Wireless energy transmission dual-frequency antenna system with self-feedback

Abstract

The invention discloses a wireless energy transmission dual-frequency antenna system with a self-feedback function. The wireless energy transmission dual-frequency antenna system 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 parasitic patch units working in a 915 MHz frequency band; the upper surface metal layer comprises a main radiation patch unit working in a 915 MHz frequency band, a one-to-four microstrip power divider for corresponding feeding, and a bent line monopole antenna working in a 433 MHz frequency band; the lower surface metal layer is a metal grounding 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 a coaxial connector connected with a central feeding point of the one-to-four microstrip power divider is arranged on the back surface of the dielectric substrate. 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 structural parameters and a feed network.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a wireless energy transmission dual-frequency antenna system with self-feedback. Background Art

[0002] The 915 MHz band, one of the most widely used ISM bands globally, plays a key role in the Internet of Things (IoT), microwave medical treatment, RFID systems, drone communications, and smart agriculture sensor networks thanks to its excellent propagation characteristics and strong penetration capabilities. In particular, in large-scale sensor networks and long-distance, low-power communication scenarios, 915 MHz array antennas can achieve directional coverage through beamforming technology, precisely focusing signal energy, effectively reducing transmission loss and suppressing multipath interference, significantly improving the stability of communication systems.

[0003] However, with the rapid evolution of wireless communication technologies and the increasing complexity of application scenarios, the design of 915 MHz array antennas still faces many challenges, including: Bandwidth and gain limitations: Traditional microstrip array antennas have a narrow operating bandwidth, making them difficult to meet broadband communication requirements. Insufficient gain also affects long-distance transmission performance. The coplanar integration of the feed network and antenna elements complicates array deployment, while parasitic coupling between the feed line and radiating elements can easily lead to pattern distortion and reduced efficiency. The 433 MHz band has irreplaceable advantages in IoT fields such as remote control due to its excellent diffraction capability and environmental adaptability (such as penetrating complex scenes such as buildings and vegetation). However, its 1 / 4 wavelength antenna size (about 17 cm) limits its application in miniaturized devices. Summary of the Invention

[0004] Purpose of the Invention: The present invention provides a dual-band wireless energy transmission antenna system with self-feedback, which efficiently integrates a 915 MHz array antenna and a 433 MHz monopole antenna on the same dielectric substrate. By optimizing structural parameters and feed networks, the system reduces manufacturing costs while ensuring performance.

[0005] Technical solution: The present invention provides a dual-band wireless energy transmission antenna system with self-feedback, comprising an aluminum sheet layer, a dielectric substrate, and upper and lower metal layers located on the upper and lower surfaces of the dielectric substrate; The aluminum sheet layer is composed of four parasitic patch units operating in the 915 MHz frequency band; The upper surface metal layer includes four main radiating patch units operating in the 915 MHz frequency band, a one-to-four-way microstrip power divider for corresponding feeds, and a meander line monopole antenna operating in the 433 MHz frequency band; The lower surface metal layer is a metal ground plate; The parasitic patch units are suspended one by one above the main radiation patch units through metal studs, and the lower surface metal layer is provided with isolation holes corresponding to the metal studs for them to pass through; A coaxial connector connected to the central feeding point of the one-to-four-way microstrip power divider is provided on the back of the dielectric substrate.

[0006] This system consists of two parts: a 915MHz microstrip antenna array and a 433MHz monopole antenna. The microstrip antenna array serves as a wireless energy receiving antenna to receive wireless energy for storage and powering other devices. The monopole antenna serves as a radiating device that detects and collects wireless energy and modulates and outputs relevant verification signals for use by the wireless energy transmitter for verification.

[0007] Furthermore, the parasitic patch units are evenly arranged in two rows and two columns.

[0008] Furthermore, the parasitic patch unit and the main radiation patch unit are both I-shaped structures, with rectangular grooves of the same size formed on both sides.

[0009] Furthermore, the main radiation patch unit and the parasitic patch unit have a length along the excitation direction of half the working wavelength.

[0010] Furthermore, the one-to-four-way microstrip power splitter includes an input port, which is divided into two branches, each of which is connected to the second-stage T-shaped microstrip power splitter by a first quarter-wavelength impedance transformation line, and outputs two branches again, and each branch is then connected to a main radiation patch unit through a second-stage quarter-wavelength impedance transformation line to feed it.

[0011] Furthermore, the inner conductor of the coaxial connector passes through the lower surface metal layer and the dielectric substrate from bottom to top through the slot, and is connected to the central feeding point of the one-to-four-way microstrip power divider in the upper surface metal layer. The lower surface metal layer has an inner conductor isolation hole.

[0012] Furthermore, the meander line monopole antenna is located at a corner of a dielectric substrate and includes a meander monopole unit, a coplanar waveguide, and an L-shaped impedance matching network; The coplanar waveguide and the bent monopole unit achieve impedance matching through an L-shaped impedance matching network; A notch is formed in the lower surface metal layer corresponding to the portion of the bent monopole unit; The coplanar waveguide includes a common metal ground, a parallel inductor and a series capacitor; The length of the meander line monopole antenna is 1 / 4 of the working wavelength.

[0013] Furthermore, 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 915 MHz; The suspension gap between the parasitic patch unit and the main radiation patch unit is set to 0.04λ0≤gap≤0.06λ0; The unit arrangement spacing p between the parasitic patch unit and the main radiation patch unit is 0.5λ0≤p≤0.7λ0.

[0014] Furthermore, the width W of the bent monopole unit is 0.0008λ0 ’ ≤W≤0.002λ0 ’ , the total arm length L is L ≥ 0.25λ0 ’ ,λ0 ’ The wavelength corresponds to 433 MHz.

[0015] Furthermore, the microstrip patch antenna operating at 915 MHz and the monopole antenna operating at 433 MHz adopt orthogonal polarization.

[0016] Beneficial effects: Compared with the existing technology, the present invention has significant improvements: it can effectively realize wireless energy collection and provide backhaul confirmation at the same time, is suitable for wireless energy transmission scenarios with high reliability, and can effectively improve the reliability and safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the stacked structure of the antenna system of the present invention; Figure 2 This is a schematic diagram of the aluminum sheet structure of the present invention; Figure 3 Schematic diagram of the upper surface metal layer structure of the present invention; Figure 4 Schematic diagram of the metal layer structure on the lower surface of the present invention; Figure 5 is the reflection coefficient simulation result of the antenna system of the present invention; Figure 6 is the gain simulation result of the antenna system of the present invention at 915 MHz; Figure 7 This is the simulation result of the directional pattern of the antenna system of the present invention at 433 MHz; Figure 8 This is an effect diagram of an application example of the antenna system of the present invention. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] like Figure 1-4As shown, the wireless energy transmission dual-band 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.

[0020] The aluminum sheet layer 1 is composed of four parasitic patch units 1-1 operating in the 915 MHz frequency band. The parasitic patch unit 1-1 is in an I-shape and is formed by cutting out rectangular grooves of the same size on the left and right sides of the parasitic patch unit.

[0021] The upper surface metal layer 2 includes four main radiation patch units 2-1 operating in the 915 MHz frequency band, a corresponding one-to-four-way microstrip power divider for feeding, and a meander line monopole antenna 5 operating in the 433 MHz frequency band.

[0022] The main radiation patch unit 2 - 1 is also in an I-shape, and is formed by cutting out rectangular grooves of the same size on the left and right sides of the main radiation patch unit.

[0023] The lower surface metal layer 4 is a metal ground plate.

[0024] The parasitic patch units 1-1 are suspended one by one above the main radiation patch unit 2-1 through the metal studs 6, and the lower surface metal layer 4 has isolation holes 4-1 corresponding to the metal studs 6 for each metal stud 6 to pass through.

[0025] A coaxial connector 7 connected to the central feeding point of the one-to-four-way microstrip power divider is provided on the back of the dielectric substrate 3 .

[0026] Parasitic patch element 1-1 and main radiating patch element 2-1 together form a 915MHz microstrip antenna array, while meanderline monopole antenna 5 forms a 433MHz monopole antenna. Their polarizations are orthogonal, effectively suppressing mutual interference. The microstrip antenna array serves as a wireless energy receiving antenna, receiving wireless energy for storage and powering other devices. The monopole antenna acts as a radiating device, detecting and collecting wireless energy, then modulating and outputting a verification signal for verification purposes at the wireless energy transmitting end.

[0027] The parasitic patch unit 1 - 1 and the main radiation patch unit 2 - 1 are evenly arranged in two rows and two columns.

[0028] The length of the main radiation patch unit 2-1 and the parasitic patch unit 1-1 along the excitation direction is half the working wavelength.

[0029] The one-to-four-way microstrip power splitter includes an input port 7-1, which serves as its central feed point. Input port 7-1 splits into two upper and lower branches. Each branch is connected to the second-stage T-shaped microstrip power splitter via a first quarter-wavelength impedance transformation line 7-2, which then outputs two left and right branches. Each branch is then connected to a main radiating patch unit 2-1 via a second quarter-wavelength impedance transformation line 7-3, feeding it.

[0030] 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 central feeding point of the one-to-four-way microstrip power divider in the upper surface metal layer 2. The lower surface metal layer 4 has an inner conductor isolation hole.

[0031] In this embodiment, the meander line monopole antenna 5 is located at the lower left corner of the dielectric substrate 3 and includes a meander monopole unit 5 - 1 , a coplanar waveguide 5 - 2 and an L-shaped impedance matching network 5 - 3 .

[0032] The coplanar waveguide 5-2 and the bent monopole unit 5-1 achieve impedance matching through an L-shaped impedance matching network 5-3.

[0033] A notch is formed in the lower surface metal layer 4 corresponding to the portion of the bent monopole unit 5 - 1 for its placement.

[0034] The coplanar waveguide 5-2 includes a common metal ground, a parallel inductor and a series capacitor; The length of the meander line monopole antenna 5 is 1 / 4 of the operating wavelength.

[0035] In the antenna system designed in this application, the dielectric constant of the dielectric substrate 3 is 2-3, the thickness is 0.002λ0≤h≤0.006λ0, and λ0 is the wavelength corresponding to 915 MHz; the suspension 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.

[0036] The unit arrangement pitch p between the parasitic patch unit 1 - 1 and the main radiation patch unit 2 - 1 is 0.5λ0≤p≤0.7λ0.

[0037] 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 ’The wavelength corresponds to 433 MHz, the characteristic impedance of the coplanar waveguide transmission line is 50 ohms, and the L-shaped impedance matching network should first connect the inductor L in parallel and then connect the capacitor C in series. The inductor L is 20 nH and the capacitor C is 2 pF.

[0038] like Figure 5 and 6 As shown in Figure 1, the impedance bandwidth with a port reflection coefficient less than -10 dB can cover 885-937 MHz and 431-434 MHz, a gain of 12 dBi can be achieved at 915 MHz, and the 3dB beamwidth covers ±23°.

[0039] like Figure 7 As shown in Figure 2, the impedance bandwidth with a port reflection coefficient less than -10 dB can cover 431-434 MHz, and a gain of -3.3 dBi can be achieved at 433 MHz.

[0040] This shows that the bandwidth and gain of the antenna in this application meet the design requirements, achieving the effect of wide bandwidth and high gain, and is suitable for the Internet of Things communication technology needs in the 915 MHz and 433 MHz communication frequency bands.

[0041] like Figure 8 As shown, the antenna system of the present application is applied, and the 915MHz microstrip antenna array is used as a wireless energy transmission and receiving antenna. The received wireless energy is rectified by the rectifier circuit and output to the ASK transmitter 8 and the energy management module 9 respectively. Among them, after obtaining the rectified voltage output, the ASK transmitter 8 can adjust the transmission according to the stored information to realize the feedback response after energy collection, and radiate through the 433MHz monopole antenna for verification of the wireless energy transmitter. The energy management module 9 processes the input DC voltage signal, and after passing through the voltage stabilization module 10, it supplies energy to the energy receiving device 11 in one of the constant voltage / constant current / constant power modes. Therefore, the dual-frequency dual-polarization antenna system with self-feedback characteristics proposed in the present application can effectively realize wireless energy collection and provide backhaul confirmation at the same time. It is suitable for wireless energy transmission scenarios with high reliability and can effectively improve the reliability and safety of the system.

Claims

1. A dual-band wireless power transmission antenna system with self-feedback, characterized by: It comprises 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 radiation patch units (2-1) operating in the 915 MHz frequency band, a corresponding one-to-four-way microstrip power divider for feeding, and a meander line monopole antenna (5) operating in the 433 MHz frequency band; The lower surface metal layer (4) is a metal grounding plate; The parasitic patch units (1-1) are suspended one-to-one and arranged directly above the main radiation patch units (2-1) 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 the metal studs (6) to pass through. A coaxial connector (7) connected to the central feeding point of the one-to-four-way microstrip power divider is provided on the back side of the dielectric substrate (3).

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

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

4. The dual-band wireless power transmission antenna system with self-feedback according to claim 1, wherein: The length of the main radiation patch unit (2-1) and the parasitic patch unit (1-1) along the excitation direction is half the working wavelength.

5. The dual-band wireless power transmission antenna system with self-feedback according to claim 2, wherein: The one-to-four-way microstrip power splitter comprises an input port (7-1), wherein the input port (7-1) is divided into two branches, each branch is connected to a second-stage T-shaped microstrip power splitter via a first quarter-wavelength impedance transformation line (7-2), and outputs two branches again, each branch is then connected to a main radiation patch unit (2-1) via a second-stage quarter-wavelength impedance transformation line (7-3), and is fed thereto.

6. The dual-band wireless power transmission antenna system with self-feedback according to claim 1, wherein: 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 central feeding point of the one-to-four-way microstrip power divider in the upper surface metal layer (2). The lower surface metal layer (4) is provided with an inner conductor isolation hole.

7. The dual-band wireless power transmission antenna system with self-feedback according to claim 1, wherein: The meander line monopole antenna (5) is located at a corner of the dielectric substrate (3), and comprises a meander 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); A notch is formed in the lower surface metal layer (4) corresponding to the portion of the bent monopole unit (5-1); The coplanar waveguide (5-2) includes a common metal ground, a parallel inductor and a series capacitor; The length of the meander line monopole antenna (5) is 1 / 4 of the operating wavelength.

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

9. The dual-band wireless power transmission antenna system with self-feedback according to claim 7, wherein: 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 ’ The wavelength corresponds to 433 MHz.

10. The dual-band wireless power transmission antenna system with self-feedback according to claim 1, wherein: The microstrip patch antenna operating at 915 MHz and the monopole antenna operating at 433 MHz adopt orthogonal polarization.

Images