A microwave prevention device for deep soil-borne diseases, pests and weeds

Abstract

The application discloses a microwave prevention and treatment device for deep soil-borne diseases and pests, and belongs to the field of agricultural machinery and physical sterilization technology. The device comprises a rectangular waveguide, a horn antenna cavity, a dielectric lens, a partition plate and double-sided metal plates. The rectangular waveguide feeds microwaves into the horn antenna cavity; the hemispherical dielectric lens is embedded in the cavity and converts divergent spherical waves into quasi-plane waves to realize energy focusing; the partition plate is arranged at the bottom opening of the antenna and is composed of a metal grid array, which is used for optimizing the near-field electric field distribution, preventing local overheating of the surface soil and making the temperature uniformly transmit; and the double-sided metal plates extend downward from the bottom of both sides of the partition plate and construct parallel plate waveguide boundaries underground, so that the microwave energy is forced to propagate longitudinally in the soil and is inhibited from leaking laterally. The application effectively solves the pain points of the traditional microwave radiation device, such as poor penetration and easy energy divergence, realizes efficient and uniform microwave physical killing of deep soil diseases and pests, and improves the prevention and treatment effect of soil-borne diseases and pests.

Description

Technical Field

[0001] This invention belongs to the field of agricultural machinery and physical disinfection technology, and relates to an agricultural soil-borne disease, pest and weed control device, specifically a microwave control device for deep soil-borne diseases, pests and weeds. Background Technology

[0002] With increasing demands for food safety and environmental protection, organic agriculture and facility agriculture have become widely popular and developed. However, due to extensive replanting and high-intensity planting in agricultural production, continuous cropping obstacles in the soil are becoming increasingly prominent. Soil-borne pests and diseases, as well as persistent weeds, have become important factors leading to soil ecological imbalance, declining arable land quality, deteriorating crop quality, and reduced crop yields. Soil-borne pests and diseases are characterized by their diversity, wide range of impact, rapid spread, strong concealment, and high explosive potential, making it difficult for existing agricultural technologies to accurately monitor, warn of, and precisely control them.

[0003] Currently, traditional manual methods for controlling soil-borne pests, diseases, and weeds are not only inefficient and extremely labor-intensive, but also significantly increase agricultural production costs. Chemical methods lead to substantial pollution, reducing the quality of agricultural products, damaging the soil, and even causing pests and diseases to develop resistance, rendering the soil unusable. Biological methods are inefficient, and biological fumigation is both time-consuming and labor-intensive, failing to meet the demands of seasonal and high-frequency agricultural planting. In contrast, physical methods for controlling soil-borne pests, diseases, and weeds are environmentally friendly and fundamentally eliminate pesticide residues on crops.

[0004] Against this backdrop, the search for an efficient and environmentally friendly physical soil disinfection technology has become an urgent need for modern green agriculture. Microwave heating, as a mature physical control method, can penetrate the soil surface and directly kill pathogens, pests, and weed seeds in the soil using thermal effects. However, in practical microwave soil disinfection equipment, how to efficiently, directionally, and uniformly radiate microwave energy to a specific depth in the soil is a key challenge in the development of this technology. The antenna, as the core component of microwave energy radiation, directly determines the disinfection and sterilization effect. Traditional microwave radiation devices often suffer from problems such as energy dispersion and insufficient penetration depth. Therefore, it is necessary to develop a microwave control device specifically for deep soil-borne diseases, pests, and weeds to improve the utilization rate of microwave energy and the control effect of soil-borne diseases, pests, and weeds. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a microwave control device for deep soil-borne diseases, pests, and weeds. Compared with traditional horn antennas, this antenna significantly optimizes the radiation characteristics of microwave energy, effectively increasing the overall heating temperature of the soil and penetrating microwave energy deep into the soil layer. Simultaneously, this design greatly improves the uniformity of the electromagnetic heat field distribution, effectively eliminating heating dead zones, thereby achieving comprehensive control of soil-borne diseases, pests, and weeds and significantly enhancing the overall effectiveness of physical disinfection and sterilization.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A microwave control device for deep soil-borne diseases, pests, and weeds mainly includes a rectangular waveguide, a horn antenna cavity, a dielectric lens, and a partition.

[0008] The rectangular waveguide is installed at the output end of the microwave generator unit and placed on top of the horn antenna cavity to transmit the microwaves generated by the magnetron of the microwave generator unit to the horn antenna cavity.

[0009] The horn antenna cavity has an opening at the bottom for radiating microwaves into the soil below the entire device.

[0010] The partition plate is installed laterally at the bottom opening of the horn antenna cavity, serving as a physical isolation and impedance transition layer between the antenna and the outside world;

[0011] The dielectric lens is embedded inside the horn antenna cavity and positioned on the partition plate, and is used for biphase compensation and energy focusing of the emitted microwaves.

[0012] In a preferred embodiment of the present invention, the top of the rectangular waveguide is used to connect to an external microwave source, and the horn antenna cavity is a pyramidal shape that gradually expands from top to bottom. Together, they constitute the basic channel for microwave transmission and radiation.

[0013] In a preferred embodiment of the present invention, the microwave propagation mode of the rectangular waveguide fed into the horn antenna cavity is the dominant mode TE. 10 The dielectric lens is a hemispherical structure made of low-loss transparent material, with its convex surface facing inwards towards the horn antenna and its flat bottom. It is supported by the grid on the partition plate at the transmitter port of the horn antenna cavity, and is used to transmit the TE signal. 10 The spherical waves radiated by the mode are converted into quasi-plane waves, reducing microwave dissipation and improving radiation directionality and efficiency.

[0014] In a preferred embodiment of the present invention, the partition is a periodic metal grid array composed of metal strips, with the spacing between each grid being less than one-quarter of the microwave wavelength. It serves as an impedance matching transition layer for microwaves entering high-dielectric soil from the air, optimizes the electric field distribution in the near field, and prevents local overheating of the surface soil, which could lead to thermal runaway and render the soil unusable.

[0015] In a preferred embodiment of the present invention, each grid of the partition has a groove and the bottom of the dielectric lens has a corresponding groove, which facilitates the connection and installation of the two.

[0016] In a preferred embodiment of the present invention, the partition has drag-reducing components on both sides, which are triangular pyramidal biomimetic sawtooth arrays. These components first disrupt the continuity of the soil by means of high stress concentration, thereby significantly reducing the physical resistance when the device is pushed deep into the soil.

[0017] In a further preferred embodiment of the invention, a double-sided metal plate is also included, connected to both sides below the bottom opening of the horn antenna cavity, and extending downward perpendicularly to the partition in the depth direction, for constructing a metallic physical boundary for microwave transmission deep in the soil.

[0018] In a preferred embodiment of the present invention, the two-sided metal plates are a pair of parallel rigid metal plates. The two plates and the soil between them together form a parallel plate waveguide structure, which forcibly suppresses the lateral attenuation and leakage of microwaves to the non-operation area. Furthermore, the bottom soil-facing surface and the periphery of each of the two-sided metal plates are streamlined or chamfered to reduce the frictional resistance when cutting into the soil.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. In this invention, a horn antenna is used as the main body of the radiation device. Its structure is simple, easy to operate and low in cost, making it convenient to promote in practical applications.

[0021] 2. This invention uses a dielectric lens to focus microwave energy. The dielectric material, polytetrafluoroethylene (PTFE), is a low-loss, microwave-transparent material. It is shaped into a spherical plano-convex lens structure and embedded within the antenna cavity, with the convex surface facing inwards. This is used for spatial phase compensation of electromagnetic waves input from the rectangular waveguide. Through this design, the divergent spherical wavefront radiating from the horn aperture is modulated into a downward-focused beam or quasi-plane wave of equal phase. This enhances the beam's depth-focusing capability at the source morphology level, altering the radiation path of the energy radiated from the upper antenna, thereby reducing divergent energy and improving heating efficiency.

[0022] 3. In this invention, multiple grids are used at the horn antenna opening to disperse the microwave energy and temperature generated by the lens focusing. The grid layer is a periodic grid array composed of metal strips, and the interval between each grid is less than one-quarter of the wavelength, so that the energy and temperature can be evenly distributed in the soil, effectively eliminating the local overheating phenomenon of the surface soil.

[0023] 4. In this invention, parallel double-sided metal plates are connected to the lower part of the partition. The property of microwave energy reflecting between metals is used to limit its diffusion, thereby extending the depth and uniformity of soil heating. These plates are made of high-strength metal material and extend parallel to the grid layer to a certain depth. After the device is inserted into the soil, the two metal side plates construct a constrained channel of parallel metal plate waveguide in the underground soil layer. This channel provides a rigid electromagnetic boundary condition, physically cutting off the lateral dissipation path of microwaves in shallow soil, forcing electromagnetic energy to be directionally transmitted and radiated only along the channel between the two side plates into the depth of the soil.

[0024] 5. The drag-reducing component on the partition plate in this invention draws inspiration from the non-smooth body surface or digging forelegs of soil-dwelling animals, and is designed as a triangular pyramidal biomimetic sawtooth array structure. This toothed array is rigidly connected to the bottom of the leading edge of the antenna cavity in the forward direction, and makes contact with the soil first when the agricultural machinery is traction-driven, transforming the originally large-area planar pushing force into multi-point high-stress concentrated cutting. By disrupting the continuity of the soil, it causes the soil to undergo brittle fracture and breakage, thereby significantly reducing the soil pressure when the device is deeply embedded in the soil and the resistance when the agricultural machinery is traction-driven. Attached Figure Description

[0025] Figure 1 This is a front view of the overall structure of the device according to an embodiment of the present invention.

[0026] Figure 2 This is a side view of the overall structure of the device according to an embodiment of the present invention.

[0027] Figure 3 This is a three-dimensional perspective view of the overall structure of the device according to an embodiment of the present invention.

[0028] Figure 4 This is a perspective front view of the overall structure of the device according to an embodiment of the present invention.

[0029] Figure 5 This is a perspective side view of the overall structure of the device according to an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of the assembly relationship between the rectangular waveguide, the horn antenna cavity, and the dielectric lens in an embodiment of the present invention.

[0031] Figure 7 This is a perspective view of the partition in an embodiment of the present invention.

[0032] Figure 8 This is a perspective front view of the partition in an embodiment of the present invention.

[0033] Figure 9 This is a perspective side view of the partition in an embodiment of the present invention.

[0034] Figure 10 This is a simulated temperature cross-section diagram of different soil depths according to an embodiment of the present invention.

[0035] Figure 11 This is a line graph showing the simulation results of soil core temperature changing with soil depth in an embodiment of the present invention.

[0036] The meanings of the reference numerals in the figure are as follows:

[0037] 1. Rectangular waveguide; 2. Horn antenna cavity; 3. Dielectric lens; 4. Spacing plate; 41. Grid; 42. Triangular pyramidal biomimetic sawtooth array; 5. Double-sided metal plate. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0039] like Figure 1-9 As shown in the figure, this embodiment proposes a microwave control device for deep soil-borne diseases, pests and weeds, which mainly includes a rectangular waveguide 1, a horn antenna cavity 2, a dielectric lens 3, a partition 4, and double-sided metal plates 5.

[0040] The partition 4 connects the horn antenna cavity 2 and the two side metal plates 5 using screws. The partition 4 contains a grid array 41. Each grid has a raised groove, while the dielectric lens has a recessed groove, facilitating connection and installation. The grid array and the two side metal plates are located at the opening of the horn antenna cavity; the installed grid array supports the dielectric lens inside the horn antenna.

[0041] A rectangular waveguide transmits microwave energy to a horn antenna, and the amount of energy supplied to the horn antenna can be adjusted by changing the power of the microwave generator. The microwave generator used in this invention supports adjustable power; a power setting of 700W was used to test the microwave sterilization device.

[0042] When microwaves are radiated from the antenna, they are first absorbed by the dielectric lens, changing their outward radiation direction and converging at the strongest point in the center of the antenna. This concentrated energy is very high; if directly radiated onto the soil surface, it would cause central thermal runaway. However, after passing through a partition with multiple grid arrays, the microwaves are more evenly distributed across the radiated area of ​​the soil. When the microwaves reach the soil, they immediately attenuate and diffuse outwards. The parallel double-sided plates installed on both sides mitigate this diffusion, causing the microwaves to refract and refocus towards the center of the soil, thus extending the heating depth. However, insertion into the soil inevitably creates damping; therefore, each side plate is rounded to reduce the damping caused by manually or mechanically pressing the microwave radiating device into the soil.

[0043] When starting field operations, press this device into the soil layer to be treated. Stop inserting it when the triangular pyramidal biomimetic sawtooth array at the leading edge of the antenna's base first contacts the compacted soil. Because the distance between the partitions and the soil affects the uniformity and depth of heating, the distance between the side plates inserted into the soil can be adjusted to improve the heating effect. When connected to agricultural machinery for mobile operations, these high-hardness sawtooth tips utilize a very small contact area to generate enormous local stress, pre-cutting and breaking up the soil clods in front. This mechanical design greatly mitigates the enormous resistance caused by blindly pushing the soil.

[0044] The microwave source is activated before the tractor moves forward at a constant speed. The microwaves travel along a rectangular waveguide at the top to the internal cavity, then pass through an embedded hemispherical lens made of polytetrafluoroethylene (PTFE). The lens compensates for the spatial phase delay of the diverging microwaves, transforming the outward-spreading beam into a quasi-plane wave. The beam then penetrates downwards through a metal grid partition. The grid layer in the partition plays a crucial role in impedance matching, effectively preventing the surface soil from overheating and carbonizing due to energy accumulation.

[0045] Microwave energy, smoothly transmitted into the soil, is significantly mitigated from lateral dissipation into non-operational areas due to the rigid physical shielding formed by the metal side plates beneath the soil, similar to parallel waveguides. High-density electromagnetic energy is forcibly confined within the channel between the two plates and deeply heats the soil along its length. As the agricultural machinery moves, the device continuously radiates a deep, uniform high-temperature disinfection zone with temperatures exceeding 60°C underground. Nematode eggs, pathogenic fungi, and weed seeds within the soil are completely inactivated by the intense dielectric loss generated by the high temperatures, effectively and efficiently completing physical plant protection operations from breaking through the soil to penetrating deep into the soil for control.

Claims

1. A microwave control device for deep soil-borne diseases, pests, and weeds, characterized in that, It mainly includes a rectangular waveguide (1), a horn antenna cavity (2), a dielectric lens (3), and a partition (4), among which, The rectangular waveguide (1) is installed at the output end of the microwave generating unit and placed on top of the horn antenna cavity (2) to transmit the microwave generated by the magnetron of the microwave generating unit to the horn antenna cavity (2). The horn antenna cavity (2) has an opening at the bottom for radiating microwaves into the soil below the entire device. The partition (4) is installed laterally at the bottom opening of the horn antenna cavity (2) as a physical isolation and impedance transition layer between the antenna and the outside world; The dielectric lens (3) is embedded inside the horn antenna cavity (2) and is disposed on the partition plate (4) for dual-phase compensation and energy focusing of the diverging microwaves.

2. The microwave control device for deep soil-borne diseases, pests, and weeds as described in claim 1, characterized in that, The top of the rectangular waveguide (1) is used to connect to an external microwave source, and the horn antenna cavity (2) is a pyramidal shape that gradually expands from top to bottom. Together, they form the basic channel for microwave transmission and radiation.

3. The microwave control device for deep soil-borne diseases, pests, and weeds as described in claim 1, characterized in that, The microwave propagation mode fed into the horn antenna cavity (2) by the rectangular waveguide (1) is the dominant mode TE. 10 The dielectric lens (3) is a hemispherical structure made of low-loss transparent material, with its convex surface facing the inside of the horn antenna and its flat bottom. It is supported by a partition at the emission port of the horn antenna cavity (2) and is used to transmit the TE signal. 10 The spherical waves radiated by the mode are converted into quasi-plane waves, reducing microwave dissipation and improving radiation directionality and efficiency.

4. The microwave control device for deep soil-borne diseases, pests, and weeds as described in claim 1, characterized in that, The partition (4) is a periodic metal grid (41) array composed of metal strips. The interval between each grid is less than one-quarter of the microwave wavelength. It serves as an impedance matching transition layer for microwaves to enter the high dielectric soil from the air, optimizes the electric field distribution in the near field, and prevents local overheating of the surface soil, which could lead to thermal runaway and make the soil unusable.

5. The microwave control device for deep soil-borne diseases, pests, and weeds as described in claim 4, characterized in that, Each grid (41) of the partition (4) has a groove, and the corresponding position of the bottom of the medium lens (3) has a groove, which facilitates the connection and installation of the two.

6. The microwave control device for deep soil-borne diseases, pests, and weeds as described in claim 1, characterized in that, The partition (4) has drag-reducing components on both sides, which are triangular pyramidal bionic sawtooth arrays (42), which first disrupt the continuity of the soil by high stress concentration, thereby greatly reducing the physical resistance when the device is pushed into the soil layer.

7. The microwave control device for deep soil-borne diseases, pests, and weeds as described in claim 1, characterized in that, It also includes two metal plates (5) connected to both sides below the bottom opening of the horn antenna cavity (2) and extending downward perpendicularly to the partition (4) in the longitudinal direction, for constructing a metal physical boundary for microwave transmission deep in the soil.

8. The microwave control device for deep soil-borne diseases, pests, and weeds as described in claim 7, characterized in that, The double-sided metal plates (5) are a pair of parallel rigid metal plates. The two plates and the soil between them together form a parallel plate waveguide structure, which forcibly suppresses the lateral attenuation and leakage of microwaves to the non-operation area. The bottom soil-facing surface and the periphery of each double-sided metal plate (5) are streamlined or chamfered to reduce the frictional resistance when cutting into the soil.

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