Microstrip antenna based on reflection cavity structure

Abstract

The invention relates to a microstrip antenna based on a reflection cavity structure, which comprises a reflection cavity and a microstrip patch antenna assembly, and is characterized in that the microstrip patch antenna assembly comprises a rectangular dielectric substrate, a coaxial line feeding point, a microstrip patch antenna and an antenna back bottom plate, the microstrip patch antenna is printed on the rectangular dielectric substrate, and the microstrip patch antenna is printed on the coaxial line feeding point; the coaxial line feeding point is located on the central axis of the rectangular dielectric substrate, the antenna back bottom plate is connected with the back face of the rectangular dielectric substrate, and a coaxial socket of the coaxial line feeding point is installed on the antenna back bottom plate and located on the back face of the microstrip patch antenna assembly; the reflection cavity is a quadrangular frustum pyramid defined by four isosceles trapezoid reflection walls, the reflection walls are single-layer dielectric plates or metal plates with the inner walls covered with metal materials, and the isosceles trapezoid upper bottoms of the reflection walls are connected with the edge of the rectangular dielectric substrate. Compared with the prior art, the antenna has the advantages of simple structure, low manufacturing cost, good gain effect and the like.

Description

Technical Field

[0001] The invention relates to the field of development and design of microstrip antennas, and in particular to a microstrip antenna based on a reflection cavity structure. Background Art

[0002] Microstrip antenna is a planar antenna consisting of a conductive patch and a substrate medium. The conductive patch is usually a metal sheet laid on an insulating substrate, and the substrate is made of a material with a low dielectric constant, such as glass fiber, ceramic or polymer. Its working principle is based on the electromagnetic coupling effect between the conductive patch and the substrate, and the electromagnetic field generated by the current in the conductive patch is used to achieve the transmission or reception function.

[0003] Microstrip antennas have the characteristics of simple structure, low cost and easy manufacturing. Due to their planar design, they can be easily integrated into circuit boards or other planar structures, saving space and simplifying system design. In addition, microstrip antennas can be designed into various shapes and sizes according to specific needs to meet different frequency and performance requirements.

[0004] Although microstrip antennas have many advantages, they also have some limitations. First, due to the surface patch structure of microstrip antennas, their radiation efficiency is usually low, especially at low frequencies, which may limit their use in certain application scenarios, such as in long-distance communications, radar systems, or high-power transmission applications that require high radiation efficiency and gain.

[0005] The reflector cavity antenna is a design that uses a reflective wall to enhance the antenna performance. Its working principle is to use a flat or curved metal plate as a reflective wall to reflect the signal emitted by the antenna, thereby enhancing the radiation directivity and gain of the signal. In the design, factors such as the position, shape, size, distance and angle between the reflective wall and the antenna need to be considered to achieve the desired radiation characteristics.

[0006] The advantages of the reflector cavity antenna are that it enhances the radiation efficiency, increases the signal transmission distance and coverage range; the radiation directivity of the antenna can be adjusted, which is suitable for scenarios that require specific directional coverage; at the same time, it reduces stray radiation and improves the signal purity and anti-interference ability.

[0007] However, the design of the reflector cavity antenna is relatively complex and needs to consider many factors, including the shape, size, and position of the reflector wall. Therefore, the design work is cumbersome and requires precise calculation and optimization. Due to the addition of the reflector wall structure, the reflector wall antenna usually occupies a large space and is not suitable for scenes with limited space or requiring a compact structure. In addition, the complex design and large structure may also lead to high manufacturing and installation costs, which is not suitable for low-cost applications or large-scale deployment. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a microstrip antenna based on a reflection cavity structure. This design can solve the problems of low gain of microstrip patch antennas and high design complexity of reflection cavity antennas, and realize a high-gain microstrip antenna with a simple reflection cavity structure.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] The present invention provides a microstrip antenna based on a reflection cavity structure, comprising a reflection cavity and a microstrip patch antenna assembly, wherein the microstrip patch antenna assembly comprises a rectangular dielectric substrate, a coaxial line feeding point, a microstrip patch antenna and an antenna back bottom plate, wherein the microstrip patch antenna is printed on the rectangular dielectric substrate, the coaxial line feeding point is located on the central axis of the rectangular dielectric substrate, the antenna back bottom plate is connected to the back side of the rectangular dielectric substrate, and the coaxial socket of the coaxial line feeding point is installed on the antenna back bottom plate and is located on the back side of the microstrip patch antenna assembly;

[0011] The reflection cavity is a quadrangular pyramid surrounded by four isosceles trapezoidal reflection walls. The reflection wall is a single-layer dielectric plate or metal plate with a metal material covering the inner wall. The isosceles trapezoidal upper base of the reflection wall is connected to the edge of the rectangular dielectric substrate.

[0012] Furthermore, the coaxial line feeding point is connected to an impedance-matched coaxial line, and the inner conductor of the coaxial line is fixedly connected to the microstrip patch antenna.

[0013] Furthermore, the inner conductor of the coaxial line and the microstrip patch antenna are connected by welding.

[0014] Furthermore, the antenna is lumped port fed through the coaxial line at the coaxial line feed point.

[0015] Furthermore, the microstrip patch antenna is rectangular, and the length and width of the rectangular dielectric substrate are greater than the length and width of the microstrip patch antenna.

[0016] Furthermore, the conductor edge of the microstrip patch antenna and the antenna back bottom plate form a radiation fringe field.

[0017] Furthermore, the main material of the single-layer dielectric board is FR-4 glass fiber, Rogers5880 or Rogers4350.

[0018] Furthermore, the metal material covering the inner wall of the single-layer dielectric plate is copper.

[0019] Furthermore, the resonant frequency of the antenna is maintained at 1.42 GHz by designing the size parameters of the reflector cavity and the microstrip patch antenna assembly.

[0020] Furthermore, the connection between the reflective walls is by welding.

[0021] According to another aspect of the present invention, there is provided a

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention arranges a reflection cavity outside the microstrip patch antenna assembly. The reflection cavity is a quadrangular pyramid surrounded by four isosceles trapezoidal reflection walls. The upper base of the isosceles trapezoid is connected to the edge of the rectangular dielectric substrate. The reflection wall is a single-layer dielectric plate or a metal plate with an inner wall covered with a metal material. After the microstrip patch assembly radiates, the beam is concentrated by adding a reflection cavity structure, thereby improving the directivity of the microstrip patch antenna and improving the gain of the microstrip patch antenna without affecting the antenna bandwidth. The structure is simple and easy to implement.

[0024] 2. The present invention feeds the microstrip patch antenna through a coaxial line to perform lumped port feeding, so that the radiation of the microstrip patch antenna is radiated from the edge field between the edge of the microstrip patch antenna conductor and the back metal floor. The microstrip patch antenna has a simple and compact structure and a wide range of applications.

[0025] 3. The material used in the reflective cavity designed by the present invention is cheap and can be realized by using low-cost FR-4 glass fiber copper clad. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of a microstrip antenna based on a reflective cavity structure of the present invention;

[0027] Figure 2 A front view of a microstrip antenna based on a reflective cavity structure according to the present invention;

[0028] Figure 3 A side view of a microstrip antenna based on a reflective cavity structure according to the present invention;

[0029] Figure 4 The S11 diagram of the microstrip antenna with a reflective cavity structure when the resonant frequency is 1.42 GHZ, where S11 is the return loss after the electromagnetic wave is incident on port 1 and received by port 1;

[0030] Figure 5 This is the gain diagram of the microstrip antenna with a reflective cavity structure when the resonant frequency is 1.42 GHZ;

[0031] Figure 6 This is the VSWR voltage standing wave ratio diagram of the microstrip antenna with a reflective cavity structure when the resonant frequency is 1.42 GHZ; in the figure, GainTotal is the total gain, Theta is the angle, and Freq is the frequency;

[0032] In the figure, 1. reflection cavity, 2. rectangular dielectric substrate, 3. coaxial line feeding point, 4. microstrip patch antenna, 5. antenna back bottom plate. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0034] This embodiment relates to a microstrip antenna device based on a reflective cavity structure, such as Figure 1 As shown, the device is composed of a microstrip patch antenna assembly and a reflection cavity 1 surrounded by a single-layer copper-clad plate structure, wherein the microstrip patch antenna assembly includes a rectangular dielectric substrate 2, a coaxial line feeding point 3, a microstrip patch antenna 4 and an antenna back bottom plate 5.

[0035] As a preferred embodiment, the reflection cavity 1 is welded by four trapezoidal reflection walls. The trapezoidal reflection walls can be made of single-layer copper-clad laminate or metal plate. The material of the single-layer copper-clad laminate can be FR-4 glass fiber, Rogers5880, Rogers4350, etc.

[0036] As a preferred embodiment, the microstrip patch antenna 4 is printed on the rectangular dielectric substrate 2. The microstrip patch antenna 4 is usually a conductive patch made of a metal sheet, while the rectangular dielectric substrate 2 is made of a material with a low dielectric constant, such as glass fiber, ceramic or polymer. Its working principle is based on the electromagnetic coupling effect between the microstrip patch antenna 4 and the rectangular dielectric substrate 2, and the electromagnetic field generated by the current in the conductive patch is used to achieve the transmission or reception function. The antenna is fed by a coaxial line, and the coaxial line feeding point 3 is located on the central axis of the rectangular dielectric substrate 2 and is connected to the coaxial line with matched impedance. The antenna back bottom plate 5 is connected to the back of the rectangular dielectric substrate 2, and the coaxial socket of the coaxial line feeding point 3 is installed on the antenna back bottom plate 5 and is located on the back of the microstrip patch antenna assembly and connected to the antenna back bottom plate 5. The microstrip patch antenna 4 is rectangular, and the inner conductor of the coaxial line is welded on the rectangular microstrip patch antenna 4.

[0037] As a preferred embodiment, the rectangular dielectric substrate 2 is slightly larger than the microstrip patch antenna 4, so as to be conveniently combined with the reflective cavity 1 structure constructed by a single-layer copper-clad laminate.

[0038] In this embodiment, the microstrip patch antenna 4 is fed with a lumped port through a coaxial line, so that the radiation of the microstrip patch antenna 4 is radiated outward from the edge field between the edge of the microstrip patch antenna conductor and the antenna back bottom plate 5, and finally the beam is concentrated by the reflection cavity 1 built by a single layer of copper clad laminate, so as to achieve high gain without affecting the antenna bandwidth, resonant frequency and return loss. Among them, the reflection cavity 1 is constructed by a single layer of copper clad laminate, which can effectively concentrate the radiation beam and thus achieve high gain. In this process, the bandwidth, resonant frequency and return loss of the antenna remain unchanged, ensuring that excellent electrical performance is maintained while improving the gain.

[0039] In this embodiment, it is necessary to reasonably adjust Figure 2 and Figure 3 The parameters marked in the figure are used to maintain the resonant frequency of the antenna at 1.42 GHZ and achieve the best working state of the antenna. Among them, L1 is the length of the rectangular dielectric substrate 2 in the antenna front view direction, L2 is the position of the coaxial line feeding point 3, θ1 is the angle between the trapezoidal reflection wall in the reflection cavity 1 and the horizontal plane in the front view direction, and H1 is the total height of the reflection cavity 1. L3 is the length of the rectangular dielectric substrate 2 in the antenna side view direction, θ2 is the angle between the trapezoidal reflection wall in the reflection cavity 1 and the horizontal plane in the side view direction, and the position of the coaxial line feeding point 3 in the side view direction is the midpoint of L3.

[0040] like Figure 4 The figure shows the S11 or return loss diagram of the microstrip antenna added with the reflection cavity 1 when the resonant frequency is 1.42 GHZ, and the relative bandwidth is 0.85%.

[0041] like Figure 5 The figure shows the gain diagram of the microstrip antenna with the reflector cavity 1 added when the resonant frequency is 1.42 GHZ, and the peak gain of the main lobe is 10.18 dB.

[0042] like Figure 6 The VSWR voltage standing wave ratio diagram is shown when the resonant frequency of the microstrip antenna added to the reflection cavity 1 is 1.42 GHZ, and the value at 1.42 GHZ is 1.01.

[0043] From the above data, it can be seen that adding the reflective cavity 1 structure to the microstrip patch antenna assembly can increase the gain of the microstrip antenna and improve the directivity of the microstrip antenna without having a significant impact on the relative bandwidth of the antenna. In addition, the reflective cavity 1 has a simple structure and is easy to process.

[0044] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A microstrip antenna based on a reflective cavity structure, characterized in that: The invention comprises a reflection cavity (1) and a microstrip patch antenna assembly, wherein the microstrip patch antenna assembly comprises a rectangular dielectric substrate (2), a coaxial line feeding point (3), a microstrip patch antenna (4) and an antenna back bottom plate (5), wherein the microstrip patch antenna (4) is printed on the rectangular dielectric substrate (2), the coaxial line feeding point (3) is located on the central axis of the rectangular dielectric substrate (2), the antenna back bottom plate (5) is connected to the back side of the rectangular dielectric substrate (2), and the coaxial socket of the coaxial line feeding point (3) is installed on the antenna back bottom plate (5) and is located on the back side of the microstrip patch antenna assembly; The reflection cavity (1) is a quadrangular pyramid surrounded by four isosceles trapezoidal reflection walls, the reflection wall being a single-layer dielectric plate or metal plate with a metal material coated on the inner wall, and the isosceles trapezoidal upper base of the reflection wall is connected to the edge of a rectangular dielectric substrate (2).

2. The microstrip antenna based on a reflective cavity structure according to claim 1, characterized in that: The coaxial line feeding point (3) is connected to an impedance-matched coaxial line, and the inner conductor of the coaxial line is fixedly connected to a microstrip patch antenna (4).

3. The microstrip antenna based on a reflective cavity structure according to claim 2, characterized in that: The inner conductor of the coaxial line and the microstrip patch antenna (4) are connected by welding.

4. The microstrip antenna based on a reflective cavity structure according to claim 2, characterized in that: The antenna is fed with lumped port power through the coaxial line at the coaxial line feeding point (3).

5. The microstrip antenna based on a reflective cavity structure according to claim 1, characterized in that: The microstrip patch antenna (4) is rectangular, and the length and width of the rectangular dielectric substrate (2) are greater than the length and width of the microstrip patch antenna (4).

6. The microstrip antenna based on a reflective cavity structure according to claim 1, characterized in that: The conductor edge of the microstrip patch antenna (4) and the antenna back bottom plate (5) form a radiation fringe field.

7. The microstrip antenna based on a reflective cavity structure according to claim 1, characterized in that: The main material of the single-layer dielectric board is FR-4 glass fiber, Rogers5880 or Rogers4350.

8. The microstrip antenna based on a reflective cavity structure according to claim 7, characterized in that: The metal material covered on the inner wall of the single-layer dielectric plate is copper.

9. The microstrip antenna based on a reflective cavity structure according to claim 1, characterized in that: The resonant frequency of the antenna is maintained at 1.42 GHZ by designing the size parameters of the reflection cavity (1) and the microstrip patch antenna assembly.

10. The microstrip antenna based on a reflective cavity structure according to claim 1, characterized in that: The connection between the reflective walls is by welding.

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