A dielectric waveguide filter

Abstract

The present invention provides a dielectric waveguide filter, which includes two interconnected half-wavelength dielectric resonators and two three-quarter wavelength dielectric resonators; a tuning hole is provided on the surface of each half-wavelength dielectric resonator and each three-quarter wavelength dielectric resonator; inductive coupling is achieved between the two half-wavelength dielectric resonators through a waveguide wide side window; and capacitive coupling is formed between the two three-quarter wavelength dielectric resonators. The dielectric waveguide filter of this structure introduces two three-quarter wavelength dielectric resonators into a plurality of half-wavelength dielectric resonators, and capacitive coupling is formed between the two three-quarter wavelength dielectric resonators, so that the cross-coupling generates a transmission zero point, thereby improving the frequency selectivity and rectangular coefficient of the dielectric filter. The dielectric waveguide filter provided by the present invention does not have a deep blind hole, which is conducive to batch processing and production, and can also ensure the strength of the dielectric waveguide filter.

Description

Technical Field

[0001] The present invention relates to the technical field of communication equipment components, and in particular to a dielectric waveguide filter. Background Art

[0002] With the rapid development of fifth-generation mobile communications, wireless LANs, and satellite communications, the utilization rate of wireless spectrum is increasing, which puts forward the requirements of miniaturization, high performance, and low cost for RF microwave filters in communication systems. Dielectric waveguide filters can be miniaturized because the dielectric constant of the internal medium can be adjusted. In addition, after the design of dielectric waveguide filters is completed, molds can be processed for batch production, which has the advantages of good batch quality and low cost. Under this background, dielectric waveguide filters with great advantages have become a research hotspot.

[0003] Generally, communication systems require filters to have good selectivity or rectangular coefficients. Dielectric waveguide filters need to achieve good selectivity through cross-coupling. To achieve the transmission zero point of cross-coupling, dielectric waveguide filters need to achieve both capacitive coupling and inductive coupling. Inductive coupling is generally achieved by adding windows to the narrow side of the waveguide, while capacitive coupling is generally achieved by adding windows to the wide side of the waveguide. In dielectric waveguide filters, because some media are very brittle, adding windows to the wide side is difficult to achieve, and other methods of achieving capacitive coupling need to be studied.

[0004] In the prior art, when designing dielectric waveguide filters, half-wavelength dielectric waveguide resonators are generally selected as resonant units. At this time, since the electric field distribution at the connection point between two half-wavelength dielectric waveguide resonators is zero, it is difficult to achieve capacitive coupling. Currently, capacitive coupling is generally achieved by machining a very deep blind hole between the two dielectric resonators. However, if the blind hole is too deep, the machining accuracy requirements are high and the debugging is difficult; at the same time, the deep blind hole will also reduce the strength of the dielectric filter. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art that the dielectric filter processes deep blind holes to achieve capacitive coupling, resulting in reduced strength of the dielectric filter, high requirements on the processing accuracy of the deep blind holes, and great difficulty in debugging.

[0006] To this end, the present invention provides a dielectric waveguide filter, comprising

[0007] at least two interconnected half-wavelength dielectric resonators;

[0008] Two three-quarter wavelength dielectric resonators; the surface of each of the half-wavelength dielectric resonators and each of the three-quarter wavelength dielectric resonators is a metal conductive layer; the surface of each of the half-wavelength dielectric resonators and each of the three-quarter wavelength dielectric resonators is provided with a tuning hole;

[0009] Inductive coupling is achieved between the half-wavelength dielectric resonators by opening windows on the broad sides of the waveguide; capacitive coupling is achieved between the two three-quarter wavelength dielectric resonators.

[0010] Optionally, the above-mentioned dielectric waveguide filter further includes at least one debugging hole arranged on the upper surface or the lower surface of the dielectric body between the two three-quarter wavelength dielectric resonators.

[0011] Optionally, in the above-mentioned dielectric waveguide filter, there are two debugging holes, and the two debugging holes are respectively located on the upper surface and the lower surface of the dielectric body between the two three-quarter wavelength dielectric resonators.

[0012] Optionally, in the above-mentioned dielectric waveguide filter, the two debugging holes are coaxially arranged.

[0013] Optionally, in the above-mentioned dielectric waveguide filter, the two debugging holes are located at equivalent open-circuit ends of two of the three-quarter wavelength dielectric resonators.

[0014] Optionally, in the above-mentioned dielectric waveguide filter, the two debugging holes are not coaxially arranged.

[0015] Optionally, in the above-mentioned dielectric waveguide filter, the thickness of the debugging hole is less than half of the thickness of the dielectric body.

[0016] Optionally, in the above-mentioned dielectric waveguide filter, the cross-sectional shape of the debugging hole is any one of a rectangular, circular, elliptical or irregular shape.

[0017] Optionally, in the above-mentioned dielectric waveguide filter, all the dielectric resonators are distributed in a single layer or multiple layers.

[0018] Optionally, in the above-mentioned dielectric waveguide filter, the interior of each dielectric resonator is a medium with any dielectric constant; and the metal conductive layer is a hard metal or any metal electroplating film.

[0019] The technical solution of the present invention has the following advantages:

[0020] 1. The dielectric waveguide filter provided by the present invention introduces two three-quarter wavelength dielectric resonators into a plurality of half-wavelength dielectric resonators, and capacitive coupling is formed between the two three-quarter wavelength dielectric resonators, so that the cross coupling generates a transmission zero point, thereby improving the frequency selectivity and rectangular coefficient of the dielectric filter. The dielectric waveguide filter provided by the present invention does not have a deep blind hole, which is conducive to batch processing and production, and can also ensure the strength of the dielectric waveguide filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A three-dimensional schematic diagram of a dielectric waveguide filter provided in Example 1 of the present invention;

[0023] Figure 2 A bottom view of the dielectric waveguide filter structure provided in Example 1 of the present invention;

[0024] Figure 3 Based Figure 2 A-A' section view;

[0025] Figure 4 The frequency response curve of the dielectric waveguide filter provided in Example 1 of the present invention;

[0026] Figure 5 A three-dimensional schematic diagram of a dielectric waveguide filter provided in Example 2 of the present invention;

[0027] Figure 6 A bottom view of the dielectric waveguide filter structure provided in Example 1 of the present invention;

[0028] Figure 7 for Figure 6 A-A' cross-sectional view. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0030] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1

[0034] This embodiment provides a dielectric waveguide filter, such as Figures 1 to 3 As shown, it includes two interconnected half-wavelength dielectric resonators 21, 22 and two three-quarter wavelength dielectric resonators 41, 42; the surface of each half-wavelength dielectric resonator and each three-quarter wavelength dielectric resonator is a metal conductive layer; the surface of each half-wavelength dielectric resonator and each three-quarter wavelength dielectric resonator is provided with a tuning hole; inductive coupling is achieved between the two half-wavelength dielectric resonators through the waveguide wide side window; capacitive coupling is formed between the two three-quarter wavelength dielectric resonators.

[0035] The dielectric waveguide filter of this structure introduces two three-quarter wavelength dielectric resonators into a plurality of half-wavelength dielectric resonators, and capacitive coupling is formed between the two three-quarter wavelength dielectric resonators, so that the cross coupling generates a transmission zero point, thereby improving the frequency selectivity and rectangular coefficient of the dielectric filter. The dielectric waveguide filter provided by the present invention does not have a deep blind hole, which is conducive to batch processing and production, and can also ensure the strength of the dielectric waveguide filter.

[0036] See also Figures 1 to 3 , all dielectric resonators are distributed in a single layer, and a debugging hole 6 and 7 are respectively provided on the upper surface and the lower surface of the dielectric body between the two three-quarter wavelength dielectric resonators. The debugging hole 6 is located on the upper surface of the dielectric body, and the debugging hole 7 is located on the lower surface of the dielectric body. Optimally, the two debugging holes are coaxially arranged and located at the equivalent open-circuit ends of the two three-quarter wavelength dielectric resonators, where the electric field is the strongest, and the depth of the debugging holes can be set shallower. The debugging holes 6 and 7 can also be set at a certain distance away from the equivalent open-circuit ends of the two three-quarter wavelength dielectric resonators, but the deviation distance should not exceed one sixteenth of the waveguide wavelength to prevent the debugging holes 6 and 7 from being too deep and affecting the strength of the dielectric filter.

[0037] See also Figure 3The depth of the debugging holes 6 and 7 is less than half of the thickness of the main body to ensure the strength of the dielectric filter. The cross-section of the debugging holes 6 and 7 is circular. The inside of each dielectric resonator is a medium with any dielectric constant; the metal conductive layer is a hard metal or any metal electroplating film.

[0038] See also Figure 1 The dielectric waveguide filter further comprises an input coaxial connector 11, an output coaxial connector 12 and three coupling windows 31, 32 and 33. The input coaxial connector and the output coaxial connector are arranged on the left side of the lower surface of the dielectric waveguide filter. The coupling window 31 is located between the half-wavelength dielectric resonator 21 and the three-quarter wavelength dielectric resonator 41, the coupling window 32 is located between the half-wavelength dielectric resonator 22 and the three-quarter wavelength dielectric resonator 42, and the coupling window 33 is located between the half-wavelength dielectric resonator 21 and the half-wavelength dielectric resonator 22.

[0039] The two half-wavelength resonators 21 and 22 operate in the fundamental mode TE101 mode, the two three-quarter wavelength resonators 41 and 42 operate in the TE101.5 mode, and the four tuning holes 51, 52, 53, and 54 are respectively located on the upper surfaces of the half-wavelength dielectric resonators 21 and 22 and the two three-quarter wavelength dielectric resonators 41 and 42. The four tuning holes 51, 52, 53, and 54 can adjust the resonant frequencies of the four dielectric resonators 21, 22, 41, and 42, respectively.

[0040] Cross coupling is formed between the dielectric resonator 21 and the dielectric resonator 22. The three coupling windows 31, 32, and 33 are all waveguide narrow-side windows, which can realize inductive coupling. The coupling value between the half-wavelength dielectric resonator 21 and the three-quarter wavelength dielectric resonator 41 can be changed by changing the size of the coupling window 31; the coupling value between the half-wavelength dielectric resonator 22 and the three-quarter wavelength dielectric resonator 42 can be changed by changing the size of the coupling window 32; the coupling value between the half-wavelength dielectric resonator 21 and the half-wavelength dielectric resonator 22 can be changed by changing the size of the coupling window 33. Capacitive coupling is formed between the two three-quarter wavelength resonators. The size of the capacitive coupling value is proportional to the depth and diameter of the debugging holes 6 and 7, and the size of the coupling value can be changed by changing the depth and diameter of the debugging holes 6 and 7. Figure 4 This is a frequency response curve of the dielectric waveguide filter provided in this embodiment.

[0041] Example 2

[0042] This embodiment provides a dielectric waveguide filter, such as Figures 5 to 7 As shown, the difference from Embodiment 1 is that the debugging hole 6 and the debugging hole 7 are not coaxially arranged, and the axes of the two debugging holes are both offset from the equivalent open-circuit ends of the two three-quarter wavelength dielectric resonators.

[0043] As an alternative implementation of Embodiment 1 and Embodiment 2, the dielectric resonators may also be arranged in multiple layers; the cross-sectional shape of the debugging hole may also be square, rectangular, elliptical or any irregular shape.

[0044] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A dielectric waveguide filter, characterized in that: include at least two interconnected half-wavelength dielectric resonators (21, 22); Two three-quarter wavelength dielectric resonators (41, 42); the surface of each of the half-wavelength dielectric resonators and each of the three-quarter wavelength dielectric resonators is a metal conductive layer; the surface of each of the half-wavelength dielectric resonators and each of the three-quarter wavelength dielectric resonators is provided with a tuning hole (51, 52, 53, 54); The half-wavelength dielectric resonators are inductively coupled by opening windows on the wide sides of the waveguides; and capacitive coupling is formed between the two three-quarter wavelength dielectric resonators. It also includes at least one debugging hole disposed on the upper surface or the lower surface of the dielectric body between the two three-quarter wavelength dielectric resonators; The two debugging holes are located at equivalent open-circuit ends of the two three-quarter wavelength dielectric resonators.

2. The dielectric waveguide filter according to claim 1, characterized in that: There are two debugging holes, and the two debugging holes are respectively located on the upper surface and the lower surface of the dielectric body between the two three-quarter wavelength dielectric resonators.

3. The dielectric waveguide filter according to claim 2, characterized in that: The two debugging holes are coaxially arranged.

4. The dielectric waveguide filter according to claim 2, characterized in that: The two debugging holes are not arranged on the same axis.

5. The dielectric waveguide filter according to claim 4, characterized in that: The thickness of the debugging hole is less than half of the thickness of the medium body.

6. The dielectric waveguide filter according to any one of claims 1 to 5, characterized in that: The cross-sectional shape of the debugging hole is any one of a rectangular, circular, elliptical or irregular shape.

7. The dielectric waveguide filter according to any one of claims 1 to 5, characterized in that: All the dielectric resonators are distributed in a single layer or multiple layers.

8. The dielectric waveguide filter according to any one of claims 1 to 5, characterized in that: Each dielectric resonator has a medium with any dielectric constant inside; the metal conductive layer is a hard metal or any metal electroplating film.

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