Wireless energy transfer dual frequency antenna system with self feedback

Abstract

The application discloses a wireless energy transmission dual-frequency antenna system with self feedback, which comprises an aluminum sheet layer, a dielectric substrate, an upper surface metal layer and a lower surface metal layer; the aluminum sheet layer is composed of a parasitic patch unit working at a 915 MHz frequency band; the upper surface metal layer comprises a main radiation patch unit working at the 915 MHz frequency band, a one-to-four microstrip power divider corresponding to a feed, and a bent-line monopole antenna working at a 433 MHz frequency band; the lower surface metal layer is a metal ground plate; the parasitic patch unit is arranged above the main radiation patch unit through a metal stud, and the lower surface metal layer is provided with an isolation hole corresponding to the metal stud; and the dielectric substrate is provided with a coaxial connector connected with a center feed point of the one-to-four microstrip power divider. The 915 MHz array antenna and the 433 MHz monopole antenna are efficiently integrated on the same dielectric substrate, and the manufacturing cost is reduced while the performance is ensured by optimizing the structure parameters and the feed network.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, in particular to a wireless energy transmission dual-frequency antenna system with self-feedback. BACKGROUND

[0002] As one of the globally widely used ISM frequency bands, the 915 MHz frequency band plays a key role in the fields of Internet of Things, microwave medical treatment, RFID system, unmanned aerial vehicle communication, and smart agricultural sensor network, etc. due to its excellent propagation characteristics and strong penetration ability. In particular, in large-scale sensor networking and long-distance low-power communication scenarios, the 915 MHz array antenna can realize directional coverage through beamforming technology, accurately focus signal energy, thereby effectively reducing transmission loss and suppressing multipath interference, and significantly improving the stability of the communication system.

[0003] However, with the rapid evolution of wireless communication technology and the increasing complexity of application scenarios, the design of the 915 MHz array antenna still faces many challenges, including:

[0004] Bandwidth and gain limitations, the working bandwidth of traditional microstrip array antennas is narrow, which is difficult to meet the wideband communication demand, and the insufficient gain will affect the long-distance transmission performance, the coplanar integration design of the feed network and the antenna unit increases the difficulty of arraying, and the parasitic coupling between the feed line and the radiation unit easily leads to pattern distortion and efficiency decline;

[0005] Multi-band integration requirements, the 433 MHz frequency band has irreplaceable advantages in the Internet of Things field such as remote control due to its excellent diffraction ability and environmental adaptability (such as penetrating through buildings, vegetation and other complex scenes), but its 1 / 4 wavelength antenna size (about 17 cm) limits its application in small-sized devices. SUMMARY

[0006] The present application provides a wireless energy transmission dual-frequency antenna system with self-feedback, which efficiently integrates the 915 MHz array antenna and the 433 MHz monopole antenna on the same dielectric substrate, and reduces the manufacturing cost while ensuring performance by optimizing the structure parameters and the feed network.

[0007] Technical scheme: The wireless energy transmission dual-frequency antenna system with self-feedback provided by the present application comprises an aluminum sheet layer, a dielectric substrate, and an upper surface metal layer and a lower surface metal layer located on the upper and lower surfaces of the dielectric substrate.

[0008] The aluminum sheet layer is composed of four parasitic patch elements working at the 915 MHz frequency band;

[0009] The upper surface metal layer comprises four main radiation patch units working at a 915 MHz frequency band, a corresponding one-to-four microstrip power divider for feeding, and a bent-line monopole antenna working at a 433 MHz frequency band;

[0010] The lower surface metal layer is a metal ground plate.

[0011] The parasitic patch units are suspended one by one above the main radiation patch units in a one-to-one correspondence manner, and the lower surface metal layer is provided with isolation holes corresponding to the metal studs for the metal studs to pass through.

[0012] The back surface of the dielectric substrate is provided with a coaxial connector connected to a center feeding point of the one-to-four microstrip power divider.

[0013] The system comprises a 915 MHz microstrip antenna array and a 433 MHz monopole antenna, the microstrip antenna array is used as a wireless energy receiving antenna to receive wireless energy and store the received wireless energy and supply power to other devices, and the monopole antenna is used as a radiation device to modulate and output a verification signal after detecting and collecting wireless energy, and verify the use of the wireless energy transmission end.

[0014] Further, the parasitic patch units are arranged in two rows and two columns in a uniform manner.

[0015] Further, the parasitic patch units and the main radiation patch units are both in an I-shaped structure, and both sides form rectangular grooves of the same size.

[0016] Further, the main radiation patch units and the parasitic patch units have a length of half a working wavelength along the excitation direction.

[0017] Further, the one-to-four microstrip power divider comprises an input port, the input port is divided into two branches, each branch is connected to a second-level T-shaped microstrip power divider through a first quarter-wavelength impedance transformation line, and two branches are output again, each branch is connected to a main radiation patch unit through a second quarter-wavelength impedance transformation line, and feeds the main radiation patch unit.

[0018] Further, the inner conductor of the coaxial connector passes through the lower surface metal layer and the dielectric substrate from bottom to top through a slot hole, and is connected to a center feeding point of a one-to-four microstrip power divider in the upper surface metal layer, and the lower surface metal layer is provided with an inner conductor isolation hole.

[0019] Further, the bent-line monopole antenna is located at a corner of the dielectric substrate, and comprises a bent monopole unit, a coplanar waveguide, and an L-shaped impedance matching network.

[0020] The coplanar waveguide and the bent monopole unit are matched in impedance through the L-shaped impedance matching network.

[0021] The lower surface metal layer corresponds to the part of the bent monopole unit and forms a notch;

[0022] The co-planar waveguide comprises a common metal ground, a parallel inductance and a series capacitance;

[0023] The bent line monopole antenna has a length of 1 / 4 working wavelength.

[0024] Further, the dielectric constant of the dielectric substrate is 2-3, the thickness is 0.002λ0≤h≤0.006λ0, and λ0 is the wavelength corresponding to 915MHz;

[0025] The suspended spacing gap between the parasitic patch unit and the main radiation patch unit is 0.04λ0≤gap≤0.06λ0.

[0026] The unit arrangement spacing p between the parasitic patch unit and the main radiation patch unit is 0.5λ0≤p≤0.7λ0.

[0027] Further, the width W of the bent monopole unit is 0.0008λ0 ’ ≤W≤0.002λ0 ’ , the total arm length L is L≥0.25λ0 ’ , and λ0 ’ is the wavelength corresponding to 433MHz.

[0028] Further, the microstrip patch antenna working at 915MHz and the monopole antenna working at 433MHz adopt an orthogonal polarization mode.

[0029] Beneficial effects: Compared with the prior art, the present application has the following significant progress: wireless energy collection can be effectively realized while providing backhaul confirmation, is suitable for wireless energy transmission scenarios with high reliability, and can effectively improve the reliability and safety of the system. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is an antenna system layer structure schematic diagram of the present application;

[0031] Figure 2 It is an aluminum sheet layer structure schematic diagram of the present application;

[0032] Figure 3 It is an upper surface metal layer structure schematic diagram of the present application;

[0033] Figure 4 It is a lower surface metal layer structure schematic diagram of the present application;

[0034] Figure 5 It is a reflection coefficient simulation result of the antenna system of the present application;

[0035] Figure 6Gain simulation result of the antenna system of the application at 915 MHz;

[0036] Figure 7 Pattern simulation result of the antenna system of the application at 433 MHz;

[0037] Figure 8 Application example effect diagram of the antenna system of the application. DETAILED DESCRIPTION

[0038] The technical solutions of the application are further described below in combination with the drawings and examples.

[0039] As shown in the drawings, Figures 1-4 The wireless energy transmission dual-frequency antenna system with self-feedback includes an aluminum sheet layer 1, a dielectric substrate 3, and an upper surface metal layer 2 and a lower surface metal layer 4 located on the upper and lower surfaces of the dielectric substrate 3.

[0040] The aluminum sheet layer 1 is composed of four parasitic patch elements 1-1 working at a 915 MHz frequency band, which are in the shape of an I-beam and each has a rectangular slot cut out on the left and right sides.

[0041] The upper surface metal layer 2 includes four main radiation patch elements 2-1 working at a 915 MHz frequency band, a one-to-four microstrip power divider for corresponding feeding, and a bent-line monopole antenna 5 working at a 433 MHz frequency band.

[0042] The main radiation patch elements 2-1 are also in the shape of an I-beam and each has a rectangular slot cut out on the left and right sides.

[0043] The lower surface metal layer 4 is a metal ground plate.

[0044] The parasitic patch elements 1-1 are respectively suspended above the main radiation patch elements 2-1 one by one through metal studs 6, and the lower surface metal layer 4 is provided with isolation holes 4-1 corresponding to the metal studs 6 for each metal stud 6 to pass through.

[0045] The dielectric substrate 3 is provided with a coaxial connector 7 connected to the center feeding point of the one-to-four microstrip power divider on the back.

[0046] The parasitic patch elements 1-1 and the main radiation patch elements 2-1 form a 915 MHz microstrip antenna array together, and the bent-line monopole antenna 5 forms a 433 MHz monopole antenna, which are polarized orthogonally to effectively suppress mutual interference. The microstrip antenna array is used as a wireless energy transmission receiving antenna to receive wireless energy for storage and power supply of other devices; the monopole antenna is used as a radiating device to modulate and output a verification signal after detecting and collecting wireless energy, which is used to verify the use of the wireless energy transmission transmitting end.

[0047] The parasitic patch units 1-1 and the main radiation patch units 2-1 are arranged in two rows and two columns.

[0048] The main radiation patch units 2-1 and the parasitic patch units 1-1 have a length of half of the working wavelength along the excitation direction.

[0049] The one-to-four microstrip power divider includes an input port 7-1, which is the center feeding point of the one-to-four microstrip power divider. The input port 7-1 is divided into two branches, each of which is connected to a second-stage T-shaped microstrip power divider by a first quarter-wavelength impedance transformation line 7-2, and then outputs two branches, each of which is connected to a main radiation patch unit 2-1 by a second quarter-wavelength impedance transformation line 7-3, and feeds the main radiation patch unit 2-1.

[0050] The inner conductor of the coaxial connector 7 passes through the lower surface metal layer 4 and the dielectric substrate 3 from bottom to top through the slot hole, and is connected to the center feeding point of the one-to-four microstrip power divider in the upper surface metal layer 2. The lower surface metal layer 4 is provided with an inner conductor isolation hole.

[0051] The folded line monopole antenna 5 in the embodiment is located at the lower left corner of the dielectric substrate 3, and includes a folded monopole unit 5-1, a coplanar waveguide 5-2, and an L-shaped impedance matching network 5-3.

[0052] The coplanar waveguide 5-2 and the folded monopole unit 5-1 are matched in impedance through the L-shaped impedance matching network 5-3.

[0053] The lower surface metal layer 4 forms a notch for the folded monopole unit 5-1.

[0054] The coplanar waveguide 5-2 includes a common metal ground, a parallel inductor, and a series capacitor.

[0055] The folded line monopole antenna 5 has a length of 1 / 4 working wavelength.

[0056] In the antenna system designed in the application, the dielectric constant of the dielectric substrate 3 is 2-3, the thickness is 0.002λ0≤h≤0.006λ0, λ0 is the wavelength corresponding to 915 MHz; the suspended spacing gap between the parasitic patch unit 1-1 and the main radiation patch unit 2-1 is 0.04λ0≤gap≤0.06λ0, adjusting the gap can adjust the working frequency band, the gap adjustment range is 0.045λ0≤gap≤0.065λ0, and the corresponding working frequency band adjustment range is: 850-950MHz.

[0057] The unit arrangement spacing p of the parasitic patch unit 1-1 and the main radiation patch unit 2-1 is 0.5λ0≤p≤0.7λ0.

[0058] The width W of the bent monopole element 5-1 is 0.0008λ0. ’ ≤W≤0.002λ0 ’ The total arm length L is L≥0.25λ0 ’ ,λ0 ’ For a wavelength of 433 MHz, the characteristic impedance of the coplanar waveguide transmission line is 50 ohms. The L-shaped impedance matching network should first connect an inductor L in parallel, and then connect a capacitor C in series. The inductor L is 20 nH and the capacitor C is 2 pF.

[0059] like Figure 5 and 6 As shown, the impedance bandwidth with a port reflection coefficient of less than -10 dB can cover 885-937 MHz and 431-434 MHz, and a gain of 12 dBi can be achieved at 915 MHz, with a 3 dB beamwidth covering ±23°.

[0060] like Figure 7 As shown, the impedance bandwidth with a port reflection coefficient of less than -10 dB can cover 431-434 MHz, and a gain of -3.3 dBi can be achieved at 433 MHz.

[0061] Based on this, the antenna bandwidth and gain of this application meet the design requirements, achieving a wide bandwidth and high gain effect, and are suitable for the communication technology needs of the Internet of Things in the 915 MHz and 433 MHz communication bands.

[0062] like Figure 8 As shown, the antenna system of this application is applied, with a 915MHz microstrip antenna array used as a wireless power transmission and receiving antenna. The received wireless energy is rectified by a rectifier circuit and output to the ASK transmitter 8 and the energy management module 9 respectively. The ASK transmitter 8, after receiving the rectified voltage output, can adjust its transmission based on stored information to achieve feedback response after energy collection, and radiates through a 433MHz monopole antenna for verification at the wireless energy transmission end. The energy management module 9 processes the input DC voltage signal, and after passing through the voltage regulator module 10, supplies power to the receiving device 11 in one of the following modes: constant voltage, constant current, or constant power. Therefore, the dual-frequency dual-polarized antenna system with self-feedback characteristics proposed in this application can effectively achieve wireless energy collection and simultaneously provide feedback confirmation, making it suitable for wireless power transmission scenarios with high reliability, and effectively improving the reliability and security of the system.

Claims

1. A wireless power transmission dual-frequency antenna system with self-feedback, characterized in that: It includes an aluminum sheet layer (1), a dielectric substrate (3), and an upper surface metal layer (2) and a lower surface metal layer (4) located on the upper and lower surfaces of the dielectric substrate (3). The aluminum sheet layer (1) is composed of four parasitic patch units (1-1) operating in the 915 MHz frequency band; The upper surface metal layer (2) includes four main radiating patch units (2-1) operating in the 915 MHz band, a corresponding one-to-four microstrip power divider, and a bent-line monopole antenna (5) operating in the 433 MHz band. The lower surface metal layer (4) is a metal ground plane; The parasitic patch units (1-1) are respectively suspended above the main radiating patch unit (2-1) by metal studs (6), and the lower surface metal layer (4) is provided with isolation holes (4-1) for the metal studs (6) to pass through. The back of the dielectric substrate (3) is provided with a coaxial connector (7) that is connected to the center feed point of the one-to-four microstrip power divider.

2. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 1, characterized in that: The parasitic patch units (1-1) are arranged in two rows and two columns evenly.

3. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 1, characterized in that: Both the parasitic patch unit (1-1) and the main radiating patch unit (2-1) are I-shaped structures with rectangular grooves of the same size formed on both sides.

4. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 1, characterized in that: The length of the main radiating patch unit (2-1) and the parasitic patch unit (1-1) along the excitation direction is half a working wavelength, which is the wavelength corresponding to 915 MHz.

5. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 2, characterized in that: The one-to-four microstrip power divider includes an input port (7-1), which is divided into two branches. Each branch is connected to the second-stage T-shaped microstrip power divider by a first quarter-wavelength impedance transformation line (7-2), and outputs two branches again. Each branch is then connected to a main radiating patch unit (2-1) through the second-stage quarter-wavelength impedance transformation line (7-3) to feed power to it.

6. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 1, characterized in that: The inner conductor of the coaxial connector (7) passes through the lower surface metal layer (4) and the dielectric substrate (3) from bottom to top through the slot, and is connected to the center feed point of the one-to-four microstrip power divider in the upper surface metal layer (2). The lower surface metal layer (4) has an inner conductor isolation hole.

7. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 1, characterized in that: The bent-line monopole antenna (5) is located at one corner of the dielectric substrate (3) and includes a bent monopole unit (5-1), a coplanar waveguide (5-2), and an L-shaped impedance matching network (5-3). The coplanar waveguide (5-2) and the bent monopole unit (5-1) achieve impedance matching through an L-shaped impedance matching network (5-3); The lower surface metal layer (4) forms a notch in the portion corresponding to the bent monopole unit (5-1); The coplanar waveguide (5-2) includes a common metallic ground, a parallel inductor, and a series capacitor; The width W of the bent monopole unit (5-1) is 0.0008λ0. ’ ≤W≤0.002λ0 ’ The total arm length L is L≥0.25λ0 ’ ,λ0 ’ This is the wavelength corresponding to 433 MHz.

8. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 1, characterized in that: The dielectric substrate (3) has a dielectric constant of 2-3 and a thickness of 0.002λ0≤h≤0.006λ0, where λ0 is the wavelength corresponding to 915 MHz; The suspension gap gap between the parasitic patch unit (1-1) and the main radiating patch unit (2-1) is 0.04λ0≤gap≤0.06λ0; The spacing p between the parasitic patch unit (1-1) and the main radiating patch unit (2-1) is 0.5λ0≤p≤0.7λ0.

9. The wireless power transmission dual-frequency antenna system with self-feedback according to claim 1, characterized in that: The microstrip patch antenna operating at 915MHz and the monopole antenna operating at 433MHz adopt orthogonal polarization.

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