Aggregated wireless power transfer with multiple coils and communication channels

Abstract

The present disclosure provides systems, devices, apparatus, and methods for wireless power transmission, including computer programs encoded on a storage medium. A wireless power transmitting device can transmit multiple wireless power signals to a wireless power receiving device configured to combine power from the multiple wireless power signals. The wireless power receiving device can present the combined wireless power signal to a load, such as a battery charger or electronic device. In some implementations, each set of primary and secondary coils can utilize a low-power wireless power signal (e.g., 15 watts or less) in accordance with a wireless charging standard. By combining power from multiple low-power wireless power signals, the wireless power receiving device can support the higher power requirements of the electronic device. Multiple communication channels may be established between the wireless power transmitting device and the wireless power receiving device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority to commonly assigned Indian Provisional Patent Application No. 201911047528, entitled "AGGREGATED WIRELESS POWER TRANSFER WITH MULTIPLE COILS AND COMMUNICATION CHANNELS," filed on November 21, 2019. The disclosures of the prior application are deemed to be part of and incorporated by reference into this patent application. [Technical field]

[0002] The present disclosure relates generally to wireless power, and more specifically to aggregated wireless power transmission using multiple coils and communication channels. [Background technology]

[0003] Conventional wireless power systems have been developed with the primary purpose of charging batteries in wireless power receiving devices, such as mobile devices, small electronic devices, gadgets, etc. In conventional wireless power systems, the wireless power transmitting device may include a primary coil that generates an electromagnetic field. The electromagnetic field may induce a voltage in a secondary coil of the wireless power receiving device when the secondary coil is placed in close proximity to the primary coil. In this configuration, the electromagnetic field may wirelessly transmit power to the secondary coil. The power may be transferred using resonant or non-resonant inductive coupling between the primary and secondary coils. The wireless power receiving device may operate using the received power or may store the received energy in a battery for subsequent use. Conventional techniques for wireless power transmission may not provide sufficient power for newer electronic devices. It is desirable to increase the reliability and amount of power that can be wirelessly transmitted to electronic devices. Summary of the Invention

[0004] The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0005] One innovative aspect of the subject matter described in this disclosure can be implemented in a wireless power transmitting device. In some implementations, the wireless power transmitting device can include multiple primary coils for transmitting wireless power to different secondary coils of a wireless power receiving device. The multiple primary coils may include at least a first primary coil and a second primary coil. The wireless power transmitting device can include a power signal generator electrically connected to the multiple primary coils and configured to selectively supply power to the multiple primary coils. The wireless power transmitting device can include a transmit (TX) controller coupled to the power signal generator and the multiple primary coils. The TX controller can be configured to control an amount of power supplied by the power signal generator to the multiple primary coils.

[0006] In some implementations, the wireless power transmitting device can include one or more communication units communicatively coupled to the TX controller and configured to communicate with the wireless power receiving device. The one or more communication units can enable communication via at least a first communication channel in the first primary coil and a second communication channel in the second primary coil.

[0007] In some implementations, the one or more communication units may be configured to receive a first communication from the wireless powered device over a first communication channel at the first primary coil, and the one or more communication units may be configured to receive a second communication from the wireless powered device over a second communication channel at the second primary coil.

[0008] In some implementations, the first communication and the second communication are received at different times.

[0009] In some implementations, the first communication includes a first identifier for identifying the first communication channel, and the second communication includes a second identifier for identifying the second communication channel.

[0010] In some implementations, the TX controller may be configured to detect a foreign object in either the first primary coil or the second primary coil based on the first communication or the second communication, respectively.

[0011] In some implementations, the TX controller may be configured to determine a first quality factor (Q factor) of the first primary coil, determine a second Q factor of the second primary coil, obtain a first reference quality value from the first communication, and obtain a second reference quality value from the second communication. The TX controller may be configured to detect a foreign object based on either a first comparison of the first Q factor to the first reference quality value or a second comparison of the second Q factor to the second reference quality value.

[0012] In some implementations, the TX controller can be configured to obtain, from the first communication, a first received power metric for wireless power received from the first primary coil by a first secondary coil of the wireless power receiving device. In some implementations, the TX controller can be configured to obtain, from the second communication, a second received power metric for wireless power received from the second primary coil by a second secondary coil of the wireless power receiving device. The TX controller can be configured to determine a first transmit power metric for the first primary coil and to determine a second transmit power metric for the second primary coil. The TX controller can be configured to detect the foreign object based on either a first comparison of the first transmit power metric to the first received power metric or a second comparison of the second transmit power metric to the second received power metric.

[0013] In some implementations, the first communication can include a first received power metric related to wireless power received by a first secondary coil of the wireless power receiving device from a first primary coil, and the second communication can include a second received power metric related to wireless power received by a second secondary coil of the wireless power receiving device from a second primary coil.

[0014] In some implementations, the one or more communication units may be further configured to transmit a third communication to the wireless power receiving device via one or both of the first primary coil and the second primary coil.

[0015] In some implementations, the first and second communications can be received by demodulating an amplitude load modulated signal, and the third communication can be transmitted by modulating wireless power with a modulation of the frequency.

[0016] In some implementations, the amplitude load modulated signal may include Amplitude Shift Keying (ASK) modulation. The frequency modulation may include Frequency Shift Keying (FSK) modulation.

[0017] In some implementations, each primary coil may be configured to generate an electromagnetic field for inductive transmission of wireless power not exceeding 15 watts. Multiple primary coils can collectively enable wireless power transmission of more than 15 watts.

[0018] In some implementations, the multiple primary coils can include at least four primary coils, and the multiple primary coils can collectively enable wireless power transmission of at least 60 watts.

[0019] In some implementations, the wireless power transmitting device can include one or more switches electrically coupled to at least one primary coil of the multiple primary coils, the one or more switches being selectively open by the TX controller to disable the at least one primary coil when the at least one primary coil is not transmitting wireless power to the wireless power receiving device or when a foreign object is detected between the at least one primary coil and the wireless power receiving device.

[0020] In some implementations, each primary coil is rated for Power Class 0 (PC0), and the primary coils collectively enable wireless power transmission rated for Power Class 1 (PC1).

[0021] In some implementations, the multiple primary coils are configured to provide power through two or more primary coils when the wireless powered device has a PC1 rated power requirement. In some implementations, the multiple primary coils are configured to provide power through one primary coil when the wireless powered device has a PC0 rated power requirement.

[0022] In some implementations, the TX controller is configured to identify whether the wireless powered device has a PC0 or PC1 rated power requirement based at least in part on communications received from the wireless powered device via at least one of the multiple primary coils.

[0023] In some implementations, a wireless power transmitting device may include a charging surface associated with multiple primary coils. The wireless power transmitting device may include one or more alignment aids to increase the likelihood that multiple secondary coils of a wireless power receiving device will be aligned correspondingly with the multiple primary coils when the wireless power receiving device is placed on the charging surface.

[0024] Another innovative aspect of the subject matter described in this disclosure can be implemented in a wireless power receiving device. In some implementations, the wireless power receiving device can include multiple secondary coils. Each secondary coil may be configured to receive wireless power from a different primary coil of the wireless power transmitting device. The multiple secondary coils may include at least a first secondary coil and a second secondary coil. The wireless power receiving device may include a power combining circuit electrically coupled to the multiple secondary coils and configured to combine wireless power from the first secondary coil and the second secondary coil. The power combining circuit may be configured to provide the combined wireless power to at least a first load.

[0025] In some implementations, the wireless power receiving device can include a receive (RX) controller coupled to the power combining circuit and the multiple secondary coils. In some implementations, the wireless power receiving device can include one or more communication units communicatively coupled to the RX controller and configured to communicate with the wireless power transmitting device. The one or more communication units can enable communication over at least a first communication channel in the first secondary coil and a second communication channel in the second secondary coil.

[0026] In some implementations, the one or more communication units are configured to transmit a first communication to the wireless power transmitting device via a first communication channel at the first secondary coil and transmit a second communication to the wireless power transmitting device via a second communication channel at the second secondary coil.

[0027] In some implementations, the first communication and the second communication are transmitted at different times.

[0028] In some implementations, the first communication includes a first identifier for identifying the first communication channel, and the second communication includes a second identifier for identifying the second communication channel.

[0029] In some implementations, the first communication includes a first received power metric related to wireless power received by the first secondary coil from a first primary coil of the wireless power transmitting device, and the second communication includes a second received power metric related to wireless power received by the second secondary coil from a second primary coil of the wireless power transmitting device.

[0030] In some implementations, the one or more communication units are further configured to receive a third communication from the wireless power transmitting device via one or both of the first secondary coil and the second secondary coil.

[0031] In some implementations, the first communication and the second communication are transmitted by modulating an amplitude load modulated signal, and the third communication is received by demodulating the wireless power using the modulation of the frequency.

[0032] In some implementations, the amplitude load modulated signal includes amplitude shift keying (ASK) modulation and the frequency modulation includes frequency shift keying (FSK) modulation.

[0033] In some implementations, each secondary coil is configured to receive not more than 15 watts of wireless power via an electromagnetic field generated by a different primary coil of the wireless power transmitting device, and the multiple secondary coils collectively receive more than 15 watts of wireless power.

[0034] In some implementations, the multiple secondary coils include at least four secondary coils, and the multiple secondary coils collectively receive at least 60 watts of wireless power.

[0035] In some implementations, each secondary coil complies with the specifications of the Power Class 0 (PC0) standard, and the secondary coils collectively receive wireless power that complies with the specifications of the Power Class 1 (PC1) standard.

[0036] In some implementations, the wireless power receiving device can include a housing for the multiple secondary coils, the housing configured to attach to the electronic device, and the load can include a charger for the electronic device.

[0037] In some implementations, the wireless power receiving device may include one or more alignment aids to increase the likelihood that the multiple secondary coils will correspond and align with the multiple primary coils associated with the charging surface of the wireless power transmitting device when the wireless power receiving device is placed on the charging surface.

[0038] Another innovative aspect of the subject matter described in this disclosure can be embodied in a method performed by a wireless power transmitting device. In some implementations, the method can include generating a power signal by a power signal generator and presenting the power signal to multiple primary coils. The method can include transmitting, by the multiple primary coils, the power signal as wireless power to different secondary coils of a wireless power receiving device. The multiple primary coils may include at least a first primary coil and a second primary coil. The method can include controlling an amount of power generated by the power signal generator.

[0039] In some implementations, the method can include communicating with a wireless power receiving device via at least a first communication channel in the first primary coil and a second communication channel in the second primary coil.

[0040] In some implementations, the method may include receiving a first communication from a wireless powered device via a first communication channel at a first primary coil, and receiving a second communication from the wireless powered device via a second communication channel at a second primary coil.

[0041] In some implementations, the first communication and the second communication are received at different times.

[0042] In some implementations, the first communication includes a first identifier for identifying the first communication channel, and the second communication includes a second identifier for identifying the second communication channel.

[0043] In some implementations, the method may include detecting a foreign object in either the first primary coil or the second primary coil based at least in part on the first communication or the second communication, respectively.

[0044] In some implementations, the first communication includes a first received power metric related to wireless power received from a first primary coil by a first secondary coil of the wireless power receiving device, and the second communication includes a second received power metric related to wireless power received from a second primary coil by a second secondary coil of the wireless power receiving device.

[0045] In some implementations, the method may further include transmitting a third communication to the wireless power receiving device via one or both of the first primary coil and the second primary coil.

[0046] In some implementations, the first communication and the second communication are received by demodulating an amplitude load modulated signal, and the third communication is transmitted by modulating wireless power using frequency modulation.

[0047] In some implementations, the amplitude load modulated signal comprises amplitude shift keying (ASK) modulation and the frequency modulation comprises frequency shift keying (FSK) modulation.

[0048] In some implementations, each primary coil complies with Power Class 0 (PC0) standard specifications, and the multiple primary coils collectively enable wireless power transmission to Power Class 1 (PC1) standard specifications.

[0049] In some implementations, the method may include selectively opening one or more switches coupled to the multiple primary coils to disable the at least one primary coil when the at least one primary coil is not transmitting wireless power to the wireless power receiving device or when a foreign object is detected between the at least one primary coil and the wireless power receiving device.

[0050] Another innovative aspect of the subject matter described in this disclosure may be embodied in a method performed by a wireless power receiving device. In some implementations, the method may include receiving wireless power from a wireless power transmitting device by a plurality of secondary coils. Each secondary coil may be configured to receive wireless power from a different primary coil of the wireless power transmitting device. The plurality of secondary coils may include at least a first secondary coil and a second secondary coil. The method may include combining, by a power combining circuit, the wireless power from the first secondary coil and the second secondary coil to form a combined wireless power. The method may include providing the combined wireless power to at least a first load.

[0051] In some implementations, the method can include communicating with a wireless power transmitting device via at least a first communication channel in the first secondary coil and a second communication channel in the second secondary coil.

[0052] In some implementations, the method may include transmitting a first communication to the wireless power transmitting device via a first communication channel at a first secondary coil, and transmitting a second communication to the wireless power transmitting device via a second communication channel at a second secondary coil. [Brief description of the drawings]

[0053] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It should be noted that the relative dimensions of the following figures may not be drawn to scale.

[0054] [Figure 1] 1 illustrates an overview of components associated with an example wireless power system, according to some implementations.

[0055] [Diagram 2]1 shows a pictorial diagram of an exemplary wireless power receiving device having multiple secondary coils for receiving wireless power from a wireless power transmitting device, in accordance with some implementations.

[0056] [Diagram 3] 1 shows a pictorial diagram of an exemplary wireless power transmitting device having multiple primary coils for transmitting wireless power to a wireless power receiving device, in accordance with some implementations.

[0057] [Figure 4] 1 shows a pictorial diagram of an exemplary wireless power system in which a wireless power receiving device is configured to provide power to an electronic device, according to some implementations.

[0058] [Diagram 5] 1 illustrates a block diagram of an exemplary wireless power transmitting device according to some implementations.

[0059] [Figure 6] 1 shows a block diagram of an exemplary wireless power receiving device according to some implementations.

[0060] [Figure 7] 1 illustrates an example of multiple communication channels between an exemplary wireless power receiving device and an exemplary wireless power transmitting device, according to some implementations.

[0061] [Figure 8] 8 illustrates an example process for detection of a foreign object based on the example communication channel described with reference to FIG. 7.

[0062] [Figure 9] 1 illustrates another example of using multiple communication channels between an exemplary wireless power receiving device and an exemplary wireless power transmitting device, according to some implementations.

[0063] [Figure 10] 1 shows a flowchart illustrating an example process for wireless power transmission, according to some implementations.

[0064] [Figure 11] 1 shows a flowchart illustrating an example process for wireless power reception, according to some implementations.

[0065] [Figure 12] 1 is a block diagram of an example apparatus for use in a wireless power system according to some implementations.

[0066] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0067] The following description is directed to specific embodiments for purposes of illustrating the innovative aspects of the present disclosure. However, those skilled in the art will readily recognize that the teachings herein may be applied in many different ways. The described embodiments may be implemented in any means, device, system, or method for transmitting or receiving wireless power.

[0068] A conventional wireless power system may include a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may include a primary coil that transmits wireless energy (as a wireless power signal) to a corresponding secondary coil of the wireless power receiving device. The primary coil refers to a source of wireless energy (such as induction or magnetic resonance energy) in the wireless power transmitting device. The secondary coil is located in the wireless power receiving device and receives the wireless energy. In some conventional wireless power systems, the primary coil can transmit wireless energy to the secondary coil depending on a predetermined rating by the wireless standard. For example, a low-power wireless power signal can transmit five watts (5W), 9W, 12W, or 15W. Power Class 0 (PC0) is defined by the standards development group Wireless Power Consortium (WPC) as a wireless power system that can support wireless power transmission rated up to 15 watts. Thus, a low-power wireless power system can provide energy up to 15 watts, which is suitable for many electronic devices.

[0069] Higher power radio systems have been developed to support wireless power transmission to electronic devices that require more power (greater than 15W). For example, laptop computers, monitors, appliances, or other electronic devices may use 65W, 90W, or 120W. Power Class 1 (PC1) is defined by the WPC as a wireless power system that can support wireless power transmission above the rated 15W. A concern with high power radio systems is the amount of electromagnetic interference (EMI) they may cause. Undesirable EMI or radiation may be caused by excess magnetic flux that is not coupled to the secondary coil. Additionally, using a larger primary coil or a larger secondary coil may support higher power transmission, but at the expense of reduced sensitivity in detecting foreign objects. For example, a larger primary coil may be less able to detect small foreign objects. Additionally, a larger primary coil may be less tolerant of misalignment compared to a smaller primary coil.

[0070] Various implementations generally relate to the use of multiple primary coils to simultaneously transmit wireless power to various secondary coils. According to the present disclosure, a wireless power system can utilize multiple primary and secondary coils to transmit wireless power from a wireless power transmitting device to a wireless power receiving device. For example, each primary coil can transmit a low-power signal (15 W or less) to a corresponding secondary coil. The wireless power receiving device can combine the wireless power from the multiple secondary coils to provide a high-power wireless power to a load. For example, the wireless power receiving device can combine 15 W from each of six secondary coils to provide a 90 W power signal to an electronic device.

[0071] In some implementations, the wireless power transmitting device and the wireless power receiving device can be manufactured according to a standardized wireless power specification, such as the Qi® specification developed by the WPC. For example, the wireless power transmitting device can include multiple primary coils, each of which can conform to the PC0 design of the Qi specification. The wireless power receiving device can include multiple secondary coils, each of which can conform to the PC0 design of the Qi specification. Thus, PC1 power requirements (greater than 15 W) can be met by combining multiple PC0 wireless power channels.

[0072] In some implementations, a wireless power transmitting device with multiple PC0 primary coils can provide flexibility for supplying wireless power to different types of wireless power receiving devices. For example, if a wireless power receiving device has one PC0 secondary coil and is placed on one PC0 primary coil (of the wireless power transmitting device), the wireless power transmitting device can supply wireless power according to a conventional PC0 system. However, if a wireless power receiving device has multiple PC0 secondary coils (which can be combined to support a PC1 rating), the wireless power transmitting device can supply wireless power to support a PC1 rating using multiple PC0 primary coils coupled to multiple PC0 secondary coils (or wireless power receiving devices). In some implementations, the wireless power transmitting device can support charging multiple PC0 wireless power receiving devices or a combination of PC0 and PC1 wireless power receiving devices simultaneously.

[0073] In some implementations, the wireless power transmitting device and the wireless power receiving device can communicate via multiple communication channels. For example, a first communication channel may include a first primary coil of the wireless power transmitting device and a first secondary coil of the wireless power receiving device. The first communication channel may be used for communication from the wireless power receiving device to the wireless power transmitting device using amplitude load modulation (such as amplitude shift keying) on ​​the first secondary coil. A second communication channel may include a second primary coil of the wireless power transmitting device and a second secondary coil of the wireless power receiving device. The wireless power receiving device can communicate with the wireless power transmitting device using amplitude load modulation on the second secondary coil. For forward communication (from the wireless power transmitting device to the wireless power receiving device), the wireless power transmitting device can utilize modulation of the frequency of the signal applied to the primary coil. This disclosure includes some examples of communication channels and communications that may be performed using amplitude modulation, frequency modulation, or both.

[0074] The communication channel may be used to communicate information regarding identification, capabilities, state of charge, and control signals, among other examples. For example, a wireless powered device may transmit information regarding receiver type, power capabilities, number of secondary coils, secondary coil identification (such as an identifier (ID) tag), load voltage, state of charge, and received power from each secondary coil. A wireless powered device may also transmit control signals or messages requesting adjustments to power levels.

[0075] In some implementations, a communication path from a wireless power receiving device to a wireless power transmitting device may be referred to as a reverse communication path. In contrast, a communication path from a wireless power transmitting device to a wireless power receiving device may be referred to as a forward communication path. A wireless power transmitting device may use one or more forward communication paths to communicate information regarding a transmitting capability, a transmitting power operating point, and a response to a control signal. For example, a wireless power transmitting device may utilize different responses to indicate whether the wireless power transmitting device acknowledges, rejects, or does not understand a control signal or information signal from a wireless power receiving device. In some implementations, each reverse or forward communication path may be associated with a channel ID (also called a tag ID) that uniquely identifies a transmitting coil pair (formed by a primary coil and a corresponding secondary coil). A channel ID or tag ID may be included in the communication between the wireless power receiving device and the wireless power transmitting device so that power metrics, reference values, quality measurements, or other information may be specific to a transmitting coil pair.

[0076] In some implementations, such as the illustrative examples of the present disclosure, one or more forward communication paths can use a first type of modulation and one or more reverse communication paths can use a second type of modulation. For example, the forward communication paths may use frequency shift keying (FSK) modulation and the reverse communication paths may use amplitude shift keying (ASK) modulation. The types of modulation described herein are for illustrative purposes and alternative types of modulation can be used within the scope of the present disclosure.

[0077] In some implementations, the design of the present disclosure can improve the detection of foreign objects. For example, the detection of foreign objects may be performed independently for each transmit coil pair (primary coil and corresponding secondary coil). For example, a communication channel may be used to communicate a reference quality factor, a received power metric, or other information related to each transmit coil pair. The information of each PC0 transmit coil pair may be used to detect foreign objects or inefficient alignment of the coil pairs. Unlike a single coil PC1 design, the design of the present disclosure uses multiple PC0 channels where wireless power transmission is distributed by multiple PC0 transmit coil pairs. As a result, each PC0 transmit coil pair may have a higher sensitivity to foreign objects than is realized by a large coil pair distributing higher power in a single PC1 channel. The higher sensitivity of the detection of foreign objects of the PC0 transmit coil pairs is advantageous for detecting foreign objects near the transmit coil pairs. Furthermore, in some implementations, one or more of the PC0 primary coils may be disabled after detecting a foreign object, while others of the PC0 primary coils may continue to transmit wireless power if the foreign object is not affecting their corresponding PC0 channel.

[0078] Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages: In some implementations, the described techniques can be used to combine wireless power received from multiple secondary coils to generate a high power output to a load; The wireless power system can reduce EMI and improve the efficiency of wireless power transmission compared to conventional wireless power systems that use only one wireless power signal; The electronics of both the wireless power transmitting device and the wireless power receiving device can utilize a modular design of components with lower power ratings; Advantageously, embodiments of the present disclosure can support higher power for devices and electronics that require greater amounts of power; By using multiple low-power wireless power signals to accommodate more wireless power transmissions, the cost and complexity of the wireless power system can be reduced; Additionally, the use of multiple communication channels can support better in-band communication for robust foreign object detection and sensitivity.

[0079] FIG. 1 shows an overview of components associated with an exemplary wireless power system, according to some implementations. The wireless power system 100 includes a wireless power transmitting device 110 having multiple primary coils 120. Each of the primary coils 120 may be associated with a power signal generator. For example, the first primary coil 121 may be electrically coupled to a power signal generator 145. Each primary coil may be a wire coil that transmits a wireless power signal (which may also be referred to as wireless energy or an electromagnetic field). The primary coils may transmit wireless energy using an induction or magnetic resonance field. The power signal generator may include components (not shown) for preparing the wireless power signal. For example, the power signal generator 145 may include one or more switches, drivers, capacitors in series with each coil, or other components. The wireless power transmitting device 110 may include a power source 140 configured to provide power to the power signal generator 145. The power source 140 may convert alternating current (AC) to direct current (DC). The power source 140 may be internal or external to the wireless power transmitting device 110. In some implementations, the primary coils 120 can be coupled to the power signal generator 145 via one or more switches so that each primary coil can be independently enabled or disabled by the TX controller 130.

[0080] The primary coils 120 may be managed by one or more controllers (such as a transmit (TX) controller 130) that control whether the primary coils are transmitting wireless power. In FIG. 1, the TX controller 130 may manage a power signal generator 145 and may also manage one or more switches (not shown) that enable or disable particular primary coils. The TX controller 130 may also be communicatively coupled to one or more communication units, such as a first channel communication unit 131, a second channel communication unit 132, and a system communication unit 133. The communication units 131, 132, 133 may be external to the TX controller 130 (as shown), internal to the TX controller 130, or implemented in the TX controller.

[0081] In some implementations, each primary coil may be associated with a different driver, voltage regulator, etc. In some implementations, each primary coil may be coupled with a separate circuit component, such as a capacitor (in series with the primary coil), a current-sensing resistor, or other element. Each TX controller 130 may determine whether to cause a particular primary coil to transmit wireless power. For example, the TX controller 130 may periodically actuate one or more switches associated with each primary coil (and series capacitor) to energize (or briefly energize) the primary coil. The TX controller 130 may perform a coil current sensing process to determine whether a wireless powered device is located near the primary coil. If a wireless powered device is detected, the TX controller 130 may actuate one or more switches associated with the primary coil to transmit wireless power to the primary coil.

[0082] A controller (e.g., the TX controller 130) may be configured to detect the presence or proximity of a wireless powered device. For example, the TX controller 130 may cause one or more primary coils to periodically transmit a detection signal and measure changes in coil current or load indicative of an object near the primary coil. In some implementations, the TX controller 130 may detect pings, wireless communications, modulation of the load, etc. to determine that a secondary coil of a wireless powered device is near the primary coil.

[0083] FIG. 1 also illustrates a wireless power receiving device 150. The wireless power receiving device may be any type of device capable of receiving wireless power, including a mobile phone, a computer, a laptop, a peripheral, a gadget, a robot, a vehicle, and the like. The wireless power receiving device 150 may have an array of secondary coils 160, including a first secondary coil 161 and a second secondary coil 162. Each of the secondary coils 160 may receive wireless power from a different primary coil. For example, when the first secondary coil 161 is placed near the first primary coil 121, the first secondary coil 161 may receive wireless power from the first primary coil 121. During the detection phase, the first primary coil 121 may transmit a detection signal (which may also be referred to as a ping). The coil current in the first primary coil 121 may be measured to determine whether the coil current exceeds a threshold indicative of an object within the electromagnetic field of the first primary coil 121. If an object is detected, the TX controller 130 (or the first channel communication unit 131) may wait for a handshake signal from the wireless powered device 150 (such as a signal strength packet, an identification signal, or a setup signal, among others) to determine whether the object is a wireless powered device or a foreign object. The handshake signal may be communicated by the wireless powered device 150 using a series of load changes (such as modulating the load). The load changes may be detectable by a sensing circuit and interpreted by the first primary coil 121. In some implementations, the load changes are generated by modulating the amplitude of the load using the first channel communication unit 181 of the wireless powered device 150. The first channel communication unit 131 may interpret the load variations to restore communication from the wireless powered device 150. The communication may include information such as charge level, required voltage, received power, receiver power capability, wireless charging standard assistance, etc.

[0084] In the wireless power receiving device 150, each of the secondary coils 160 may be part of a separate receive (RX) circuit. For example, each RX circuit may include one or more secondary coils, a rectifier, a DC capacitor, and other elements (not shown). Each secondary coil 160, properly aligned, may generate an induced voltage based on the wireless power signal received from one of the primary coils 120. A capacitor (not shown) may be in series between the secondary coil and the rectifier. The rectifier may rectify the voltage and provide the voltage to a power combining circuit 185 that combines the power from the multiple secondary coils. The power combining circuit 185 may provide the combined wireless power to a load 190, such as a battery module (not shown). The load 190 may be in the wireless power receiving device 150 or may be an external device coupled by an electrical interface, such as a power output 187 of the wireless power receiving device 150. The load 190 may include a charger stage, protection circuits, such as a temperature detection circuit, and overvoltage and overcurrent protection circuits.

[0085] In some implementations, the wireless power transmitting device 110 or the wireless power receiving device 150 can have an alignment mechanism to ensure that the multiple secondary coils 160 and the multiple primary coils 120 are properly aligned. The alignment mechanism can include a physical guide, a tray, a magnetic alignment, or a socket, among other examples. In some implementations, a fixed alignment can ensure that the multiple primary coils and multiple secondary coils are aligned to support high total wireless power transmission from the multiple primary coils 120 to the multiple secondary coils 160.

[0086] Returning to communication capabilities, the wireless power transmitting device 110 may have a receive (RX) controller that monitors the power combining circuit 185 and communicates information regarding the state of the load or charge. The RX controller 180 may communicate using the first channel communication unit 181, the second channel communication unit 182, or both. Similarly, the RX controller 180 may receive communication from the wireless power transmitting device 110 via the system communication unit 183. The system communication unit 183 may sense the voltage of one or both AC terminals of the rectifiers 171 and 172. In some implementations, a forward communication path (from the system communication unit 133 via the power signal generator 145 to the rectifiers 171 and 172 and the system communication unit 183) may be used for communication from the wireless power transmitting device 110 to the wireless power receiving device 150. A reverse communication path (e.g., a first path including first channel communication unit 181 and first channel communication unit 131) may be used for communication from wireless power receiving device 150 to wireless power transmitting device 110. A second path may include second channel communication unit 182 and second channel communication unit 132. The first and second reverse communication paths may be utilized for quality metrics or received power metrics for a particular pair of primary and secondary coils.

[0087] In some examples of the present disclosure, the reverse communication path may use ASK modulation and the forward communication path may use FSK modulation. The type of modulation for each path may be different or even opposite, so long as the modulations used in the reverse and forward communication paths do not interfere with each other. Additionally, while some examples show the use of a single forward communication path, in some implementations, each transmit coil pair (formed by a primary coil and a secondary coil) may form separate forward and reverse communication paths.

[0088] FIG. 2 shows a pictorial diagram of an exemplary wireless power receiving device 150 having multiple secondary coils for receiving wireless power from a wireless power transmitting device, according to some implementations. The number and arrangement of secondary coils are provided as an example. Other numbers of secondary coils, number of layers, or arrangements may be possible. Although shown as a laptop, the wireless power receiving device 150 may be any type of electronic device. Also, the wireless power receiving device 150 may be an integrated part of the electronic device or an external part or attachment that couples to the electronic device. In FIG. 2, the wireless power receiving device 150 may be manufactured such that it may be placed on a charging surface (not shown) such that multiple secondary coils 160 are configured to receive wireless power. Inside the wireless power receiving device 150 (e.g., inside the bottom part 255 of the laptop), there are multiple secondary coils 160 for receiving wireless power.

[0089] When the secondary coil and primary coil are aligned for the transmission of wireless power, they can form a transmit coil pair. Each transmit pair of coils can transmit wireless power according to the specifications of the technology standard. In some implementations, each transmit coil pair can be a PC0 design that complies with the low power transmission ratings of the technology standard specifications. By combining power from multiple PC0 transmit coil pairs, the wireless power receiving device 150 can receive a higher total amount of wireless power, such as that required for a PC1 design.

[0090] There may be various ways to align the wireless power receiving device 150 with the wireless power transmitting device such that the multiple secondary coils 160 can be aligned with the corresponding multiple primary coils in the wireless power transmitting device. In some implementations, the wireless power transmitting device 110 or the wireless power receiving device 150 (or both) may include alignment aids to increase the likelihood that the multiple secondary coils 160 will align with the corresponding multiple primary coils when the wireless power receiving device 150 is placed on the charging surface of the wireless power transmitting device 110. The alignment aids may include any one or combination of magnetic alignment, physical structures, visual markers, optical alignment aids, audio alignment aids, and the like.

[0091] 3 shows a pictorial diagram of an exemplary wireless power transmitting device having multiple primary coils for transmitting wireless power to a wireless power receiving device, according to some implementations. The exemplary wireless power transmitting device 110 includes six primary coils (shown in portion 315). The number and arrangement of the primary coils are provided as an example. Other numbers of primary coils, number of layers, or arrangements may be possible. A charging surface may house the primary coils. A wireless power receiving device may be disposed on the charging surface 315. A first set of primary coils 120 may be activated to transmit wireless power to corresponding secondary coils (not shown) of the wireless power receiving device.

[0092] In some implementations, the wireless power transmitting device or the wireless power receiving device (or both) may implement overlapping coils. The overlapping coil pattern may reduce the extent to which the wireless power signal is exposed (or not aligned with the secondary coil). This may reduce EMI. Alternatively or additionally, the coils may be spaced apart such that multiple coils may be energized without affecting nearby coils. For example, in some implementations, the distance between the centers of any two primary coils may be greater than 1.5 times the maximum diameter of the largest primary coil.

[0093] By using multiple primary coils 120 to transmit wireless power, the total wireless power transmitted can be higher while keeping the amount of wireless power provided by each primary coil lower. The lower power transmission of each primary coil can reduce the amount of EMI and other interference to other components of the wireless power receiving device (or the electronics it powers). Thus, in some implementations, the use of multiple transmit coil pairs can be superior to using a single large coil for transmitting high power wireless signals.

[0094] The wireless power transmitting device 110 can be configured with grooves, notches, magnets, or line markers to aid in the alignment of one or more wireless power receiving devices, among other examples. For example, the alignment design can allow a single wireless power receiving device to be placed on the charging surface 315 such that the multiple primary coils 120 align with the corresponding multiple secondary coils of the wireless power receiving device. Alternatively or additionally, the charging surface 315 can support wireless charging for wireless power receiving devices of different sizes. For example, the charging surface 315 may be used with wireless power receiving devices that support either or both a PC0 design or a PC1 design. In some implementations, a phone or other small electronic device can receive wireless power from a subset of the multiple primary coils 120 according to a PC0 design. A laptop or other larger electronic device can receive wireless power from a larger subset or all of the multiple primary coils 120 according to a PC1 design that aggregates wireless power from multiple PC0 transmitting coil pairs.

[0095] FIG. 4 illustrates a pictorial diagram of an example wireless power system 400 in which a wireless power receiving device is configured to provide power to an electronic device, according to some implementations. In FIG. 4, the wireless power receiving device 150 may be a wireless power pad with multiple secondary coils 160. In the example of FIG. 4, the secondary coils are arranged in a non-overlapping pattern. The wireless power receiving device 150 may have an electrical interface 455 or other connection that provides power from the wireless power receiving device 150 to the electronic device 450. In some implementations, a fastener 457 (e.g., a clip, a magnet, a button, a casing, etc.) may be used to physically couple the wireless power receiving device 150 to the electronic device 450. The fastener 457 may be part of the wireless power receiving device 150, the electronic device 450, or both. For example, the wireless power receiving device 150 includes a housing that houses the secondary coil, and the housing may be attached to a laptop or tablet.

[0096] FIG. 5 illustrates a block diagram 500 of an example wireless power transmitting device 110 according to some implementations. The first primary coil 121 may have a capacitor 123 and a switch 125 for selectively enabling or disabling wireless power transmission through the first primary coil 121. Similarly, the second primary coil 122 may have a capacitance 124 and a switch 126. The number of primary coils illustrated in FIG. 5 is for illustrative purposes, and other designs may use a greater number of primary coils (not shown). In some implementations, each of the primary coils may transmit power according to a PC0 design, but the total amount of wireless power transmitted may support PC1, or above wireless power requirements. The TX controller 130 may control the switches 125 and 126, as well as the amount of power generated by the power signal generator 145. The power signal generator 145 is expanded to illustrate an example of a circuit that may include a diode and a switch. The TX controller 130 may control the switches of the power signal generator 145 to manage, among other things, the amount of voltage or frequency.

[0097] The system communication unit 133 may use frequency modulation (such as Frequency Shift Keying (FSK) modulation) in the power signal generator 145 to communicate over the forward communication path. The first channel communication unit 131 and the second channel communication unit 132 may be coupled to at least a portion of the first primary coil 121 and the second primary coil 122, respectively. The first channel communication unit 131 and the second channel communication unit 132 may include an amplitude demodulator (such as an Amplitude Shift Keying (ASK) demodulator) for receiving load modulated communications over the respective primary coils 121 and 122.

[0098] 5, there may be two reverse communication paths (using first channel communication unit 131 and second channel communication unit 132) and one forward communication path (using system communication unit 133). In other configurations, there may be a separate communication unit (similar to system communication unit 133) for each of the primary coils 121 and 122.

[0099] FIG. 6 shows a block diagram 600 of an example wireless power receiving device 150 according to some implementations. The first secondary coil 161 may have a first channel communication unit 181 including an amplitude modulator. The RX controller 180 may control a switch of the first channel communication unit 181 to generate a modulation of the load for communicating with the wireless power transmitting device via the first channel (including the first secondary coil 161). Similarly, the second secondary coil 162 may have a separate second channel communication unit 182 having an amplitude modulator controlled by the RX controller 180 for the second channel. Each of the secondary coils 161 and 162 may be connected to a corresponding rectifier 171 and 172, respectively. A switch 610 of the wireless power receiving device 150 may be capable of disconnecting the load. For example, among other examples, the load may be disconnected to allow calibration of the system to detect foreign objects prior to power transmission, to isolate the system during any fault on the load side, to protect the load from a system fault, or to keep the load disconnected until the initial handshake with the wireless power transmitting device is complete.

[0100] The system communication unit 183 may be coupled to one or both AC terminals of the rectifiers 171 and 172. The system communication unit 183 may receive and demodulate frequency modulated (such as FSK) communications from a corresponding modulator of the wireless power transmitting device (such as that shown in FIG. 5). Thus, the system communication unit 183 may receive forward path communications (from the wireless power transmitting device to the wireless power receiving device 150). The system communication unit 183 may transmit the received communications to the RX controller 180. The RX controller 180 may have control lines (not shown) to each of the first channel communication unit 181 and the second channel communication unit 182, which may be used for the reverse communication path to the wireless power transmitting device.

[0101] FIG. 7 illustrates an example 700 of multiple communication channels between an exemplary wireless power receiving device and an exemplary wireless power transmitting device, according to some implementations. A first communication channel 751 (using modulation of the load of the return channel) may include the first secondary coil 161 and the first primary coil 121. The first communication channel 751 may use amplitude modulation (such as ASK modulation). A second communication channel 752 may include the second secondary coil 162 and the second primary coil 122. The second communication channel 752 may also use amplitude modulation. The first and second communication channels 751, 752 may be referred to as reverse channels because they provide a communication technique from the wireless power receiving device 150 to the wireless power transmitting device 110. A third communication channel 753 may be referred to as a forward channel because they provide a technique for communication from the wireless power transmitting device 110 to the wireless power receiving device 150. The third communication channel 753 may include modulation of the frequency of the wireless signal (e.g., FSK modulation). The third communications channel 753 may use either or both of the primary coils 121 and 122 to transmit FSK modulated communications that may be picked up by the secondary coils 161 and 162, respectively.

[0102] FIG. 8 illustrates an example process for detection of a foreign object based on the example communication channel described with reference to FIG. 7. FIG. 8 includes the same elements as described in FIG. 8, with the addition of a foreign object 810 in proximity to the PC0 transmit coil pair including the first primary coil 121 and the first secondary coil 161. The foreign object 810 may be any type of object that affects the transmission of wireless power through the transmit coil pair, such as a key, a paper clip, a magnet, or a wire, among other examples. For example, the foreign object 810 may have ferrite or metallic properties that affect the electromagnetic waves used for wireless power transmission. FIG. 8 can be used to illustrate at least two example processes for detection of a foreign object.

[0103] The first process for the detection of a foreign object can be based on a quality factor measurement performed before the power transmission phase. Typically, before the power transmission phase, the wireless power receiving device 150 and the wireless power transmitting device 110 can exchange some information regarding the quality factor of the power transmission. Changes in the environment of the primary coil (such as the presence of a foreign object) can cause the inductance measured at the terminals of the primary coil to decrease, or its equivalent series resistance to increase, or both. These effects of the environment can lead to a degradation of the quality factor (Q factor) of the primary coil. To enable the wireless power transmitting device 110 to determine whether the degradation of the measured Q factor is due to the combination of the wireless power receiving device 150 and the foreign object 810, the wireless power receiving device 150 can present a reference quality factor to the wireless power transmitting device 110. The reference quality factor consists of an ideal Q factor tested in a laboratory, which can be measured at the terminals of the primary coil of a standard test power transmitter when the wireless power receiving device 150 is correctly aligned and there is no foreign object nearby. The reference quality factor is based on the quality of the wireless power receiving device 150 through a calibration or manufacturing process. The wireless power receiving device 150 may store the reference quality factor and transmit the reference quality factor to the wireless power transmitting device 110 before the power transmission phase. In this disclosure, each secondary coil 161 and 162 may communicate their reference quality factor via reverse communication channels 751 and 752, respectively. The TX controller 130 of the wireless power transmitting device 110 may compare the reference quality factor of the secondary coils 161 and 162 with the measured Q factor of the corresponding primary coils 121 and 122. For example, for each primary coil, when the presence of a receiver is detected, the TX controller 130 may determine a Q factor as the ratio of the voltage across the primary coil to the voltage applied to the resonant tank on the transmitter side. The TX controller 130 may compare each Q factor with the reference quality factor from the wireless power receiving device for each corresponding secondary coil. In the example of FIG. 8, the Q factor of the first primary coil 121 may be significantly lower than the reference quality factor of the first secondary coil 161 due to the presence of the foreign object 810.Conversely, if the foreign object 810 does not affect the transmit coil pair including the second primary coil 122 and the second secondary coil 162, the Q factor of the second primary coil 122 may approximate the reference quality factor of the second secondary coil 162.

[0104] The TX controller 130 may determine that a foreign object 810 is present near the first transmit coil pair if the Q factor of the first primary coil 121 is lower than the reference quality factor of the first secondary coil 161 by a threshold amount. The TX controller 130 may determine that a foreign object 810 is not present near the second transmit coil pair if the Q factor of the second primary coil 122 is not lower than the reference quality factor of the second secondary coil 162 by a threshold amount. This allows the TX controller 130 to detect foreign objects for each transmit coil pair individually. The Q factor sensitivity (variation) in the presence of the foreign object 810 may be higher for each PC0 transmit coil pair than the Q factor sensitivity of the PC1 transmit coil pair using a larger coil. The higher sensitivity of the Q factor variation of the PC0 transmit coil pair is advantageous for detecting foreign objects near the transmit coil pair. In response to detecting a foreign object 810 near the first transmit coil pair, the TX controller 130 may disable the first primary coil 121. If the foreign object 810 does not affect the second transmit coil pair, the TX controller 130 may maintain wireless power transmission via the second primary coil 122.

[0105] A second process for detecting a foreign object can be based on power loss accounting during the power transmission phase. For example, during the power transmission phase, the RX controller 180 can measure the voltage and current of the wireless power received at each secondary coil 161 and 162. The measurements at each secondary coil 161 and 162 can be used to determine a power metric for the power each secondary coil is receiving from the corresponding primary coil 121 and 122 of the wireless power transmitting device 110. The RX controller 180 can communicate the power metric to the communication channel units 181 and 182 via the first communication channel 751 and the second communication channel 752, respectively. For example, the first channel communication unit 181 can communicate a first power metric packet via the first communication channel 751. The first power metric packet can include a first power metric based on the power received by the first secondary coil 161. The second channel communication unit 182 can communicate the power metric packet via the second communication channel 752. The second power metric packet may include a second power metric based on the power received by the first secondary coil 161.

[0106] The first channel communication unit 131 and the second channel communication unit 132 may demodulate the first and second power metric packets, respectively. In some implementations, the power metric packets may include a channel ID or tag ID that uniquely identifies each transmit coil pair (or communication paths 751 and 752). The TX controller 130 may measure the voltage and current of each primary coil 121 and 122 to determine the transmit power that each primary coil 121 and 122 is transmitting. For each transmit coil pair, the TX controller 130 may compare the magnitude of the transmit power and the receive power metric. The difference between the magnitude of the transmit power and the receive power metric may represent a power loss due to misalignment or the presence of a foreign object. For example, the foreign object 810 may absorb a portion of the power transmitted by the first primary coil 121. The power metric of the first secondary coil 161 may be less than the magnitude of the transmit power measured for the first primary coil 121. If the difference exceeds a threshold, the TX controller 130 can determine that a foreign object 810 is present near the coil pair including the first primary coil 121 and the first secondary coil 161. Meanwhile, the power metric of the second secondary coil 162 may be within a threshold amount of the transmit power value of the second primary coil 122.

[0107] Other techniques for foreign object detection may be possible because of the availability of different communication channels, channel IDs, or tag IDs associated with each transmit coil pair. By being able to detect a foreign object with different coil pairs, the affected coil pair can be disabled while the unaffected coil pair can continue. This flexibility and sensitivity is not possible with a PC1 system that uses only a single large primary coil and a single large secondary coil. Thus, being able to use the combined power transmitted by multiple PC0 transmit coil pairs can improve foreign object detection and flexibility for wireless power transmission, even for wireless power receiving devices that require a PC1 power rating.

[0108] FIG. 9 illustrates another example 900 of using multiple communication channels between an exemplary wireless power receiving device 150 and an exemplary wireless power transmitting device 110, according to some implementations. Each transmitting coil pair (represented by a primary coil and a secondary coil) can form a communication channel. Such freedom may be available if each primary coil 121 and 122 has a separate power signal generator (such as a separate driver not shown). Each channel may use ASK and FSK for reverse and forward communication, respectively. For example, the first channel communication unit 931 of the wireless power transmitting device 110 may have an ASK demodulator and an FSK modulator. The first channel communication unit 981 of the wireless power receiving device 150 may have an ASK modulator and an FSK demodulator. Similarly, the second channel communication unit 932 of the wireless power transmitting device 110 may have an ASK demodulator and an FSK modulator. The second channel communication unit 982 of the wireless power receiving device 150 may have an ASK modulator and an FSK demodulator. The techniques for detecting foreign objects described with reference to FIG. 8 are also applicable to the example 800 of FIG.

[0109] 10 shows a flowchart illustrating an example process for wireless power transmission, according to some implementations. Flowchart 1000 begins at block 1010. In block 1010, the process includes generating a power signal by a power signal generator and presenting the power signal to a plurality of primary coils. In block 1020, the process includes transmitting the power signal by the plurality of primary coils as wireless power to different secondary coils of a wireless power receiving device, the plurality of primary coils including at least a first primary coil and a second primary coil. In block 1030, the process includes controlling an amount of power generated by the power signal generator.

[0110] FIG. 11 shows a flowchart illustrating an example process for wireless power reception, according to some implementations. The flowchart 1100 begins at block 1110. At block 1110, the process includes receiving wireless power from a wireless power transmitting device by a plurality of secondary coils. Each secondary coil is configured to receive wireless power from a different primary coil of the wireless power transmitting device, and the plurality of secondary coils includes at least a first secondary coil and a second secondary coil. At block 1120, the process includes combining, by a power combining circuit, the wireless power from the first secondary coil and the second secondary coil to form a combined wireless power. At block 1130, the process includes supplying the combined wireless power to at least a first load.

[0111] FIG. 12 is a block diagram of an exemplary device for use in a wireless power system according to some implementations. In some implementations, the device 1200 may be a wireless power transmitting device (such as the wireless power transmitting device 110) or a wireless power receiving device (such as the wireless power receiving device 150). The device 1200 may include a processor 1202 (possibly including multiple processors, multiple cores, multiple nodes, or implementation multithreading, etc.). The device 1200 may also include a memory 1206. The memory 1206 may be a system memory or any one or more of the possible implementations of the computer-readable media described herein. The device 1200 may also include a bus 1211 (e.g., PCI, ISA, PCI-Express, HyperTransport®, InfiniBand®, NuBus®, AHB, AXI, etc.).

[0112] The apparatus 1200 may include one or more controllers 1262 configured to manage multiple primary or secondary coils (such as a coil array 1264). In some implementations, the controller 1262 may be distributed within the processor 1202, the memory 1206, and the bus 1211. The controller 1262 may perform some or all of the operations described herein. For example, the controller 1262 may be a TX controller, a RX controller, or both. The controller 1262 may also include one or more communication units (not shown) for modulation or demodulation of communications transmitted or received by the coil array 1264.

[0113] The memory 1206 may include computer instructions executable by the processor 1202 to perform the functions of the embodiments described in Figures 1-11. Any one of these functions may be implemented partially (or entirely) in hardware or in the processor 1202. For example, the functions may be implemented in an application specific integrated circuit, logic implemented in the processor 1202, a co-processor in a peripheral device or card, etc. Furthermore, the implementation may include fewer or additional components not shown in Figure 12. The processor 1202, the memory 1206, and the local controller 1262 may be coupled to a bus 1211. Although shown as being coupled to the bus 1211, the memory 1206 may be coupled to the processor 1202.

[0114] 1-12 and the operations described herein are examples intended to aid in understanding example implementations and should not be used to limit potential implementations or to limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some different operations.

[0115] As used herein, phrases referring to a list of items such as "at least one of" or "one or more of" refer to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover the possibilities of a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0116] The various example components, logic, logic blocks, modules, circuits, operations and algorithmic processes described in connection with the embodiments disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed herein and structural equivalents thereof. Interoperability of the hardware, firmware, and software has been described generally in terms of functionality and illustrated in the various example components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware, firmware, or software depends on the particular application and design constraints imposed on the overall system.

[0117] The hardware and data processing devices used to implement the various example components, logic, logic blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed using general purpose single or multi-chip processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices (PLDs), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. In some implementations, certain processes, operations, and methods may be performed by circuitry specific to a given function.

[0118] As mentioned above, in some aspects, implementations of the subject matter described herein can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of methods, operations, processes or algorithms disclosed herein, can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor or computer executable instructions encoded in one or more tangible processor or computer readable storage media for execution by or to control the operation of a data processing device, including the components of the device described herein. By way of example and not limitation, such storage media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, or any other medium that can be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

[0119] Various modifications to the embodiments described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the present disclosure. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with the present disclosure, the principles, and novel features disclosed herein.

[0120] Moreover, various features described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Thus, although features may be described above as acting in a particular combination and may even initially be claimed as such, one or more features from the claimed combination may, in some cases, be deleted from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0121] Similarly, although operations are shown in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or in sequential order, or that all of the operations shown be performed, to achieve desirable results. Additionally, the figures may generally depict one or more exemplary processes in the form of a flowchart or flow diagram. However, other operations not shown may be incorporated into the exemplary process depicted generally. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the depicted operations. In some circumstances, multitasking and parallel processing may be advantageous. Additionally, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the components and systems of the described programs may generally be integrated together in a single software product or packaged in multiple software products.

Claims

1. A wireless power transmitting device, A plurality of primary coils for transmitting wireless power to different secondary coils of one wireless power receiving device, the plurality of primary coils including at least a first primary coil and a second primary coil; a power signal generator electrically connected to the plurality of primary coils and configured to selectively power the plurality of primary coils; a transmit (TX) controller coupled to the power signal generator and to the plurality of primary coils, the TX controller configured to control an amount of power provided by the power signal generator to the plurality of primary coils; A wireless power transmitting device comprising: a plurality of communication units communicatively coupled to the TX controller and configured to communicate with the wireless power receiving device, the plurality of communication units including a plurality of channel communication units coupled to the plurality of primary coils and a system communication unit coupled to the power signal generator, the plurality of communication units enabling communication via at least a first communication channel in the first primary coil and a second communication channel in the second primary coil.

2. The plurality of communication units include receiving a first communication from the wireless power receiving device via the first communication channel at the first primary coil; The wireless power transmitting device of claim 1 , configured to receive a second communication from the wireless power receiving device via the second communication channel at the second primary coil.

3. The wireless power transmitting device according to claim 2 , wherein the first communication and the second communication are received at different times.

4. The wireless power transmitting device according to claim 2 , wherein the first communication includes a first identifier for identifying the first communication channel, and the second communication includes a second identifier for identifying the second communication channel.

5. 3. The wireless power transmitting device of claim 2, wherein the TX controller is configured to detect a foreign object in either the first primary coil or the second primary coil based at least in part on the first communication or the second communication, respectively.

6. The TX controller determining a first quality factor (Q factor) of the first primary coil; determining a second quality factor of the second primary coil; obtaining a first reference quality value from the first communication; obtaining a second reference quality value from the second communication; 6. The wireless power transmitting device of claim 5, further configured to detect the foreign object based on either a first comparison of the first Q factor with the first reference quality value or a second comparison of the second Q factor with the second reference quality value.

7. The TX controller obtaining, from the first communication, a first received power metric related to wireless power received by a first secondary coil of the wireless power receiving device from the first primary coil; obtaining a second received power metric related to wireless power received by a second secondary coil of the wireless power receiving device from the second primary coil from the second communication; determining a first transmit power metric for the first primary coil; determining a second transmit power metric for the second primary coil; 6. The wireless power transmitting device of claim 5, configured to detect the foreign object based on either a first comparison of the first transmit power metric to the first receive power metric or a second comparison of the second transmit power metric to the second receive power metric.

8. The wireless power transmitting device according to claim 3 , wherein the plurality of communication units are further configured to transmit a third communication to the wireless power receiving device via one or both of the first primary coil and the second primary coil.

9. 9. The wireless power transmitting device of claim 8, wherein the first communication and the second communication are received by demodulating an amplitude load modulated signal, and the third communication is transmitted by modulating the wireless power using frequency modulation.

10. The wireless power transmitting device of claim 9 , wherein the amplitude load modulation signal includes amplitude shift keying (ASK) modulation and the frequency modulation includes frequency shift keying (FSK) modulation.

11. 11. The wireless power transmitting device of claim 1, wherein each primary coil is configured to generate an electromagnetic field for inductive transmission of wireless power not exceeding 15 watts, and the multiple primary coils collectively enable wireless power transmission of more than 15 watts.

12. 12. The wireless power transmitting device according to claim 1, wherein the plurality of primary coils includes at least four primary coils, and the plurality of primary coils collectively enable wireless power transmission of at least 60 watts.

13. 13. The wireless power transmitting device of claim 1, further comprising: one or more switches electrically coupled to at least one primary coil of the multiple primary coils, the one or more switches being selectively openable by the TX controller to disable the at least one primary coil when the at least one primary coil is not transmitting wireless power to the wireless power receiving device or when a foreign object is detected between the at least one primary coil and the wireless power receiving device.

14. 14. The wireless power transmission device according to claim 1, wherein each primary coil complies with a power class 0 (PC0) rating, and the multiple primary coils collectively enable wireless power transmission rated at a power class 1 (PC1).

15. the plurality of primary coils are configured to provide power through two or more primary coils when the wireless power receiving device has a PC1 rated power requirement; 15. The wireless power transmitting device of claim 14, wherein the multiple primary coils are configured to provide power through one primary coil when the wireless power receiving device has a PC0 rated power requirement.

16. 16. The wireless power transmitting device of claim 15, further comprising the TX controller configured to identify whether the wireless power receiving device has the PC0 or PC1 rated power requirement based at least in part on communications received from the wireless power receiving device via at least one of the plurality of primary coils.

17. a charging surface associated with the plurality of primary coils; 17. The wireless power transmitting device of claim 1, further comprising one or more alignment aids for increasing the likelihood that multiple secondary coils of the wireless power receiving device will be aligned correspondingly with the multiple primary coils when the wireless power receiving device is placed on the charging surface.

18. A wireless power receiving device, a plurality of secondary coils, each configured to receive wireless power from a different primary coil of a wireless power transmitting device, the plurality of secondary coils including at least a first secondary coil and a second secondary coil; a power combining circuit electrically coupled to the plurality of secondary coils and configured to combine the wireless power from the first secondary coil and the second secondary coil and provide the combined wireless power to at least a first load; a receive (RX) controller coupled to the power combining circuit and the plurality of secondary coils; a plurality of communication units communicatively coupled to the RX controller and configured to communicate with the wireless power transmitting device, the plurality of communication units including a plurality of channel communication units coupled to the plurality of secondary coils and a system communication unit coupled to a rectifier coupled to the power combining circuit, the plurality of communication units enabling communication via at least a first communication channel in the first secondary coil and a second communication channel in the second secondary coil.

19. The plurality of communication units include transmitting a first communication to the wireless power transmitting device via the first communication channel in the first secondary coil; The wireless power receiving device of claim 18 , configured to transmit a second communication at the second secondary coil over the second communication channel to the wireless power transmitting device.

20. The wireless power receiving device according to claim 19 , wherein the first communication and the second communication are transmitted at different times.

21. The wireless power receiving device according to claim 20 , wherein the first communication includes a first identifier for identifying the first communication channel, and the second communication includes a second identifier for identifying the second communication channel.

22. 22. The wireless power receiving device of claim 19, wherein the first communication includes a first received power metric related to wireless power received by the first secondary coil from a first primary coil of the wireless power transmitting device, and the second communication includes a second received power metric related to wireless power received by the second secondary coil from a second primary coil of the wireless power transmitting device.

23. 23. The wireless power receiving device of claim 19, wherein the plurality of communication units are further configured to receive a third communication from the wireless power transmitting device via one or both of the first secondary coil and the second secondary coil.

24. 24. The wireless power receiving device of claim 23, wherein the first communication and the second communication are transmitted by modulating an amplitude load modulated signal, and the third communication is received by demodulating the wireless power using frequency modulation.

25. 25. The wireless power receiving device of claim 24, wherein the amplitude load modulated signal comprises an amplitude shift keying (ASK) modulation and the frequency modulation comprises a frequency shift keying (FSK) modulation.

26. 26. A wireless power receiving device according to any one of claims 18 to 25, wherein each secondary coil is configured to receive wireless power not exceeding 15 watts via an electromagnetic field generated by a different primary coil of the wireless power transmitting device, and the multiple secondary coils collectively receive wireless power exceeding 15 watts.

27. 27. The wireless power receiving device of claim 18, wherein the plurality of secondary coils includes at least four secondary coils, and the plurality of secondary coils collectively receive at least 60 watts of wireless power.

28. 28. The wireless power receiving device of claim 18, wherein each secondary coil complies with the specifications of the Power Class 0 (PC0) standard, and the multiple secondary coils collectively receive wireless power that complies with the specifications of the Power Class 1 (PC1) standard.

29. 29. The wireless power receiving device of claim 18, further comprising a housing for the plurality of secondary coils, the housing configured to be attached to an electronic device, the load including a charger for the electronic device.

30. 30. The wireless power receiving device of claim 18, further comprising one or more alignment aids for increasing the likelihood that the multiple secondary coils will align correspondingly with multiple primary coils associated with a charging surface of the wireless power transmitting device when the wireless power receiving device is placed on a charging surface of the wireless power transmitting device.

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