TW201427223A - Wireless power transmission system using width and pulse shape modulation - Google Patents

Abstract

The invention provides a wireless power transmission (WPT) system using width and pulse shape modulation. Instead of using continuous wave for WPT, the wireless power transmission (WPT) system enhances the output voltage and power conversion efficiency (PCE) of a radio frequency direct current (RF-DC) rectifier by adjusting duty cycles and pulse shapes. The PCE of RF-DC rectifier can be improved 2.5 times under constraint of low input power. The performance of the wireless power transmission (WPT) system using width and pulse shape modulation is verified to optimize the PCE under constraint of low input power in biomedical applications.

Description

Wireless energy transfer system with width and waveform modulation

The invention relates to the technical field of wireless power transmission (WPT), in particular to a wireless energy transmission system which is modulated by width and waveform.

In recent years, with the rapid development of wireless transmission technology, the data transmission type of wired transmission has been gradually replaced by wireless transmission. For example, wireless earphones, wireless microphones, wireless keyboards, wireless mouse and other electronic products have been introduced. However, the range and time of use of many common electronic products often suffer from many limitations due to power cord or battery capacity. In view of this, the power supply method of electronic products replaces the traditional wired transmission energy by wireless transmission, thereby eliminating the annoying power cord and various charging devices of different specifications, and greatly increasing the portability of the product and improving the convenience of life. Sex and reduce the consumption of resources.

In order to promote the development of wireless energy transmission technology, the industry established the Wireless Power Consortium (WPC) in 2008. At present, 109 internationally renowned companies such as HTC, Nokia, Texas Instruments, Philips, and Samsung Electronics have joined and developed international standardization (Qi). The specification (Qi) targets many low-power electronic products, such as mobile phones, portable music players, digital cameras, electric toothbrushes, etc., and can be wirelessly charged using a unified charging platform.

With the gradual increase of the proportion of the elderly population, coupled with modern people's attention to long-term health care, as well as advances in microelectronics, physiological sensing, and wireless communication technology, miniaturized biomedical implant devices are growing. Through the miniaturized biomedical implant device, in addition to long-term observation and monitoring of the patient's physiological signals, it can be further developed into a remote home care medical model, enabling patients to maintain a higher quality of life and reduce medical care. cost. For example, glaucoma monitoring, the miniaturized biomedical device is implanted in the rabbit eye to monitor changes in intraocular pressure for a long time to detect the presence of glaucoma lesions. The implantable biomedical devices utilize microwave wireless energy transfer to provide a source of energy for the implanted device from the outside.

Since the biomedical implant device needs to measure and transmit physiological signals for a long time, the wireless charging system needs to provide power for the biomedical implant device for a long time, so as to improve the feasibility and applicability of the biomedical implant device. At the same time, in the safety considerations, wireless charging behavior that is too high load cannot be performed, so currently only the wireless charging of electronic products is regulated. That is, the specification of the Wireless Charging Alliance (WPC) (Qi) does not provide a special specification for implantable biomedical devices. Since biomedical implant devices require long-term measurement and transmission of physiological signals, the transmission efficiency of conventional wireless charging is an important key technology for biomedical implant devices. Therefore, the present invention proposes a wireless energy transfer system that is modulated in width and waveform to solve the above problems.

The main object of the present invention is to provide a wireless energy transfer system with width and waveform modulation, which can replace the traditional continuous wave. The quantity transmission can effectively improve the output voltage (Vout) and energy conversion efficiency of the RF DC rectifier circuit, and is particularly suitable for charging the biomedical implant device.

According to a feature of the present invention, the present invention provides a wireless energy transfer system that is modulated in width and waveform, and includes a transmitting end circuit, a wireless transmission channel, and a receiving end circuit. The transmitting end circuit modulates a carrier electrical signal to generate an RF modulated signal, and transmits the RF modulated signal by a first antenna. The wireless transmission channel is coupled to the antenna for transmitting an RF modulated signal. The receiving end circuit is coupled to the wireless transmission channel to receive the RF modulation signal via a receiving antenna and rectify the driving signal to drive a load circuit; wherein the transmitting end circuit performs pulse wave width adjustment on the carrier electrical signal change.

1 is a block diagram of a width and waveform modulated wireless energy transfer system 100 of the present invention for transmitting energy to a receiving end via an infinite transmission channel. The wireless energy transmission system 100 includes a transmitting end circuit 110, a wireless transmission channel 120, and a receiving end circuit 130.

The transmitting end circuit 110 modulates a carrier electrical signal to generate an RF modulated signal, and transmits the RF modulated signal by a transmitting antenna (not shown).

The wireless transmission channel 120 is coupled to the transmission antenna for transmitting radio frequency modulation signals.

The RF source of the transmitting circuit 110 converts DC or AC energy into microwave energy (and the RF modulation signal) and transmits the signal through the RF source. The transmitting antenna (Transmitter Antenna) radiates the microwave energy, and passes through the wireless transmission channel 120 and is received by a receiving antenna of the receiving end circuit 130. Among them, the wireless transmission channel 120 is generally air.

The receiving end circuit 130 is coupled to the wireless transmission channel 120 to receive the RF modulated signal via the receiving antenna and rectify it to drive a load circuit. The transmitting end circuit 110 performs Pulse Width Modulation (PWM) on the carrier electrical signal.

2 is a circuit diagram of the receiving end circuit 130 of the present invention. The receiving circuit 130 includes a matching circuit 210, a radio frequency DC rectifying circuit 220, the load circuit 230, and the receiving antenna 240.

The matching circuit 210 includes a first inductor 211 and a first capacitor 213. One end of the first inductor 211 is connected to the receiving antenna 240, and one end of the first capacitor 213 is connected to the other end of the first inductor 211. One end of the first capacitor 213 is connected to a low potential (GND). The matching circuit 210 enables the energy of the RF modulated signal received by the receiving antenna 240 to be effectively introduced into the RF DC rectifier circuit 220 to reduce losses caused by reflection.

The RF DC rectifier circuit 220 is a voltage doubler rectifier circuit for converting the microwave energy of the output signal of the matching circuit 210 into DC energy. In addition to the voltage doubler circuit, other forms of the rectifier circuit can also be applied to the present technology.

The voltage doubler rectifier circuit 220 includes a low pass filter 221, a first diode 223, a second diode 225, and a DC band pass filter 227. The low pass filter 221 is a second capacitor, and the DC band pass filter 117 is a third capacitor.

One end of the low-pass filter 221 is connected to the other end of the first inductor 211, and one end of the first diode 223 is connected to the other end of the low-pass filter 221, and the other end of the first diode 223 Connected to the low potential GND, one end of the second diode 225 is connected to the other end of the low pass filter 221, and one end of the DC band pass filter 227 is connected to the other end of the second diode 225. The other end of the DC band pass filter 227 is connected to the low potential GND.

The load circuit 230 includes a fourth capacitor 231, a variable resistor 233, and a load 235. The variable resistor 233 is a third diode (see the paper p60 line 2 "and a diode D3 is added as a variable resistor at the load end").

One end of the fourth capacitor 231 is connected to the other end of the second diode 225, the other end of the fourth capacitor 231 is connected to the low potential GND, and one end of the variable resistor 233 is connected to the second diode. At the other end of the 225, one end of the load 235 is connected to the other end of the variable resistor 233, and one end of the load 235 is connected to the low potential GND.

3 is a circuit diagram of another embodiment of the RF DC rectifier circuit 220 of the present invention. The RF DC rectifier circuit 220 is a voltage doubler rectifier circuit and is an N-order voltage doubler rectifier circuit, where N is an integer greater than one. As shown in FIG. 3, the circuit framed by block 310 is a first-order voltage doubler rectifier circuit, and the voltage doubler rectifier circuit 220 in FIG. 2 is a first-order voltage doubler rectifier circuit. The circuit framed by block 320 is a second order voltage doubler rectifier circuit. The entire circuit of Figure 3 is an N-order voltage doubler rectifier circuit.

The overall system energy conversion efficiency (η _total ) of the wireless energy transfer system 100 is determined by the efficiency of the transmitting end circuit 110 (η _t ), the efficiency of the wireless transmission channel 120 (η _c ), and the efficiency of the receiving end circuit 130 (η _rect ). As shown in the formula (1): η _total = η _t × η _c × η _rect .

The efficiency (η _t ) of the transmitting end circuit 110 includes the efficiency of the microwave signal source and the transmitting antenna. The efficiency of the transmitting antenna is determined by the gain (Gain) and directivity of the antenna itself. In the frequency range less than 5 GHz, the efficiency of the microwave signal source to convert DC or AC energy into microwave energy is about 70% to 85%. The efficiency (η _c ) of the wireless transmission channel 120 is mainly determined by the free space path loss (FSPL), the refraction and reflection loss caused by other objects in the transmission channel or different transmission media. The efficiency of the receiving end circuit 130 (η _rect ) includes the efficiency of the receiving antenna 240 and the RF DC rectifying circuit 220. The efficiency of the RF DC rectifying circuit 220 is the magnitude of the microwave energy power received by the receiving end receiving antenna 240 and the receiving end circuit 130 The load is determined and optimized according to the actual situation to improve efficiency. By improving and optimizing the efficiency of the transmitting end circuit 110, the wireless transmission channel 120, and the receiving end circuit 130, the wireless energy transmitting system 100 can achieve better overall energy conversion efficiency.

The transmitting end circuit 110 changes the duty cycle and the waveform when the electrical signal is pulse width modulated (PWM) to adjust the transmission power of the wireless energy transmitting system 100. The waveform can be one of the following waveforms: square wave, sine wave, pulse wave, and triangular wave.

The invention utilizes a new waveform modulation technology and adjusts the duty cycle (Duty Cycle) with the width modulation technology, and systematically designs and edits For the same kind of special waveform, the average input power and load are fixed separately, and the time domain waveform and spectrum distribution of the special waveform are measured by the oscilloscope and the spectrum analyzer. The effects of different duty cycles, waveforms on bandwidth, power distribution and RF DC rectifier circuit 220 are utilized, and the effects of power saving and energy conversion efficiency are achieved by the width modulation and waveform modulation technology.

4A and 4B are schematic diagrams showing waveforms generated by the transmitting terminal circuit 110 of the present invention. The transmitting end circuit 110 performs special waveform design and editing from the angle of the time domain. By gradually concentrating the microwave energy to a specific moment and matching with the width modulation technology, the working cycle of the waveform is adjusted, and many different kinds of specials can be generated. Waveforms, including common waveforms such as square waves, sine waves, pulse waves, and triangular waves, achieve a systematic design of waveform modulation, and set the duty cycle to 100% and 50%, respectively. Figure 4A is a schematic diagram of a waveform generated with a duty cycle of 100%. Figure 4B is a schematic diagram of a waveform generated with a duty cycle of 50%.

The special waveform generated by the transmitting end circuit 110 is modulated by a carrier having a frequency of 433 MHz, and the fixed peak-to-peak value is 1 V. 5A to 5F are schematic diagrams showing time domain waveforms generated after the modulation terminal circuit 110 of the present invention is modulated. As shown in Figures 5A through 5F, the time domain waveforms are all consistent with the designed waveform.

6A-6B are schematic diagrams showing the time domain waveform generated by the modulation of the present invention measured by a spectrum analyzer. The spectrum was measured with a spectrum analyzer of the type N9010A produced by Agilent, as shown in Figs. 6A to 6B. Fig. 6A is a spectrum measurement diagram of a special waveform numbered from 1 to 3. Fig. 6B is a spectrum measurement diagram of a special waveform numbered from 4 to 6. At the same average input power, the microwave energy is gradually concentrated at a specific moment by means of waveform modulation. Observed from the spectrum at this time, the peak microwave energy at a frequency of 433 MHz Gradually, the microwave energy is gradually spread around the center of the frequency of 433 MHz, and is distributed to other frequencies, which is characterized by a wider bandwidth when the time domain is narrower.

The transmitting end circuit 110 transmits an RF modulated signal generated by a carrier electrical signal to the RF DC rectifier circuit 220 via the wireless transmission channel 120 and the matching circuit 210. The present invention adjusts the load resistance of the load circuit 230 at the back end, measures the output voltage, and calculates the energy conversion efficiency to verify the effect of the waveform modulation technique to improve the output voltage and energy conversion efficiency of the RF DC rectifier circuit 220.

7A-7B are schematic views of the output voltage of the present invention under different load resistances. The fixed average input power is -10 dBm. When the duty cycle is set to 100% and 50%, the output voltages under different waveforms and loads are shown in Figure 7A and Figure 7B. As the load resistance gradually increases, using the Wave#1~Wave#6 special waveform as the input source, the output voltage of the RF DC rectifier circuit 220 can be effectively increased to be greater than when a continuous wave (CW) is used as an input source. The output voltage.

8A-8B are schematic views of the output voltage of the present invention at different on-currents. When the load is converted to the on-current, the fixed average input power is -10 dBm, and the set voltage is 100% and 50%, the output voltages under different waveforms and on-current are shown in Figures 8A-8B. The trend of waveform adjustment of different waveforms can be interpreted in the working cycle of 100% (no pulse width modulation). It can be seen that Wave#1~Wave#6 has a intersection point between the special waveform and the continuous wave. When the conduction current is less than the intersection point, this The present invention uses different kinds of special waveforms to make the output voltage greater than the output voltage using continuous waves, and as the waveform becomes more concentrated (Wave#1→Wave#6), the effect of the enhancement is more significant, and When the duty cycle is reduced from 100% to 50%, the intersection point can be moved to the high conduction current direction, and the applicable range and output voltage of the waveform modulation technology are increased.

9A-9B are schematic views of energy conversion efficiency of the present invention under different load resistances. The output voltage of the RF DC rectifier circuit 220 is calculated and converted into energy conversion efficiency. It can be seen that the fixed average input power is -10 dBm, and the energy conversion efficiency under different waveforms and loads is set when the duty cycle is 100% and 50%, as shown in the figure. 9A to 9B, under the high load resistance, the output voltage of the Wave#1~Wave#6 special waveform is greater than the continuous wave, and the optimal energy conversion efficiency is reduced when the duty cycle is reduced from 100% to 50%. The operating point moves significantly toward the high load resistance.

10A-10B are schematic views of energy conversion efficiency of the present invention at different on-currents. Converting the load to the on-current, it can be seen that the fixed average input power is -10 dBm, and the energy conversion efficiency under different waveforms and on-current is set when the duty cycle is 100% and 50%, as shown in FIG. 10A to FIG. 10B. With the concentration of microwave energy, the optimal energy conversion efficiency operating point of Wave#1~Wave#6 special waveform gradually moves toward the low conduction current, and when the duty cycle is reduced from 100% to 50%, the moving trend is more obvious. It can be seen that the energy conversion efficiency is improved due to the decrease of the duty cycle, so different types of duty cycles and waveforms can be selected according to the conduction current, thereby achieving the effect of improving the energy conversion efficiency.

The special waveform generated by the transmitting end circuit 110 is modulated by a carrier having a frequency of 433 MHz, and the fixed load resistance is 20 kΩ and 100 kΩ, respectively, and transmitted to the RF DC rectifying circuit 220 via the wireless transmission channel 120 and the matching circuit 210. Use different special waveforms as input sources and adjust the average Input power, measure the output voltage and calculate the energy conversion efficiency, and verify the effect of the waveform modulation technology to improve the output voltage and energy conversion efficiency of the RF DC rectifier circuit 220.

11A-11B are schematic diagrams of output voltages of the present invention at different waveforms and average input power. When the fixed load resistance is 20 kΩ and 100 kΩ, and the duty cycle is 50%, Wave#1, Wave#3, Wave#5, Wave#6 special waveforms are used as input sources respectively, and the RF DC rectifier circuit 220 is measured. The output voltage of different waveforms as the input source, as shown in Fig. 11A to Fig. 11B, can be seen that when the load is 20 kΩ, with the increase of the average input power, Wave#1, Wave#3, Wave#5 special waveforms The output voltage is greater than the continuous wave.

When the load is 100 kΩ, the output voltages of Wave#1, Wave#3, Wave#5, Wave#6 special waveforms are also larger than continuous waves. It can be seen that the RF modulation circuit is improved by the width modulation and waveform modulation technology. The output voltage of 220 is effective, and because the load resistance is 100 kΩ, which is closer to the optimal load of the special waveform, when the load resistance is 100 kΩ, the voltage boosted by the waveform modulation technique is more obvious than the load resistance of 20 kΩ.

12A-12B are schematic diagrams of energy conversion efficiencies of the present invention at different waveforms and average input power. The RF DC rectification circuit 220 is converted into an energy conversion efficiency by an output voltage with different waveforms as an input source, as shown in FIG. 12A to FIG. 12B, and the energy conversion efficiency at the time when the load resistance is 20 kΩ can be seen. From high to low, Wave#1 special waveform, Wave#3, Wave#5, continuous wave, Wave#6, because the load is 20 kΩ Compared with the optimal load operation point of Wave#1 and Wave#3 special waveforms, the energy conversion efficiency of Wave#1 and Wave#3 special waveforms is obviously improved.

When the load resistance is 100 kΩ, the output voltage and energy conversion efficiency at this time are from high to low, Wave#5 special waveform, Wave#6, Wave#3, Wave#1, continuous wave, because the load is 100 kΩ. Compared with the optimal load operation point of Wave#5 and Wave#6 special waveforms, the energy conversion efficiency of Wave#5 and Wave#6 special waveforms is obviously improved.

It can be seen from the foregoing FIG. 7A to FIG. 12B that the optimal loads of different types of special waveforms are not the same, and the selection of the optimum waveform is mainly related to the on-current of the back-end load resistor. The present invention is the first to propose the study of the influence of the optimal load on the waveform, and the average input power mainly affects the amplitude of the energy conversion efficiency, and the smaller the average input power or the closer the load resistance is to the optimal load of the special waveform. At the same time, the output voltage and energy conversion efficiency improved by the waveform modulation technique are more obvious.

The LED is driven by the RF DC rectifier circuit 220 to show the effect of using the waveform modulation and width modulation technology to improve energy conversion efficiency and reduce input power. Generally, the rated voltage required for a small-sized circuit is 1.5 V, and a large current is required to drive the light-emitting diode, so that the driving voltage of the light-emitting diode as a back-end load is 1.5 V. At the same time, the transmitting end circuit 110 generates microwave energy with a center frequency of 433 MHz, and uses Wave#1, Wave#3, Wave#5, Wave#6 special waveforms as inputs under the same average input power and 50% duty cycle. The source is transmitted to the RF DC rectifier circuit 220, and finally the microwave energy is transferred through the RF DC rectifier circuit 220. Switching to DC energy drives the LED, and measures the voltage across the LED (Vout_LED) and current, and calculates the energy conversion efficiency (PCE_LED).

Figure 13 is a schematic illustration of the output voltage of the present invention at different waveforms and average input power. When different special waveforms are used as the input source, the RF DC rectifier circuit 220 drives the voltage across the LEDs. As shown in FIG. 13, when the voltage required by the LED is less than 1.58 V, different special waveforms are used as inputs. The source, the smaller average input power, allows Figure 13 to produce the drive voltage required for the LED.

For example, if the required voltage across the LED is 1.5 V, when the input source is continuous wave (C.W.), the average input power is required to be -5.55 dBm. When the input source is a Wave#6 special waveform, the average input power required is -7.26 dBm. When the input source is a Wave#1 special waveform, the average input power required is -7.78 dBm. When the input source is a Wave#3 special waveform, the average input power required is -8.00 dBm. When the input source is Wave#5 special waveform, only the average input power is -8.58 dBm. The invention adopts the waveform modulation technology to effectively reduce the average input power by 3.03 dB when the required voltage across the voltage is 1.5 V. When the required voltage across the voltage is 1.2 V, the average input power is reduced by 4.30 dB more effectively.

Figure 14 is a graphical representation of the energy conversion efficiency of the present invention at different waveforms and average input power. Using different special waveforms as input sources, the RF DC rectifier circuit 220 drives the energy conversion efficiency of the LEDs. As shown in FIG. 14, the average input power of the optimal energy conversion efficiency operating point gradually increases with the concentration of the special waveform energy. Low power movement, so when the average input power is gradually reduced, the energy conversion efficiency is improved more effectively. Fixed average When the input power is -8 dBm, the energy conversion efficiency can be greatly improved from 1.3% to 34.5% by using the waveform modulation and width modulation technology of the present invention. Therefore, the RF conversion is performed by using a waveform modulation with a width modulation technique. The LED of the circuit 220 is driven to effectively verify the efficiency of the energy conversion and reduce the average input power.

In summary, the present invention proposes a new waveform modulation technology, and adjusts the duty cycle (Duty Cycle) with the width modulation technology, systematically designs and edits different types of special waveforms, and respectively fixes the average input power and load. Measuring the time domain waveform and spectrum distribution of the special waveform, and discussing the effects of different duty cycles, waveforms on the bandwidth, power distribution and the RF DC rectification circuit 220, and also driving the LEDs, the width modulation of the present invention The waveform modulation technology achieves the effect of saving power and improving energy conversion efficiency, and is particularly suitable for charging a biomedical implant device.

From the above, it can be seen that the present invention is extremely useful in terms of its purpose, means, and efficacy, both of which are different from those of the prior art. It is to be noted that the various embodiments described above are merely illustrative for ease of description, and the scope of the claims is intended to be limited by the scope of the claims.

100‧‧‧Wireless Energy Transfer System

110‧‧‧Transmitter circuit

120‧‧‧Wireless transmission channel

130‧‧‧ Receiver circuit

210‧‧‧Matching circuit

220‧‧‧RF DC rectifier circuit

230‧‧‧The load circuit

240‧‧‧The receiving antenna

211‧‧‧first inductance

213‧‧‧first capacitor

221‧‧‧Low-pass filter

223‧‧‧First Diode

225‧‧‧second diode

227‧‧‧DC Bandpass Filter

231‧‧‧fourth capacitor

233‧‧‧Variable resistor

235‧‧‧load

310‧‧‧ box

320‧‧‧ box

1 is a block diagram of a wireless energy transfer system in accordance with the present invention in width and waveform modulation.

2 is a circuit diagram of a receiving end circuit of the present invention.

3 is a circuit diagram of another embodiment of the radio frequency DC rectification circuit of the present invention.

4A and 4B are schematic diagrams showing waveforms generated by the transmitting end circuit of the present invention.

5A to 5F are schematic diagrams showing time domain waveforms generated after modulation of the transmitting end circuit of the present invention.

6A-6B are schematic diagrams showing the time domain waveform generated by the modulation of the present invention measured by a spectrum analyzer.

7A-7B are schematic views of the output voltage of the present invention under different load resistances.

8A-8B are schematic views of the output voltage of the present invention at different on-currents.

9A-9B are schematic views of energy conversion efficiency of the present invention under different load resistances.

10A-10B are schematic views of energy conversion efficiency of the present invention at different on-currents.

11A-11B are schematic diagrams of output voltages of the present invention at different waveforms and average input power.

12A-12B are schematic diagrams of energy conversion efficiencies of the present invention at different waveforms and average input power.

Figure 13 is a schematic illustration of the output voltage of the present invention at different waveforms and average input power.

Figure 14 is a graphical representation of the energy conversion efficiency of the present invention at different waveforms and average input power.

100‧‧‧Wireless Energy Transfer System

110‧‧‧Transmitter circuit

120‧‧‧Wireless transmission channel

130‧‧‧ Receiver circuit

Claims (11)

A wireless energy transmission system with width and waveform modulation, comprising: a transmitting end circuit, which modulates a carrier electrical signal to generate an RF modulated signal, and transmits the RF modulated signal by a transmitting antenna; a wireless transmission channel coupled to the transmission antenna for transmitting an RF modulation signal; and a receiving end circuit coupled to the wireless transmission channel for receiving the RF modulation signal via a receiving antenna and rectifying the same to drive a load a circuit; wherein the transmitting end circuit performs pulse width modulation on the carrier electrical signal. The wireless energy transmission system of claim 1, wherein the receiving circuit comprises a matching circuit, a radio frequency DC rectifying circuit, and the load circuit. The wireless energy transmission system of claim 2, wherein the matching circuit comprises a first inductor and a first capacitor, one end of the first inductor is connected to the receiving antenna, and one end of the first capacitor Connected to the other end of the first inductor, one end of the first capacitor is connected to a low potential, and the matching circuit enables the energy of the RF modulated signal received by the receiving antenna to be effectively introduced into the RF DC rectifier circuit to reduce the cause Loss caused by reflection. The wireless energy transfer system of claim 3, wherein the RF DC rectifier circuit is a voltage doubler rectifier circuit to The microwave energy of the output signal of the circuit is converted into DC energy. In addition to the voltage doubler circuit, the rectifier circuit of other forms can also be applied to the technology. The wireless energy transfer system of claim 4, wherein the voltage doubler rectifier circuit comprises a low pass filter, a first diode, a second diode, and a DC band pass filter. One end of the low pass filter is connected to the other end of the first inductor, one end of the first diode is connected to the other end of the low pass filter, and the other end of the first diode is connected to the low potential One end of the second diode is connected to the other end of the low pass filter, and one end of the DC band pass filter is connected to the other end of the second diode, and the other end of the DC band pass filter is connected To this low potential. The wireless energy transmission system of claim 5, wherein the low pass filter is a second capacitor, and the DC band pass filter is a third capacitor. The wireless energy transfer system of claim 4, wherein the voltage doubler rectifier circuit is an N-order voltage doubler rectifier circuit, and N is an integer greater than one. The wireless energy transmission system of claim 6, wherein the load circuit comprises a fourth capacitor, a variable resistor and a load, and one end of the fourth capacitor is connected to the second diode One end of the fourth capacitor is connected to the low potential, one end of the variable resistor is connected to the other end of the second diode, and one end of the load is connected to the other end of the variable resistor, the load One end is connected to the low potential. The wireless energy transmission system of claim 8, wherein the variable resistance is a third diode. The wireless energy transmission system of claim 1, wherein the transmitting end circuit changes the duty cycle and the waveform when adjusting the pulse width of the electrical signal to adjust the transmission of the wireless energy transmission system. power. The wireless energy transmission system of claim 8, wherein the waveform is one of the following waveforms: a square wave, a sine wave, a pulse wave, and a triangular wave.