CN114530948A - Wireless energy transmission system and method using second harmonic wave for positioning - Google Patents
Wireless energy transmission system and method using second harmonic wave for positioning Download PDFInfo
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Abstract
The invention discloses a wireless energy transmission system and a method using second harmonic positioning, wherein the transmission system comprises at least three radio frequency energy transmitting ends and at least three radio frequency energy receiving ends, each radio frequency energy transmitting end comprises an energy transmitting device, a second harmonic receiving antenna and a signal processing module, each radio frequency energy receiving end comprises an energy receiving rectifying antenna and a second harmonic radiation antenna, the energy receiving rectifying antenna is used for receiving the energy of a frequency modulation continuous wave signal from the energy transmitting end and converting the energy into electric energy, and the second harmonic is generated by a nonlinear device in the process; the second harmonic radiation antenna is used for radiating out the second harmonic generated by the energy receiving rectification antenna. The invention can not only improve the distance of wireless energy transmission, but also realize the alignment of the radio frequency energy transmitting terminal antenna and the energy receiving terminal antenna under the condition of not consuming the energy of the energy receiving terminal, thereby improving the transmission efficiency of the radio frequency wireless energy transmission system.
Description
Technical Field
The invention belongs to the technical field of radio frequency wireless energy, and relates to a wireless energy transmission system and a wireless energy transmission method utilizing second harmonic positioning.
Background
Wireless energy transfer refers to the way in which an energy source propagates energy to an energy receiving end without contact. The wireless energy transmission technology mainly comprises modes of electromagnetic induction type coupling, magnetic resonance coupling, laser wireless energy transmission, radio frequency wireless energy transmission and the like. The electromagnetic induction type coupling and the magnetic resonance coupling belong to near-field wireless energy transmission modes, and have the advantages of high transmission efficiency but the defect of short transmission distance. Electromagnetic induction coupling is the most mature wireless energy transmission technology at present, and has been widely applied to various digital products and household appliances, but electromagnetic induction coupling can only be used for short-distance (millimeter to centimeter level) energy transmission. Laser wireless energy transmission and radio frequency wireless energy transmission belong to far-field energy transmission modes, but the anti-interference performance of the laser wireless energy transmission is weak, when an obstacle exists in a transmission path, the transmission efficiency of energy can be seriously influenced, and the application of laser is dangerous. In comparison, the rf wireless energy transmission is less affected by the environment and is suitable for long-distance energy transmission.
Radio frequency wireless energy transmission is a wireless transmission mode that transmits energy by radiating radio frequency electromagnetic waves. The energy transmitting end radio frequency converts direct current electric energy into radio frequency energy, the radio frequency energy realizes space energy radiation through the antenna, the radio frequency energy receiver converts the space radiation energy into direct current convenient to use through the antenna and the rectifying circuit by collecting the space radiation energy, and the converted direct current electric energy can directly supply power for a low-power consumption device or be stored in a battery. Compared with laser energy transmission, the radio frequency wireless energy transmission has certain anti-interference capability due to the penetrability of electromagnetic waves; compared with a near-field wireless energy transmission mode, the radio frequency wireless energy transmission mode has potential long-distance transmission capability, but the radio frequency wireless energy transmission mode has the problem of low energy transmission efficiency. The reason for influencing the radio frequency wireless energy transmission efficiency is mainly that path attenuation exists when radio frequency electromagnetic waves propagate in space; energy conversion efficiency of energy conversion circuits of the radio frequency energy transmitting end and the radio frequency energy receiving end; the rf energy transmitting antenna is misaligned with the rf energy receiving antenna. Attenuation of the path of radio frequency electromagnetic waves propagating in space is inevitable; the problem of low energy conversion efficiency of the energy conversion circuits at the radio frequency energy transmitting end and the radio frequency energy receiving end has been studied about more efficient conversion circuits.
For the alignment problem of the energy transmitting antenna and the radio frequency energy receiving antenna, the current solution is mostly based on a method of using beam forming at the energy transmitting end, that is, using a phased array antenna at the energy transmitting end to form a beam pointing to an energy receiving end antenna, but this method either requires the energy receiving end to send a signal first to make the energy transmitting end determine its position, which requires extra power consumption for the low-power consumption device; or the position of the energy receiving end is determined at the energy transmitting end by means of beam scanning, but the collected energy power value needs to be measured at the energy receiving end and fed back to the energy transmitting end, which not only needs a complex scanning algorithm, but also only needs to integrate a signal processing module inside the energy receiving end, and also increases unnecessary energy loss.
Disclosure of Invention
In order to solve the above problems, the present invention provides a wireless energy transmission system using second harmonic positioning, which not only can increase the distance of wireless energy transmission, but also can achieve the alignment of the rf energy transmitting end antenna and the energy receiving end antenna without consuming the energy of the energy receiving end, thereby increasing the transmission efficiency of the rf wireless energy transmission system and solving the problems existing in the prior art.
Another object of the present invention is to provide a wireless energy transmission method using second harmonic location.
The invention adopts the technical scheme that a wireless energy transmission system utilizing second harmonic positioning comprises
The number of the radio frequency energy transmitting ends is at least three, the radio frequency energy transmitting ends are not coplanar, and each radio frequency energy transmitting end comprises
The energy transmitting device is used for transmitting the frequency modulation continuous wave signals; and
the second harmonic receiving antenna is used for receiving a second harmonic signal from the energy receiving end; and
the signal processing module is used for carrying out signal processing on the received second harmonic signal to obtain the position information of the energy receiving end and feeding back the position information of the energy receiving end to the energy transmitting device, and the energy transmitting device adjusts the beam center in real time to align to the radio frequency energy receiving end;
a radio frequency energy receiving terminal, the radio frequency energy receiving terminal comprising
The energy receiving rectification antenna is used for receiving the energy of the frequency modulation continuous wave signal from the energy transmitting end and converting the energy into electric energy, and secondary harmonic waves are generated through a nonlinear device in the process; and
and the second harmonic radiation antenna is used for radiating the second harmonic generated by the energy receiving rectification antenna.
Further, the radio frequency energy transmitting terminal also comprises
The signal source is used for generating an original frequency modulation continuous wave signal and realizing the conversion from electric energy to radio frequency energy;
and the power amplifier is used for amplifying the power of the generated signal and sending the amplified signal to the energy transmitting device.
Further, the energy receiving rectenna comprises
The energy receiving antenna is used for receiving the frequency modulation continuous wave signals transmitted by the energy transmitting device;
and the rectification circuit is used for converting the radio frequency energy into electric energy and radiating the generated second harmonic signal outwards through the second harmonic radiation antenna.
Further, the frequency modulated continuous wave signals transmitted by the three radio frequency energy transmitting terminals are respectively marked as S1、S2And S3Signal S1、S2And S3The second harmonic signals respectively generated by the radio frequency energy receiving ends are respectively marked as Sr1、Sr2And Sr3Calculating the distance between the corresponding radio frequency energy transmitting end and the radio frequency energy receiving end based on the second harmonic signals corresponding to the three groups of radio frequency energy transmitting ends at different positions, and recording the distance as R1、R2、R3Obtaining R centered on three RF energy emitting ends1、R2、R3Is the intersection point of three circles with the radius, namely the position of the radio frequency energy receiving end.
Further, the distance R between the rf energy transmitting end and the rf energy receiving end is determined according to the following formula:
wherein c represents the propagation velocity of electromagnetic waves, TsThe frequency sweep period is the period of the frequency modulation continuous wave signal; b is the bandwidth of the frequency modulated continuous wave signal, fbRepresenting the frequency of the difference frequency signal and tau the transmission delay.
Furthermore, the frequency modulation continuous wave signals transmitted by the three radio frequency energy transmitting ends are not coherent.
A wireless energy transmission method utilizing second harmonic positioning adopts the wireless energy transmission system utilizing second harmonic positioning, and concretely comprises the following steps:
step S1, the energy emission devices of at least three radio frequency energy emission ends emit non-coherent frequency modulation continuous wave signals, and the emitted frequency modulation continuous wave signals are spread in space, received by the energy receiving rectification antenna of the radio frequency energy receiving end and converted into electric energy;
step S2, in the process that the energy receiving rectification antenna receives the frequency modulation continuous wave signal, the nonlinear device generates a second harmonic wave which is radiated by a second harmonic wave radiation antenna;
step S3, a second harmonic receiving antenna of the radio frequency energy transmitting end receives a second harmonic signal from the energy receiving end;
step S4, the radio frequency energy transmitting terminal processes the received second harmonic signal through the signal processing module to obtain the position information of the energy receiving terminal;
and step S5, the signal processing module feeds back the position information of the energy receiving end to the energy transmitting device, and the energy transmitting device adjusts the beam center in real time to align with the radio frequency energy receiving end.
Further, in the steps S2 and S3, the second harmonic signal S is emitted from the second harmonic radiation antenna at the rf energy receiving end0Expressed as:
where ρ is0Amplitude, omega, of signals transmitted by second-harmonic radiating antennas0Representing the frequency, omega, of the input signal0＝2πf0A represents an intermediate parameter, A ═ 2 π B/Ts，TsThe frequency sweep period is the period of the frequency modulation continuous wave signal; t is time;
second harmonic signal S received by second harmonic receiving antenna of radio frequency energy transmitting terminalHExpressed as: sH＝ρ1cos(2ω0(t-τ)+A(t-τ)2) Where ρ is1Representing the amplitude of a signal received by a second harmonic receiving antenna, and tau is transmission delay;
the circuit of the energy transmitting end generates a second harmonic signal S of the transmitting signalkExpressed as: sk＝ρ2cos(2ω0t+At2) Where ρ is2Representing the amplitude of a second harmonic signal generated by the circuitry of the energy transmitting end;
signal SkAnd SHAfter mixing, obtaining:
Further, in the step S4, the coordinates of the first rf energy emitting end are respectively obtained as (x) according to the positions of the three rf energy emitting ends in the spatial coordinate system1,y1,z1) The coordinate of the radio frequency energy transmitting end two is (x)2,y2,z2) The coordinate of the radio frequency energy transmitting end three is (x)3,y3,z3) (ii) a Assuming that the coordinates of the radio frequency energy receiving end are (x, y, z), the distances between the radio frequency energy transmitting end I, the radio frequency energy transmitting end II and the radio frequency energy transmitting end III and the radio frequency energy receiving end are respectively marked as R1、R2、R3Because the three radio frequency energy transmitting ends are not on the same plane, the three radio frequency energy transmitting ends are used as the center and R is used as the center1、R2、R3The intersection point of the three circles with the radius is the position coordinate of the radio frequency energy receiving end.
Further, the coordinates of the radio frequency energy receiving end are (x, y, z) and are solved by the following equation system:
the invention uses three radio frequency energy transmitting devices to transmit frequency modulation continuous wave signals with the same frequency, in order to reduce the loss of energy in space transmission and avoid causing extra energy expenditure at an energy receiving end, the invention utilizes the characteristic that frequency modulation continuous wave radar signals can generate harmonic signals in a nonlinear device, radiates second harmonic signals generated at the energy receiving end out through an antenna, then three energy receiving devices perform signal processing on the received second harmonic signals to calculate the position information of the energy receiving end, and further feeds the information back to a transmitting antenna at the energy transmitting end, and the transmitting antenna adjusts the beam direction thereof to realize the alignment of the radio frequency energy transmitting antenna and the energy receiving antenna.
The invention has the beneficial effects that:
1. the radio frequency wireless transmission system provided by the invention has the advantages of long energy transmission distance and interference resistance, and can adjust the antenna beam direction of the radio frequency energy transmitting end in real time, realize the alignment of the transmitting end antenna and the energy receiving end antenna, thereby being capable of carrying out long-distance wireless energy transmission for equipment in motion.
2. The invention uses frequency modulation continuous wave signals to realize long-distance and high-efficiency radio frequency wireless energy transmission, and in order to realize the alignment of a transmitting terminal antenna and an energy receiving terminal antenna, the invention utilizes the physical characteristic that radio frequency electromagnetic waves can generate harmonic waves through a nonlinear device, and obtains the position information of an energy receiving terminal by recycling secondary harmonic wave energy. Unlike other radio frequency wireless energy transmission systems, the invention does not need to consume the electric energy of the energy receiving end to finish the alignment of the energy transmitting end and the energy receiving end antenna, and carries out long-distance energy transmission for the moving equipment; for example, the intelligent carrying and sorting robot in the logistics warehouse can be charged in a working state, so that the robot is not required to return to a fixed place for rest and charging under low electric quantity, and the working efficiency of the robot can be improved. Compared with other methods, the method provided by the invention is more suitable for charging movable equipment with low power consumption, and has the advantages of longer transmission distance and higher transmission efficiency.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a block diagram of a wireless energy transfer system using second harmonic location in accordance with an embodiment of the present invention.
Fig. 2 is a diagram of an energy transfer model between an energy transmitting end and an energy receiving end according to an embodiment of the present invention.
FIG. 3 is a flow chart of a rectifier circuit system according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of a rectifier circuit according to an embodiment of the invention.
Fig. 5 is a schematic diagram of a positioning algorithm in accordance with an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the case of the example 1, the following examples are given,
a wireless energy transmission system using second harmonic location, as shown in fig. 1, includes a radio frequency energy transmitting end and a radio frequency energy receiving end.
The radio frequency energy transmitting end comprises three energy transmitting devices, each energy transmitting device comprises a signal source, a power amplifier, an energy transmitting antenna, a second harmonic receiving antenna and a signal processing module, and the three energy transmitting devices are arranged on a non-same plane, so that the position information of the energy receiving end can be conveniently acquired subsequently.
And the signal source is used for generating an original frequency modulation continuous wave signal and realizing the conversion from electric energy to radio frequency energy.
A power amplifier for amplifying the power of the generated signal.
And the energy transmitting antenna is used for transmitting the amplified frequency-modulated continuous wave signal.
And the second harmonic receiving antenna is used for receiving the second harmonic signal from the energy receiving end.
The signal processing module is used for carrying out signal processing on the received second harmonic signal to obtain the position information of the energy receiving end and feeding back the position information of the energy receiving end to the energy transmitting device, and the energy transmitting device adjusts the beam center in real time to align to the radio frequency energy receiving end;
the energy receiving end is a radio frequency energy receiving device which comprises an energy receiving rectification antenna and a second harmonic radiation antenna. The energy receiving rectification antenna comprises an energy receiving antenna and a rectification circuit, wherein the energy receiving antenna is used for capturing the energy of the frequency modulation continuous wave signal from the energy transmitting end; the rectification circuit converts the received radio frequency energy into electric energy, secondary harmonic waves are generated through the nonlinear device in the process, and the generated secondary harmonic waves are emitted through the secondary harmonic wave radiation antenna.
An energy transfer model between the radio frequency energy transmitting end and the radio frequency energy receiving end is shown in fig. 2, and the three radio frequency energy transmitting ends are respectively marked as a radio frequency energy transmitting end I, a radio frequency energy transmitting end II and a radio frequency energy transmitting end III. Each radio frequency energy transmitting end comprises two modules of radio frequency energy transmitting and second harmonic receiving. The emission signals of the three radio frequency energy emission ends are respectively marked as S1、S2And S3The second harmonic signals generated by the energy transmitting signal passing through the energy receiving end circuit are respectively marked as Sr1、Sr2And Sr3。
The embodiment of the invention adopts three energy transmitting ends to obtain three groups of second harmonic signals at different positions, and the distances between the energy transmitting ends and the energy receiving ends are calculated and recorded as R1、R2、R3And as a positioning signal, the position information of the energy receiving end is calculated through subsequent signal processing, and the direction of the beam center of the antenna is adjusted through the position information, so that the alignment from the energy transmitting end to the energy receiving end antenna is realized, and the maximum power transmission efficiency is further obtained.
In the case of the example 2, the following examples are given,
a wireless energy transfer method using second harmonic localization, comprising the steps of:
step S1, the energy emission devices of at least three radio frequency energy emission ends emit non-coherent frequency modulation continuous wave signals; the energy transmitting end generates a frequency modulation continuous wave signal through a signal source, and the generated frequency modulation continuous wave signal realizes the conversion from electric energy to radio frequency energy. Because the power of the frequency modulated continuous wave signal generated by the signal source is generally low, a power amplifier is used for amplifying the radio frequency signal behind the signal source. And the radio-frequency signal amplified by the power amplifier is transmitted by an energy transmitting antenna at a radio-frequency energy transmitting end. The transmitted frequency modulated continuous wave signal propagates in space and is finally captured by an energy receiving antenna at a radio frequency energy receiving end. After the radio frequency energy receiving end receives signals through the energy receiving antenna, the conversion of the radio frequency energy and the electric energy is completed through the rectifying circuit.
Step S2, in the process that the energy receiving rectification antenna receives the frequency modulation continuous wave signal, a nonlinear device of the energy receiving rectification antenna generates a second harmonic, and the generated second harmonic signal is radiated outwards through a second harmonic radiation antenna;
the system flow of the rectifier circuit is shown in FIG. 3; the rectification circuit comprises a low-pass filter, a matching circuit, a rectifier diode, a through filter and a load, wherein signals pass through the low-pass filter, then pass through the matching circuit and the rectification circuit, and finally are transmitted to the load through the through filter to complete wireless energy transmission; the rectification circuit is used for converting radio frequency energy into electric energy.
Firstly, an input low-pass filter filters frequency modulation continuous wave signals, then a matching circuit realizes matching between the input low-pass filter and a rectifier diode, the rectifier diode rectifies radio-frequency signals into direct-current electric energy, and finally, the rectified direct-current voltage is subjected to smooth filtering through a direct-current filter to obtain stable direct-current voltage.
The rectifying diode adopts a Schottky barrier diode which is the core of the rectifying circuit and plays a decisive role in the rectifying efficiency of the rectifying circuit. The Schottky diode is a nonlinear device, and the received frequency-modulated continuous wave signal passes through the nonlinearityThe device generates harmonic components consisting of integer multiples of the signal frequency. The relationship between current and voltage through a schottky diode can be expressed as
Where q is the charge, k represents the Boltzmann constant, T is the temperature, n represents the ideality factor, ISIndicating the saturation current, i (v) the voltage across the diode, v the conduction voltage drop of the diode.
Voltage V ═ V of input signal of rectifier (rectifying circuit)scos(ω0t) wherein VSIs the amplitude, omega, of the signal (i.e. frequency-modulated continuous wave)0Representing the input signal frequency and t represents time.
The output response of a non-linear diode rectifier can be described by a Taylor series, where the sinusoidal input signal voltage can be represented as V0＝x0+x1Vscos(ω0t)+x2[Vscos(ω0t)]2+x3[Vscos(ω0t)]3+ … where x0,x1,x2,.. representing taylor expansion coefficients.
Because of the fact that
Therefore, the first and second electrodes are formed on the substrate,
V0representing a sinusoidal input signal voltage.
Thus, the output voltage comprises the DC rectified output and the AC signal ω0,2ω0,3ω0.... The second harmonic of the rectifier can be expressed as
And the second harmonic is also the harmonic component with the highest power value in the harmonic response. The embodiment of the invention utilizes the physical characteristic to emitThe frequency energy receiving end radiates the generated second harmonic out through a second harmonic radiation antenna to serve as a positioning signal.
A schematic diagram of a rectifier circuit with recovered second harmonic is shown in fig. 4, wherein the rf input of fig. 4, i.e., the energy receiving antenna, matching and filtering circuit, rectifier diode, and pass-through filter of fig. 1 correspond to the rectifier circuit of fig. 1; the matching and filtering circuit realizes the matching between the input low-pass filter and the rectifier diode and simultaneously completes the low-pass filtering function, and the matching circuit and the filter are important aspects influencing the rectification efficiency. The low-pass filter is used for filtering noise and clutter, and the ratio of voltage to current is called characteristic impedance on a section of radio frequency transmission line; the ratio of the voltage and the current is equal to the load impedance across the load. When the load impedance is different from the characteristic impedance, the voltage current on the transmission line is not continuous with the voltage current on the load, and a part of the reflected wave is generated. When the load impedance is equal to the characteristic impedance, no reflection occurs and the load absorbs all the energy. That is, when the circuits are mismatched, the rf signal is not effectively transmitted into the diode and is reflected and lost, or the power is unstable, so the matching circuit is required to achieve maximum energy transmission. The capacitors C1 and C2 are used for isolating direct current signals, and the inductor L is used for isolating radio frequency signals. Two diodes realize double voltage rectification, and the rectified direct current signal is transmitted to a load through an inductor L. The second harmonic generated by the diode passes through capacitor C2 and is ultimately radiated by the second harmonic radiating antenna.
Step S3, the energy emission devices of the three radio frequency energy emission ends receive the second harmonic signal generated by the energy receiving end through the second harmonic receiving antenna; the radar has certain interference resistance, and because the signals transmitted by the three energy transmitting ends are not coherent, the initial phase of the signal transmitted by each radar is different, so that only the echo of the radar is coherent when the echo signal is received, and the second harmonic generated by the signal transmitted by the radar can be distinguished after matched filtering.
Step S4, the radio frequency energy transmitting end processes the received frequency modulation continuous wave signal and then demodulates the signalThe position information is calculated. Assuming a transmission frequency range of f0,f0+B]The frequency-modulated continuous wave signal is
Where ρ is0Amplitude of signal transmitted by second harmonic transmitting antenna, f0Is the starting frequency of the frequency modulated continuous wave signal, B is the bandwidth of the frequency modulated continuous wave signal, omega0＝2πf0A represents an intermediate parameter, A ═ 2 π B/Ts。
The expression of the second harmonic signal received by the second harmonic receiving antenna of the radio frequency energy transmitting end is SH＝ρ1cos(2ω0(t-τ)+A(t-τ)2) Wherein A is 2 pi B/Ts，ρ1Representing the amplitude, T, of the signal received by the second harmonic receiving antennasThe frequency sweep period is a frequency sweep period, which is a period of a frequency modulation continuous wave signal, is set when a transmitting signal parameter is designed and is a known parameter; t is time and τ is transmission delay. The second harmonic not only exists at the energy receiving end, but also can be generated when a signal source in the energy transmitting end circuit generates a linear frequency modulation continuous wave signal, and the second harmonic signal generated by the signal source is expressed as Sk＝ρ2cos(2ω0t+At2) Therefore, the embodiment of the present invention mixes the second harmonic of the energy transmitting end with the second harmonic received from the energy receiving end.
Signal SkAnd the received second harmonic signal SHAfter mixing, obtaining:
After the three radio frequency energy transmitting terminals obtain the distance information between the three radio frequency energy transmitting terminals and the radio frequency energy receiving terminal, the three-dimensional position coordinates of the radio frequency energy receiving terminal are solved through a positioning algorithm.
The principle of the positioning algorithm, as shown in fig. 5, can obtain the coordinates (x) of the first rf energy transmitting end according to the positions of the three rf energy transmitting ends in the spatial coordinate system1,y1,z1) The coordinate of the radio frequency energy transmitting end two is (x)2,y2,z2) The coordinate of the radio frequency energy transmitting end three is (x)3,y3,z3). Assuming that the coordinates of the radio frequency energy receiving end are (x, y, z), obtaining distance information with the radio frequency energy receiving end according to the obtained three radio frequency energy transmitting ends, and respectively recording the distances between the radio frequency energy transmitting end I, the radio frequency energy transmitting end II and the radio frequency energy transmitting end III and the radio frequency energy receiving end as R1,R2,R3Since the three transmitting ends are not in the same plane, according to R1,R2,R3Can be centered at three radio frequency energy transmitting ends, R1,R2,R3Determining the position coordinates of the radio frequency energy receiving end for the intersection point of the circles with the radius, namely solving the three-dimensional coordinates (x, y, z) of the receiving end through the following equation set;
and step S5, according to the obtained position information of the receiving end, the three radio frequency energy transmitting ends adjust the beam center in real time to point to the radio frequency energy receiving end, so that the radio frequency energy receiving end obtains the maximum energy, the energy loss is reduced, and the energy transmission efficiency of the wireless energy transmission system is improved.
According to the embodiment of the invention, the second harmonic signal generated by the non-linear physical characteristic of the rectifier diode in the rectifying circuit is used for positioning the energy receiving end, and the radio frequency wireless energy transmission system is designed according to the second harmonic signal. Firstly, in order to carry out positioning by utilizing a second harmonic signal generated by an energy receiving end circuit, three energy transmitting ends are adopted to transmit linear frequency modulation continuous wave signals. When the signals of the three energy transmitting ends reach the rectifying circuit of the energy receiving end, the three transmitting signals S from the radio frequency energy transmitting end are transmitted due to the nonlinear characteristic of the diode in the rectifying circuit1、S2And S3When the electric energy is converted into the electric energy, the corresponding second harmonic signal S can be generatedr1、Sr2And Sr3. Secondly, the generated second harmonic signal is weak, although the second harmonic signal still radiates outwards, the second harmonic signal may not be captured at the energy receiving end, and in order to feed back the second harmonic signal generated in the rectifying circuit to the three radio frequency energy transmitting ends, in the embodiment of the invention, the second harmonic radiation antenna is added in the rectifying circuit, and the generated second harmonic signal is radiated by using the second harmonic radiation antenna, so that the radio frequency energy transmitting end can receive the second harmonic signal. Finally, due to the three energy emitting endsThe transmitted signals are non-coherent, so that the three energy transmitting terminals respectively receive second harmonic signals of the transmitted signals, and then the signals are processed to obtain the distance R between the energy receiving terminal and the energy receiving terminal1、R2、R3The three-dimensional position information of the energy receiving end can be solved through the positioning algorithm provided by the invention. The energy transmitting antenna beam of the energy transmitting end can be adjusted to point to the receiving antenna of the energy receiving end through the obtained three-dimensional position information, and therefore the maximum energy transmission efficiency is obtained.
Compared with the prior art, the invention combines the advantages of the radar system and the radar signal processing field with the wireless energy transmission system, provides the wireless energy transmission system which can be remotely and adaptively, realizes the alignment of the energy transmitting end and the energy receiving end antenna by utilizing the second harmonic signal generated by the characteristics of the rectifier diode of the energy receiving end, does not consume the electric energy of the energy receiving end, only uses the antenna to radiate the energy receiving end, does not need to add redundant hardware circuits at the energy receiving end, has the advantages of higher energy transmission efficiency, less energy loss and simple circuit, and is more suitable for the wireless energy transmission of low-power consumption equipment.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (10)
1. A wireless energy transfer system using second harmonic location, comprising
The number of the radio frequency energy transmitting ends is at least three, the radio frequency energy transmitting ends are not coplanar, and each radio frequency energy transmitting end comprises
The energy transmitting device is used for transmitting the frequency modulation continuous wave signals; and
the second harmonic receiving antenna is used for receiving a second harmonic signal from the energy receiving end; and
the signal processing module is used for carrying out signal processing on the received second harmonic signal to obtain the position information of the energy receiving end and feeding back the position information of the energy receiving end to the energy transmitting device, and the energy transmitting device adjusts the beam center in real time to align to the radio frequency energy receiving end;
a radio frequency energy receiving terminal, the radio frequency energy receiving terminal comprising
The energy receiving rectification antenna is used for receiving the energy of the frequency modulation continuous wave signal from the energy transmitting end and converting the energy into electric energy, and secondary harmonic waves are generated through a nonlinear device in the process; and
and the second harmonic radiation antenna is used for radiating the second harmonic generated by the energy receiving rectification antenna.
2. The system for wireless energy transfer using second harmonic positioning according to claim 1, wherein the rf energy transmitting end further comprises
The signal source is used for generating an original frequency modulation continuous wave signal and realizing the conversion from electric energy to radio frequency energy;
and the power amplifier is used for amplifying the power of the generated signal and sending the amplified signal to the energy transmitting device.
3. The system of claim 1, wherein the energy receiving rectenna comprises a second harmonic positioning
The energy receiving antenna is used for receiving the frequency modulation continuous wave signals transmitted by the energy transmitting device;
and the rectification circuit is used for converting the radio frequency energy into electric energy and radiating the generated second harmonic signal outwards through the second harmonic radiation antenna.
4. The wireless energy transmission system using second harmonic localization according to claim 1, wherein the frequency modulated continuous wave signals emitted by the three rf energy emitting terminals are denoted as S respectively1、S2And S3Signal S1、S2And S3The second harmonic signals respectively generated by the radio frequency energy receiving ends are respectively marked as Sr1、Sr2And Sr3Calculating the distance between the corresponding radio frequency energy transmitting end and the radio frequency energy receiving end based on the second harmonic signals corresponding to the three groups of radio frequency energy transmitting ends at different positions, and recording the distance as R1、R2、R3Obtaining R centered on three RF energy emitting ends1、R2、R3Is the intersection point of three circles with the radius, namely the position of the radio frequency energy receiving end.
5. The wireless energy transmission system using second harmonic localization according to claim 4, wherein the distance R between the RF energy transmitting end and the RF energy receiving end is determined according to the following formula:
wherein c represents the propagation velocity of electromagnetic waves, TsThe frequency sweep period is the period of the frequency modulation continuous wave signal; b is the bandwidth of the frequency modulated continuous wave signal, fbRepresenting the frequency of the difference frequency signal and tau the transmission delay.
6. The system according to claim 1, wherein the three rf energy emitters emit frequency-modulated continuous wave signals that are non-coherent.
7. A wireless energy transmission method using second harmonic localization, characterized by using the wireless energy transmission system using second harmonic localization as claimed in claim 1, and specifically performing the following steps:
step S1, the energy emission devices of at least three radio frequency energy emission ends emit non-coherent frequency modulation continuous wave signals, and the emitted frequency modulation continuous wave signals are spread in space, received by the energy receiving rectification antenna of the radio frequency energy receiving end and converted into electric energy;
step S2, in the process that the energy receiving rectification antenna receives the frequency modulation continuous wave signal, the nonlinear device generates a second harmonic wave which is radiated by a second harmonic wave radiation antenna;
step S3, a second harmonic receiving antenna of the radio frequency energy transmitting end receives a second harmonic signal from the energy receiving end;
step S4, the radio frequency energy transmitting terminal processes the received second harmonic signal through the signal processing module to obtain the position information of the energy receiving terminal;
and step S5, the signal processing module feeds back the position information of the energy receiving end to the energy transmitting device, and the energy transmitting device adjusts the beam center in real time to align with the radio frequency energy receiving end.
8. The method for wireless energy transmission using second harmonic location according to claim 7, wherein the second harmonic signal S emitted from the second harmonic radiation antenna at the RF energy receiving end in the steps S2 and S30Expressed as:
where ρ is0Amplitude, omega, of signals transmitted by second-harmonic radiating antennas0Representing the frequency, omega, of the input signal0＝2πf0A represents an intermediate parameter, A ═ 2 π B/Ts，TsThe frequency sweep period is the period of the frequency modulation continuous wave signal; t is time;
second harmonic signal S received by second harmonic receiving antenna of radio frequency energy transmitting terminalHExpressed as: sH＝ρ1cos(2ω0(t-τ)+A(t-τ)2) Where ρ is1Representing the amplitude of a signal received by a second harmonic receiving antenna, wherein tau is transmission time delay;
the circuit of the energy transmitting end generates a second harmonic signal S of the transmitting signalkExpressed as: sk＝ρ2cos(2ω0t+At2) Where ρ is2Representing energy emitting endsThe amplitude of the second harmonic signal generated by the circuit of (1);
signal SkAnd SHAfter mixing, obtaining:
9. The method for wireless energy transmission using second harmonic localization according to claim 8, wherein in step S4, the coordinates of the first rf energy emitting end are obtained as (x) according to the positions of the three rf energy emitting ends in the spatial coordinate system1,y1,z1) The coordinate of the radio frequency energy transmitting end two is (x)2,y2,z2) The coordinate of the radio frequency energy transmitting end three is (x)3,y3,z3) (ii) a Assuming that the coordinates of the radio frequency energy receiving end are (x, y, z), the distances between the radio frequency energy transmitting end I, the radio frequency energy transmitting end II and the radio frequency energy transmitting end III and the radio frequency energy receiving end are respectively marked as R1、R2、R3Because the three radio frequency energy transmitting ends are not on the same plane, the three radio frequency energy transmitting ends are used as the center and R is used as the center1、R2、R3The intersection point of the three circles with the radius is the position coordinate of the radio frequency energy receiving end.
10. The method of claim 9, wherein the coordinates (x, y, z) of the rf energy receiving end are solved by the following equations:
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170118714A1 (en) * | 2015-10-22 | 2017-04-27 | Canon Kabushiki Kaisha | Power receiving apparatus for wirelessly receiving power from external apparatus |
| US20180205144A1 (en) * | 2017-01-17 | 2018-07-19 | Delta Electronics, Inc. | Rf energy transmitting apparatus, rf energy harvesting apparatus and method of rf energy transmitting |
| CN108702018A (en) * | 2015-12-24 | 2018-10-23 | 艾诺格思公司 | The system and method for carrying out wireless charging by multiple receiving devices |
| CN113708515A (en) * | 2021-08-31 | 2021-11-26 | 西北工业大学太仓长三角研究院 | Wireless power transmission system with automatic regulation and control function and secondary harmonic feedback function |
-
2022
- 2022-03-11 CN CN202210238741.8A patent/CN114530948B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170118714A1 (en) * | 2015-10-22 | 2017-04-27 | Canon Kabushiki Kaisha | Power receiving apparatus for wirelessly receiving power from external apparatus |
| CN108702018A (en) * | 2015-12-24 | 2018-10-23 | 艾诺格思公司 | The system and method for carrying out wireless charging by multiple receiving devices |
| US20180205144A1 (en) * | 2017-01-17 | 2018-07-19 | Delta Electronics, Inc. | Rf energy transmitting apparatus, rf energy harvesting apparatus and method of rf energy transmitting |
| CN113708515A (en) * | 2021-08-31 | 2021-11-26 | 西北工业大学太仓长三角研究院 | Wireless power transmission system with automatic regulation and control function and secondary harmonic feedback function |
Non-Patent Citations (1)
| Title |
|---|
| 张青芳: "TDD-LTE Band40设计与实现", 《中国优秀硕士学位论文全文数据库》, no. 7, pages 1 - 61 * |
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