Antenna feed device and method

Abstract

The invention discloses an antenna feed device and method. The device comprises a coaxial transmitter, a microstrip transmission line, a dielectric substrate and a connecting structure. And a probe of the coaxial transmitter is in contact with the microstrip transmission line. The microstrip transmission line is etched on the dielectric substrate. A gap exists between the end face of the outer conductor of the coaxial transmitter and the dielectric substrate in the axial direction of the probe. And the connecting structure is connected with the dielectric substrate and the coaxial transmitter and is used for providing impedance matching for transmission of the probe and the microstrip transmission line. According to the invention, the problem of stray capacitance caused by difficulty in guaranteeing the processing and assembling consistency of microstrip transmission line signal transmission in a large-scale antenna array through coaxial probe feeding is solved, and the feasibility and practicability in practical application are improved.

Description

Technical Field

[0001] This application relates to the field of electromagnetic fields and microwave technologies, and particularly to an antenna feeding device and method. Background Art

[0002] In the field of electromagnetic fields and microwave technologies, the design and optimization of antennas have always been an important research direction. As a key component in a wireless communication system, the performance of an antenna directly affects the transmission quality and efficiency of the entire system. Among various antenna designs, the feeding structure and method play a crucial role because they determine how signals are transmitted from the emission source to the antenna and finally radiated out.

[0003] The feeding method based on a coaxial probe is a relatively common coaxial feeding method. This method transmits signals to the transmission line of the antenna through a coaxial probe. However, in practical applications, how to ensure a good and stable connection and impedance matching between the end of the coaxial transmitter and the antenna transmission line remains a technical difficulty. Especially when there is a gap between the coaxial transmitter and the antenna transmission line in the probe axial direction due to processing or assembly errors, parasitic capacitance will be generated. Since processing errors are inevitable and it is difficult to guarantee the consistency of processing or assembly, the application of the traditional coaxial probe feeding method in large-scale antenna arrays is limited.

[0004] To solve the above problems, a coaxial feeding method with high reliability, stable impedance matching and suitable for mass production is needed, which has become a major demand in the current technical field. Especially in application scenarios such as radar antennas and communication antennas that require high performance and high reliability, improving the existing coaxial feeding method and enhancing its application effect in large-scale antenna arrays are of great significance for improving the performance of the entire system. Summary of the Invention

[0005] This application proposes an antenna feeding device and method to solve the problem of parasitic capacitance generated due to processing or assembly errors in the prior art.

[0006] In a first aspect, an embodiment of this application provides an antenna feeding device, including a coaxial transmitter, a microstrip transmission line, a dielectric substrate, and a connection structure. The probe of the coaxial transmitter is in contact with the microstrip transmission line. The microstrip transmission line is etched on the dielectric substrate. There is a gap between the end face of the outer conductor of the coaxial transmitter and the dielectric substrate in the probe axial direction. The connection structure connects the dielectric substrate and the coaxial transmitter and is used to provide impedance matching for the transmission between the probe and the microstrip transmission line.

[0007] Preferably, the volume of the connection structure is a set multiple larger than that of the probe.

[0008] Preferably, the outer conductor and the dielectric substrate are arranged in a vacuum environment.

[0009] Preferably, the connection structure is a metal sheet structure. One side of the metal sheet structure is fixedly connected to the side of the dielectric substrate away from the microstrip transmission line, and the other side is fixedly connected to the outer conductor of the coaxial transmitter.

[0010] Preferably, the inner conductor and the outer conductor of the coaxial transmitter are made of non-metallic conductors.

[0011] In one embodiment, it further includes a base. The base is connected to the end of the coaxial transmitter, and the base is provided with a through hole having the same inner diameter as the outer conductor. The dielectric of the coaxial transmitter extends out from the end face of the outer conductor to fill the through hole. The probe passes through the through hole. There is a gap between the end face of the through hole and the dielectric substrate in the axial direction of the probe.

[0012] Furthermore, the connection structure is fixedly connected to the coaxial transmitter through a connection base.

[0013] In a second aspect, an antenna feeding method provided by an embodiment of the present application is used to produce the antenna feeding device according to any one of the embodiments in the first aspect, and includes the steps of:

[0014] Construct a coaxial transmitter, and set a gap between the end face of the outer conductor of the coaxial transmitter and the dielectric substrate in the axial direction of the probe;

[0015] Extend the probe of the coaxial transmitter to contact the microstrip transmission line;

[0016] Analyze the equivalent model of the antenna feeding device, optimize the structural parameters, and achieve impedance matching; the structural parameters include parasitic capacitance.

[0017] Preferably, it further includes the step of:

[0018] Determine the magnitude of the distance error generated when the coaxial transmitter and the dielectric substrate are installed, and the size of the gap is at least one order of magnitude higher than the error.

[0019] In one embodiment, the structural parameters further include the width and length of the microstrip transmission line, the gap between the outer conductor of the coaxial connector and the dielectric substrate where the microstrip transmission line is located, or the structural parameters of the radiator.

[0020] The above at least one technical solution adopted by the embodiment of the present application can achieve the following beneficial effects:

[0021] Through theoretical analysis, constructing an equivalent circuit model, feeding structure modeling and optimization, the present application realizes broadband impedance matching when the coaxial transmitter and the microstrip transmission line are physically isolated. Compared with the traditional method, the present invention effectively solves the problem of parasitic capacitance caused by the difficulty in ensuring the processing and assembly consistency of the microstrip transmission line signal transmission by the coaxial probe feeding in a large-scale antenna array, and improves its feasibility and practicality in actual applications. Brief Description of the Drawings

[0022] The drawings described herein are provided to further understand the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0023] Figure 1 is a structural diagram of an antenna feeding device provided by an embodiment of the present application;

[0024] Figure 2 is a flowchart of an antenna feeding method provided by an embodiment of the present application. Detailed Description of the Embodiments

[0025] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0026] The following will, with reference to the drawings, elaborate on the technical solutions provided by each embodiment of the present application.

[0027] By actively separating the coaxial connector and the microstrip transmission line in the present application and simultaneously optimizing the structural parameters for impedance characteristics, impedance mutation caused by installation errors during the installation process is avoided, which affects the feeding performance, thereby ensuring the stability of the antenna while reducing the installation difficulty.

[0028] Figure 1 is a structural diagram of an antenna feeding device provided by an embodiment of the present application, including a coaxial transmitter 11, a microstrip transmission line 12, a dielectric substrate 13, and a connection structure 14.

[0029] The probe of the coaxial transmitter contacts the microstrip transmission line.

[0030] For example, the coaxial transmitter is a columnar structure, and a hierarchical structure is concentrically arranged inside. Specifically, from the outside to the inside, it includes:

[0031] An outer conductor 111, for example, usually a metal shielding layer (such as a copper braid layer), wraps around the inner conductor to shield external interference and provide grounding.

[0032] An inner conductor 113-1, for example, usually a metal wire (such as copper), is used to transmit signals.

[0033] It should be noted that if the working environment is high-frequency electromagnetic waves, the inner and outer conductors can use non-metallic conductor materials.

[0034] Insulating medium 112 (hereinafter referred to as the medium). For example, it is filled between the inner conductor and the outer conductor to support the inner conductor and provide electrical isolation. Common medium materials include polyethylene (PE), polytetrafluoroethylene (PTFE), or air.

[0035] The probe 113-2 is formed by the outward extension of the inner conductor 113-1 of the coaxial transmitter.

[0036] The microstrip transmission line is etched on the dielectric substrate.

[0037] There is a gap between the end face of the outer conductor of the coaxial transmitter and the dielectric substrate in the axial direction of the probe.

[0038] The connection structure connects the dielectric substrate and the coaxial transmitter, and is used to provide impedance matching for the transmission between the probe and the microstrip transmission line.

[0039] The connection structure can be a metal sheet structure, a wire, or other dielectric materials, and is used to achieve mechanical connection and electrical matching between the dielectric substrate and the coaxial transmitter. Since the volume of the connection structure is close to or smaller than the volume of the probe, impedance mismatch will occur. Therefore, preferably, the volume of the connection structure is larger than the volume of the probe by a set multiple.

[0040] The set multiple refers to the difference value of the volume of the metal plate adjusted specifically according to the specific requirements of impedance matching with respect to the size of the probe.

[0041] More preferably, the volume of the connection structure is at least one order of magnitude larger than the volume of the probe.

[0042] In order to prevent air from filling the gap in the vacuum isolation and affecting the transmission of electromagnetic waves, therefore, preferably, the outer conductor and the dielectric substrate are arranged in a vacuum environment.

[0043] Furthermore, the antenna feeding device of the present application is sealed in a sealed box body by vacuum pumping, so that the outer conductor and the dielectric substrate are arranged in a vacuum environment.

[0044] Due to the existence of the gap, electromagnetic waves will leak. Therefore, preferably, the connection structure is a metal sheet structure. One side of the metal sheet structure is fixedly connected to the side of the dielectric substrate away from the microstrip transmission line, and the other side is fixedly connected to the outer conductor of the coaxial transmitter.

[0045] The significance of the metal sheet structure is that during the process of guiding the electromagnetic field from the coaxial connector to the microstrip transmission line, the metal sheet structure restricts the electromagnetic field and prevents it from radiating in an undesired direction, ensuring the electrical performance of the feeding device.

[0046] The leakage refers to the electromagnetic field not being effectively confined and radiating in an undesired direction, resulting in energy loss and affecting the electrical performance of the device itself.

[0047] Further preferably, the metal sheet structure can be a metal plate or a metal mesh structure.

[0048] Since high-frequency electromagnetic waves are more affected by parasitic capacitance interference than low-frequency electromagnetic waves, the antenna feeding device of the present application is preferably used under high-frequency electromagnetic wave conditions. Under the conditions of high-frequency electromagnetic wave transmission, the inner conductor and the outer conductor of the coaxial transmitter can be made of non-metallic materials, and the cost of non-metallic materials is lower than that of metallic materials. Therefore, preferably, the inner conductor and the outer conductor of the coaxial transmitter are made of non-metallic conductors.

[0049] In one embodiment, a base 15 is further included.

[0050] The base is connected to the end of the coaxial transmitter, and a through hole having the same inner diameter as the outer conductor is provided on the base.

[0051] The dielectric of the coaxial transmitter extends from the end face of the outer conductor and fills the through hole.

[0052] It should be noted that since the dielectric may be air, when the dielectric is air, only the probe passes through the through hole.

[0053] The probe passes through the through hole. There is a gap between the end face of the through hole and the dielectric substrate in the axial direction of the probe.

[0054] The base of the present application is used to fix the positional relationship with the dielectric substrate. A plurality of mounting holes are also provided on the surface of the base that is provided with the through hole and is close to the dielectric substrate. Corresponding mounting holes are provided on the dielectric substrate, and the base and the dielectric substrate are fixedly connected through a connecting rod structure.

[0055] It should be noted that the through hole of the base accommodates the dielectric and the probe extending from the end face of the outer conductor, playing the same role as the outer dielectric. Its purpose is to fix the approximate positions of the coaxial transmitter and the dielectric substrate.

[0056] Further, the connection structure is fixedly connected to the coaxial transmitter through the connection base.

[0057] For example, the connection structure is a metal plate. One end of the metal plate is fixedly connected to the base, and the other end is fixedly connected to the side of the dielectric substrate away from the microstrip transmission line. Since the base accommodates the dielectric of the coaxial transmitter through the through hole, it is equivalent to the base being fixedly connected to the coaxial transmitter. The connection structure connects the base, which is equivalent to fixedly connecting the coaxial transmitter.

[0058] Figure 2A flowchart of an antenna feeding method provided by an embodiment of the present application, which is used to manufacture the antenna feeding device described in any embodiment of the first aspect, includes steps: 210 to 240.

[0059] Step 210: Select a microstrip transmission line and a dielectric substrate;

[0060] According to the specific characteristics and operating frequency band of the antenna radiator, design and construct a microstrip transmission feeding model (i.e., the structural model of the microstrip transmission line and the dielectric substrate).

[0061] According to the operating frequency and environmental requirements of the antenna, select a microstrip substrate material with an appropriate dielectric constant and thickness. Commonly used materials include FR4, Rogers, etc.

[0062] Based on the characteristics of the antenna radiator, determine the width and length of the microstrip transmission line.

[0063] Use electromagnetic simulation software to simulate the microstrip transmission line model, analyze its transmission characteristics, and optimize the design parameters according to the simulation results to ensure good impedance matching and low-loss characteristics within the target frequency band.

[0064] Step 220: Construct a coaxial transmission line;

[0065] Select an appropriate coaxial transmission line, determine the materials of its inner and outer conductors, dielectric material, and geometric dimensions to ensure good transmission characteristics within the target frequency band. The length and diameter of the coaxial probe are key parameters and are accurately constructed in the model. Use electromagnetic simulation software to simulate the coaxial transmission line and analyze its transmission characteristics and impedance matching.

[0066] Step 230: Extend the probe of the coaxial transmission line to contact the microstrip transmission line, and set a gap along the probe axis on the end face of the outer conductor of the coaxial transmission line with respect to the dielectric substrate;

[0067] Extend the inner conductor of the coaxial transmission line from the end of the coaxial cable to form a probe. The size of the gap between the coaxial transmission line and the microstrip transmission line needs to be precisely adjusted in combination with the equivalent model and impedance characteristics of the feeding structure to achieve the best broadband impedance matching effect.

[0068] Step 240: Analyze the equivalent model of the antenna feeding device, optimize the structural parameters, and achieve impedance matching; the structural parameters include parasitic capacitance.

[0069] Simplify the antenna feeding device into an equivalent circuit model and analyze its impedance characteristics. The equivalent circuit model usually includes parasitic inductance, capacitance, etc. Use electromagnetic simulation software to comprehensively simulate and analyze the entire antenna feeding device, and observe parameters such as impedance matching, reflection coefficient, and standing wave ratio within the target frequency band. According to the simulation results, optimize and adjust the key parameters.

[0070] The key parameters include parasitic capacitance.

[0071] In one embodiment, the structural parameters further include the width and length of the microstrip transmission line, the gap between the outer conductor of the coaxial connector and the dielectric substrate where the microstrip transmission line is located, or the structural parameters of the radiator.

[0072] The goal of adjusting the key parameters is to achieve broadband impedance matching and ensure that the antenna has good transmission characteristics within the entire operating frequency band.

[0073] Preferably, when setting the gap in step 230, the following steps are further included:

[0074] Determine the magnitude of the distance error generated when the coaxial transmitter is installed on the dielectric substrate. The size of the gap is at least one order of magnitude higher than the error.

[0075] Since the purpose of the gap is to dilute the parasitic capacitance caused by the control between the coaxial transmitter and the dielectric substrate generated during the production or assembly process, preferably, the gap is set to be at least one order of magnitude higher than the error.

[0076] The method described in this application first constructs an antenna microstrip transmission feeding model based on the characteristics of the antenna radiator, and then constructs a feeding model of the coaxial transmitter. At this time, the coaxial transmitter and the antenna microstrip transmission line are spatially separated. It is necessary to extend the inner conductor of the coaxial transmitter as a probe to contact the feeding end of the microstrip transmission line. Through theoretical analysis, adjust the structural parameters of the feeding structure, regulate the impedance characteristics of the feeding position in the operating frequency band, eliminate the reflection in the operating frequency band, and achieve impedance matching. It improves the consistency of processing and assembly and reduces the impact of processing errors on the antenna performance.

[0077] Based on the method of feeding the microstrip transmission line with a traditional coaxial probe, this application further separates the coaxial transmitter and the microstrip transmission line in space. It improves the stability of this feeding method during mass production and solves the problem that it is difficult to ensure the consistency of processing and assembly of the traditional coaxial probe feeding method in large-scale antenna arrays.

[0078] It should also be noted that the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. Without further limitation, the elements defined by the statement "comprising..." do not exclude the existence of additional identical elements in the process, method, commodity or device including the said elements.

[0079] Those skilled in the art can understand that, unless specifically stated otherwise, the singular forms "a", "an", and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention means the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or their groups. It should be understood that when an element is "connected" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements..

[0080] Those skilled in the art can understand that, unless otherwise defined, all terms used herein (including technical, terminological, and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention pertains.

[0081] The above are only embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. An antenna feeding device, characterized in that: It includes a coaxial transmitter, a microstrip transmission line, a dielectric substrate and a connection structure; The probe of the coaxial transmitter is in contact with the microstrip transmission line; The microstrip transmission line is etched on a dielectric substrate; There is a gap between the outer conductor end face of the coaxial transmitter and the dielectric substrate in the axial direction of the probe; The connection structure connects the dielectric substrate and the coaxial transmitter, and is used to provide impedance matching for the transmission between the probe and the microstrip transmission line.

2. The antenna feeding device according to claim 1, characterized in that: The volume of the connection structure is a set multiple larger than that of the probe.

3. The antenna feeding device according to claim 1, characterized in that: The outer conductor and the dielectric substrate are arranged in a vacuum environment.

4. The antenna feeding device according to claim 1, characterized in that: The connecting structure is a metal sheet structure; One side of the metal sheet structure is fixedly connected to a side of the dielectric substrate away from the microstrip transmission line, and the other side is fixedly connected to an outer conductor of the coaxial transmitter.

5. The antenna feeding device according to claim 1, characterized in that: The inner conductor and the outer conductor of the coaxial transmitter are made of non-metallic conductors.

6. The antenna feeding device according to claim 1, characterized in that: Also includes a base; The base is connected to the end of the coaxial transmitter, and the base is provided with a through hole having the same inner diameter as that of the outer conductor; The medium of the coaxial transmission extends from the end surface of the outer conductor and fills the through hole; The probe passes through the through hole; There is a gap between the end surface of the through hole and the dielectric substrate in the axial direction of the probe.

7. The antenna feeding device according to claim 6, characterized in that: The connection structure is fixedly connected to the coaxial transmitter via a connection base.

8. An antenna feeding method for producing the antenna feeding device according to any one of claims 1 to 7, characterized in that: Contains steps: Constructing a coaxial transmitter, and providing a gap between the outer conductor end face of the coaxial transmitter and the dielectric substrate along the axial direction of the probe; Extend the probe of the coaxial transmitter to contact the microstrip transmission line; An equivalent model of an antenna feeding device is analyzed, structural parameters are optimized, and impedance matching is achieved; the structural parameters include parasitic capacitance.

9. The antenna feeding method according to claim 8, characterized in that: Also includes the steps: The magnitude of the distance error generated when the coaxial transmitter and the dielectric substrate are installed is determined, and the size of the gap is at least one order of magnitude higher than the error.

10. The antenna feeding method according to claim 8, characterized in that: The structural parameters also include the width and length of the microstrip transmission line, the gap between the outer conductor of the coaxial connector and the dielectric substrate where the microstrip transmission line is located, or the structural parameters of the radiator.

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