High-frequency narrow-band dielectric filter

Abstract

The high-frequency narrow-band dielectric filter comprises two resonators which are arranged in an attached mode, resonance holes are formed in the top faces of the resonators, and conductive layers are arranged on the surfaces of the resonators and the inner walls of the resonance holes. The coupling windows without the conducting layers are arranged on the bonding surfaces of the resonators, so that the positions of the coupling windows on the two resonators correspond to each other, and during bonding, the coupling cavity formed by butting the two coupling windows can be used for coupling; the exposed rings without the conducting layers are arranged on the same side faces, perpendicular to the coupling cavity, of the two resonators, the conducting layers surrounded by the exposed rings can form the input electrode and the output electrode of the dielectric filter, the coupling cavity is wrapped in the binding face and is not exposed, the input electrode and the output electrode are located on the same side face, and after welding, the coupling cavity is not exposed. The input and output electrodes can be prevented from being exposed, the shielding effect is good, a shielding shell does not need to be arranged, meanwhile, the top face where the resonance hole is located is provided with the conductive layer, smaller coupling can be achieved in cooperation with the coupling cavity, and therefore the technical effect of high frequency and narrow band is achieved.

Description

Technical Field

[0001] This invention relates to the field of dielectric filter technology, and specifically to a high-frequency narrowband dielectric filter. Background Technology

[0002] A dielectric filter is a microwave filter that achieves frequency selection through multi-stage coupling using a dielectric resonant cavity. It boasts advantages such as miniaturization, low loss, and good temperature characteristics, and is widely used in mobile and microwave communication systems. Generally, the higher the frequency of a dielectric filter, the smaller its width. When the frequency reaches or exceeds 8000MHz, its width is less than 3mm. Under these width conditions, setting up a resonant aperture (or cavity) is already difficult, and setting up the coupling structure and input / output electrodes is even more challenging. Traditionally, coupling is achieved by creating a coupling slot 3 perpendicular to the resonant aperture 2 on one side of the resonator 1, and then setting up L-shaped desilvering regions on two adjacent sides perpendicular to the opening 4 to form the input / output electrodes 5. This structure carries a certain risk of signal leakage, affecting out-of-band rejection performance, requiring the addition of a shielding shell 6 to improve it. Figure 1 As shown. Summary of the Invention

[0003] The purpose of this invention is to overcome one or more shortcomings in the prior art and provide a high-frequency narrowband dielectric filter with good shielding effect.

[0004] To achieve the above objectives, the present invention employs a high-frequency narrowband dielectric filter comprising two resonators fitted together. Each resonator has a resonant aperture on its top surface and a conductive layer on its surface and the inner wall of the resonant aperture. The fitting surfaces of the resonators have coupling windows for removing the conductive layer, and the coupling windows on the two resonators are positioned correspondingly. When fitted together, these two coupling windows align to form a coupling cavity. The two resonators have exposed rings on the same side perpendicular to the coupling cavity, and the conductive layer enclosed by these exposed rings constitutes the input and output electrodes of the dielectric filter.

[0005] Preferably, the coupling window is positioned in a manner corresponding to the exposed ring. This correspondence means that, in the vertical direction, the coupling window is neither higher than the highest point of the exposed ring nor lower than the lowest point of the exposed ring.

[0006] More preferably, the resonant hole is a through hole, and the exposed ring is located in the middle of the side of the resonator where it is located.

[0007] More preferably, the resonant hole is a blind hole, the exposed ring is located on the side near the top surface of the resonator, and the coupling window is staggered and intersecting with the resonant hole, wherein the staggered and intersecting arrangement means that the highest point of the coupling window is higher than the lowest point of the resonant hole.

[0008] More preferably, the depth of the resonant hole is 15% to 85% of the height of the resonator in which it is located.

[0009] More preferably, the depth of the resonant hole is less than or equal to 40% of the height of the resonator in which it is located.

[0010] Preferably, the exposed ring has the shape of a rectangular ring, a circular ring, or an elliptical ring, and the distance from the exposed ring to the two sides of the resonator side where it is located is equal.

[0011] More preferably, the exposed ring is equidistant from the top edge and side edge of the resonator where it is located.

[0012] Preferably, the shape of the coupling window includes rectangle, circle, and ellipse, and the distance from the coupling window to the two sides of the resonator side where it is located is equal.

[0013] More preferably, the distance from the coupling window to the top edge and side edge of the resonator where it is located is equal.

[0014] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: The high-frequency narrowband dielectric filter provided by this invention includes two resonators mounted together. Each resonator has a resonant aperture on its top surface, and a conductive layer is provided on the surface of the resonator and the inner wall of the resonant aperture. By setting coupling windows with the conductive layer removed on the mounting surfaces of the resonators, the positions of the coupling windows on the two resonators correspond. During mounting, coupling can be achieved using the coupling cavity formed by the connection of these two coupling windows. By setting exposed rings with the conductive layer removed on the same side of the two resonators perpendicular to the coupling cavity, the conductive layer enclosed by the exposed rings can form the input and output electrodes of the dielectric filter. Since the coupling cavity is enclosed within the mounting surface and not exposed, and the input and output electrodes are located on the same side, the input and output electrodes are prevented from being exposed after welding, resulting in good shielding and eliminating the need for a shielding shell. Furthermore, the conductive layer on the top surface where the resonant aperture is located allows for closer coupling with the coupling cavity, thereby achieving the technical effect of high-frequency narrowband. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a high-frequency dielectric filter in the prior art.

[0016] Figure 2 yes Figure 1 Electrical performance diagram.

[0017] Figure 3 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0018] Figure 4 , Figure 5 yes Figure 3 A schematic diagram of the two resonators after they are separated.

[0019] Figure 6 yes Figure 3 Electrical performance diagram.

[0020] Figure 7 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0021] Figure 8 , Figure 9 yes Figure 7 A schematic diagram of the two resonators after they are separated.

[0022] Figure 10 yes Figure 7 A diagram showing the usage state.

[0023] Figure 11 yes Figure 7 Electrical performance diagram.

[0024] Among them: 1. Resonator; 2. Resonant hole; 3. Coupling slot; 4. Open surface; 5. Input and output electrodes; 6. Shielding shell; 10. Resonator; 11. Resonant hole; 12. Coupling window; 13. Exposed ring; 14. Input and output electrodes; 20. Conductive layer. Detailed Implementation

[0025] Example 1, as Figures 3 to 6 As shown, the high-frequency narrowband dielectric filter provided by the present invention includes two resonators 10 that are fitted together. A resonant hole 11 is provided on the top surface of the resonator 10. A conductive layer 20 is provided on the surface of the resonator 10 and the inner wall of the resonant hole 11. The mating surface of the resonator 10 is provided with a coupling window 12 to remove the conductive layer, and the positions of the coupling windows 12 on the two resonators 10 are corresponding. When mated, the two coupling windows 12 are connected to form a coupling cavity. The two resonators 10 are provided with an exposed ring 13 to remove the conductive layer on the same side perpendicular to the coupling cavity. The conductive layer surrounded by the exposed ring 13 constitutes the input and output electrodes 14 of the dielectric filter.

[0026] The advantage of this setup is that it can enclose the coupling cavity within the mating surface and prevent the input and output electrodes from being exposed after welding, resulting in good shielding and eliminating the need for a shielding shell. At the same time, the top surface where the resonant hole is located has a conductive layer, which can work with the coupling cavity to achieve a smaller coupling, thereby achieving the technical effect of high-frequency narrowband.

[0027] In this embodiment, the coupling window 12 and the exposed ring 13 are positioned correspondingly. This corresponding positioning means that the coupling window 12 is neither higher than the highest point of the exposed ring 13 nor lower than the lowest point of the exposed ring 13 in the vertical direction. The resonant hole 11 is a through hole. The exposed ring 13 is located in the middle of the side (front side) of the resonator 10 where it is located. The exposed ring 13 is rectangular in shape. The exposed ring 13 is equidistant from both sides (left and right sides) of the side (front) of the resonator 10 where it is located. The coupling window 12 is rectangular in shape. The coupling window 12 is equidistant from both sides (left and right sides) of the side (front) of the resonator 10 where it is located.

[0028] Specifically, in this embodiment, the resonator 10 has an external dimension of 3*3*6mm. Two resonators 10 are vertically arranged and attached to each other. The resonant hole 11 penetrates the resonator 10 vertically. The surface of the resonator 10 and the inner wall of the resonant hole 11 are metallized to form a conductive layer 20. A 1.8*1.8mm desilvered area is opened on the side wall where the two resonators 10 are attached, serving as a coupling window 12. The size of the coupling window 12 is proportional to the coupling amount. The front side of the two resonators 10 (perpendicular to the coupling window 12) Each of the two resonators 10 has a "U"-shaped exposed silver ring 13 on one side, and the conductive layer formed by the rings creates input and output electrodes 14, which serve as the input and output ports for signals. In use, the front sides of the two resonators 10 are soldered to pads or other components, placed vertically or horizontally, so that the input and output electrodes 14 and the coupling cavity formed by the coupling window 12 are not exposed, thus improving the shielding effect. No shielding shell is needed. Because the top surface of the resonator 10 has a conductive layer 20, it can cooperate with the coupling cavity to achieve smaller coupling, realizing high-frequency narrowband. Figure 6 It can be seen that the frequency range that this scheme can achieve is 8080~8150MHz. It can achieve good out-of-band suppression without the need for an external shielding shell, and can achieve a small passband. It significantly improves the problems of existing dielectric filters in the high-frequency range (especially when the frequency is greater than 8000MHz) due to their small size, difficulty in manufacturing, difficulty in making narrowband, and poor out-of-band suppression due to large signal leakage.

[0029] Example 2, as Figures 7 to 11As shown, Embodiment 2 is basically the same as Embodiment 1, except that in Embodiment 2, the resonant hole 11 is a blind hole, and the exposed ring 13 is located on the side near the top surface of the resonator 10. The exposed ring 13 is equidistant from the top edge and side edge (left and right sides) of the side (front side) of the resonator 10 where it is located. The coupling window 12 is equidistant from the top edge and side edge (left and right sides) of the side (front) of the resonator 10 where it is located. The coupling window 12 and the resonant hole 11 are staggered and intersecting, meaning that the highest point of the coupling window 12 is higher than the lowest point of the resonant hole 11. This arrangement allows for... To further enhance the coupling amount and overcome the limitation of coupling amount caused by the inability to further adjust the position and size of the coupling window 12, specifically, the closer the coupling window 12 is to the opening of the resonant hole 11, the greater the coupling amount; the deeper the resonant hole 11, the lower the frequency of the dielectric filter; the shallower the depth, the higher the frequency of the dielectric filter. Preferably, the depth of the resonant hole 11 is 15% to 85% of the height of the resonator 10 in which it is located. More preferably, the depth of the hole is less than or equal to 40% of the height of the resonator 10 in which it is located. The table below shows the correspondence between different resonant hole depths and frequencies.

[0030]

[0031] Specifically, in this embodiment, the resonator 10 has an external dimension of 3*3*6mm. Two resonators 10 are vertically arranged and attached to each other. The resonant hole 11 is a blind hole, which is opened on the top surface of the resonator 10 and has a depth of 1.5mm. The surface of the resonator 10 and the inner wall of the resonant hole 11 are metallized to form a conductive layer 20. A 1.2*0.9mm desilvered area is opened on the side wall where the two resonators 10 are attached, which serves as a coupling window 12. The size of the coupling window 12 is proportional to the coupling amount. The front side of the two resonators 10 ( On the side perpendicular to the coupling window 12, a "U"-shaped exposed silver ring 13 is designed. The conductive layer formed by these rings constitutes the input and output electrodes 14, serving as the signal input and output ports. In use, the front sides of the two resonators 10 are soldered to pads or other components, placed vertically or horizontally, so that the input and output electrodes 14 and the coupling cavity formed by the coupling window 12 are not exposed, thereby improving their shielding effect. No shielding shell is required. Since the top surface of the resonator 10 has a conductive layer 20, it can cooperate with the coupling cavity to achieve a smaller coupling, realizing high-frequency narrowband. Figure 11 It can be seen that the frequency range that this scheme can achieve is 11330~11440MHz. It can achieve good out-of-band suppression without the need for an external shielding shell. It can achieve a smaller passband and a higher frequency range, so that the width of the dielectric filter can still meet about 6mm when the frequency reaches above 10G, and it is easy to manufacture.

[0032] The embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-frequency narrowband dielectric filter, comprising two resonators fitted together, wherein a resonant aperture is formed on the top surface of each resonator, and a conductive layer is formed on the surface of each resonator and the inner wall of the resonant aperture; characterized in that: The resonator has a coupling window on its mating surface to remove the conductive layer, and the coupling windows on the two resonators are positioned correspondingly. When mating, the two coupling windows connect to form a coupling cavity. The two resonators have an exposed ring on the same side perpendicular to the coupling cavity to remove the conductive layer. The conductive layer surrounded by the exposed ring constitutes the input and output electrodes of the dielectric filter.

2. The high-frequency narrowband dielectric filter according to claim 1, characterized in that: The coupling window is positioned corresponding to the exposed ring.

3. The high-frequency narrowband dielectric filter according to claim 2, characterized in that: The resonant hole is a through hole, and the exposed ring is located in the middle of the side of the resonator where it is located.

4. The high-frequency narrowband dielectric filter according to claim 2, characterized in that: The resonant hole is a blind hole, the exposed ring is located on the side of the resonator near the top surface of the resonator, and the coupling window is staggered and intersecting with the resonant hole.

5. The high-frequency narrowband dielectric filter according to claim 4, characterized in that: The depth of the resonant hole is 15% to 85% of the height of the resonator in which it is located.

6. The high-frequency narrowband dielectric filter according to claim 5, characterized in that: The depth of the resonant hole is less than or equal to 40% of the height of the resonator in which it is located.

7. The high-frequency narrowband dielectric filter according to claim 1, characterized in that: The exposed ring can be rectangular, circular, or elliptical in shape, and the distance from the exposed ring to the two sides of the resonator side where it is located is equal.

8. The high-frequency narrowband dielectric filter according to claim 7, characterized in that: The exposed ring is equidistant from the top edge and side edge of the resonator where it is located.

9. The high-frequency narrowband dielectric filter according to claim 1, characterized in that: The coupling window can be rectangular, circular, or elliptical in shape, and the distance from the coupling window to the two sides of the resonator side where it is located is equal.

10. The high-frequency narrowband dielectric filter according to claim 9, characterized in that: The coupling window is equidistant from the top and side edges of the resonator where it is located.

Images