Large-bandwidth high-suppression low-loss ceramic dielectric band-pass filter

Abstract

The invention provides a large-bandwidth high-suppression low-loss ceramic dielectric band-pass filter, and relates to the technical field of filters. The ceramic dielectric band-pass filter is composed of a ceramic dielectric main body and a metal shielding cover. The ceramic dielectric main body is provided with an open surface and a short-circuit surface, and is provided with five third resonance through holes, two second resonance through holes (located on the two sides of the five third resonance through holes) and two first resonance through holes (located on the two sides of the second resonance through holes). And the metal shielding cover covers part of the open surface. The surface of the main body is covered with a metal covering layer, and one side of the open surface of the metal covering layer is provided with a first isolation groove (surrounding the first and second resonance through holes) and first and second capacitance grooves (located between the first and second resonance through holes) to form a first metal loading layer, a second metal loading layer and an output electrode. And a second isolation groove is additionally arranged to surround the third resonance through hole and the third metal loading layer. And an inductance line layer is formed between the two isolation grooves. The output electrode extends from the open surface to the side surface.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and in particular to a ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss. Background Art

[0002] Ceramic dielectric filters are used in modern microwave communication systems to obtain the required frequency range through precise filtering. The design of this filter utilizes the coupling between dielectric resonators to achieve high Q value, low insertion loss, miniaturization and light weight. These characteristics have led to the widespread use of ceramic dielectric filters in routers, wireless base stations, satellite communications, navigation systems, and electronic countermeasures.

[0003] With the continuous advancement of communication technology, especially in the application of WiFi6 and WiFi7 communication protocols, the performance requirements for filters are getting higher and higher. These new generation communication protocols require filters to have a larger bandwidth to accommodate more frequency bands and provide higher data throughput. In addition, in order to ensure the quality of communication, the filter also needs to have stronger interference signal suppression capabilities and lower loss performance to ensure high-quality signal transmission.

[0004] Therefore, the design and optimization of ceramic dielectric filters has become a difficult problem in the development of communication technology. Researchers are faced with the challenge of how to improve the bandwidth and signal processing capabilities while keeping the filters small and lightweight. Summary of the invention

[0005] The present invention provides a ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss, aiming to improve at least one of the above technical problems.

[0006] In order to solve the above technical problems, the present invention provides a ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss, which comprises a ceramic dielectric body and a metal shielding cover connected to the ceramic dielectric body.

[0007] The ceramic dielectric body is constructed with an open surface and a short-circuit surface, and two first resonant through holes, two second resonant through holes and five third resonant through holes are arranged through the open surface and the short-circuit surface. The two second resonant through holes are arranged on both sides of the five third resonant through holes. The two first resonant through holes are arranged on both sides of the two first resonant through holes. The metal shield is suitable for covering at least part of the open surface.

[0008] The bandpass filter further includes a metal covering layer disposed on the surface of the ceramic dielectric body.

[0009] The metal covering layer is provided with a first isolation groove on the open surface that encloses the first resonant through hole and the second resonant through hole on the same side, and a first capacitor groove and a second capacitor groove that are provided between the first resonant through hole and the second resonant through hole, so as to form a first metal loading layer at one end of the first resonant through hole located at the open surface, a second metal loading layer at one end of the second resonant through hole located at the open surface, and an output electrode between the first metal loading layer and the second metal loading layer. The first isolation groove encloses the first metal loading layer, the second metal loading layer and the output electrode. The output electrode extends from the open surface to the side between the open surface and the short-circuit surface.

[0010] The metal covering layer is further provided with a second isolation slot encircling the five third resonant through holes on the open surface, and four third capacitance slots arranged between the five third resonant through holes, so that a third metal loading layer is arranged at one end of the third resonant through hole located on the open surface. The second isolation slot encircles the five third metal loading layers.

[0011] An inductor layer is formed between the first isolation trench and the second isolation trench.

[0012] In an optional embodiment, the metal covering layer is a silver covering layer, a gold covering layer or a copper covering layer.

[0013] In an optional implementation, the output electrode and the first metal loading layer are configured as capacitive coupling.

[0014] The output electrode and the second metal loading layer are configured as a capacitive coupling electrode.

[0015] The second resonant through hole and the adjacent third resonant through hole are inductively coupled via an inductor layer.

[0016] Two adjacent third resonant through holes are capacitively coupled via a third capacitor slot.

[0017] In an optional embodiment, at least a portion of the output electrode extends along the length direction of the ceramic dielectric body to one side of the first resonance through hole.

[0018] The output electrode is provided with a plurality of first coupling tooth-shaped portions. The second metal loading layer is provided with a plurality of second coupling tooth-shaped portions. The plurality of first coupling tooth-shaped portions and the plurality of second coupling tooth-shaped portions are staggered in three directions in which the second resonant through hole portion is not close to the third resonant through hole.

[0019] The third metal loading layer is provided with a plurality of third coupling tooth-shaped parts, and the third coupling tooth-shaped parts between two adjacent third metal loading layers are arranged alternately.

[0020] In an optional embodiment, the surface of the ceramic dielectric body is covered with the metal covering layer except for the first isolation groove, the second isolation groove, the first capacitor groove, the second capacitor groove and the third capacitor groove.

[0021] The first isolation groove, the second isolation groove, the first capacitor groove, the second capacitor groove and the third capacitor groove are obtained by laser engraving process.

[0022] In an optional embodiment, the first resonant through hole is configured as a resonance-suppressing step through hole. The first resonant through hole includes a large resonant hole disposed on one side of the open surface, and a small resonant hole disposed on one side of the short-circuit surface. The aperture of the large resonant hole is larger than the aperture of the small resonant hole.

[0023] In an optional embodiment, the diameter D2 of the small resonance hole is 0.2 to 0.85 times the diameter D1 of the large resonance hole.

[0024] The depth of the large resonance hole is 0.1 to 0.7 times the depth of the small resonance hole.

[0025] In an optional embodiment, the two first resonant through holes, the two second resonant through holes and the five third resonant through holes are symmetrically arranged; Two first isolation slots, a second isolation slot, two first capacitor slots, two second capacitor slots, four third capacitor slots, two output electrodes, two first metal loading layers, two second metal loading layers, and five third metal loading layers are axially symmetrically arranged.

[0026] In an optional embodiment, the central axes of the first resonant through hole and the second resonant through hole are respectively located on both sides of the width center plane of the ceramic dielectric body.

[0027] A distance A from the central axis of the first resonant through hole to the width center plane of the ceramic dielectric body is 0.3 mm to 0.9 mm.

[0028] A distance B from the central axis of the second resonant through hole to the width center plane of the ceramic dielectric body is 0.1 mm to 0.5 mm.

[0029] A distance C from the central axis of the third resonance through hole to the width center plane of the ceramic dielectric body is 0 mm to 0.2 mm.

[0030] In an optional embodiment, the distance A is 0.3 mm.

[0031] The distance B is 0.12 mm.

[0032] The diameter of the second resonant through hole is 9 mm.

[0033] The thickness of the metal covering layer is 10um.

[0034] In an optional embodiment, the metal shield is made of copper alloy and is obtained by a stamping process. The metal shield is bonded to the porcelain dielectric body by a conductive metal.

[0035] By adopting the above technical solution, the present invention can achieve the following technical effects: In the embodiment of the present invention, a bandpass filter of a ceramic dielectric with large bandwidth, high suppression and low loss is provided with a first resonant through hole, which can conveniently control the frequency position of the desired suppression point and enhance the filtering effect. The second resonant through hole and the adjacent third-type resonant through hole are coupled by an inductor line, and the high-frequency end suppression effect is good. The third resonant through holes are coupled to each other by a capacitor slot, which can increase the amount of capacitive coupling, obtain a larger bandwidth and smaller insertion loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the specific embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 is an axonometric diagram of a bandpass filter.

[0038] Figure 2 is an exploded diagram of a bandpass filter.

[0039] Figure 3 It is an axonometric view of the front side of the ceramic dielectric body.

[0040] Figure 4 It is a front view of the ceramic dielectric body.

[0041] Figure 5 is an axonometric view of the back side of a ceramic dielectric body.

[0042] Figure 6 This is the actual test waveform of the ceramic dielectric bandpass filter (the horizontal axis is frequency).

[0043] Markings in the figure: 1-ceramic dielectric body, 2-metal shielding cover, 3-first resonant through hole, 4-second resonant through hole, 5-third resonant through hole, 6-inductor layer, 7-third metal loading layer, 8-second metal loading layer, 9-first metal loading layer, 10-first capacitor slot, 11-second capacitor slot, 12-first isolation slot, 13-output electrode, 14-second isolation slot, 15-third capacitor slot, 16-side surface, 17-open surface, 18-third coupling tooth-shaped portion, 19-second coupling tooth-shaped portion, 20-first coupling tooth-shaped portion, 21-short-circuit surface. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0045] Depend on Figures 1 to 6 As shown, an embodiment of the present invention provides a ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss, which includes a ceramic dielectric body 1 and a metal shielding cover 2 connected to the ceramic dielectric body 1.

[0046] The ceramic dielectric body 1 is constructed with an open surface 17 and a short-circuit surface 21. Two first resonant through holes 3, two second resonant through holes 4 and five third resonant through holes 5 are arranged through the open surface 17 and the short-circuit surface 21. The two second resonant through holes 4 are respectively arranged on both sides of the five third resonant through holes 5. The two first resonant through holes 3 are respectively arranged on both sides of the two first resonant through holes 3. The metal shield 2 is suitable for covering at least part of the open surface 17.

[0047] The metal covering layer is provided with a first isolation slot 12 on the open surface 17 that encloses the first resonant through hole 3 and the second resonant through hole 4 on the same side, and a first capacitor slot 10 and a second capacitor slot 11 that are provided between the first resonant through hole 3 and the second resonant through hole 4, so that a first metal loading layer 9 is formed at one end of the first resonant through hole 3 located at the open surface 17, a second metal loading layer 8 is formed at one end of the second resonant through hole 4 located at the open surface 17, and an output electrode 13 is formed between the first metal loading layer 9 and the second metal loading layer 8. The first isolation slot 12 encloses the first metal loading layer 9, the second metal loading layer 8 and the output electrode 13. The output electrode 13 extends from the open surface 17 to the side surface 16 between the open surface 17 and the short-circuit surface 21.

[0048] The metal covering layer is further provided with a second isolation slot 14 enclosing the five third resonant through holes 5 on the open surface 17, and four third capacitor slots 15 arranged between the five third resonant through holes 5, so that a third metal loading layer 7 is arranged at one end of the third resonant through hole 5 located on the open surface 17. The second isolation slot 14 encloses the five third metal loading layers 7.

[0049] An inductor layer 6 is formed between the first isolation trench 12 and the second isolation trench 14 .

[0050] A bandpass filter of a ceramic dielectric with large bandwidth, high suppression and low loss in an embodiment of the present invention is provided with a first resonant through hole 3, which can conveniently control the frequency position of the desired suppression point and enhance the filtering effect. The second resonant through hole 4 is coupled with the adjacent third-type resonant through hole by an inductor line, and the high-frequency end suppression effect is good. The third resonant through holes 5 are coupled with each other by capacitor slots, which can increase the amount of capacitive coupling, obtain a larger bandwidth and smaller insertion loss.

[0051] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 3As shown, the output electrode 13 and the first metal loading layer 9 are configured as capacitive coupling. The output electrode 13 and the second metal loading layer 8 are configured as capacitive coupling electrodes. The second resonant through hole 4 and the adjacent third resonant through hole 5 are inductively coupled through the inductor layer 6. The adjacent two third resonant through holes 5 are capacitively coupled through the third capacitor slot 15. Specifically, at least part of the output electrode 13 extends to one side of the first resonant through hole 3 along the length direction of the ceramic dielectric body 1. The output electrode 13 is provided with a plurality of first coupling tooth-shaped portions 20. The second metal loading layer 8 is provided with a plurality of second coupling tooth-shaped portions 19. The plurality of first coupling tooth-shaped portions 20 and the plurality of second coupling tooth-shaped portions 19 are staggered in three directions where the second resonant through hole 4 is not close to the third resonant through hole 5. The third metal loading layer 7 is provided with a plurality of third coupling tooth-shaped portions 18. The third coupling tooth-shaped portions 18 between two adjacent third metal loading layers 7 are staggered.

[0052] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 3 As shown, the surface of the ceramic dielectric body 1 is covered with the metal covering layer except for the first isolation groove 12, the second isolation groove 14, the first capacitor groove 10, the second capacitor groove 11 and the third capacitor groove 15. Preferably, the metal covering layer is a silver covering layer. The silver covering layer is adhered to the ceramic dielectric body 1 by a silver immersion metallization process; the thickness of the metal covering layer is 10um. In other embodiments, silver can be replaced with other existing conductive metals such as gold or copper.

[0053] After the surface of the ceramic dielectric body 1 is completely covered with the metal covering layer, the first isolation groove 12, the second isolation groove 14, the first capacitor groove 10, the second capacitor groove 11 and the third capacitor groove 15 are engraved on the metal covering layer by laser engraving technology. Thus, the output electrode 13, the first metal loading layer 9, the second metal loading layer 8 and the third metal loading layer 7 are obtained. In other embodiments, the existing processing methods other than the laser engraving process can also be used for processing, and the present invention does not specifically limit this.

[0054] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 3 and Figure 4As shown, the first resonant through hole 3 is constructed as a resonance-suppressing step through hole. The first resonant through hole 3 includes a large resonant hole arranged on one side of the open surface 17, and a small resonant hole arranged on one side of the short-circuit surface 21. The aperture of the large resonant hole is larger than the aperture of the small resonant hole. Preferably, the diameter D2 of the small resonant hole is 0.2 to 0.85 times the diameter D1 of the large resonant hole. The depth of the large resonant hole is 0.1 to 0.7 times the depth of the small resonant hole.

[0055] Specifically, the large resonant hole and the small resonant hole are coaxially arranged. The diameter D1 of the large resonant hole is 8 mm. The diameter D2 of the small resonant hole is 0.53 times the diameter D1 of the large resonant hole. The depth of the large resonant hole is 0.42 times the depth of the small resonant hole. The diameter of the second resonant through hole 4 is 9 mm. The diameter of the third resonant through hole 5 is 5 mm.

[0056] Based on the above embodiments, in an optional embodiment of the present invention, as Figures 2 to 4 As shown, two first resonant through holes 3, two second resonant through holes 4 and five third resonant through holes 5 are symmetrically arranged; two first isolation slots 12, second isolation slots 14, two first capacitor slots 10, two second capacitor slots 11, four third capacitor slots 15, two output electrodes 13, two first metal loading layers 9, two second metal loading layers 8, and five third metal loading layers 7 are axially symmetrically arranged. Preferably, the central axes of the first resonant through hole 3 and the second resonant through hole 4 are respectively located on both sides of the width center plane of the ceramic dielectric body. The distance A from the central axis of the first resonant through hole 3 to the width center plane of the ceramic dielectric body is 0.3mm to 0.9mm. The distance B from the central axis of the second resonant through hole 4 to the width center plane of the ceramic dielectric body is 0.1mm to 0.5mm. The distance C from the central axis of the third resonant through hole 5 to the width center plane of the ceramic dielectric body is 0mm to 0.2mm. Specifically, the distance A is 0.3mm. The distance B is 0.12mm. The distance C is 0.06mm.

[0057] The present invention is a bandpass filter of a ceramic medium with large bandwidth, high suppression and low loss. Different types of resonant through holes are cleverly arranged on the ceramic medium body 1, including a first resonant through hole 3, a second resonant through hole 4 and a third resonant through hole 5. These through holes achieve precise control of the frequency response characteristics through specific design parameters (such as the ratio of the diameter of the small hole to the large hole, the position of the deviation from the central axis, etc.). In particular, the existence of the first resonant through hole 3 enables the filter to easily adjust the position of the suppression point, so as to better adapt to different application requirements. In addition, by using an inductor line for inductive coupling between the second resonant through hole 4 and the adjacent third resonant through hole 5, the suppression effect of the high frequency end is enhanced, and the signal quality is guaranteed.

[0058] Overall, this filter achieves the goal of wide bandwidth, high suppression and low insertion loss, and meets the requirements of modern communication technology for greater throughput and stronger anti-interference ability without sacrificing signal quality. It is compact in size while maintaining high performance, and is very suitable for use in routers, wireless base stations, satellite communications, navigation systems, electronic countermeasures and other fields, providing strong support for the future development of broadband communications.

[0059] Based on the above embodiments, in an optional embodiment of the present invention, as Figure 1 and Figure 2 As shown, the material of the metal shielding cover 2 is copper alloy, which is obtained by a stamping process. The metal shielding cover 2 is connected to the porcelain dielectric body through a conductive metal.

[0060] The metal shield 2 is constructed as an L-shaped structure, and the two pins are bent downward by stamping in the middle to limit the open surface 17. The metal shield 2 is tightly matched with the ceramic dielectric body 1 by soldering solder paste. The present invention provides a bandpass filter of a ceramic medium with large bandwidth, high suppression and low loss. Two first resonant through holes 3 are arranged on the ceramic medium body 1. The suppression frequency can be controlled by adjusting the size and position of the two first resonant through holes 3, so that the position of the desired suppression point can be conveniently controlled. The second resonant through hole 4 is inductively coupled with the adjacent third resonant through hole 5 by means of an inductor line, so that a better suppression effect at the high frequency end can be obtained. The third resonant through holes 5 are capacitively coupled to each other by means of a capacitor slot, so that the capacitive coupling amount can be conveniently increased to obtain a larger bandwidth and smaller insertion loss.

[0061] like Figure 6 The actual test waveform of the present invention is shown. The center frequency of the product is 6525MHz, the center insertion loss is minimum 0.8dB, the passband range is 5925MHz-7125MHz, and there is a large bandwidth of 1200MHz. As shown in the figure, the suppression of 0-5835MHz is greater than 50db, and the suppression of 7737.5MHz-8500MHz is greater than 50dB. The bandpass filter of the present invention has the characteristics of high suppression.

[0062] It should be noted that Figure 6"db / div" is a unit used to describe the relationship between the amplitude-frequency characteristics of the filter. "db / div" means that in the amplitude-frequency characteristic diagram of the filter, when the decibel (dB) value of the ordinate increases by one unit, the frequency of the abscissa increases by a multiple. "ref.pos" usually represents a reference position (Reference Position) used to control the frequency response characteristics of the filter. This control variable is used to set the nominal frequency of the filter or the reference point of other technical indicators. For example, the nominal frequency (Reference Frequency) specifies the frequency value used to characterize the operating frequency of the filter.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss, characterized in that: It comprises a ceramic dielectric body (1) and a metal shielding cover (2) joined to the ceramic dielectric body (1); The ceramic dielectric body (1) is constructed with an open surface (17) and a short-circuit surface (21); two first resonant through holes (3), two second resonant through holes (4) and five third resonant through holes (5) are arranged through the open surface (17) and the short-circuit surface (21); the two second resonant through holes (4) are arranged on both sides of the five third resonant through holes (5); the two first resonant through holes (3) are arranged on both sides of the two first resonant through holes (3); the metal shielding cover (2) is suitable for covering at least a portion of the open surface (17); The bandpass filter further comprises a metal covering layer arranged on the surface of the ceramic dielectric body (1); The metal covering layer is provided with a first isolation groove (12) on the open surface (17) enclosing the first resonant through hole (3) and the second resonant through hole (4) on the same side, and a first capacitor groove (10) and a second capacitor groove (11) provided between the first resonant through hole (3) and the second resonant through hole (4), so that a first metal loading layer (9) is formed at one end of the first resonant through hole (3) located on the open surface (17), a second metal loading layer (8) is formed at one end of the second resonant through hole (4) located on the open surface (17), and an output electrode (13) is formed between the first metal loading layer (9) and the second metal loading layer (8); the first isolation groove (12) encloses the first metal loading layer (9), the second metal loading layer (8) and the output electrode (13); the output electrode (13) extends from the open surface (17) to the side surface (16) between the open surface (17) and the short-circuit surface (21); The metal covering layer is further provided with a second isolation slot (14) enclosing the five third resonant through holes (5) on the open surface (17), and four third capacitor slots (15) arranged between the five third resonant through holes (5), so that a third metal loading layer (7) is arranged at one end of the third resonant through hole (5) located on the open surface (17); the second isolation slot (14) encloses the five third metal loading layers (7); An inductor layer (6) is formed between the first isolation trench (12) and the second isolation trench (14); The metal covering layer is a silver covering layer, a gold covering layer or a copper covering layer.

2. A ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to claim 1, characterized in that: The output electrode (13) and the first metal loading layer (9) are configured to be capacitively coupled; A capacitive coupling electrode is constructed between the output electrode (13) and the second metal loading layer (8); The second resonant through hole (4) and the adjacent third resonant through hole (5) are inductively coupled via an inductor layer (6); Two adjacent third resonant through holes (5) are capacitively coupled via a third capacitor slot (15).

3. A ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to claim 2, characterized in that: At least part of the output electrode (13) extends along the length direction of the ceramic dielectric body (1) to one side of the first resonance through hole (3); The output electrode (13) is provided with a plurality of first coupling tooth-shaped portions (20); the second metal loading layer (8) is provided with a plurality of second coupling tooth-shaped portions (19); the plurality of first coupling tooth-shaped portions (20) and the plurality of second coupling tooth-shaped portions (19) are arranged alternately in three directions where the second resonance through hole (4) is not close to the third resonance through hole (5); The third metal loading layer (7) is provided with a plurality of third coupling tooth-shaped portions (18); the third coupling tooth-shaped portions (18) between two adjacent third metal loading layers (7) are arranged in an alternating manner.

4. The ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to claim 1, characterized in that: The surface of the ceramic dielectric body (1) is covered with the metal covering layer except for the first isolation groove (12), the second isolation groove (14), the first capacitor groove (10), the second capacitor groove (11) and the third capacitor groove (15); The first isolation groove (12), the second isolation groove (14), the first capacitor groove (10), the second capacitor groove (11) and the third capacitor groove (15) are obtained by laser engraving processing technology.

5. The ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to claim 1, characterized in that: The first resonant through hole (3) is constructed as a resonance-suppressing step through hole; the first resonant through hole (3) comprises a large resonant hole arranged on one side of the open surface (17), and a small resonant hole arranged on one side of the short-circuit surface (21); the aperture of the large resonant hole is larger than the aperture of the small resonant hole.

6. The ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to claim 5, characterized in that: The diameter D2 of the small resonance hole is 0.2 to 0.85 times the diameter D1 of the large resonance hole; The depth of the large resonance hole is 0.1 to 0.7 times the depth of the small resonance hole.

7. The ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to claim 1, characterized in that: The two first resonant through holes (3), the two second resonant through holes (4) and the five third resonant through holes (5) are symmetrically arranged; Two first isolation slots (12), a second isolation slot (14), two first capacitor slots (10), two second capacitor slots (11), four third capacitor slots (15), two output electrodes (13), two first metal loading layers (9), two second metal loading layers (8), and five third metal loading layers (7) are arranged axially symmetrically.

8. The ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to claim 7, characterized in that: The central axes of the first resonant through hole (3) and the second resonant through hole (4) are respectively located on both sides of the width center plane of the ceramic dielectric body; The distance A between the central axis of the first resonant through hole (3) and the width center plane of the ceramic dielectric body is 0.3 mm to 0.9 mm; The distance B between the central axis of the second resonant through hole (4) and the width center plane of the ceramic dielectric body is 0.1 mm to 0.5 mm; The distance C from the central axis of the third resonance through hole (5) to the width center plane of the ceramic dielectric body is 0 mm to 0.2 mm.

9. A ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to any one of claims 1 to 8, characterized in that: Distance A is 0.3mm; distance B is 0.12mm; The diameter of the second resonant through hole (4) is 9 mm; The thickness of the metal covering layer is 10um.

10. A ceramic dielectric bandpass filter with large bandwidth, high suppression and low loss according to any one of claims 1 to 8, characterized in that: The material of the metal shielding cover (2) is a copper alloy obtained through a stamping process; the metal shielding cover (2) is joined to the porcelain dielectric body through a conductive metal.

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