High-suppression ceramic dielectric band-pass filter
By setting specific resonant vias and coupling inductors and capacitor slots in ceramic dielectric filters, the problem of insufficient bandwidth and signal processing capabilities of filters in modern communications is solved, achieving high suppression and low insertion loss filtering effects. It is suitable for applications such as routers, wireless base stations, satellite communications, and electronic countermeasures.
Patent Information
- Application Number
- CN202423049189.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-12-11
AI Technical Summary
Existing ceramic dielectric filters struggle to improve bandwidth and signal processing capabilities while maintaining miniaturization and lightweight design in modern communications, especially with the increasingly demanding performance requirements of WiFi 6 and WiFi 7 communication protocols, which require greater bandwidth, stronger interference signal suppression, and lower losses.
A high-suppression ceramic dielectric bandpass filter was designed, comprising a ceramic dielectric body and a metal shield. By setting different types of resonant vias on the ceramic dielectric body and coupling them with inductor lines and capacitor slots to form a metal loading layer and output electrode, capacitive and inductive coupling is achieved, thereby enhancing the filtering effect.
A filter with large bandwidth, high suppression and low insertion loss has been realized to meet the requirements of modern communication technology for greater throughput and stronger anti-interference capability, while maintaining the high performance and miniaturization characteristics of the filter.
Smart Images
Figure CN223514216U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of filter technology, and more specifically, to a high-suppression ceramic dielectric bandpass filter. Background Technology
[0002] Ceramic dielectric filters achieve the desired frequency range through precise filtering in modern microwave communication systems. This filter design utilizes the coupling between dielectric resonant cavities, resulting in high Q values, low insertion loss, miniaturization, and lightweight characteristics. These properties have led to the widespread adoption of ceramic dielectric filters in fields including routers, wireless base stations, satellite communications, navigation systems, and electronic warfare.
[0003] With the continuous advancement of communication technologies, especially in the application of WiFi 6 and WiFi 7 communication protocols, the performance requirements for filters are becoming increasingly stringent. These next-generation communication protocols require filters to have greater bandwidth to accommodate more frequency bands and provide higher data throughput. Furthermore, to ensure communication quality, filters also need stronger interference signal suppression capabilities and lower loss performance to guarantee high-quality signal transmission.
[0004] Therefore, the design and optimization of ceramic dielectric filters has become a major challenge in the development of communication technology. Researchers face the challenge of improving the bandwidth and signal processing capabilities of filters while maintaining their miniaturization and lightweight design. Utility Model Content
[0005] This invention provides a high-suppression ceramic dielectric bandpass filter, which aims to improve at least one of the above-mentioned technical problems.
[0006] To solve the above-mentioned technical problems, this utility model provides a high-suppression ceramic dielectric bandpass filter, which includes a ceramic dielectric body and a metal shielding cover bonded to the ceramic dielectric body.
[0007] The ceramic dielectric body has an open surface and a short surface, through which two first resonant through-holes, two second resonant through-holes, and five third resonant through-holes are arranged. The two second resonant through-holes are respectively located on both sides of the five third resonant through-holes. The two first resonant through-holes are respectively located on both sides of the two first resonant through-holes. The metal shield is adapted to cover at least a portion of the open surface.
[0008] The ceramic dielectric bandpass filter also includes a metal overlay layer disposed on the surface of the ceramic dielectric body.
[0009] The metal covering layer is provided with a first isolation groove at the open face, which encloses the first resonant via and the second resonant via on the same side, and a first capacitance groove and a second capacitance groove between the first resonant via and the second resonant via, so as to form a first metal loading layer at one end of the open face where the first resonant via is located, a second metal loading layer at one end of the open face where the second resonant via is located, 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 face to a side face between the open face and the short-circuit face.
[0010] The metal covering layer is further provided with a second isolation groove at the open face, which encloses five third resonant vias, and four third capacitance grooves between the five third resonant vias, so as to provide a third metal loading layer at one end of the open face where the third resonant via is located. The second isolation groove encloses the five third metal loading layers.
[0011] An inductance line layer is formed between the first isolation groove and the second isolation groove.
[0012] In an optional embodiment, a capacitive coupling is configured between the output electrode and the first metal loading layer.
[0013] A capacitive coupling electrode is configured between the output electrode and the second metal loading layer.
[0014] An inductive coupling is performed between the second resonant via and the adjacent third resonant via through the inductance line layer.
[0015] A capacitive coupling is performed between two adjacent third resonant vias through the third capacitance groove.
[0016] In an optional embodiment, at least part of the output electrode extends to one side of the first resonant via along the length direction of the ceramic medium body.
[0017] The output electrode is provided with a plurality of first coupling tooth-shaped parts. The second metal loading layer is provided with a plurality of second coupling tooth-shaped parts. The plurality of first coupling tooth-shaped parts and the plurality of second coupling tooth-shaped parts are staggered in three directions away from the third resonant via at the second resonant via part.
[0018] The third metal loading layer is provided with a plurality of third coupling tooth-shaped parts. The third coupling tooth-shaped parts between two adjacent third metal loading layers are staggered.
[0019] In an alternative embodiment, the surface of the ceramic dielectric body is covered by the metal covering layer except for the first isolation groove, the second isolation groove, the first capacitance groove, the second capacitance groove, and the third capacitance groove.
[0020] The first isolation groove, the second isolation groove, the first capacitance groove, the second capacitance groove, and the third capacitance groove are obtained by a laser engraving process.
[0021] In an alternative embodiment, the first resonant via is configured as a resonant stepped via. The first resonant via includes a large resonant hole disposed on one side of the open face, and a small resonant hole disposed on one side of the short-circuit face. The aperture of the large resonant hole is larger than the aperture of the small resonant hole.
[0022] In an alternative embodiment, the diameter D2 of the small resonant hole is 0.2 to 0.85 times the diameter D1 of the large resonant hole.
[0023] The depth of the large resonant hole is 0.1 to 0.7 times the depth of the small resonant hole.
[0024] In an alternative embodiment, two first resonant vias, two second resonant vias, and five third resonant vias are symmetrically disposed.
[0025] Two first isolation grooves, two second isolation grooves, two first capacitance grooves, two second capacitance grooves, four third capacitance grooves, two output electrodes, two first metal loading layers, two second metal loading layers, and five third metal loading layers are symmetrically disposed on the axis.
[0026] In an alternative embodiment, the center axes of the first resonant via and the second resonant via are respectively located on both sides of the width center plane of the ceramic dielectric body.
[0027] The distance A from the center axis of the first resonant via to the width center plane of the ceramic dielectric body is 0.3mm to 0.9mm.
[0028] The distance B from the center axis of the second resonant via to the width center plane of the ceramic dielectric body is 0.1mm to 0.5mm.
[0029] The distance C from the center axis of the third resonant via to the width center plane of the ceramic dielectric body is 0mm to 0.2mm.
[0030] In an alternative embodiment, the distance A is 0.3mm.
[0031] The distance B is 0.12mm.
[0032] The diameter of the second resonant through-hole is 9mm.
[0033] The thickness of the metal coating is 10 μm.
[0034] In one optional embodiment, the metal shield is made of a copper alloy and is obtained through a stamping process. The metal shield is bonded to the ceramic dielectric body via a conductive metal.
[0035] By adopting the above technical solution, the present invention can achieve the following technical effects:
[0036] This invention provides a high-suppression ceramic dielectric bandpass filter with a first resonant via, which allows for convenient control of the desired suppression frequency and enhances the filtering effect. The second resonant via is inductively coupled to an adjacent third resonant via, resulting in excellent high-frequency suppression. The third resonant vias are coupled to each other via capacitive slots, increasing capacitive coupling, achieving a wider bandwidth, and reducing insertion loss. Attached Figure Description
[0037] To more clearly illustrate the technical solutions of the specific embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.
[0038] Figure 1 This is an isometric view of a ceramic dielectric bandpass filter.
[0039] Figure 2 This is an exploded view of a ceramic dielectric bandpass filter.
[0040] Figure 3 It is an isometric view of the front of the ceramic substrate.
[0041] Figure 4 This is a front view of the ceramic medium.
[0042] Figure 5 It is an isometric view of the back side of the ceramic substrate.
[0043] Figure 6 This is a test waveform diagram of a ceramic dielectric bandpass filter (the horizontal axis represents frequency).
[0044] The markings in the diagram are: 1-Ceramic dielectric body, 2-Metal shield, 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, 19-Second coupling tooth, 20-First coupling tooth, 21-Short surface. Detailed Implementation
[0045] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0046] Depend on Figures 1 to 6 As shown, this embodiment of the present invention provides a high-suppression ceramic dielectric bandpass filter, which includes a ceramic dielectric body and a metal shield bonded to the ceramic dielectric body.
[0047] The ceramic dielectric body has an open surface and a short surface, through which two first resonant through-holes, two second resonant through-holes, and five third resonant through-holes are arranged. The two second resonant through-holes are respectively located on both sides of the five third resonant through-holes. The two first resonant through-holes are respectively located on both sides of the two first resonant through-holes. The metal shield is adapted to cover at least a portion of the open surface.
[0048] The metal overlay layer has a first isolation groove enclosing the first resonant through-hole and the second resonant through-hole on the same side of the open surface, and a first capacitor groove and a second capacitor groove disposed between the first resonant through-hole and the second resonant through-hole. This forms a first metal loading layer at one end of the first resonant through-hole located on the open surface, a second metal loading layer at one end of the second resonant through-hole located on 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 surface between the open surface and the short surface.
[0049] The metal overlay layer also has a second isolation groove surrounding the five third resonant through holes on the open surface, and four third capacitor grooves disposed between the five third resonant through holes, so that a third metal loading layer is disposed at one end of the third resonant through hole located on the open surface. The second isolation groove surrounds the five third metal loading layers.
[0050] An inductor layer is formed between the first isolation trench and the second isolation trench.
[0051] This invention provides a high-suppression ceramic dielectric bandpass filter with a first resonant via, which allows for convenient control of the desired suppression frequency and enhances the filtering effect. The second resonant via is inductively coupled to an adjacent third resonant via, resulting in excellent high-frequency suppression. The third resonant vias are coupled to each other via capacitive slots, increasing capacitive coupling, achieving a wider bandwidth, and reducing insertion loss.
[0052] Based on the above embodiments, in an optional embodiment of the present invention, such as... Figure 3 As shown, the output electrode and the first metal loading layer are capacitively coupled. The output electrode and the second metal loading layer are capacitively coupled electrodes. The second resonant via and the adjacent third resonant via are inductively coupled through an inductor layer. Two adjacent third resonant vias are capacitively coupled through a third capacitor slot. Specifically, at least a portion of the output electrode extends along the length of the ceramic dielectric body to one side of the first resonant via. The output electrode is provided with a plurality of first coupling teeth. The second metal loading layer is provided with a plurality of second coupling teeth. The plurality of first coupling teeth and the plurality of second coupling teeth are staggered in three directions in which the second resonant via is not close to the third resonant via. The third metal loading layer is provided with a plurality of third coupling teeth. The third coupling teeth between two adjacent third metal loading layers are staggered.
[0053] Based on the above embodiments, in an optional embodiment of the present invention, such as... Figure 3 As shown, the surface of the ceramic dielectric body, except for the first isolation groove, the second isolation groove, the first capacitor groove, the second capacitor groove, and the third capacitor groove, is covered with the metal capping layer. Preferably, the metal capping layer is a silver capping layer. The silver capping layer is obtained by adhering it to the ceramic dielectric body through a silver immersion metallization process; the thickness of the metal capping layer is 10 μm. In other embodiments, other existing conductive metals such as gold or copper can be used instead of silver.
[0054] After the ceramic dielectric substrate is completely covered with a metal capping layer, the first isolation groove, the second isolation groove, the first capacitor groove, the second capacitor groove, and the third capacitor groove are engraved on the metal capping layer using a laser engraving process. This results in the output electrode, the first metal loading layer, the second metal loading layer, and the third metal loading layer. In other embodiments, existing processing methods other than laser engraving can also be used to obtain the desired structure; this invention does not specifically limit the application of these methods.
[0055] Based on the above embodiments, in an optional embodiment of the present invention, such as... Figure 3 and Figure 4 As shown, the first resonant through-hole is constructed as a resonance-suppressing stepped 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 the short surface side. The diameter of the large resonant hole is larger than the diameter 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.
[0056] Specifically, the large resonant aperture and the small resonant aperture are coaxially arranged. The diameter D1 of the large resonant aperture is 8 mm. The diameter D2 of the small resonant aperture is 0.53 times the diameter D1 of the large resonant aperture. The depth of the large resonant aperture is 0.42 times the depth of the small resonant aperture. The diameter of the second resonant through-hole is 9 mm. The diameter of the third resonant through-hole is 5 mm.
[0057] Based on the above embodiments, in an optional embodiment of the present invention, such as... Figures 2 to 4As shown, two first resonant vias, two second resonant vias, and five third resonant vias are symmetrically arranged; two first isolation slots, two second isolation slots, 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. Preferably, the central axes of the first and second resonant vias are 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 via to the width center plane of the ceramic dielectric body is 0.3 mm to 0.9 mm. The distance B from the central axis of the second resonant via to 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 resonant via to the width center plane of the ceramic dielectric body is 0 mm to 0.2 mm. Specifically, distance A is 0.3 mm, distance B is 0.12 mm, and distance C is 0.06 mm.
[0058] This invention discloses a high-suppression ceramic dielectric bandpass filter that cleverly incorporates different types of resonant vias on the ceramic dielectric body, including a first resonant via, a second resonant via, and a third resonant via. These vias achieve precise control of frequency response characteristics through specific design parameters (such as the ratio of small to large aperture diameters and their offset from the central axis). In particular, the presence of the first resonant via allows for convenient adjustment of the suppression point position, thus better adapting to different application requirements. Furthermore, by using an inductive line for inductive coupling between the second resonant via and the adjacent third resonant via, the suppression effect at high frequencies is enhanced, ensuring signal quality.
[0059] Overall, this filter achieves the goals of wide bandwidth, high suppression, and low insertion loss, meeting the requirements of modern communication technology for higher throughput and stronger anti-interference capabilities without sacrificing signal quality. It maintains high performance while being compact in size, making it ideal for applications in routers, wireless base stations, satellite communications, navigation systems, and electronic warfare, providing strong support for the future development of broadband communications.
[0060] Based on the above embodiments, in an optional embodiment of the present invention, such as... Figure 1 and Figure 2 As shown, the metal shield is made of copper alloy and is obtained through a stamping process. The metal shield is bonded to the ceramic dielectric body via conductive metal.
[0061] The metal shield has an L-shaped structure, with two pins bent downwards in the middle through stamping to confine it to the open surface. The metal shield is then tightly fitted to the ceramic dielectric substrate using solder paste.
[0062] This invention discloses a high-suppression ceramic dielectric bandpass filter. Two first resonant vias are provided on the ceramic dielectric body. The suppression frequency can be controlled by adjusting the size and position of the two first resonant vias, allowing for convenient control of the desired suppression point location. The second resonant via is inductively coupled to an adjacent third resonant via through an inductor line, achieving better suppression at high frequencies. The third resonant vias are capacitively coupled to each other through capacitor slots, allowing for easy increase in capacitive coupling to obtain a wider bandwidth and lower insertion loss.
[0063] like Figure 6 The image shows the actual test waveform of this invention. The product has a center frequency of 6525MHz, a minimum center insertion loss of 0.8dB, a passband range of 5925MHz-7125MHz, and 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. This ceramic dielectric bandpass filter of this invention has the characteristic of high suppression.
[0064] It should be noted that, Figure 6 In a filter's amplitude-frequency response graph, "db / div" is a unit used to describe the relationship between the vertical and horizontal axes. "db / div" represents the factor by which the frequency on the horizontal axis increases for every unit increase in the vertical axis (dB) value in the filter's amplitude-frequency response graph. "ref.pos" typically represents a reference position used to control the filter's frequency response characteristics. This control variable is used to set the reference point for the filter's nominal frequency or other technical specifications. For example, the nominal frequency (Reference Frequency) specifies the frequency value used to characterize the filter's operating frequency.
[0065] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A high-suppression ceramic dielectric bandpass filter, characterized in that, It includes a ceramic dielectric body and a metal shielding cover bonded to the ceramic dielectric body; The ceramic dielectric body has an open surface and a short surface. 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 surface. The two second resonant through holes are respectively arranged on both sides of the five third resonant through holes. The two first resonant through holes are respectively arranged on both sides of the two first resonant through holes. The metal shield is adapted to cover at least part of the open surface. The ceramic dielectric bandpass filter also includes a metal covering layer disposed on the surface of the ceramic dielectric body; The metal cover layer has a first isolation groove enclosing the first resonant through-hole and the second resonant through-hole on the same side of the open surface, and a first capacitor groove and a second capacitor groove disposed between the first resonant through-hole and the second resonant through-hole, thereby forming a first metal loading layer at one end of the first resonant through-hole located on the open surface, forming a second metal loading layer at one end of the second resonant through-hole located on the open surface, and forming 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 surface between the open surface and the short surface; The metal cover layer is further provided with a second isolation groove enclosing the five third resonant through holes on the open surface, and four third capacitor grooves disposed between the five third resonant through holes, so that a third metal loading layer is disposed at one end of the third resonant through hole located on the open surface; the second isolation groove encloses the five third metal loading layers; An inductor layer is formed between the first isolation trench and the second isolation trench.
2. The high-suppression ceramic dielectric bandpass filter according to claim 1, characterized in that, The output electrode and the first metal loading layer are configured to be capacitively coupled. The output electrode and the second metal loading layer are configured as a capacitive coupling electrode; The second resonant via and the adjacent third resonant via are inductively coupled through an inductor layer; The two adjacent third resonant through holes are capacitively coupled through a third capacitor slot.
3. The high-suppression ceramic dielectric bandpass filter according to claim 2, characterized in that, At least a portion of the output electrode extends along the length of the ceramic dielectric body to one side of the first resonant via; 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; The third metal loading layer is provided with a plurality of third coupling tooth-shaped portions; the third coupling tooth-shaped portions between two adjacent third metal loading layers are staggered.
4. The high-suppression ceramic dielectric bandpass filter according to claim 1, characterized in that, Except for the first isolation groove, the second isolation groove, the first capacitor groove, the second capacitor groove, and the third capacitor groove, the rest of the surface of the ceramic dielectric body is covered by the metal covering layer; 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.
5. A high-suppression ceramic dielectric bandpass filter according to claim 1, characterized in that, The first resonant through-hole is constructed as a resonant suppression stepped 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 the short surface side; the diameter of the large resonant hole is larger than the diameter of the small resonant hole.
6. A high-suppression ceramic dielectric bandpass filter according to claim 5, characterized in that, The diameter D2 of the small resonant aperture is 0.2 to 0.85 times the diameter D1 of the large resonant aperture; The depth of the large resonant aperture is 0.1 to 0.7 times the depth of the small resonant aperture.
7. A high-suppression ceramic dielectric bandpass filter according to claim 1, characterized in that, Two first resonant through-holes, two second resonant through-holes, and five third resonant through-holes are symmetrically arranged; Two first isolation slots, two second isolation slots, 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 arranged symmetrically along an axis.
8. A high-suppression ceramic dielectric bandpass filter according to claim 7, characterized in that, The central axes of the first resonant through-hole and the second resonant through-hole are located on both sides of the width center plane of the ceramic dielectric body, respectively. The distance A from the central axis of the first resonant through-hole to the center plane of the width of the ceramic dielectric body is 0.3 mm to 0.9 mm; The 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; The distance C from the central axis of the third resonant through hole to the width center plane of the ceramic dielectric body is 0 mm to 0.2 mm.
9. A high-suppression ceramic dielectric bandpass filter according to any one of claims 1 to 8, characterized in that, Distance A is 0.3 mm; distance B is 0.12 mm; The diameter of the second resonant through-hole is 9mm; The thickness of the metal coating is 10 μm.
10. A high-suppression ceramic dielectric bandpass filter according to any one of claims 1 to 8, characterized in that, The metal shield is made of copper alloy and is obtained through a stamping process; the metal shield is bonded to the ceramic dielectric body by conductive metal.