Coupling structure with double symmetrical zero points and high suppression dielectric waveguide filter

Abstract

The present invention relates to a coupling structure with double symmetrical zero points and a high suppression dielectric waveguide filter, wherein the coupling structure comprises a dielectric substrate, two first resonant cavities are symmetrically arranged on the upper surface of the dielectric substrate along the central axis, a second resonant cavity is arranged on the upper surface of the dielectric substrate, a first through slot is arranged between the first resonant cavity and the second resonant cavity on the side of the dielectric substrate, two second through slots are arranged between the two first resonant cavities, a coupling port is formed between the two second through slots, a third resonant cavity is arranged between the two second resonant cavities on the same side, and the third resonant cavity corresponds to the coupling port. The present invention forms two pairs of symmetrical balanced transmission zero points by adopting 8 resonant cavities, greatly improving the suppression performance of the filter on the basis of a limited number of resonant cavities, and the scheme can be widely used in dielectric waveguide filters, thereby reducing the size of the filter while improving the suppression of the passband.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic communications, and in particular to a coupling structure with double symmetrical zero points and a high-suppression dielectric waveguide filter. Background Art

[0002] With the rapid development of communication systems, 5G communication technology has brought new technological impetus to the industry. Traditional metal filters can no longer meet new requirements such as miniaturization and low cost, thus deriving dielectric waveguide filters. Current dielectric waveguide filters usually produce a set of symmetrical transmission zeros on both sides of the passband, and the filter's suppression ability is still insufficient. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a coupling structure with double symmetrical zero points and a high suppression dielectric waveguide filter, which has the advantages of reducing the filter size and improving the suppression capability.

[0004] To achieve the above object, the technical solution of the present invention is as follows:

[0005] A coupling structure with double symmetrical zero points comprises a dielectric substrate arranged in a rectangular shape, wherein two first resonant cavities are symmetrically arranged along a central axis on the upper surface of the dielectric substrate, a second resonant cavity is arranged on one side of the upper surface of the dielectric substrate, a first through slot is arranged on the side of the dielectric substrate between the first resonant cavity and the second resonant cavity, two second through slots are arranged between the two first resonant cavities, a coupling port is formed between the two second through slots, a third resonant cavity is arranged between the two second resonant cavities located on the same side, and the third resonant cavity corresponds to the coupling port; a first main coupling is formed between the first resonant cavity and the second resonant cavity located on the same side, a first cross coupling is formed between the two first main couplings, a fourth resonant cavity is arranged between the two second resonant cavities, and the fourth resonant cavity forms a second main coupling; a third main coupling is formed between the first resonant cavity and the third resonant cavity located on the same side, and a second cross coupling is formed between the two third main couplings.

[0006] As a preferred solution of the present invention, the first main coupling and the second main coupling are inductive couplings.

[0007] As a preferred solution of the present invention, the second main coupling is capacitive coupling.

[0008] As a preferred solution of the present invention, one of the third main couplings is a capacitive coupling.

[0009] As a preferred solution of the present invention, the axis line of the third resonant cavity deviates from the center of the coupling port and is close to the center of the dielectric matrix.

[0010] As a preferred solution of the present invention, the axis line of the third resonant cavity deviates from the center of the coupling port and is close to the outer end of the dielectric substrate.

[0011] As a preferred solution of the present invention, a metal shielding layer is provided on the outer side of the dielectric substrate.

[0012] On the other hand, the present invention also provides a high-suppression dielectric waveguide filter, comprising the coupling structure described in any of the above technical solutions.

[0013] In summary, the present invention has the following beneficial effects:

[0014] The present invention adopts 8 resonant cavities to form two pairs of symmetrical balanced transmission zero points, which greatly improves the suppression performance of the filter on the basis of a limited number of resonant cavities. At the same time, this scheme can be widely used in dielectric waveguide filters, thereby reducing the size of the filter while improving the suppression of the passband. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a structural diagram of embodiment 1 of the present invention.

[0017] Figure 2 This is a schematic diagram of the first embodiment of the present invention.

[0018] Figure 3 This is a frequency response curve of the first embodiment of the present invention.

[0019] Figure 4 It is a structural diagram of embodiment 2 of the present invention.

[0020] Figure 5 This is a frequency response curve of the first embodiment of the present invention.

[0021] Figure 6 This is a schematic diagram of the structure of the third embodiment of the present invention.

[0022] Figure 7 This is the frequency response curve of the third embodiment of the present invention.

[0023] The numbers and letters in the figure represent the corresponding component names:

[0024] 100, dielectric substrate; 101, metal shielding layer; 102, first resonant cavity; 103, second resonant cavity; 104, third resonant cavity; 105, first through slot; 106, second through slot; 107, coupling port; 200, first main coupling; 201, first cross coupling; 300, second main coupling; 400, third main coupling; 401, second cross coupling. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1

[0027] A coupling structure with double symmetrical zeros, such as Figures 1 to 3 As shown, it includes a rectangular dielectric substrate 100, and two first resonant cavities 102 are symmetrically arranged on the upper surface of the dielectric substrate 100 along the central axis, namely Figure 1 In the resonant cavities No. 1, 3, 6, and 8, a second resonant cavity 103 is provided on one side of the upper surface of the dielectric substrate 100, that is, Figure 1 In the resonant cavities No. 4 and 5, a first through slot 105 is provided between the first resonant cavity 102 and the second resonant cavity 103 on the side of the dielectric substrate 100, two second through slots 106 are provided between the two first resonant cavities 102, a coupling port 107 is formed between the two second through slots 106, and a third resonant cavity 104 is provided between the two second resonant cavities 103 on the same side, that is, Figure 1 The resonant cavities No. 2 and 7 in the structure, the third resonant cavity 104 corresponds to the coupling port 107; a first main coupling 200 is formed between the first resonant cavity 102 and the second resonant cavity 103 located on the same side, a first cross coupling 201 is formed between the two first main couplings 200, a fourth resonant cavity is provided between the two second resonant cavities 103, and the fourth resonant cavity forms a second main coupling 300; a third main coupling 400 is formed between the first resonant cavity 102 and the third resonant cavity 104 located on the same side, and a second cross coupling 401 is formed between the two third main couplings 400.

[0028] In this embodiment, the second main coupling 300 and the third main coupling 400 between the No. 2 resonant cavity and the No. 3 resonant cavity are negative couplings formed by deep holes, that is, capacitive couplings, and the coupling amount is determined by the depth of the second resonator cavity and the third resonant cavity 104. The deeper the depth, the greater the coupling amount, and vice versa.

[0029] The first main coupling 200 is a window-type inductive coupling, and the coupling amount is determined by the window size of the second through slot 106 . The larger the window, the stronger the coupling, and vice versa. The window size is adjusted by the opening width of the second through slot 106 .

[0030] Furthermore, a metal shielding layer 101 is provided on the outer side of the dielectric substrate 100 .

[0031] Figure 3 is the frequency response curve of this embodiment, Figure 3 It can be seen that two pairs of symmetrical transmission zero points are generated at the same positions on the left and right. One pair of symmetrical transmission zero points close to the passband is formed by resonant cavities 3, 4, 5, and 6, and the symmetry of the transmission zero points can be adjusted by adjusting the positions of resonant cavities 4 and 5; the symmetry of the other pair of symmetrical transmission zero points can be adjusted by adjusting the positions of resonant cavities 2 and 7.

[0032] The present invention adopts 8 resonant cavities to form two pairs of symmetrical balanced transmission zero points, which greatly improves the suppression performance of the filter on the basis of a limited number of resonant cavities. At the same time, this scheme can be widely used in dielectric waveguide filters, thereby reducing the size of the filter while improving the suppression of the passband.

[0033] Embodiment 2

[0034] The difference between this embodiment and the first embodiment is that: in this embodiment, Figure 4 and Figure 5 As shown in FIG. 1 , the axis line of the third resonant cavity 104 deviates from the center of the coupling port 107 and is close to the center of the dielectric substrate 100. At this time, the transmission zero point on the right is further away from the passband, and the transmission zero point on the left is closer to the passband. When the strength of the transmission zero point on the left is large enough, it can be merged with the transmission zero point on the right, thereby generating the following: Figure 5 The effect shown on the left in the figure.

[0035] Embodiment 3

[0036] The difference between this embodiment and the first embodiment is that: in this embodiment, Figure 6 and Figure 7 As shown, the axis line of the third resonant cavity 104 deviates from the center of the coupling port 107 and is close to the outer end of the dielectric substrate 100. At this time, the transmission zero point on the right is closer to the passband, and the transmission zero point on the left is further away from the passband.

[0037] Embodiment 4

[0038] A high-suppression dielectric waveguide filter comprises the coupling structure of the first embodiment, the second embodiment or the third embodiment.

[0039] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coupling structure with double symmetrical zero points, characterized in that: The invention comprises a dielectric substrate arranged in a rectangular shape, wherein two pairs of first resonant cavities are symmetrically arranged on the upper surface of the dielectric substrate along the central axis, two second resonant cavities are arranged on one side of the upper surface of the dielectric substrate and are respectively located on both sides of the central axis, a first through-groove is arranged on the side of the dielectric substrate between the first resonant cavity and the second resonant cavity, two second through-grooves are arranged between the two pairs of the first resonant cavities, a coupling port is formed between the two second through-grooves, a third resonant cavity is arranged between the two first resonant cavities on the same side, and the third resonant cavity corresponds to the coupling port; a first main coupling is formed between the first resonant cavity and the second resonant cavity on the same side, a first cross coupling is formed between the two first main couplings, a fourth resonant cavity is arranged between the two second resonant cavities, and the fourth resonant cavity forms a second main coupling; a third main coupling is formed between the first resonant cavity and the third resonant cavity on the same side, and a second cross coupling is formed between the two third main couplings; Among them, the axial line of the third resonant cavity deviates from the center of the coupling port and is close to the center of the dielectric matrix. At this time, the transmission zero point on the right side deviates further from the passband, and the transmission zero point on the left side is closer to the passband, or the axial line of the third resonant cavity deviates from the center of the coupling port and is close to the outer end of the dielectric matrix. At this time, the transmission zero point on the right side deviates closer to the passband, and the transmission zero point on the left side deviates further from the passband.

2. The coupling structure with double symmetrical zero points according to claim 1, characterized in that: The first main coupling is an inductive coupling.

3. The coupling structure with double symmetrical zero points according to claim 2, characterized in that: The second main coupling is a capacitive coupling.

4. The coupling structure with double symmetrical zero points according to claim 3, characterized in that: The third main coupling is a capacitive coupling.

5. The coupling structure with double symmetrical zero points according to claim 1, characterized in that: A metal shielding layer is arranged on the outer side of the dielectric substrate.

6. A high suppression dielectric waveguide filter, characterized in that: The coupling structure comprises the coupling structure as claimed in any one of claims 1 to 5.

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