CN216529289U - A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission - Google Patents

Abstract

The utility model provides a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, which comprises a dielectric substrate, and the dielectric substrate includes an upper surface metal layer, a lower surface metal layer, a microstrip transmission line structure, and Two capacitor-enhanced quarter-mode slow-wave resonators, and two capacitor-enhanced quarter-mode slow-wave resonators are cascaded through magnetic coupling; among them, the capacitor-enhanced quarter-mode slow-wave resonator The cavity includes a combination of M peripheral ring grooves etched on the upper surface metal layer, an inner metal patch, and a metallized through hole connected to the inner metal patch and grounded, where M is a positive integer greater than or equal to 1. Among them, the microstrip transmission line structure is bent to form a source-load coupling structure, which is used to generate a transmission zero and improve filter selectivity and out-of-band rejection. The filter not only has good performance in out-of-band suppression performance, but also reduces volume and cost.

Description

A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission

technical field

The utility model relates to the field of microwave technology, in particular to a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission.

Background technique

Substrate Integrated Waveguide (SIW), also known as Substrate Integrated Waveguide, Substrate Integrated Waveguide, and Substrate Integrated Waveguide, is a high-quality guided wave structure. Due to its excellent performance, such as high Q value, low insertion loss, and easy integration with planar circuits, dielectric integrated waveguide filters have received more attention in the past two decades, and some research results have been achieved. Technology filters and other microwave devices have been initially applied in related wireless communication systems. With the continuous development of communication technology, the demand for filters will be further increased, and higher performance requirements will be put forward, such as requiring smaller volume, wider stopband suppression performance, high selectivity, and so on.

In recent years, the design of filters based on dielectric integrated waveguides mostly adopts the combination of fractional mode miniaturization technology (such as: one-quarter, one-eighth, etc.) and multi-layer substrate structure miniaturization technology. For example, the publication number is The Chinese invention of CN112952322A discloses the following technical scheme: a top dielectric substrate, a bottom dielectric substrate and an intermediate metal layer disposed between the two. The intermediate metal layer is in a square shape, and two diagonal corners of the metal layer are etched with a first L-shaped groove and a second L-shaped groove whose length is smaller than that of the first L-shaped groove. The technical indicators such as insertion loss, return loss, and out-of-band suppression are achieved within the working bandwidth, and the advantages of quarter-mode folded dielectric integrated waveguide and dual-mode filter are brought into play, and at the same time, it is greatly reduced. The size of the filter. Although the size of the filter is reduced, the application of the multilayer dielectric plate increases the thickness of the microwave device on the one hand, and increases the complexity and cost of the processing process on the other hand.

Therefore, it is necessary to explore to further reduce the size of the microwave device without increasing the thickness, processing complexity and processing cost of the microwave device, so as to facilitate the integration with other components.

Utility model content

The purpose of the present invention is to provide a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, which aims to solve the problems pointed out in the background art.

The embodiments of the present invention are realized by the following technical solutions: a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, comprising a dielectric substrate, the dielectric substrate includes a metal layer on an upper surface, a lower surface A surface metal layer, a microstrip transmission line structure, and two capacitance-enhanced quarter-mode slow-wave resonators, two capacitance-enhanced quarter-mode slow-wave resonators are cascaded through magnetic coupling;

Wherein, the capacitance-enhanced quarter-mode slow-wave resonator includes a combination of M peripheral ring grooves etched on the upper surface metal layer, an inner metal patch, and a metallized through hole connected to the inner metal patch and grounded constitute, M is a positive integer greater than or equal to 1.

According to a preferred embodiment, a grounded metallized through hole is provided between two capacitor-enhanced quarter-mode slow-wave resonators, the two capacitor-enhanced quarter-mode slow-wave resonators and their connected micro-channels The strip transmission line is mirror-symmetrical left and right about the ground metallization via.

According to a preferred embodiment, the metal patch is a triangular metal patch, and the ring groove is a triangular ring groove.

According to a preferred embodiment, the metallized through hole is connected to the center of the metal patch.

According to a preferred embodiment, each combination in the capacitance-enhanced quarter-mode slow-wave resonator is periodically arranged and connected to each other through a metal layer on the upper surface.

According to a preferred embodiment, the microstrip transmission line structure is bent to form a source-load coupling structure, which is used to generate a transmission zero point and improve filter selectivity and out-of-band rejection.

According to a preferred embodiment, both the upper surface metal layer and the lower surface metal layer are copper.

The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects: the slow-wave dielectric integrated waveguide filter proposed by the present invention not only has good performance in out-of-band suppression performance, but also has relatively good frequency selectivity, At the same time, due to the use of a quarter-mode slow-wave dielectric integrated waveguide structure, the volume and cost are reduced; at the same time, the number or geometric parameters of the metallized through holes shared between the two slow-wave resonators can be adjusted by increasing or decreasing. The coupling strength of the two cavities is to achieve the purpose of improving the performance of the filter.

Description of drawings

1 is a schematic two-dimensional plan view of a quarter-mode slow-wave dielectric integrated waveguide filter according to Embodiment 1 of the present invention;

2 is a schematic three-dimensional structural diagram of a quarter-mode slow-wave dielectric integrated waveguide filter according to Embodiment 1 of the present invention;

3 is a triangular loading unit of a capacitance-enhanced quarter-mode slow-wave resonator provided in Embodiment 1 of the present utility model;

4 is an equivalent circuit of a triangular unit provided in Embodiment 1 of the present utility model;

5 is a simulation curve of group delay and frequency provided by Embodiment 1 of the present invention;

Fig. 6 is the simulation curve of S parameter and frequency that the utility model embodiment 1 provides;

Icon: 1-dielectric substrate, 2-metal patch, 3-metallized through hole, 4-ground metallized through hole, 5-ring groove, 6-top metal layer, 7-bottom metal layer, 8- Microstrip Transmission Line, 9-Metalized Via Array.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. The embodiments described above are a part of the embodiments of the present invention, but not all of the embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Example 1

The applicant's research found that in recent years, the design of filters based on dielectric integrated waveguides mostly adopts the miniaturization technology of fractional mode resonators (for example: one-quarter, one-eighth, etc.) and the multi-layer substrate structure. For example, the Chinese invention with publication number CN112952322A discloses the following technical solutions: a top dielectric substrate, a bottom dielectric substrate and an intermediate metal layer disposed therebetween. The intermediate metal layer is in a square shape, and two diagonal corners of the metal layer are etched with a first L-shaped groove and a second L-shaped groove whose length is smaller than that of the first L-shaped groove. The technical indicators such as insertion loss, return loss, and out-of-band suppression are achieved within the working bandwidth, and the advantages of double-folded quarter-mode folded dielectric integrated waveguides and double-mode filters are brought into play. Reduced filter size. Although the size of the filter is reduced, the application of the multi-layer dielectric plate increases the thickness of the microwave device on the one hand, and on the other hand undoubtedly increases the complexity of the processing process and the processing cost. Therefore, it is necessary to explore further reducing the size of the microwave device without increasing the thickness of the microwave device, so as to facilitate the integration with other components.

Based on this, this embodiment provides a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, which abandons the traditional slow-wave dielectric integrated waveguide structure of double-layer dielectric plates, and adopts a single-layer slow-wave dielectric integrated waveguide structure that is easy to process. The wave structure is realized by periodically loading a triangular loading unit on the upper surface of the dielectric integrated waveguide, that is, by combining the design of 1/n mode cutting technology and slow wave loading technology to achieve miniaturization. It should be noted that, based on The dielectric integrated waveguide filter of 1/n mode cutting technology is cut along the center line of the dielectric integrated waveguide cavity, and the cut surface is equivalent to a virtual magnetic wall. After cutting, the filter can retain the original The propagation characteristics of the mode can be reduced, and the volume can be reduced, while the miniaturization of the dielectric integrated waveguide based on the slow wave loading technology is achieved by enhancing the equivalent inductance or capacitance effect to reduce the resonant frequency. At the same time, the microstrip transmission line of the input and output ports is bent to form a source-load coupling structure, and transmission zeros are generated on both sides of the passband to improve the frequency selectivity and out-of-band rejection of the filter.

Specifically to the slow wave loading technical solution in this embodiment, the upper surface metal layer is divided into an outer ring groove and an inner metal patch by a triangular ring groove, and the metallized through hole is only connected with the inner metal patch and the lower surface metal layer. The structure can be regarded as a flat metal ring groove surrounding a small triangular loading unit; through the periodic arrangement of indirect connections, the adjacent metal ring grooves form a mesh grid, and the traditional dielectric integrated waveguide metallized through holes on the side The array constitutes a metal electrical wall.

In actual use, according to the electromagnetic field distribution inside the full-mode resonator dielectric integrated waveguide, the full-mode resonator dielectric integrated waveguide is divided into two parts along the symmetrical position of its electric field, and the half-mode dielectric integrated waveguide resonator is obtained. The waveguide resonator is bisected again along the equivalent magnetic wall to obtain a quarter-mode dielectric integrated waveguide resonator; the filter provided in this embodiment is composed of two first-order quarter-mode slow-wave resonators cascaded through magnetic coupling Together to form a second-order quarter-mode slow-wave integrated waveguide filter, the two quarters can be adjusted by increasing or decreasing the number or geometric parameters of the metallized vias shared between the two slow-wave resonators. One-mode dielectric integrates the resonant frequency and coupling strength of the waveguide slow-wave resonator, and at the same time, the microstrip transmission line is bent to form a source-load coupling structure to generate a transmission zero to achieve the purpose of improving the filter performance, so as to solve the problems in the background art. problems pointed out.

The technical solutions adopted are as follows:

A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, specifically, as shown in FIG. 2 , it includes a rectangular dielectric substrate 1, and the dielectric substrate 1 includes a metal copper layer on the upper surface , the metal copper layer on the lower surface, the microstrip transmission line 8 structure, and two capacitance-enhanced quarter-mode slow-wave resonators, which are cascaded through magnetic coupling; A grounded metallized through hole 4 is arranged between the two capacitor-enhanced quarter-mode slow-wave resonators, and one side of the capacitor-enhanced quarter-mode slow-wave resonator away from the metallized through hole array 9 is connected to a The microstrip transmission line 8 , and the two capacitance-enhanced quarter-mode slow-wave resonators and the microstrip transmission line 8 connected thereto are left and right mirror-symmetrical with respect to the ground metallized through hole 4 .

Referring to FIG. 1 , the capacitance-enhanced quarter-mode slow-wave resonator includes M peripheral ring grooves 5 etched on the upper surface of the metal layer 6 and not directly connected, the inner metal patch 2 and the inner metal patch 2 . A combination of metallized through holes 3 connected to and grounded by the patch 2 is formed, each combination is arranged in a periodic arrangement, and is connected to each other through a metal copper layer on the upper surface, M is a positive integer greater than or equal to 1.

In this embodiment, the two capacitor-enhanced quarter-mode slow-wave resonators are formed by cascading two triangular slow-wave resonators. Referring to FIG. 3 , the outer ring groove 5, the inner The metal patch 2 is etched, the metal patch 2 is a triangular metal patch 2, the ring groove 5 is a triangular ring groove 5, and the metal copper layer on the upper surface is etched by the triangular ring groove 5. The sheet 2 and the metallized vias 3 together form a triangular loading unit, and the metallized vias 3 are connected to the lower surface metal copper layer.

It should be noted that, in the structure provided by this embodiment, the mesh grid corresponds to the upper surface of the traditional dielectric integrated waveguide, and the internal metal patch 2 surrounded by the mesh grid is actually connected and elevated through the metallized through holes 3 ground plane. Because the electric field is captured by the inner metal patch 2 at the top of the metallized via 3 and the ring groove 5 between the mesh grids, the electric field originally concentrated in the middle of the dielectric integrated waveguide is concentrated in the triangular ring groove 5 and the triangular metal patch between the sheets 2, thereby greatly enhancing the capacitance effect on the surface of the metal layer 6 on the upper surface of the dielectric integrated waveguide.

The metallized through hole 3 is connected to the center of the triangular metal patch 2 , and the triangular metal patch 2 and the metallized through hole 3 in the center of the metal patch 2 together constitute the upper surface capacitance-enhanced array loading area.

To better understand the characteristics of the proposed slow-wave dielectric integrated waveguide structure, refer to Fig. 4, where C1 and C3 represent the mesh grid and the parasitic capacitance between the internal metal patch 2 and the bottom ground, respectively, and C2 represents the internal metal The enhanced capacitance between the patch 2 and the mesh grid, L2 represents the parasitic inductance brought by the ground metallization via 4, and L1 represents the series inductance introduced by the electrical signal flowing through the mesh grid.

In conclusion, based on the dual application of the fractional mode dielectric integrated waveguide miniaturization technology and the slow-wave effect dielectric integrated waveguide miniaturization technology, the size of the filter provided in this embodiment is significantly reduced, thereby obtaining a good miniaturization effect.

In order to verify the filtering performance of the quarter-mode slow-wave dielectric integrated waveguide filter, the proposed filter structure is simulated in this embodiment, and the simulation results are shown in FIG. 4 and FIG. 5 . It can be seen from Figure 4 that the in-band group delay of the filter is relatively flat in the middle passband, slightly deteriorated near the upper and lower roll-off edges, and the in-band group delay is less than 1.1ns. As can be seen from Figure 5, the S-parameter simulation curve has two poles, 3.54GHz and 3.73GHz, the in-band return loss is lower than 23dB, the insertion loss is lower than 0.92dB, and the S21 curves of the upper and lower stopbands are relatively steep. , the overall out-of-band rejection in the range of 4.2-9.0GHz is lower than 13dB, and two transmission zero points are achieved at 4.35GHz and 7.0GHz, and the rejection is 25dB and 50dB respectively, indicating that it has good out-of-band rejection effect and frequency selection. sex.

To sum up, the technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects: the slow-wave dielectric integrated waveguide filter proposed by the present invention has good performance in both out-of-band suppression performance and frequency selectivity. At the same time, due to the use of a quarter-mode slow-wave dielectric integrated waveguide structure, the volume and cost are reduced. The resonant frequency and coupling strength of the two resonators are adjusted to improve the filter performance and compress the filter size.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. 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 (7)

1. A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission is characterized by comprising a dielectric substrate (1), wherein the dielectric substrate (1) comprises an upper surface metal layer (6), a lower surface metal layer (7), a microstrip transmission line (8) structure and two capacitance-enhanced quarter-mode slow-wave resonant cavities, and the two capacitance-enhanced quarter-mode slow-wave resonant cavities are cascaded in a magnetic coupling mode;

the capacitance enhancement type quarter-mode slow wave resonant cavity comprises a combination of M peripheral ring grooves (5) etched in an upper surface metal layer (6), an internal metal patch (2) and a metalized through hole (3) which is connected with the internal metal patch (2) and is grounded, wherein M is a positive integer greater than or equal to 1.

2. A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission according to claim 1, wherein a grounded metallized via (4) is provided between two capacitance-enhanced quarter-mode slow-wave resonators, and the two capacitance-enhanced quarter-mode slow-wave resonators and their connected microstrip transmission lines (8) are mirror-symmetric with respect to the grounded metallized via (4).

3. A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission according to claim 1, characterized in that the metal patch (2) is a triangular metal patch (2) and the ring groove (5) is a triangular ring groove (5).

4. A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission according to claim 1, characterized in that said metallized through-hole (3) is connected to a central position of said metal patch (2).

5. A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission according to claim 1, wherein the capacitance-enhanced quarter-mode slow-wave resonators are arranged in a periodic arrangement and connected to each other through the upper surface metal layer (6).

6. A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission according to claim 5, characterized in that the microstrip transmission line (8) structure is bent to form a source-load coupling structure for generating transmission zero and improving the filter selectivity and out-of-band rejection.

7. A quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission according to claim 1, characterized in that the upper surface metal layer (6) and the lower surface metal layer (7) are both copper.

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