High-roll-reduction loss-reduction broadband filter based on three-dimensional composite right / left-handed transmission line
By using a three-dimensional composite left- and right-handed transmission line structure, combined with an EMSIW resonant cavity and a three-dimensional coupling capacitor and inductor, the problem of insufficient energy constraint of existing CRLH resonators in the millimeter-wave band is solved, and the high selectivity and low loss effect of the high roll-off low loss broadband filter is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIDIAN UNIV
- Filing Date
- 2026-01-23
- Publication Date
- 2026-05-15
AI Technical Summary
Existing CRLH resonators have difficulty in precisely controlling parasitic parameters in the millimeter-wave band, and their two-dimensional planar energy constraint capability is limited, which restricts the improvement of filter selectivity and out-of-band rejection capability.
A three-dimensional composite left- and right-handed transmission line structure is adopted. By constructing an EMSIW resonant cavity and etching grooves on the first metal layer, and combining three-dimensional coupling capacitors and inductors, a high roll-off and low-loss broadband filter is formed. The vertical integration advantage of glass-based three-dimensional packaging is utilized to achieve complex electromagnetic coupling.
The filter was miniaturized and compacted, improving energy confinement capability and Q value, creating a highly selective broadband passband with a bandwidth of 72.72% and significant out-of-band suppression.
Smart Images
Figure CN122052735A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of integrated circuit manufacturing and advanced packaging technology, specifically relating to a high-roll-off loss-reducing broadband filter based on a three-dimensional composite left- and right-handed transmission line. Background Technology
[0002] The slowdown in Moore's Law and the diversification of integrated circuit applications are two important characteristics of the current integrated circuit industry. With the rise of products in fields such as smartphones, the Internet of Things, automotive electronics, high-performance computing, 5G and artificial intelligence, especially the high-speed, high-frequency and heterogeneous integration requirements of 5G, advanced packaging technology needs to be continuously innovated and developed.
[0003] Composite Right- / Left-Handed (CRLH) transmission line theory is widely used in filter miniaturization design. The CRLH structure utilizes the phase lead of the left-handed characteristic and the phase delay of the right-handed characteristic to generate zero-order resonance, thereby lowering the resonant frequency without increasing size. However, current CRLH resonators are mostly based on planar structures (such as interdigitated capacitors and spiral inductors). In the millimeter-wave band, their parasitic parameters are difficult to control precisely, and the energy constraint capability of a two-dimensional plane is limited, making it difficult to obtain extremely high Q values. This restricts further improvements in filter selectivity and out-of-band rejection. Summary of the Invention
[0004] To address the aforementioned problems in the existing technology, this invention provides a high roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line. The technical problem to be solved by this invention is achieved through the following technical solution: This invention provides a high roll-off and low loss broadband filter based on a three-dimensional composite left- and right-handed transmission line, comprising a first metal layer, a glass dielectric layer, and a second metal layer stacked sequentially from top to bottom; the glass dielectric layer has a plurality of through dielectric vias, the through dielectric vias are filled with metal conductor pillars, and the two ends of the metal conductor pillars are respectively connected to the first metal layer and the second metal layer, together forming at least one resonant cavity; The first metal layer comprises: a main metal sheet, a first metal sheet, a second metal sheet, a first auxiliary metal sheet, a second auxiliary metal sheet, and a third auxiliary metal sheet; wherein, The first metal sheet and the second metal sheet are connected to the main metal sheet as the input port and output port of the broadband filter, respectively, and are symmetrically arranged. A first coupling metal sheet is provided on both sides of the outer end of the first metal sheet away from the main metal sheet, and a second coupling metal sheet symmetrical to the first coupling metal sheet is provided on both sides of the outer end of the second metal sheet away from the main metal sheet. The first metal sheet, the second metal sheet, and the third metal sheet surround the outer periphery of the main metal sheet to form an EMSIW resonant cavity, and a groove structure is provided between them and the main metal sheet; the ends of the first metal sheet and the second metal sheet are connected to the main metal sheet; the third metal sheet is connected to the main metal sheet through a fourth metal sheet. The main metal sheet has a fifth groove, and the fifth groove has an eleventh metal sheet and a twelfth metal sheet connected to the main metal sheet, forming a three-dimensional coupling capacitor loaded in the EMSIW resonant cavity. A sixth groove, a seventh groove, and an eighth groove are respectively provided on the second metal layer at the positions corresponding to the EMSIW resonant cavity region, the first coupling metal sheet region, and the second coupling metal sheet region; a thirteenth metal sheet and a fourteenth metal sheet are provided in the sixth groove; The seventh groove contains a third coupling metal sheet that forms a three-dimensional coupling inductance with the first coupling metal sheet, and the eighth groove contains a fourth coupling metal sheet that forms a three-dimensional coupling inductance with the second coupling metal sheet. The two three-dimensional coupling inductors are connected to the first metal sheet and the second metal sheet respectively.
[0005] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The high roll-off low loss broadband filter based on three-dimensional composite left and right hand transmission lines of the present invention significantly reduces the resonant frequency of the resonant cavity by constructing an EMSIW resonant cavity on the first metal layer and etching grooves around it, thereby achieving miniaturization and compactness of the filter area.
[0006] 2. The high roll-off and low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line of this invention creatively constructs a composite left- and right-handed transmission line structure in three-dimensional space. Specifically, it generates a transmission zero on the left side of the passband by setting a coupling metal sheet of a specific shape within the main metal sheet to form a three-dimensional coupling capacitor, thereby accelerating low-frequency roll-off; and it generates a transmission zero on the right side of the passband by loading a three-dimensional coupling inductor composed of interlayer metal sheets at the input / output ports to enhance high-frequency suppression. The synergistic effect of the zeros on the left and right sides together shapes a broadband passband with steep edges and extremely high selectivity.
[0007] 3. The high roll-off low loss broadband filter based on three-dimensional composite left and right hand transmission lines of the present invention utilizes the vertical integration advantages of glass-based three-dimensional packaging. Through the precise layout of metal conductor pillars and interlayer metal sheets, a complex and controllable three-dimensional electromagnetic coupling is formed, which effectively improves the energy confinement capability and Q value, thereby achieving low-loss broadband filtering. The measured relative bandwidth is as high as 72.72%, demonstrating excellent performance.
[0008] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description
[0009] Figure 1 This is a front view cross-sectional view of a high-roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line provided in an embodiment of the present invention. Figure 2 This is a top view of the first metal layer provided in an embodiment of the present invention; Figure 3 This is a top view of the second metal layer provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the frequency response of a high-roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line provided in an embodiment of the present invention.
[0010] icon: 1-First metal layer; 2-Glass dielectric layer; 3-Second metal layer; 4-Metal conductor pillar; 101-Main metal sheet; 102-First metal sheet; 103-Second metal sheet; 104-Third metal sheet; 105-Fourth metal sheet; 5-First metal sheet; 6-Second metal sheet; 7-First groove; 8-Second groove; 9-Third groove; 10-Fourth groove; 11-Third metal sheet; 12-Fourth metal sheet; 13-Fifth metal sheet; 14-Sixth metal sheet; 15-Seventh metal sheet; 16-Eighth metal sheet; 17-Ninth metal sheet; 18-Tenth metal sheet; 19-Fifth groove; 20-Eleventh metal sheet; 21-Twelfth metal sheet; 22-Sixth groove; 23-Seventh groove; 24-Eighth groove; 25-Thirteenth metal sheet; 26-Fourteenth metal sheet; 27-Fifteenth metal sheet; 28-Sixteenth metal sheet; 29-Seventeenth metal sheet; 30-Eighteenth metal sheet. Detailed Implementation
[0011] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following describes in detail a high-roll-off loss-reducing broadband filter based on a three-dimensional composite left- and right-handed transmission line proposed according to the present invention, in conjunction with the accompanying drawings and specific embodiments.
[0012] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.
[0013] This invention provides a high roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line. Please refer to [link / reference]. Figure 1 , Figure 1 This is a front cross-sectional view of a high-roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to an embodiment of the present invention. Figure 1 As shown, the high roll-off low loss broadband filter based on a three-dimensional composite left-handed transmission line of the present invention has an overall three-layer vertical stacked structure, including a first metal layer 1, a glass dielectric layer 2, and a second metal layer 3 stacked sequentially from top to bottom. The glass dielectric layer 2 has a thickness of 200 μm and is made of glass. Multiple through-holes are formed in the glass dielectric layer 2, and the through-holes are frustoconical in shape, with a diameter d1 of 50 μm near the first metal layer 1 and a diameter d2 of 25 μm near the second metal layer 3. Each through-hole is filled with a copper metal conductor pillar 4. The two ends of the metal conductor pillar 4 are electrically connected to the first metal layer 1 and the second metal layer 3, respectively, together forming and defining an electromagnetic bandgap integrated substrate waveguide resonant cavity.
[0014] In this embodiment, the first metal layer 1 is entirely composed of copper. Please refer to [link / reference]. Figure 2 , Figure 2 This is a top view of the first metal layer provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the first metal layer 1 includes: a main metal sheet 101, a first metal sheet 5, a second metal sheet 6, a first branch metal sheet 102, a second branch metal sheet 103, and a third branch metal sheet 104. The main metal sheet 101 is formed by combining a rectangular portion and an inverted triangular portion. The two ends of the rectangular portion of the main metal sheet 101 along its length are respectively connected to the first metal sheet 5 as an input port and the second metal sheet 6 as an output port. The first metal sheet 5 and the second metal sheet 6 are symmetrically arranged, each with a length w1 of 840 μm and a width w2 of 400 μm. They are separated from the other parts of the main metal sheet 101 by etched gaps.
[0015] First coupling metal sheets are provided on both sides of the outer end of the first metal sheet 5, which is away from the main metal sheet 101. These first coupling metal sheets include a third metal sheet 11, a fourth metal sheet 12, a fifth metal sheet 13, and a sixth metal sheet 14. The third metal sheet 11 and the fifth metal sheet 13 are disposed opposite each other on both sides of the outer end of the first metal sheet 5, with the same gap between them. The length w3 of both the third metal sheet 11 and the fifth metal sheet 13 is 150 μm, and the distance w0 between them is 210 μm. The fourth metal sheet 12 is disposed adjacent to and spaced apart from the fifth metal sheet 13, and connected to the first metal sheet 5. The length w4 of the fourth metal sheet 12 is 130 μm.
[0016] The sixth metal sheet 14 is disposed adjacent to and spaced apart from the fourth metal sheet 12 and extends downward toward the fourth metal sheet 12. The length w5 of the sixth metal sheet 14 is 389 μm. Symmetrically, on both sides of the outer end of the second metal sheet 6 away from the main metal sheet 101, second coupling metal sheets are provided. Their structure is mirror-symmetrical to the first coupling metal sheet and includes a seventh metal sheet 15, an eighth metal sheet 16, a ninth metal sheet 17, and a tenth metal sheet 18. The relevant dimensions are the same as the aforementioned corresponding components.
[0017] The outer periphery of the main metal sheet 101 is surrounded by a first metal sheet 102, a second metal sheet 103, and a third metal sheet 104, which together form the boundary of the EMSIW resonant cavity. The first metal sheet 102 is separated from the main metal sheet 101 by a first groove 7, and the second metal sheet 103 is separated from the main metal sheet 101 by a second groove 8. The third metal sheet 104 is connected to the middle of the rectangular long side of the main metal sheet 101 by a fourth metal sheet 105. A third groove 9 and a fourth groove 10 are formed on both sides of the fourth metal sheet 105 between the third metal sheet 104 and the main metal sheet 101. The width w6 of both the third groove 9 and the fourth groove 10 is 50 μm. The length w9 of the third metal sheet 104 is 1420 μm. The first metal sheet 102 and the second metal sheet 103 are located on both sides of the inverted triangular portion of the main metal sheet 101 and are connected to form a V-shaped structure. The top of the V-shaped structure is connected to the top of the inverted triangular portion of the main metal sheet 101. The width w10 of the first metal sheet 102 and the second metal sheet 103 is 90 μm. The base w11 of the inverted triangular portion of the main metal sheet 101 is 1820 μm, the height w12 of the main metal sheet 101 is 950 μm, and the distance w13 from the geometric center line of the main metal sheet 101 to the outer end of the first metal sheet 5 or the second metal sheet 6 is 1750 μm.
[0018] In the central region of the main metal sheet 101, a rectangular fifth groove 19 is etched, with a length w7 of 778 μm and a width w8 of 420 μm. Two eleventh metal sheets 20 and twelfth metal sheets 21, connected to the main metal sheet 101, are disposed within the fifth groove 19, forming a three-dimensional coupling capacitor loaded within the EMSIW resonant cavity. Specifically, the eleventh metal sheet 20 consists of a first rectangular portion perpendicularly connected to a short sidewall of the fifth groove 19, a second rectangular portion perpendicularly connected to the free end of the first rectangular portion, and a third rectangular portion perpendicularly connected to the free end of the second rectangular portion, wherein the free end of the third rectangular portion is 529 μm long (w15) from the short sidewall of the first rectangular portion. The twelfth metal sheet 21 consists of a fourth rectangular portion perpendicularly connected to the other short sidewall of the fifth groove 19, and a fifth rectangular portion perpendicularly connected to the fourth rectangular portion, wherein the fourth rectangular portion has a length w16 of 529 μm, and the fifth rectangular portion has a length w14 of 270 μm. The eleventh metal sheet 20 and the twelfth metal sheet 21 are 60 μm apart in the length direction (w17) and 110 μm apart in the width direction (w18).
[0019] Multiple dielectric vias and metal conductor pillars 4 are distributed on the first metal sheet 102, the second metal sheet 103, the third metal sheet 104, and the main metal sheet 101 on the first metal layer 1, for connecting to the second metal layer 3 below. Specifically, the center-to-center distance pTGV1 between adjacent metal conductor pillars 4 on the third metal sheet 104 located above the third groove 9 and the fourth groove 10 is 120 μm; the center-to-center distance pTGV2 between adjacent metal conductor pillars 4 on the first metal sheet 102 and the second metal sheet 103 located below the EMSIW cavity and forming a V-shaped structure is 120 μm.
[0020] The second metal layer 3 is also made of copper and serves as the ground layer for the filter. (See also...) Figure 3 , Figure 3 This is a top view of the second metal layer provided in an embodiment of the present invention, as shown below. Figure 3As shown, on the second metal layer 3, corresponding to the EMSIW resonant cavity region, the first coupling metal sheet region, and the second coupling metal sheet region above, a sixth groove 22, a seventh groove 23, and an eighth groove 24 are etched, respectively. The sixth groove 22 has a length w19 of 778 μm and a width w20 of 420 μm, and a thirteenth metal sheet 25 and a fourteenth metal sheet 26 are disposed therein for vertical coupling and tuning with the three-dimensional coupling capacitor structure above. Specifically, the thirteenth metal sheet 25 includes a sixth rectangular portion and a seventh rectangular portion. The first end of the sixth rectangular portion is connected to the second end of the fourth rectangular portion of the twelfth metal sheet 21 through a metal conductor post 4. The first end of the seventh rectangular portion is perpendicularly connected to the second end of the sixth rectangular portion, and the second end of the seventh rectangular portion is connected to the second end of the fifth rectangular portion of the twelfth metal sheet 21 through a metal conductor post 4. The fourteenth metal sheet 26 includes an eighth rectangular portion and a ninth rectangular portion. The eighth rectangular portion is arranged parallel to the sixth rectangular portion of the thirteenth metal sheet 25, and the ninth rectangular portion is arranged parallel to the seventh rectangular portion of the thirteenth metal sheet 25. The first end of the eighth rectangular portion is connected to the second end of the third rectangular portion of the eleventh metal sheet 20 through a metal conductor post 4. The first end of the ninth rectangular portion is perpendicularly connected to the second end of the eighth rectangular portion, and the second end of the ninth rectangular portion is connected to the junction of the first and second rectangular portions of the eleventh metal sheet 20 through a metal conductor post 4. The length w21 of both the thirteenth metal sheet 25 and the fourteenth metal sheet 26 is 420 μm, and the width w22 of both is 270 μm. The distance w23 between the thirteenth metal sheet 25 and the fourteenth metal sheet 26 in the length direction is 60 μm, and the distance w24 in the width direction is 110 μm.
[0021] The seventh groove 23 contains a third coupling metal sheet, specifically a fifteenth metal sheet 27 and a sixteenth metal sheet 28 arranged parallel to each other along the length direction. They are connected to the first coupling metal sheet of the first metal layer 1 through a specific metal conductor post 4 to form a three-dimensional coupled inductor. Specifically, the first end of the fifteenth metal sheet 27 is connected to the fourth metal sheet 12 through a metal conductor post 4, and the second end is connected to the end of the sixth metal sheet 14 located below the fourth metal sheet 12 through a metal conductor post 4; the first end of the sixteenth metal sheet 28 is connected to the end of the sixth metal sheet 14 located on the side of the fourth metal sheet 12 through a metal conductor post 4, and the second end is connected to the second metal layer 3 on the long side of the seventh groove 23.
[0022] The seventh groove 23 comprises two parts, with widths w25 of 400 μm and w29 of 370 μm, and lengths w26 of 340 μm and w31 of 150 μm. The lengths w27 of the fifteenth metal sheet 27 and w28 of the sixteenth metal sheet 28 are 321 μm and 330 μm, respectively, and are 60 μm apart by w30. Symmetrically, the eighth groove 24 contains the fourth coupling metal sheets, namely the seventeenth metal sheet 29 and the eighteenth metal sheet 30, whose structure is mirror-symmetrical to the third coupling metal sheet, and is used to form another three-dimensional coupled inductor with the second coupling metal sheet of the first metal layer 1. The eighth groove 24 has a width w32 of 490 μm and a length w33 of 340 μm. The widths w35 of the seventeenth metal sheet 29 and w34 of the eighteenth metal sheet 30 are 450 μm and 321 μm, respectively, and are 60 μm apart by w36.
[0023] This invention relates to a high roll-off and low-loss broadband filter based on a three-dimensional composite left-handed and right-handed transmission line. By constructing an EMSIW resonant cavity on the first metal layer and etching grooves around it, the resonant frequency of the cavity is significantly reduced, achieving miniaturization and compactness of the filter area. The invention creatively constructs a composite left-handed and right-handed transmission line structure in three-dimensional space. Specifically, a three-dimensional coupling capacitor is formed by setting a coupling metal sheet of a specific shape within the main metal sheet, generating a transmission zero on the left side of the passband to accelerate low-frequency roll-off. A three-dimensional coupling inductor composed of interlayer metal sheets is loaded at the input / output ports, generating a transmission zero on the right side of the passband to enhance high-frequency suppression. The synergistic effect of the left and right zeros together creates a broadband passband with steep edges and extremely high selectivity.
[0024] The working principle of the filter in this embodiment is as follows: The electromagnetic wave signal is fed in from the first metal plate 5, i.e., the input port. The input signal directly excites the input-side EMSIW resonant cavity formed by the main metal plate 101, the peripheral metal plates, and the metal conductor pillars 4; on the other hand, the signal energy is coupled through the first metal plate 5 to the port structure formed by the third, fourth, fifth, and sixth metal plates on both sides and below it. This port structure is connected to the fifteenth and sixteenth metal plates in the seventh groove 23 of the second metal layer 3 through the vertical metal conductor pillars 4, forming a three-dimensional spiral inductor structure. This parallel inductor generates a transmission zero at a high frequency on the right side of the passband, realizing out-of-band suppression of high-frequency signals.
[0025] Inside the EMSIW resonant cavity, the main signal transmission path needs to pass through the three-dimensional coupling capacitor structure formed by the eleventh and twelfth metal plates within the fifth groove 19. This series capacitor generates a transmission zero at a low frequency on the left side of the passband, thus achieving a steep roll-off at the low-frequency end. Simultaneously, the thirteenth and fourteenth metal plates within the sixth groove 22 of the second metal layer 3 below the resonant cavity, through vertical electromagnetic coupling with the capacitor structure above, finely tune the resonant mode of the cavity, helping to expand the bandwidth and optimize in-band flatness.
[0026] Finally, the filtered signal is coupled to the EMSIW resonant cavity on the output side through a symmetrical path and output from the second metal plate 6, i.e., the output port. This is achieved thanks to the combined effect of the zero points of the capacitor on the left and the inductor on the right, as well as the high Q value and controllable coupling provided by the three-dimensional structure. (See also...) Figure 4 , Figure 4 This is a schematic diagram of the frequency response of a high-roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line provided in an embodiment of the present invention, as shown below. Figure 4 As shown, this filter achieves a center frequency of 50.785 GHz, a 3dB bandwidth of 36.93 GHz, a relative bandwidth of 72.72%, and excellent performance with high out-of-band rejection, steep roll-off, and low insertion loss.
[0027] The high roll-off low loss broadband filter structure based on three-dimensional composite left and right hand transmission lines in this invention can be fabricated using mature glass via technology and electroplating technology. It has good process compatibility, is easy to integrate heterogeneously with active chips, and is suitable for advanced system-in-package.
[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device comprising said element. Terms such as "connected" or "linked" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by terms such as "upper," "lower," "left," and "right" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.
[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.
[0030] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.
Claims
1. A high-roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line, characterized in that, It includes a first metal layer (1), a glass dielectric layer (2), and a second metal layer (3) stacked sequentially from top to bottom; the glass dielectric layer (2) has multiple through-holes, and the through-holes are filled with metal conductor pillars (4). The two ends of the metal conductor pillars (4) are respectively connected to the first metal layer (1) and the second metal layer (3), which together form at least one resonant cavity; The first metal layer (1) includes: a main metal sheet (101), a first metal sheet (5), a second metal sheet (6), a first auxiliary metal sheet (102), a second auxiliary metal sheet (103), and a third auxiliary metal sheet (104); wherein, The first metal sheet (5) and the second metal sheet (6) are connected to the main metal sheet (101) as the input port and output port of the broadband filter, respectively, and are arranged symmetrically. A first coupling metal sheet is provided on both sides of the outer end of the first metal sheet (5) away from the main metal sheet (101), and a second coupling metal sheet symmetrical to the first coupling metal sheet is provided on both sides of the outer end of the second metal sheet (6) away from the main metal sheet (101). The first metal sheet (102), the second metal sheet (103), and the third metal sheet (104) surround the outer periphery of the main metal sheet (101) to form an EMSIW resonant cavity, and a groove structure is provided between them and the main metal sheet (101); the end of the first metal sheet (102) is connected to the end of the second metal sheet (103) and is connected to the main metal sheet (101); the third metal sheet (104) is connected to the main metal sheet (101) through a fourth metal sheet (105); The main metal sheet (101) is provided with a fifth groove (19), and the fifth groove (19) is provided with an eleventh metal sheet (20) and a twelfth metal sheet (21) connected to the main metal sheet (101), forming a three-dimensional coupling capacitor loaded in the EMSIW resonant cavity; A sixth groove (22), a seventh groove (23), and an eighth groove (24) are respectively provided on the second metal layer (3) at the positions corresponding to the EMSIW resonant cavity region, the first coupling metal sheet region, and the second coupling metal sheet region; a thirteenth metal sheet (25) and a fourteenth metal sheet (26) are provided in the sixth groove (22); The seventh groove (23) is provided with a third coupling metal sheet that forms a three-dimensional coupling inductance with the first coupling metal sheet, and the eighth groove (24) is provided with a fourth coupling metal sheet that forms a three-dimensional coupling inductance with the second coupling metal sheet. The two three-dimensional coupling inductors are connected to the first metal sheet (5) and the second metal sheet (6) respectively.
2. The high roll-off low loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 1, characterized in that, The first coupling metal sheet includes: a third metal sheet (11), a fourth metal sheet (12), a fifth metal sheet (13), and a sixth metal sheet (14); wherein, The third metal sheet (11) and the fifth metal sheet (13) are disposed opposite to each other on both sides of the outer end of the first metal sheet (5). The fourth metal sheet (12) is disposed adjacent to the fifth metal sheet (13) and connected to the first metal sheet (5). The sixth metal sheet (14) is disposed adjacent to the fourth metal sheet (12) and extends downward toward the fourth metal sheet (12).
3. The high roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 2, characterized in that, The third coupling metal sheet includes a fifteenth metal sheet (27) and a sixteenth metal sheet (28) arranged parallel to each other along the length direction; wherein, The first end of the fifteenth metal sheet (27) is connected to the fourth metal sheet (12) through a metal conductor post (4), and the second end is connected to the end of the sixth metal sheet (14) located below the fourth metal sheet (12) through a metal conductor post (4). The first end of the sixteenth metal sheet (28) is connected to the end of the sixth metal sheet (14) located on the side of the fourth metal sheet (12) via a metal conductor post (4), and the second end is connected to the second metal layer (3) on the long side of the seventh groove (23).
4. The high roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 1, characterized in that, The second coupling metal sheet includes: a seventh metal sheet (15), an eighth metal sheet (16), a ninth metal sheet (17), and a tenth metal sheet (18); wherein, The seventh metal sheet (15) and the tenth metal sheet (18) are disposed opposite to each other on both sides of the outer end of the second metal sheet (6). The eighth metal sheet (16) is disposed adjacent to the tenth metal sheet (18) and connected to the second metal sheet (6). The ninth metal sheet (17) is disposed adjacent to the eighth metal sheet (16) and extends downward toward the eighth metal sheet (16).
5. The high roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 4, characterized in that, The fourth coupling metal sheet includes a seventeenth metal sheet (29) and an eighteenth metal sheet (30) arranged parallel to each other along the length direction; wherein, The first end of the seventeenth metal sheet (29) is connected to the end of the ninth metal sheet (17) located on the side of the eighth metal sheet (16) via a metal conductor post (4), and the second end is connected to the second metal layer (3) on the long side of the eighth groove (24). The first end of the eighteenth metal sheet (30) is connected to the eighth metal sheet (16) through a metal conductor post (4), and the second end is connected to the end of the ninth metal sheet (17) located below the eighth metal sheet (16) through a metal conductor post (4).
6. The high roll-off low loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 1, characterized in that, The groove structure includes: a first groove (7) between the first metal sheet (102) and the main metal sheet (101), a second groove (8) between the second metal sheet (103) and the main metal sheet (101), and a third groove (9) and a fourth groove (10) between the third metal sheet (104) and the main metal sheet (101) located on both sides of the fourth metal sheet (105).
7. The high roll-off low loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 1, characterized in that, The main metal sheet (101) includes a rectangular portion and an inverted triangular portion connected to the rectangular portion; The first metal sheet (5) and the second metal sheet (6) are connected to the two ends of the long side of the rectangular portion of the main metal sheet (101); The first metal sheet (102) and the second metal sheet (103) are disposed on both sides of the inverted triangular portion of the main metal sheet (101) and connected to form a V-shaped structure. The top of the V-shaped structure is connected to the top of the inverted triangular portion of the main metal sheet (101). The third metal sheet (104) is disposed on one side of the long side of the rectangular portion of the main metal sheet (101) and located between the first metal sheet (5) and the second metal sheet (6); The main metal sheet (101), the first metal sheet (102), the second metal sheet (103) and the third metal sheet (104) are all connected to the second metal layer (3) through multiple metal conductor pillars (4).
8. The high roll-off low-loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 1, characterized in that, The fifth groove (19) is a rectangular groove; the eleventh metal sheet (20) includes a first rectangular part, a second rectangular part and a third rectangular part, the first end of the first rectangular part is perpendicularly connected to the main metal sheet (101) on one short side of the rectangular groove, the first end of the second rectangular part is perpendicularly connected to the second end of the first rectangular part, and the first end of the third rectangular part is perpendicularly connected to the second end of the second rectangular part. The twelfth metal sheet (21) includes a fourth rectangular portion and a fifth rectangular portion. The first end of the fourth rectangular portion is perpendicularly connected to the main metal sheet (101) on the other short side of the rectangular groove. The first end of the fifth rectangular portion is perpendicularly connected to the first rectangular portion and close to the first end of the fourth rectangular portion.
9. The high roll-off low loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 8, characterized in that, The thirteenth metal sheet (25) includes a sixth rectangular portion and a seventh rectangular portion. The first end of the sixth rectangular portion is connected to the second end of the fourth rectangular portion of the twelfth metal sheet (21) through a metal conductor post (4). The first end of the seventh rectangular portion is perpendicularly connected to the second end of the sixth rectangular portion. The second end of the seventh rectangular portion is connected to the second end of the fifth rectangular portion of the twelfth metal sheet (21) through a metal conductor post (4). The fourteenth metal sheet (26) includes an eighth rectangular portion and a ninth rectangular portion. The eighth rectangular portion is arranged parallel to the sixth rectangular portion of the thirteenth metal sheet (25), and the ninth rectangular portion is arranged parallel to the seventh rectangular portion of the thirteenth metal sheet (25). The first end of the eighth rectangular portion is connected to the second end of the third rectangular portion of the eleventh metal sheet (20) through a metal conductor post (4). The first end of the ninth rectangular portion is perpendicularly connected to the second end of the eighth rectangular portion. The second end of the ninth rectangular portion is connected to the connection between the first rectangular portion and the second rectangular portion of the eleventh metal sheet (20) through a metal conductor post (4).
10. The high roll-off low loss broadband filter based on a three-dimensional composite left- and right-handed transmission line according to claim 1, characterized in that, The diameter of the end of the medium through hole near the first metal layer (1) is greater than the diameter of the end near the second metal layer (3).