Microstrip double-path coupling resonant filter

Abstract

The invention relates to the technical field of wireless communication, and provides a microstrip two-way coupling resonant filter which comprises a metal layer, a silicon substrate stacked on the metal layer and a filter structure stacked on the silicon substrate. The filter structure passes through the silicon substrate and is electrically connected with the metal layer; the filter structure comprises two microstrip transmission lines, two open-circuit microstrip resonators, a short-circuit resonator and a tight coupling feed structure, wherein the two microstrip transmission lines are stacked and fixed on a silicon substrate and are oppositely arranged along a first direction; the two microstrip transmission lines and the two open-circuit microstrip resonators are arranged in a staggered manner, and the open-circuit microstrip resonators and the short-circuit resonators are spaced from the two microstrip transmission lines respectively; each microstrip transmission line is provided with two tight coupling feed structures, and the other ends of the two tight coupling feed structures are respectively connected with the two open-circuit microstrip resonators. The microstrip dual-path coupling resonant filter has high integration and reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication, and in particular to a microstrip dual-path coupled resonant filter. Background Art

[0002] Filters are essential components in multi-band wireless communications. With the rapid development of wireless communication technology, modern communication systems have increasingly stringent requirements on the performance of filters. As an important component in communication systems, the performance of filters directly affects the overall efficiency and quality of the system. Existing filter technology has some shortcomings, such as narrow bandwidth, large insertion loss, and poor out-of-band suppression. These defects limit the application of filters in broadband communication systems, especially in microwave and millimeter wave band applications that require high performance and low loss. The performance of traditional filters cannot meet the requirements.

[0003] At present, microstrip filters are widely used in various communication devices due to their advantages such as small size, light weight, and easy integration. Commonly used microstrip filters include an intermediate dielectric substrate, a single-section step impedance resonator on the front, a front feeder, a back ground metal, and a defective ground structure etched on the back ground metal. By designing a single-section step impedance resonator on the front, a low-pass filter with high frequency selectivity is realized. Combined with the defective ground structure etched on the back, the defective ground structure has the characteristic of notching. By reasonably designing the size and number of the defective ground structure, a low-pass filter with a wide stopband and high frequency selectivity is realized.

[0004] However, existing microstrip filters still face many challenges in design and manufacturing. The above-mentioned structures are prone to complex design, high manufacturing process requirements, poor device performance and reliability, etc. Summary of the invention

[0005] In view of the above shortcomings of the prior art, the present invention proposes a microstrip two-way coupled resonant filter to solve the problems of complex structure and poor reliability of the existing microstrip two-way coupled resonant filter.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: An embodiment of the present invention provides a microstrip two-way coupled resonant filter, the microstrip two-way coupled resonant filter comprising a metal layer, a silicon substrate stacked on the metal layer, and a filter structure stacked on the silicon substrate; the filter structure passes through the silicon substrate and is electrically connected to the metal layer; The filter structure comprises two microstrip transmission lines which are stacked and fixed on the silicon substrate and arranged oppositely along a first direction, two open-circuit microstrip resonators which are stacked on the silicon substrate and arranged oppositely along a second direction, a short-circuit resonator connected between the two open-circuit microstrip resonators, and a tightly coupled feeding structure; the two microstrip transmission lines and the two open-circuit microstrip resonators are arranged in an alternating manner, and the open-circuit microstrip resonators and the short-circuit resonator are respectively spaced apart from the two microstrip transmission lines; each microstrip transmission line is configured with two tightly coupled feeding structures, and one end of each of the two tightly coupled feeding structures is respectively connected to the microstrip transmission line, and the other end of each of the two tightly coupled feeding structures is respectively connected to the two open-circuit microstrip resonators; the two microstrip transmission lines are used as feeding ports of the filter structure; The short-circuit resonator includes a short-circuit resonator body with a diamond structure, a plurality of through holes penetrating the short-circuit resonator body, and two first metal wires extending in opposite directions from the short-circuit resonator body on opposite sides along the second direction, wherein one end of the two first metal wires away from the short-circuit resonator body is fixedly connected to the two open-circuit microstrip resonators respectively, the inner surfaces of all the through holes are copper-plated, and the through holes penetrate the silicon substrate and are connected to the surface of the metal layer close to the silicon substrate.

[0007] Preferably, the short-circuit resonator body is made of an annular rhombus-shaped metal sheet.

[0008] Preferably, the first direction and the second direction are perpendicular to each other, the filter structure is an axisymmetric structure with the straight line where the first metal wire is located as the axis, and the filter structure is an axisymmetric structure with the straight line where the microstrip transmission line is located as the axis.

[0009] Preferably, the microstrip transmission line includes a transmission line body disposed on the silicon substrate and extending along the first direction and a first connecting portion formed by extending from the transmission line body toward a side close to the short-circuit resonator; one end of the tightly coupled feeding structure is connected to the first connecting portion.

[0010] Preferably, the open-circuit microstrip resonator includes an open-circuit microstrip resonator body stacked on the silicon substrate and extending along the second direction, and a second connecting portion formed by extending from the open-circuit microstrip resonator body to a side close to the short-circuit resonator; the second connecting portion is fixed to the other end of the tightly coupled feeding structure, and one end of the second connecting portion close to the short-circuit resonator is fixed to the first metal wire.

[0011] Preferably, each of the tightly coupled feeding structures comprises a second metal wire and a third metal wire which are parallel to and spaced from each other; In the two tightly coupled feeding structures configured in each of the microstrip transmission lines, the first connecting portion includes a first contact portion and a second contact portion formed by extending the corresponding transmission line body in a direction close to the two tightly coupled structures, one end of the two second metal wires close to the first connecting portion is fixed to the first contact portion and the second contact portion, respectively, and one end of the two second metal wires away from the first connecting portion is spaced from the corresponding two open microstrip resonators; one end of the two third metal wires close to the first connecting portion is spaced from the first connecting portion, respectively, and one end of the two third metal wires away from the first connecting portion is fixedly connected to the two open microstrip resonators.

[0012] Preferably, the angle formed at the connection between the third metal line and the open-circuit microstrip resonator is an acute angle.

[0013] Preferably, the width and length of the microstrip transmission line are defined as W1 and L1, respectively, wherein W1 is 0.25 mm and L1 is 0.5 mm; The width and length of the open circuit microstrip resonator body are defined as W2 and L2, respectively, wherein W2 is 0.18 mm and L2 is 0.29 mm; The lengths of the short-axis diagonal and the long-axis diagonal of the short-circuit resonator body are defined as W3 and L3, respectively, wherein W3 is 0.31 mm and L3 is 0.62 mm; The lengths of the second metal wire and the third metal wire are the same and are both defined as L4, L4 is 0.81 mm; the width of the second metal wire is defined as W4, W4 is 0.03 mm; the width of the third metal wire is defined as W5, W5 is 0.02 mm; the spacing between the second metal wire and the third metal wire is defined as S4, S4 is 0.03 mm.

[0014] Preferably, the silicon substrate is made of a high-resistance silicon-based substrate with a dielectric constant of 11.9; the metal layer is made of copper material, and the filter structure is made of copper material.

[0015] Preferably, the through holes are tubular, and the through holes include 32 through holes, which are neatly and evenly arranged directly below the short-circuit resonator body.

[0016] Compared with the related art, in the embodiments of the present invention, by using the microstrip transmission line as the feeding port, the signal can be effectively transmitted; the design of the open-circuit microstrip resonator and the diamond short-circuit resonator improves the frequency selectivity and out-of-band suppression capability of the filter; the tightly coupled feeding structure further reduces the insertion loss and increases the bandwidth; at the same time, the application of the silicon substrate makes the entire filter have good thermal and mechanical stability. By using silicon-based MEMS processing technology, the filter has a high degree of integration and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be described in detail below in conjunction with the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings. In the accompanying drawings: Figure 1 A schematic diagram of the structure of a microstrip dual-path coupled resonant filter provided by an embodiment of the present invention; Figure 2 A top view of a microstrip dual-path coupled resonant filter provided by an embodiment of the present invention; Figure 3 A schematic diagram of the dimensions of a microstrip dual-path coupled resonant filter provided in an embodiment of the present invention; Figure 4 This is a performance simulation diagram of the microstrip dual-path coupled resonant filter provided in an embodiment of the present invention.

[0018] Among them, 100, microstrip two-way coupled resonant filter, 1, metal layer, 2, filter structure, 21, microstrip transmission line, 211, transmission line body, 212, first connecting portion, 2121, first contact portion, 2122, second contact portion, 22, open-circuit microstrip resonator, 221, open-circuit microstrip resonator body, 222, second connecting portion, 23, short-circuit resonator, 231, short-circuit resonator body, 232, through hole, 233, first metal wire, 24, tightly coupled feeding structure, 241, second metal wire, 242, third metal wire, 3, silicon substrate. DETAILED DESCRIPTION

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0020] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0021] 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 only 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 are within the scope of protection of the present invention.

[0022] See also Figure 1-Figure 2 As shown, an embodiment of the present invention provides a microstrip two-way coupled resonant filter 100, which includes a metal layer 1, a silicon substrate 3 stacked on the metal layer 1, and a filter structure 2 stacked on the silicon substrate 3; the filter structure 2 passes through the silicon substrate 3 and is electrically connected to the metal layer 1.

[0023] The filter structure 2 includes two microstrip transmission lines 21 stacked and fixed on the silicon substrate 3 and arranged oppositely along a first direction, two open-circuit microstrip resonators 22 stacked on the silicon substrate 3 and arranged oppositely along a second direction, a short-circuit resonator 23 connected between the two open-circuit microstrip resonators 22, and a tightly coupled feeding structure 24. The two microstrip transmission lines 21 and the two open-circuit microstrip resonators 22 are arranged in an alternating manner, and the open-circuit microstrip resonators 22 and the short-circuit resonator 23 are spaced apart from the two microstrip transmission lines 21, respectively. Each microstrip transmission line 21 is configured with two tightly coupled feeding structures 24, and one end of each of the two tightly coupled feeding structures 24 is connected to the microstrip transmission line 21, and the other end of each of the two tightly coupled feeding structures 24 is connected to the two open-circuit microstrip resonators 22, respectively; the two microstrip transmission lines 21 are used as feeding ports of the filter structure 2.

[0024] The short-circuit resonator 23 includes a short-circuit resonator body 231 with a rhombus structure, a plurality of through holes 232 penetrating the short-circuit resonator body 231, and two first metal wires 233 extending in opposite directions from the short-circuit resonator body 231 on opposite sides along the second direction, and the ends of the two first metal wires 233 away from the short-circuit resonator body 231 are fixedly connected to the two open-circuit microstrip resonators 22, respectively. The inner surfaces of all the through holes 232 are copper-plated, and the through holes 232 penetrate the silicon substrate 3 and are connected to the surface of the metal layer 1 close to the silicon substrate 3. The short-circuit resonator 23 can be electrically connected to the metal layer 1 by copper plating the inner wall of the through hole 232. By using the microstrip transmission line 21 as a feeding port, the signal can be effectively transmitted; the design of the open-circuit microstrip resonator 22 and the rhombus-shaped short-circuit resonator 23 improves the frequency selectivity and out-of-band suppression capability of the filter. Connecting the microstrip transmission line 21 and the open-circuit microstrip resonator 22 through a tightly coupled feeding structure 24 further reduces the insertion loss and increases the bandwidth. At the same time, the application of the silicon substrate 3 makes the entire filter have good thermal stability and mechanical stability. By using silicon-based MEMS processing technology, the filter has a high degree of integration and reliability.

[0025] Among them, MEMS processing technology (Microelectromechanical systems, MEMS) is a microstructure processing technology from nanoscale to millimeter scale.

[0026] In this embodiment, the short-circuit resonator body 231 is made of an annular diamond-shaped metal sheet.

[0027] In this embodiment, the first direction and the second direction are perpendicular to each other, the filter structure 2 is an axisymmetric structure with the straight line where the first metal line 233 is located as the axis, and the filter structure 2 is an axisymmetric structure with the straight line where the microstrip transmission line 21 is located as the axis. The overall structure surrounded by multiple tightly coupled feeding structures 24 corresponds to the outer peripheral side interval of the short-circuited resonator 23, thereby forming a diamond-shaped tightly coupled feeding structure 24, further reducing the insertion loss.

[0028] In this embodiment, the microstrip transmission line 21 includes a transmission line body 211 disposed on the silicon substrate 3 and extending along the first direction, and a first connecting portion 212 formed by extending the transmission line body 211 toward a side close to the short-circuit resonator 23; one end of the tightly coupled feeding structure 24 is connected to the first connecting portion 212.

[0029] In this embodiment, the open-circuit microstrip resonator 22 includes an open-circuit microstrip resonator body 221 stacked on the silicon substrate 3 and extending along the second direction, and a second connecting portion 222 formed by extending from the open-circuit microstrip resonator body 221 to a side close to the short-circuit resonator 23. The second connecting portion 222 is fixed to the other end of the tightly coupled feeding structure 24, and one end of the second connecting portion 222 close to the short-circuit resonator 23 is fixed to the first metal wire 233.

[0030] In this embodiment, each of the tightly coupled feeding structures 24 includes a second metal wire 241 and a third metal wire 242 that are parallel to and spaced apart from each other.

[0031] In the two tightly coupled feeding structures 24 configured for each microstrip transmission line 21, the first connection portion 212 includes a first contact portion 2121 and a second contact portion 2122 formed by the corresponding transmission line body 211 extending in the direction close to the two tightly coupled structures; one end of the two second metal wires 241 close to the first connection portion 212 is fixed to the first contact portion 2121 and the second contact portion 2122 respectively, and one end of the two second metal wires 241 away from the first connection portion 212 is spaced from the two open microstrip resonators 22 respectively. One end of the two third metal wires 242 close to the first connection portion 212 is spaced from the corresponding first connection portion 212 respectively, and one end of the two third metal wires 242 away from the first connection portion 212 is fixedly connected to the two open microstrip resonators 22 respectively.

[0032] In this embodiment, the angle formed by the connection between the third metal line 242 and the open microstrip resonator 22 is an acute angle.

[0033] In this embodiment, refer to the attached Figure 1-Figure 3 As shown, the width and length of the microstrip transmission line 21 are defined as W1 and L1 respectively, wherein W1 is 0.25 mm and L1 is 0.5 mm.

[0034] The width and length of the open-circuit microstrip resonator body 221 are defined as W2 and L2, respectively, wherein W2 is 0.18 mm and L2 is 0.29 mm.

[0035] The lengths of the short-axis diagonal and the long-axis diagonal of the short-circuit resonator body 231 are defined as W3 and L3, respectively, wherein W3 is 0.31 mm and L3 is 0.62 mm.

[0036] It is defined that the lengths of the second metal wire 241 and the third metal wire 242 are the same, and are both L4, L4 is 0.81 mm; the width of the second metal wire 241 is W4, W4 is 0.03 mm; the width of the third metal wire 242 is W5, W5 is 0.02 mm; the spacing between the second metal wire 241 and the third metal wire 242 is S4, S4 is 0.03 mm.

[0037] Specifically, by determining the type of metal material and the type of material of the silicon substrate 3, determining the length and width of the microstrip transmission line 21, the length and width of the open-circuit microstrip resonator 22, the size of the short-circuit resonator 23, the length, width and spacing of two parallel metal lines of the tightly coupled feeding structure 24, and the size and thickness of the silicon substrate 3, a broadband, low insertion loss, high out-of-band suppression bandpass filter that can be used for chip integration can be obtained.

[0038] Refer to the attached Figure 4 As shown in the figure, the S parameter simulation curve measured by simulation is shown. It can be seen from the figure that the operating frequency of the microstrip dual-path coupled resonant filter 100 is 20GHz~55GHz, there are three different resonance points in the band, the filtering insertion loss is less than 0.7dB, the out-of-band suppression is below 30dB, and the passband flatness is less than 0.2dB.

[0039] In this embodiment, by adjusting the width of the microstrip transmission line 21, a microstrip transmission line 21 that meets the characteristic impedance of the corresponding frequency can be obtained. It plays the role of feeding and impedance matching in the design of the filter structure 2. The purpose of adjusting the length and width of the open-circuit microstrip resonator 22 is to achieve that when it is used as an open-circuit microstrip line, it is equivalent to the corresponding reactance value, and plays the role of corresponding frequency resonance in the overall design of the filter structure 2. The size of the rhombus-shaped short-circuit resonator 23 is a key parameter for the short-circuit resonator 23 to be equivalent to the corresponding reactance value, and plays the role of corresponding frequency resonance in the overall design of the filter. The open-circuit microstrip resonator 22 is directly connected to the rhombus-shaped short-circuit resonator 23, which can be equivalent to a series-parallel circuit of inductors and capacitors for realizing bandpass filtering. The tightly coupled feeding structure 24 is a key link in the feeding structure, which not only restricts the resonant frequency of the filter, but also affects the insertion loss within the filter band. By precisely controlling the parameters of the open-circuit microstrip resonator 22 and the rhombus short-circuit resonator 23, a broadband bandpass filter in any frequency range can be obtained, and due to this connection method, a filter prototype with a higher degree of out-of-band suppression can be obtained. In addition, the dual-path coupling structure increases the overall Q value of the filter, so the designed filter has obvious low insertion loss and high out-of-band suppression characteristics among all broadband filters.

[0040] In this embodiment, the silicon substrate 3 is made of a high-resistance silicon-based substrate with a dielectric constant of 11.9; the metal layer 1 is made of copper material, and the filter structure 2 is made of copper material.

[0041] In this embodiment, the through holes 232 are tubular in shape. There are 32 through holes 232 , which are neatly and evenly arranged directly below the short-circuit resonator body 231 .

[0042] Specifically, in order to achieve superior bandpass filtering performance and integration capability with silicon-based chips, the silicon substrate 3 uses a high-resistance silicon-based substrate with a dielectric constant of 11.9. The metal layer 1 and the filter structure 2 are made of pure copper with high conductivity. The number of through holes 232 below the rhombus-shaped short-circuit resonator 23 is 32, and they are neatly and evenly arranged below the rhombus-shaped annular copper sheet. The through hole 232 is hollow and the inner surface is plated with metal copper; the type of metal material and the type of material of the silicon substrate 3 will affect the performance of the filter.

[0043] It should be noted that the various embodiments described above with reference to the accompanying drawings are only used to illustrate the present invention rather than to limit the scope of the present invention. Those skilled in the art should understand that any modification or equivalent substitution of the present invention without departing from the spirit and scope of the present invention should be included within the scope of the present invention. In addition, unless otherwise indicated by the context, words appearing in the singular include the plural form, and vice versa. In addition, unless otherwise specified, all or part of any embodiment may be used in combination with all or part of any other embodiment.

Claims

1. A microstrip dual-path coupled resonant filter, characterized in that: The microstrip dual-path coupled resonant filter comprises a metal layer, a silicon substrate stacked on the metal layer, and a filter structure stacked on the silicon substrate; the filter structure passes through the silicon substrate and is electrically connected to the metal layer; The filter structure comprises two microstrip transmission lines stacked and fixed on the silicon substrate and arranged oppositely along a first direction, two open-circuit microstrip resonators stacked on the silicon substrate and arranged oppositely along a second direction, a short-circuit resonator connected between the two open-circuit microstrip resonators, and a tightly coupled feeding structure; The two microstrip transmission lines and the two open-circuit microstrip resonators are arranged in a staggered manner, and the open-circuit microstrip resonators and the short-circuit resonators are spaced apart from the two microstrip transmission lines respectively; Each of the microstrip transmission lines is configured with two tightly coupled feeding structures, and one end of each of the two tightly coupled feeding structures is connected to the microstrip transmission line, and the other end of each of the two tightly coupled feeding structures is connected to two open-circuit microstrip resonators; the two microstrip transmission lines are used as feeding ports of the filter structure; The short-circuit resonator includes a short-circuit resonator body with a diamond structure, a plurality of through holes penetrating the short-circuit resonator body, and two first metal wires extending in opposite directions from the short-circuit resonator body on opposite sides along the second direction, wherein one end of the two first metal wires away from the short-circuit resonator body is fixedly connected to the two open-circuit microstrip resonators respectively, the inner surfaces of all the through holes are copper-plated, and the through holes penetrate the silicon substrate and are connected to the surface of the metal layer close to the silicon substrate.

2. The microstrip dual-path coupled resonant filter according to claim 1, characterized in that: The short-circuit resonator body is made of an annular rhombus-shaped metal sheet.

3. The microstrip two-way coupled resonant filter according to claim 1, characterized in that: The first direction is perpendicular to the second direction, the filter structure is an axisymmetric structure with the straight line where the first metal line is located as the axis, and the filter structure is an axisymmetric structure with the straight line where the microstrip transmission line is located as the axis.

4. The microstrip two-way coupled resonant filter according to claim 1, characterized in that: The microstrip transmission line includes a transmission line body disposed on the silicon substrate and extending along the first direction and a first connection portion formed by extending the transmission line body toward a side close to the short-circuit resonator; one end of the tightly coupled feeding structure is connected to the first connection portion.

5. The microstrip two-way coupled resonant filter according to claim 4, characterized in that: The open-circuit microstrip resonator includes an open-circuit microstrip resonator body stacked on the silicon substrate and extending along the second direction, and a second connecting portion formed by extending the open-circuit microstrip resonator body toward a side close to the short-circuit resonator; the second connecting portion is fixed to the other end of the tightly coupled feeding structure, and one end of the second connecting portion close to the short-circuit resonator is fixed to the first metal wire.

6. The microstrip two-way coupled resonant filter according to claim 5, characterized in that: Each of the tightly coupled feeding structures comprises a second metal wire and a third metal wire which are parallel to and spaced from each other; In the two tightly coupled feeding structures configured in each of the microstrip transmission lines, the first connecting portion includes a first contact portion and a second contact portion formed by extending the corresponding transmission line body in a direction close to the two tightly coupled structures, one end of the two second metal wires close to the first connecting portion is fixed to the first contact portion and the second contact portion, respectively, and one end of the two second metal wires away from the first connecting portion is spaced from the corresponding two open microstrip resonators; one end of the two third metal wires close to the first connecting portion is spaced from the first connecting portion, respectively, and one end of the two third metal wires away from the first connecting portion is fixedly connected to the two open microstrip resonators.

7. The microstrip two-way coupled resonant filter according to claim 6, characterized in that: The angle formed at the connection between the third metal line and the open microstrip resonator is an acute angle.

8. The microstrip two-way coupled resonant filter according to claim 6, characterized in that: The width and length of the microstrip transmission line are defined as W1 and L1, respectively, wherein W1 is 0.25 mm and L1 is 0.5 mm; The width and length of the open circuit microstrip resonator body are defined as W2 and L2, respectively, wherein W2 is 0.18 mm and L2 is 0.29 mm; The lengths of the short-axis diagonal and the long-axis diagonal of the short-circuit resonator body are defined as W3 and L3, respectively, wherein W3 is 0.31 mm and L3 is 0.62 mm; The lengths of the second metal wire and the third metal wire are the same and are both defined as L4, L4 is 0.81 mm; the width of the second metal wire is defined as W4, W4 is 0.03 mm; the width of the third metal wire is defined as W5, W5 is 0.02 mm; the spacing between the second metal wire and the third metal wire is defined as S4, S4 is 0.03 mm.

9. The microstrip two-way coupled resonant filter according to claim 1, characterized in that: The silicon substrate is made of a high-resistance silicon-based substrate with a dielectric constant of 11.9; the metal layer is made of a copper material, and the filter structure is made of a copper material.

10. The microstrip two-way coupled resonator filter according to claim 1, characterized in that: The through holes are tubular in shape, and there are 32 through holes, which are neatly and evenly arranged directly below the short-circuit resonator body.

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