material which may allow for signal or wave transmission and/or reception, for example plastic or hard rubber. Transducer elements  104  may include suitable transducer types for operating in frequency bands suitable for sound transmission over predetermined distances to receivers on electronic devices to be charged. Transducer elements  104  may include ultrasonic sensors that are known as transceivers when the transducer elements  104  both send and receive high frequency sound waves. Typically, receivers may communicate to transmitter  100  through short signals (such as SW) or through communications component  110  for determining optimum times and locations for pocket-forming. Communications component  110  may he based on standard wireless communication protocols which may include Bluetooth, Wi-Fi or ZigBee. In addition, communications component  110  may be used to transfer other information such as an identifier for the device or user, battery level, location or other such information. Other communications component  110  may be possible which may include radar, infrared cameras or sound devices for sonic triangulation for determining the device&#39;s position. Transmitter  100  may also include an external power source  112 . 
       FIG. 2  shows an example of a receiver  200  that can be used for multiple pocket-forming. In this embodiment, receiver  200  may be used for powering or charging an electronic device. Receiver  200  may also include a housing  202  having at least one ultrasonic sensor element  204 , one rectifier  206 , one power converter  208  and one or more communications component  210 , housing  202  can be made of any suitable material which may allow for signal or sound wave transmission and/or reception, for example plastic or hard rubber. Housing  202  may be an external hardware that may be added to different electronic equipment, for example in the form of cases, or can be embedded within electronic equipment as well. Sensor element  204  may include suitable sensors types for operating in frequency bands such as those described for transmitter  100  from  FIG. 1 . Sensor element  204  may include an ultrasonic sensor or a transceiver if the sensor both send and receives sound waves. As described above, transceiver  200  may communicate with transmitter  100  using short signals (such as SW) or through communications component  210  as described in  FIG. 1 . 
       FIG. 3  illustrates wireless power transmission using multiple pocket-forming  300  which may include one transmitter  100  and at least two or more receivers  200 . Receivers  200  may communicate with transmitter  100  as described above though  FIG. 1  and  FIG. 2 . Once transmitter  100  identifies and locates receiver  200 , a channel or path can be established by knowing the gain and phases coming from receiver  200 , Transmitter  100  may start to transmit controlled Sound Waves (SW)  302  which may converge in 3-d space by using a minimum of two transducer elements  104 , These SW waves  302  may be produced using an external power source  112  and a local oscillator chip using a suitable piezoelectric material. SW waves  302  may be controlled by SWIC  106  which may include a proprietary chip for adjusting phase and/or relative magnitudes of SW signals which may serve as inputs for transducer elements  104  to form constructive and destructive interference patterns (pocket-forming). Pocket-forming may take advantage of interference to change the directionality of the transducer elements  104  where constructive interference generates a pocket of energy  304  and deconstructive interference generates a null space. Receiver  200  may then utilize pocket of energy  304  produced by pocket-forming for charging or powering an electronic device, for example a laptop computer  306  and a smartphone  308  and thus effectively providing wireless sound power transmission. 
     Multiple pocket-forming  300  may be achieved by computing the phase and gain from each transducer of transmitter  100  to each receiver  200 . The computation may be calculated independently because multiple paths may be generated by transducer element  104  from transmitter  100  to sensor element  204  from receiver  200 . 
     An example of the computation for two transducer elements  104  may be as follow (in terms of signals A and B): (A+B) for the first transducer and (A−B) for the second transducer. One receiver  200  may be at a point where (A+B)+(A−B)=2A. For a second receiver  200  located at some other point, the computation may vary such as (A+B)−(A−B)=2B. This computation may easily be expanded to any number of transducer elements  104 . 
     In some embodiments, two or more receivers  200  may operate at different sound wave frequencies to avoid power losses during wireless sound power transmission. This may be achieved by including multiple embedded transducer elements  104  in an array of transmitter  100 . In one embodiment, a single frequency may be transmitted by each transducer in the array. For example, ½ of the transducers in the array may operate at less than 60 KHz while the other ½ may operate at another frequency lower than 60 KHz. In another example, ⅓ of the transducers in the array may operate at less than 60 KHz, another ⅓ may operate at second frequency less than 60 KHz and the remaining transducers in the array may operate at a third frequency less than 60 KHz. 
     In another embodiment, a single transducer element  104  may be virtually divided into several transducers during wireless sound power transmission. For example, one transducer element  104  may transmit less than 60 KHz, but a receiver  200  may require another frequency less than 60 KHz; thus, transducer element  104  may be virtually divided in 4 patches which may be fed independently. As a result, ¼ of this transducer element  104  may be able to transmit the sound wave frequency of less than 60 KHz needed for receiver  200 . Therefore, by virtually dividing a single transducer element  104 , power losses during wireless power transmission may be avoided. The foregoing may be beneficial because, for example, one transducer element  104  transmitting at about 60 KHz or less may be divided into 4 transducers transmitting at still another frequency less than 60 KHz, and thus, reducing the number of transducer elements  104  in a given array when working with receivers  200  operating at different frequencies. 
       FIG. 4  is an exemplary illustration of multiple adaptive pocket-forming  400 . In this embodiment, a user  402  may be inside a room and may hold on his hands an electronic device which in this case may be a tablet  404 . In addition, smartphone  308  may be on furniture  406  inside the room. Tablet  404  and smartphone  308  may each include a receiver  200  either embedded to each electronic device or as a separate adapter connected to tablet  404  and smartphone  308 . Receivers  200  may include all the components described in  FIG. 2 . 
     A transmitter  100  may be hanging on one of the walls of the room right behind user  402 , as shown in  FIG. 4 . Transmitter  100  may also include all the components described in  FIG. 1 . As user  402  may seem to be obstructing the path between receiver  200  and transmitter  100 , SW waves  408  may not be easily aimed to each receiver  200  in a linear direction. However, since the short signals generated from receivers  200  may be omni-directional for the type of transducer elements  104  used, these signals may bounce over the walls until they find transmitter  100 . Almost instantly, a micro-controller  108  which may reside in transmitter  100 , may recalibrate the signals, sent by each receiver  200 , by adjusting gain and phases and forming conjugates taking into account the built-in phases of transducer elements  104 . Once calibration is peSWormed, transmitter  100  may focus SW waves  408  in two channels following the paths described in  FIG. 4 , which may be the most efficient paths. Subsequently, a pocket of energy  304  may form on tablet  404  and another pocket of energy  304  in smartphone  308  while avoiding obstacles such as user  402  and furniture  406 . The foregoing property may be beneficial in that wireless power transmission using multiple pocket-forming  300  may inherently be safe as signals may never go through living tissue or other such obstacles. 
     While various aspects and embodiments have been disclosed herein, other aspects and embodiments may be contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.