Wireless charging of reconfigurable radio waveforms

Abstract

A system (17) includes a power supply device (18) and a portable device (19) for wirelessly powering a load (3) of the portable device (19). The power supply device (18) includes a transmitter stage (21) for generating a carrier signal and an antenna (22) connected to the transmitter stage (21) for transmitting a magnetic field having a first waveform of the carrier signal. The portable device (19) includes an antenna (24) exposed to the magnetic field of the power supply device (18) for receiving an antenna signal and a receiver stage (23) connected to the antenna (24) for rectifying the antenna signal to provide power to the load (3) of the portable device. The power supply device (18) is configured to transmit a magnetic field having a first waveform of the carrier signal in a power transmission mode and a magnetic field having a second waveform of the carrier signal in a communication mode.

Description

Technical Field

[0001] The present invention relates to a system comprising a power supply device and a portable device for wirelessly powering a load of the portable device. The power supply device includes: a transmitter stage for generating a carrier signal; and an antenna connected to the transmitter stage for transmitting a magnetic field having a first waveform of the carrier signal. The portable device includes: an antenna exposed to the magnetic field of the power supply device for receiving an antenna signal; and a receiver stage connected to the antenna for rectifying the antenna signal to power the load of the portable device. Background Technology

[0002] Wireless charging is used for a variety of portable devices, such as mobile phones or headphones. The portable device simply needs to be brought close to a power source, which generates and emits a magnetic field through its antenna. The advantage is that no wires are needed to charge the portable device. In some of these systems, the power source simply emits the magnetic field, while some newer systems include a feedback loop from the portable device to the power source to regulate the power of the magnetic field.

[0003] Figure 1 This system illustrates a power supply device 1 and a portable device 2 with a battery 3 as a load, as known to those skilled in the art. For example, the NFC Forum... TM This system is described in technical specification version 1.0. Power device 1 is a reader referred to as a "poller" and includes an antenna 4 that transmits a magnetic field at a frequency of 13.56 MHz with a sinusoidal carrier signal. Portable device 2 is a tag referred to as a "listener" and includes an antenna 5 exposed to the magnetic field emitted by power device 1. Matching circuit 15 matches the impedance of the output pin of antenna 5 to the input pin of rectifier 6, which uses a bridge rectifier to rectify the antenna signal and provide a DC voltage. Charging stage 7 of portable device 2 is used to charge battery 3. Charging stage 7 includes a charger IC 8 that requires a 5V + / - 10% power supply voltage, and a DC / DC converter 9 for converting the DC voltage provided by rectifier 6 to the appropriate input voltage U at input pin 10 of charging stage 7. I .

[0004] Battery 3 is a lithium-ion battery, which requires charging stage 7 to charge it at different currents I at different times. C The battery is charged using a charging voltage. To achieve this, charging stage 7 includes a series ohmic resistor component 11 in the path between input pin 10 and battery 3 to generate a measurement voltage, which is measured by current measurement stage 12 to measure the charging current I of battery 3. C The charging stage 7 also includes a digital control stage 13, which receives an input voltage U at input pin 10. IAnd / or the charging current I used to charge battery 3 C In cases of excessively low or high power levels, power adjustment information 16 is generated. This power adjustment information 16 is provided by the digital control stage 13 to the Cless communication stage 14, which conforms to the NFC communication protocol, to transmit the power adjustment information 14 to the power supply device 1. Through a feedback loop from the portable device 2 to the power supply device 1, the charging stage 7 can request more or less power in the magnetic field provided by the power supply device 1. This increase or decrease in power in the magnetic field is achieved by a higher or lower amplitude of the carrier signal of the magnetic field.

[0005] Figure 2 The diagram shows the charging current Ic during three different time periods, TA, TB, and TC, when battery 3 is loaded. Figure 2 The input voltage U at input pin 10 of charging stage 7 during the periods TA, TB, and TC of battery 3 is also shown. I and actual battery voltage U BAT To actually load battery 3, only the battery voltage U is used. BAT Multiply by the charging current Ic. The wireless transmission power from power device 1 to portable device 2 is within a maximum range of 1W, as specified by the NFC-Forum specification, for example. This energy is sufficient to charge, for example, the battery of an earphone, but insufficient to charge, for example, a mobile phone within a reasonable timeframe. Furthermore, there has been ongoing interest in reducing the total charging time for batteries in portable devices.

[0006] US2016 / 087452 A1, US2014 / 035521 A1, and US2018 / 262049A1 disclose other systems that use the magnetic field of a power supply device to wirelessly power portable devices to charge their batteries. Summary of the Invention

[0007] The purpose of this invention is to provide a system for power supply devices and portable devices for wirelessly powering the load of portable devices, which enables more power to be wirelessly transmitted in a shorter time.

[0008] This objective is achieved in the system according to claim 1.

[0009] The power supply device of the claimed system is configured to transmit a magnetic field as a first waveform of a carrier signal in a power transfer mode and as a second waveform of a carrier signal in a communication mode. In a preferred embodiment, the second waveform used in the communication mode may be a sine wave to transmit power adjustment information or any other information between the power supply device and the portable device. This communication may be based on protocols defined in the NFC Forum specification and / or protocols and waveforms that comply with the requirements of FCC Part 15 for products used in the United States. The FCC has different requirements depending on the use case; for wireless transmission applications, Part 18 requirements must be met. The first waveform of the carrier signal used in the power transfer mode may be a waveform with higher energy or power content, such as a square wave. Generally, the energy or power content of a waveform is characterized by the area under its waveform. Therefore, a sawtooth waveform has less energy content than a sine wave, and a sine wave has less energy content than a square wave. By using a magnetic field with higher energy content in the power transfer mode, more energy or power is transferred from the power supply device to the portable device within a specific time range. This means that the receiver stage of the portable device can collect more energy, which reduces the total charging time of the portable device's battery and enables the battery to be charged at a higher capacity within a reasonable time range. All of this is achieved without altering the amplitude of the carrier signal of the magnetic field. In another preferred embodiment, the waveform and amplitude of the carrier signal can be changed to further increase or decrease the energy content of the magnetic field. Furthermore, since the requirements for equipment vary depending on the testing standards, application-based modifications to the waveform can optimize system performance while still meeting regulations.

[0010] A transmitter stage for providing an antenna signal to the antenna of a power supply device to transmit a magnetic field with different carrier signal waveforms can be implemented in various ways. In one embodiment of the invention, the transmitter stage includes a driver stage implemented by a power amplifier disclosed in EP 3 182 585B 1. This known power amplifier includes N / 2 driver blocks connected to a first output pin of the power amplifier and another N / 2 driver blocks connected to its second output pin. Each of these parallel-arranged driver blocks includes a level shifter, a buffer or inverter, and a series capacitor loaded to a charging stage depending on the waveform of the signal to be output at the first and second output pins. These parallel capacities of all driver blocks are loaded to a specific charging stage at a clock frequency M times the carrier signal frequency of the magnetic field used for wirelessly charging the battery of a portable device. The sum of these charging stages is provided to the first and second output pins, realizing the output current of the power amplifier. An advantage of using such a power amplifier as a shaping stage in the transmitter stage of a power supply device is that switching between different waveforms provided at the output pins of the driver stage can be achieved simply by adjusting the bit combination at the input pins of the driver blocks. Therefore, switching between waveforms such as sine, sawtooth, or rectangular is easy and very energy-efficient. Any other waveform can be achieved simply by changing the bit combination at the input pins of the driver block.

[0011] In another embodiment of the invention, the transmitter stage may include a driver stage and multiple filter banks, and the driver stage is configured to switch between different filter banks, each with a different filtering profile. A carrier signal with a fixed waveform (e.g., a sine wave) generated by the driver stage is used as the input signal to the multiple filter banks, and waveform deformation is achieved according to the filter banks selected by the driver stage to form different waveforms for different modes of power supply and portable devices. In a preferred embodiment, the fixed sine wave of the carrier signal is used as a second waveform in the communication mode, and the waveform generated using one of the filter banks is used as a first waveform in the power transmission mode.

[0012] In another embodiment of the invention, the power supply device includes two or more transmitter stages, each including its own antenna and emitting its own magnetic field. The system also includes two or more receiver stages, each including its own antenna to harvest power from the magnetic field of the transmitter stage exposed to the antenna of the receiver stage. Such a system is known in principle from US2014 / 0266031A1, which discloses the use of two transmitter stages and two receiver stages in a portable device. Using two or more parallel transmitter stages and / or receiver stages with a first waveform of a carrier signal optimized for high-power transmission is highly advantageous for fast wireless power transmission. Furthermore, it is highly advantageous that, in a communication mode, only one transmitter stage is wirelessly coupled to one receiver stage for data and information communication based on a magnetic field with a second waveform of a carrier signal, wherein the second waveform of the carrier signal is optimized for high-quality data transmission and low power consumption of the power supply device.

[0013] In another embodiment of the invention, power adjustment information from a receiver stage or from more than one receiver stage, used to adjust the magnetic field strength emitted by an antenna of a transmitter stage or by more than one transmitter stage, will improve the efficiency of the system of the invention.

[0014] In another preferred embodiment of the invention, the power supply device and the portable device can be configured in a different application mode, and in this different application mode, the transmitter stage is configured to transmit a magnetic field with a third waveform having a carrier signal, which is different from the first and second waveforms of the carrier signal. For example, the third waveform can be a sawtooth waveform, which transmits less power or energy compared to a sine waveform. This minimum power transmission can be used in an energy-saving mode for the power supply device and the portable device to maintain contact for extended periods (such as weeks or months) to exchange information such as the battery state of the portable device's battery using the minimum power consumed by the power supply device. Other application modes with different waveforms of the carrier signal having a magnetic field transmitted from the power supply device to the portable device may also be useful.

[0015] These and other aspects of the invention will become apparent and will be illustrated with reference to the embodiments described below. Those skilled in the art will understand that various embodiments can be combined. Attached Figure Description

[0016] Figure 1 A system known to those skilled in the art is shown, comprising a power supply device and a portable device with a wirelessly rechargeable battery.

[0017] Figure 2 Showing according to Figure 1 A time-varying diagram of the charging current and input voltage of the charging stage for the portable device system charging the battery.

[0018] Figure 3 A system according to the present invention is shown, comprising a power supply device and a portable device having a load to be wirelessly powered.

[0019] Figure 4 and Figure 5 Show Figure 3 The timeline of relevant signals and data transmitted by the system is publicly available.

[0020] Figure 6 A test circuit is shown that is used to measure the power of wireless transmission when using magnetic fields with different waveforms of carrier signals.

[0021] Figure 7 and Figure 8 Showing Figure 6 The test data measured by the publicly disclosed test circuit. Detailed Implementation

[0022] Figure 3 A system 17 illustrating a power supply device 18 and a portable device 19 according to a first embodiment of the present invention is provided for wirelessly charging the battery 3 of the portable device 19. The power supply device 18 is powered by an AC voltage connected to a power stage 20, which is configured to power other stages of the power supply device 18. The power supply device 18 also includes a transmitter stage 21 connected to an antenna 22, which transmits a magnetic field based on a carrier signal having a frequency of 13.56 MHz and a specific waveform of a carrier signal provided to the antenna 22 by the transmitter stage 21. This carrier signal may be modulated to transmit data in a communication mode, or it may not be modulated. The power supply device 18 also includes a receiver stage, with or without demodulation, which... Figure 3 It is not shown in the diagram, but can be used to receive data from portable device 19.

[0023] Portable device 19 includes a receiver stage 23 connected to antenna 24, which is exposed to a magnetic field emitted by antenna 22 of power supply device 18. Wireless communication between transmitter stage 21 and receiver stage 23 is processed in a communication mode between power supply device 18 and portable device 19. In this embodiment of the invention, the protocols and data exchanged during this communication mode conform to the standard ISO 18.092, known as near-field communication. Any other similar standard may also be used. Figure 3 In the embodiments, the receiver level 23 includes technical elements with a basic structure similar to... Figure 1 The same as disclosed in the paper, as it includes a matching circuit 15 and a rectifier, a DC / DC converter, and a charging stage as part of a receiver stage 23, providing a charging current I to the battery 3. CThe battery 3 is charged during charging cycles of time periods TA, TB, and TC. In other embodiments of the invention, the receiver stage 23 can be implemented as a discrete solution that does not use a DC / DC converter and can handle input voltages below 4.5V. Other implementations of the receiver stage for receiving data within the RFID frequency range are known to those skilled in the art. The implemented charging stage can be... Figure 1 The specific power management level disclosed herein may be merely a general power management level that can be implemented by those skilled in the art for such embodiments.

[0024] Receiver stage 23 includes an NFC tag 26 with a unique serial number and everything required to comply with the NFC protocol to communicate with power device 18. In a preferred embodiment, as based on Figure 1 The NFC tag 26, which is part of the described charging stage, provides power adjustment information to the receiver stage of the power supply device 18 via the wireless interface of antennas 24 and 22 to increase or decrease the power of the magnetic field emitted by antenna 22.

[0025] The power supply device 18 is further configured to transmit a magnetic field with a first waveform of a carrier signal in a power transmission mode between the power supply device 18 and the portable device 19, and is configured to transmit a magnetic field with a second waveform of a carrier signal in a communication mode between the power supply device 18 and the portable device 19. The first waveform of the carrier signal is a square wave, and the second waveform of the carrier signal is a sine wave, with the first waveform having a higher energy content than the second waveform. By using a magnetic field with a higher energy content in the power transmission mode, more energy or power is transferred from the power supply device 18 to the portable device 19 within a specific time range. This means that the receiver stage 23 of the portable device 19 can collect more energy, thereby reducing the total charging time of the battery 3 loaded on the portable device 19, and enabling the battery to be loaded with a higher capacity within a reasonable time range. All of this is achieved without changing the amplitude of the carrier signal of the magnetic field. In another preferred embodiment, both the waveform and the amplitude of the carrier signal can be changed to further increase or decrease the energy content of the magnetic field.

[0026] The transmitter stage 21 has at least two fundamentally different possible implementations, enabling it to provide carrier signals with different waveforms to the antenna 22. Figure 3The first of these embodiments is shown, in which the transmitter stage 21 includes a controller stage 27 and an NFC driver stage 28, which can also be implemented as a single stage. The NFC driver stage 28 generates a 13.56MHz carrier signal with a sinusoidal waveform used in communication mode. A modulation stage of the NFC driver stage 28 is used to modulate data onto the carrier signal, and a demodulation stage is used to demodulate data received from the portable device 19. The controller stage 27 controls the NFC driver stage 28 and the overall communication and charging protocol, such as those based on… Figure 4 and Figure 5 Explanation.

[0027] Figure 3 The transmitter stage 21 of the power supply device 17 disclosed includes an NFC driver stage 28 connected to an antenna 22 via a matching and filter stage 29. The matching and filter stage 29 includes matching circuitry to match the impedance of the NFC driver stage 28 to the impedance of the antenna 22 for maximum power transfer. The matching and filter stage 29 also includes multiple filter banks, wherein a first filter bank has a first filter curve used in power transfer mode to filter a generated carrier signal having a sinusoidal waveform (second waveform) to transmit a magnetic field with a square wave (first waveform) having a carrier signal. Those skilled in the art know what kind of filter curve is needed to filter the square wave to approximate a sinusoidal waveform. In another embodiment of the invention, the NFC driver stage 28 generates a square wave (first waveform) to be used in power transfer mode, and the NFC driver stage 28 is configured to select a second filter bank with a second filter curve from the multiple filter banks in a communication mode to transmit a magnetic field with a sinusoidal waveform (second waveform) having a carrier signal. In another embodiment of the invention, the NFC driver stage 28 generates another waveform of the carrier signal, and the transmitter stage 21 includes a switch between the NFC driver stage 28 and the match and filter stage 29 for switching multiple filter banks to a first filter bank to generate a square wave used in power transmission mode, and switching to a second filter bank to generate a sine wave used in communication mode.

[0028] In another possible implementation of transmitter stage 21 (not shown in the figure), the NFC driver stage includes parallel capacitor charging stages for generating a first waveform and a second waveform of the carrier signal by summing different capacitor charging states for each wave of the carrier signal, thus producing different waveforms. This NFC driver stage is implemented using a power amplifier disclosed in EP 3 182585B 1. This known power amplifier includes N / 2 driver blocks connected to a first output pin and another N / 2 driver blocks connected to its second output pin. Each of these parallel-arranged driver blocks includes a level shifter, a buffer, or an inverter, and a series capacitor loaded into a charging stage depending on the waveform of the signal to be output at the first and second output pins. These parallel capacitances of all driver blocks are loaded into a specific charging stage at a clock frequency M times the carrier signal frequency of the magnetic field used for wirelessly charging the battery of a portable device. The sum of these charging stages is provided to the first and second output pins, providing the output current of the power amplifier. The advantage of using this type of power amplifier as a shaping stage in the transmitter stage of a power supply is that switching between different waveforms provided at the output pins of the driver stage can be achieved simply by adjusting the bit combination at the input pins of the driver block. Therefore, switching between waveforms such as sine, sawtooth, or rectangular waveforms is easy and highly energy-efficient. Any other waveform can be achieved simply by changing the bit combination at the input pins of the driver block.

[0029] Figure 4 and Figure 5 The communication protocol 30 between the power supply device 18 and the portable device 19 is shown from time point t1 to t8. In the top row, the common clock signal CLK used is shown. In the middle row, the communication processed between the power supply device 18 and the portable device 19 is shown. In the bottom row, the configuration of the NFC driver stage 28 for generating the waveform of the carrier signal is shown. At the first time point t1, the power supply 20 of the power supply device 18 is turned on, and the powered NFC driver stage 28 is configured to generate a carrier signal with a frequency of 13.56 MHz and a sinusoidal waveform to enable the communication mode starting at time point t2. After a communication link (e.g., including an anti-collision protocol) is established between the power supply device 18 and the portable device 19, power transfer negotiation is performed. During this power transfer negotiation, the portable device 19 can transmit data about the loading status of the battery 3 and / or can send power adjustment information. At time point t4 after the power transfer negotiation, the power supply device 18 knows how much power needs to be transferred within the magnetic field generated by the antenna 22 to enable [further actions]. Figure 2The next step in the charging cycle is shown. From time point t4 to t5, the NFC driver stage 28 switches to another filter bank to generate a square wave carrier signal, enabling high power transmission in the magnetic field. From time point t5 to t6, the antenna 22 transmits a magnetic field with a carrier signal having a square wave, enabling the charger IC of the portable device to load the battery 3. The time period from time point t5 to t6 is a fixed time period negotiated during power transfer negotiation. In another embodiment, this time period may also depend on other factors. During the time period from time point t6 to t7, the NFC driver stage 28 switches back to the filter bank used during time point t2 to t4, or uses the carrier signal generated by the NFC driver stage without using the filter bank to provide a sine wave of the carrier signal to enable the NFC standard-based communication mode. These time periods in the communication mode used for subsequent power transfer negotiation and the time periods in the power transfer mode used for transmitting high power in the magnetic field are repeated several times until all charging cycles of time periods TA, TB, and TC have been processed. The same communication protocol 30 can be used between the power supply and the portable device. Other possible implementations of the transmitter stage with the NFC driver stage include parallel capacitor charging stages to generate different waveforms of the carrier signal.

[0030] In another embodiment of the invention, not shown in the figures, the power supply device includes at least a second transmitter stage with a second antenna to transmit a second magnetic field. The portable device may also include a second antenna exposed to the magnetic field of antenna 22 or the second magnetic field of the power supply device to receive the second antenna signal. A second receiver stage of the portable device is configured to rectify the second antenna signal and provide additional power to the portable device's load. In this embodiment, energy is wirelessly transferred from the power supply device to the portable device in parallel, thereby utilizing more antennas and magnetic fields to transfer more energy. For some or all of these magnetic fields used, the transmitter stage of the power supply device, or more than one transmitter stage, may switch the waveform of the carrier signal to enable a communication mode and a power transfer mode.

[0031] In another embodiment of the invention, not shown in the figures, the power supply device is configured to activate an alternative application mode. The transmitter stage is configured to transmit a magnetic field with a third waveform of a carrier signal in this alternative application mode, the third waveform of which differs from the first and second waveforms of the carrier signal. For example, the third waveform could be a sawtooth waveform, which transmits less power or energy compared to a sine wave. This minimum power transmission can be used in energy-saving modes of the power supply device and portable devices to maintain contact for extended periods (such as weeks or months), exchanging information such as the battery state of the portable device's battery at the minimum power used by the power supply device. Other application modes with different waveforms of the carrier signal of the magnetic field transmitted from the power supply device to the portable device may also be useful.

[0032] Figure 6 Test circuit 31 is shown for measuring the power of wireless transmission using magnetic fields with different waveforms of a carrier signal. DC / DC stage 32 is connected to the mains power supply voltage and generates the required DC voltage. Power supply stage 33 generates a carrier signal with a specific frequency and waveform. Antenna stage 34 includes a transmitter antenna that transmits the magnetic field based on the carrier signal and a receiver antenna exposed to the magnetic field of the transmitter antenna and providing the antenna signal to power receiver stage 35. Power receiver stage 35 rectifies the antenna signal and provides DC voltage to power loading stage 36.

[0033] Figure 7 and Figure 8 Showing Figure 6 The test data measured by the test circuit 31 disclosed in the paper. Figure 7 Test data obtained from applications using power stage 33 to generate a carrier signal with a sinusoidal waveform are shown. The power generated and measured in power stage 33 is shown as transmitter power signal 38, and the power received and measured in power receiver stage 35 is shown as receiver power signal 39. The efficiency of this power transfer based on the sinusoidal waveform is... Figure 7 The signal is shown as a sinusoidal efficiency signal 40. Figure 8 Test data obtained for the use of power supply stage 33 generating a square wave carrier signal is shown. The power generated and measured in power supply stage 33 is shown as transmitter power signal 42, and the power received and measured in power receiver stage 35 is shown as receiver power signal 43. The efficiency of this power transmission based on the square wave is... Figure 8 The square wave efficiency signal 44 is shown in the diagram. Comparing the sinusoidal efficiency signal 40 with the square wave efficiency signal 44, a 10% increase in efficiency is observed, demonstrating how useful it is to switch waveforms between communication mode and power transmission mode.

Claims

1. A system (17) comprising a power supply device (18) and a portable device (19) for wirelessly powering a load (3) of the portable device (19), The power supply device (18) includes: The transmitter stage (21), which is configured to generate a carrier signal, and Antenna (22), which is connected to the transmitter stage (21) and configured to transmit a magnetic field having a first waveform of the carrier signal, and The portable device (19) includes: Antenna (24), which is exposed to the magnetic field of the power supply device (18) and is configured to receive antenna signals, and A receiver stage (23), which is connected to the antenna (24) and configured to rectify the antenna signal, thereby providing power to the load (3) of the portable device. The power supply device (18) is characterized in that it is configured to switch between a first waveform and a second waveform, the first waveform being different from a sine wave, and the area under a single wave of the first waveform being larger than the area under a single wave of the sine wave, the second waveform being a sine wave, and the power supply device (18) is configured to transmit a magnetic field with a first waveform having a carrier signal in a power transmission mode and to transmit a magnetic field with a second waveform having a carrier signal in a communication mode, wherein the power supply device (18) is configured to transmit a magnetic field with a first waveform having a carrier signal without changing the amplitude of the carrier signal of the magnetic field, the magnetic field with the first waveform having a carrier signal having a higher energy content than the magnetic field with the second waveform having a carrier signal.

2. The system of claim 1, wherein the transmitter stage of the power supply device includes a driver stage connected to the antenna of the power supply device via a matching circuit, the driver stage including a parallel capacitor charging stage configured to generate a first waveform and a second waveform of the carrier signal by adding different capacitor charging states for each wave of the carrier signal, thereby generating different waveforms.

3. The system (17) of claim 1, wherein the transmitter stage (21) of the power supply device (18) includes a driver stage (28) connected to an antenna (22) of the transmitter stage (21) via multiple filter banks and matching circuitry, and the driver stage (28) is configured to generate a carrier signal having a fixed waveform, and the transmitter stage (21) is configured to select a first filter bank having a first filter curve in the power transmission mode to filter the generated carrier signal to transmit a magnetic field having a first waveform of the carrier signal, and / or the driver stage is configured to select a second filter bank having a second filter curve in the communication mode to transmit a magnetic field having a second waveform of the carrier signal.

4. The system (17) of claim 3, wherein the transmitter stage (21) includes a switch between the driver stage (28) and the multiple filter banks, the switch being configured to switch between the first filter bank used in the power transmission mode and the second filter bank used in the communication mode.

5. The system according to any one of claims 1 to 4, wherein the power supply device includes at least a second transmitter stage having a second antenna configured to transmit a second magnetic field, and / or the portable device includes at least a second antenna of the portable device exposed to the magnetic field or the second magnetic field of the power supply device, the second antenna of the portable device being configured to receive a second antenna signal, and the second receiver stage of the portable device being configured to rectify the second antenna signal and provide additional power to the load of the portable device.

6. The system according to any one of claims 1 to 5, wherein the power supply device is configured to activate another application mode, and the transmitter stage is configured to transmit a magnetic field having a third waveform of the carrier signal in the other application mode, the third waveform of the carrier signal being different from the first and second waveforms of the carrier signal.

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