CN216529289U - Quarter-mode slow wave dielectric integrated waveguide filter for wireless data transmission - Google Patents
Quarter-mode slow wave dielectric integrated waveguide filter for wireless data transmission Download PDFInfo
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- CN216529289U CN216529289U CN202220193515.8U CN202220193515U CN216529289U CN 216529289 U CN216529289 U CN 216529289U CN 202220193515 U CN202220193515 U CN 202220193515U CN 216529289 U CN216529289 U CN 216529289U
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Abstract
The utility model provides a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, which comprises a dielectric substrate, wherein the dielectric substrate comprises an upper surface metal layer, a lower surface metal layer, a microstrip transmission line 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 enhanced quarter-mode slow wave resonant cavity comprises a combination of M peripheral ring grooves etched in a metal layer on the upper surface, an internal metal patch and a metalized through hole which is connected with the internal metal patch and is grounded, wherein M is a positive integer greater than or equal to 1. The microstrip transmission line structure is bent to form a source-load coupling structure which is used for generating a transmission zero point and improving the selectivity and the out-of-band rejection degree of the filter. The filter not only has good performance on out-of-band rejection performance, but also reduces the volume and saves the cost.
Description
Technical Field
The utility model relates to the technical field of microwaves, in particular to a quarter-mode slow wave dielectric integrated waveguide filter for wireless data transmission.
Background
The dielectric Integrated Waveguide (SIW), also called Substrate Integrated Waveguide, is a kind of high quality Waveguide structure. Dielectric integrated waveguide filters have received much attention over the past two decades due to their excellent properties, such as high Q-factor, low insertion loss, easy integration with planar circuits, etc., and have achieved some research results, and filters and other microwave devices based on dielectric integrated waveguide technology have been primarily used in related wireless communication systems. With the continuous development of communication technology, the filter requirements will further increase, and higher requirements are put on the performance thereof, such as smaller size, wider stop band rejection performance, high selectivity, and the like.
In recent years, filter designs based on dielectric integrated waveguides mostly adopt the combination of fractional mode miniaturization technology (such as quarter, eighth, etc.) and multilayer substrate structure miniaturization technology, for example, the chinese invention with publication number CN112952322A discloses the following technical solutions: the device comprises a top dielectric substrate, a bottom dielectric substrate and an intermediate metal layer arranged between the top dielectric substrate and the bottom dielectric substrate. The middle metal layer is square, and a first L-shaped groove and a second L-shaped groove which is shorter than the first L-shaped groove are etched on two opposite corners of the middle metal layer. The requirements of technical indexes such as insertion loss, return loss, out-of-band rejection and the like in the working bandwidth are met, the advantages of the quarter-mode folded dielectric integrated waveguide and the dual-mode filter are exerted, and meanwhile, the size of the filter is greatly reduced. Although the size of the filter is reduced, the application of the multi-layer dielectric plate increases the thickness of the microwave device on one hand, and increases the complexity of the processing process and the processing cost on the other hand.
It is therefore desirable to seek to further reduce the size of microwave devices for integration with other components without increasing the thickness of the microwave device, the processing complexity and the processing cost.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, and aims to solve the problems pointed out in the background art.
The embodiment of the utility model is realized by the following technical scheme: a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission comprises a dielectric substrate, wherein the dielectric substrate comprises an upper surface metal layer, a lower surface metal layer, a microstrip transmission line 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 enhanced quarter-mode slow wave resonant cavity comprises a combination of M peripheral ring grooves etched in an upper surface metal layer, an internal metal patch and a metalized through hole which is connected with the internal metal patch and is grounded, wherein M is a positive integer greater than or equal to 1.
According to a preferred embodiment, a grounding metallized through hole is arranged between the two capacitance enhanced quarter-mode slow-wave resonant cavities, and the two capacitance enhanced quarter-mode slow-wave resonant cavities and the microstrip transmission lines connected with the two capacitance enhanced quarter-mode slow-wave resonant cavities are in left-right mirror symmetry with respect to the grounding metallized through hole.
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 a central position of the metal patch.
According to a preferred embodiment, the capacitance-enhanced quarter-mode slow-wave resonant cavity is periodically arranged in combination and connected with each other through an upper surface metal layer.
According to a preferred embodiment, the microstrip transmission line structure is bent to form a source-load coupling structure for generating transmission zero and improving the filter selectivity and out-of-band rejection.
According to a preferred embodiment, the upper surface metal layer and the lower surface metal layer are both copper.
The technical scheme of the embodiment of the utility model at least has the following advantages and beneficial effects: the slow wave dielectric integrated waveguide filter provided by the utility model not only has good performance on out-of-band rejection performance, but also has good frequency selectivity, and meanwhile, because a quarter-mode slow wave dielectric integrated waveguide structure is adopted, the volume is reduced, and the cost is saved; meanwhile, the coupling strength of the two cavities can be adjusted by increasing or reducing the number of the metalized through holes shared by the two slow wave resonant cavities or the geometric parameters so as to achieve the purpose of improving the performance of the filter.
Drawings
Fig. 1 is a schematic two-dimensional plan view of an integrated waveguide filter based on a quarter-mode slow-wave medium according to embodiment 1 of the present invention;
fig. 2 is a schematic three-dimensional structure diagram of an integrated waveguide filter based on a quarter-mode slow-wave medium according to embodiment 1 of the present invention;
fig. 3 is a triangular loading unit of the capacitance-enhanced quarter-mode slow-wave resonator according to embodiment 1 of the present invention;
fig. 4 is an equivalent circuit of a delta unit provided in embodiment 1 of the present invention;
fig. 5 is a simulation curve of group delay versus frequency provided in embodiment 1 of the present invention;
fig. 6 is a simulation curve of S parameter and frequency provided in embodiment 1 of the present invention;
icon: 1-dielectric substrate, 2-metal patch, 3-metalized through hole, 4-grounding metalized through hole, 5-ring groove, 6-upper surface metal layer, 7-lower surface metal layer, 8-microstrip transmission line and 9-metalized through hole array.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Example 1
The applicant researches and discovers that in recent years, filter designs based on dielectric integrated waveguides are mostly combined by adopting fractional mode resonant cavity miniaturization technologies (such as quarter, eighth and the like) and multilayer substrate structure miniaturization technologies, for example, the chinese invention with the publication number of CN112952322A discloses the following technical scheme: the dielectric substrate comprises a top dielectric substrate, a bottom dielectric substrate and an intermediate metal layer arranged between the top dielectric substrate and the bottom dielectric substrate. The middle metal layer is square, and a first L-shaped groove and a second L-shaped groove which is shorter than the first L-shaped groove are etched on two opposite corners of the middle metal layer. The requirements of technical indexes such as insertion loss, return loss, out-of-band rejection and the like are met in the working bandwidth, the advantages of the double-folded quarter-mode folded dielectric integrated waveguide and the double-mode filter are exerted, and meanwhile, the size of the filter is greatly reduced. 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 undoubtedly increases the complexity of the manufacturing process and the manufacturing cost on the other hand. It is therefore sought to further reduce the size of the microwave device without increasing the thickness of the microwave device, in order to facilitate integration with other components.
Based on this, the embodiment provides a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, which abandons the conventional slow-wave dielectric integrated waveguide structure of a double-layer dielectric slab, adopts a single-layer slow-wave structure easy to process, the structure is realized by periodically loading triangular loading units on a metal layer on the upper surface of the dielectric integrated waveguide, namely, the miniaturization is realized by combining the design of the 1/n die cutting technology and the slow wave loading technology, it is noted that, the dielectric integrated waveguide filter based on the 1/n die cutting technology, the method is to cut along the central line of the dielectric integrated waveguide cavity, the cut surface is equivalent to a virtual magnetic wall, the cut filter can not only keep the propagation characteristic of the original mode, but also reduce the volume, the miniaturization of the dielectric integrated waveguide based on the slow wave loading technology is realized by enhancing the equivalent inductance or capacitance effect to reduce the resonance frequency. Meanwhile, the microstrip transmission line of the input/output port is bent to form a source-load coupling structure, and transmission zero points are generated on two sides of a passband so as to improve the frequency selectivity and the out-of-band rejection degree of the filter.
Specifically, in the slow-wave loading technical scheme of the embodiment, the upper surface metal layer is divided into the outer ring groove and the inner metal patch by the triangular ring groove, the metalized through hole is only connected with the inner metal patch and the lower surface metal layer, and the whole structure can be regarded as a small triangular loading unit surrounded by the planar metal ring groove; through the non-direct connection periodic arrangement, the adjacent metal ring grooves form a net-shaped grid, and the side edge of the metal electric wall is formed by the traditional dielectric integrated waveguide metalized through hole array.
When the half-mode dielectric integrated waveguide resonant cavity is actually used, the full-mode resonant cavity dielectric integrated waveguide is divided into two parts along the symmetrical position of an electric field according to the distribution of the electromagnetic field in the full-mode resonant cavity dielectric integrated waveguide, so that a half-mode dielectric integrated waveguide resonant cavity is obtained, and the half-mode dielectric integrated waveguide resonant cavity is divided equally again along an equivalent magnetic wall so as to obtain a quarter-mode dielectric integrated waveguide resonant cavity; the filter provided by the embodiment is a second-order quarter-mode slow wave integrated waveguide filter formed by cascading two first-order quarter-mode slow wave resonant cavities together through magnetic coupling, the resonant frequency and the coupling strength of the two quarter-mode medium integrated waveguide slow wave resonant cavities can be adjusted by increasing or reducing the number or geometric parameters of metalized through holes shared between the two slow wave resonant cavities, and meanwhile, a microstrip transmission line forms a source-load coupling structure through bending to generate a transmission zero point so as to achieve the purpose of improving the performance of the filter, so that the problems pointed out in the background art are solved.
The adopted technical scheme is as follows:
a quarter-mode slow-wave dielectric integrated waveguide filter for wireless data transmission, specifically referring to FIG. 2, comprises a rectangular dielectric substrate 1, wherein the dielectric substrate 1 comprises an upper surface metal copper layer, a lower surface metal copper layer, 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 manner; a grounding metallized through hole 4 is arranged between the two capacitance enhanced quarter-mode slow-wave resonant cavities, one sides of the capacitance enhanced quarter-mode slow-wave resonant cavities far away from the metallized through hole array 9 are respectively connected with a microstrip transmission line 8, and the two capacitance enhanced quarter-mode slow-wave resonant cavities and the connected microstrip transmission lines 8 are in left-right mirror symmetry about the grounding metallized through hole 4.
Referring to fig. 1, the capacitance-enhanced quarter-mode slow-wave resonator includes M combinations of peripheral ring grooves 5 etched in an upper surface metal layer 6 and not directly connected, an internal metal patch 2, and metalized through holes 3 connected to the internal metal patch 2 and grounded, the combinations are periodically arranged and connected to each other through an upper surface copper layer, and M is a positive integer greater than or equal to 1.
In this embodiment, what two electric capacity enhancement mode quarter mode slow wave resonant cavities adopted is that two triangle-shaped's slow wave resonant cavity cascade forms, and it is shown with reference to fig. 3, peripheral annular 5, the etching of inside metal paster 2 form, metal paster 2 is triangle-shaped metal paster 2, annular 5 is triangle-shaped annular 5, and the upper surface metal copper layer is etched by triangle-shaped annular 5 and the inside triangle-shaped metal paster 2 and the metallization through-hole 3 that form constitute a triangle-shaped loading unit jointly, metallization through-hole 3 is connected to lower surface metal copper layer.
It should be noted that the mesh grid in the structure provided by the present embodiment corresponds to the upper surface of the conventional dielectric integrated waveguide, and the inner metal patch 2 surrounded by the mesh grid is actually connected to the raised ground plane through the metalized via 3. Because the electric field is captured by the annular groove 5 between the internal metal patch 2 at the top of the metalized through hole 3 and the mesh grid, the electric field originally concentrated in the middle of the dielectric integrated waveguide is concentrated between the triangular annular groove 5 and the triangular metal patch 2, and the capacitance effect on the surface of the metal layer 6 on the upper surface of the dielectric integrated waveguide is greatly enhanced.
The metalized through holes 3 are connected to the center positions of the triangular metal patches 2, and the triangular metal patches 2 and the metalized through holes 3 in the centers of the metal patches 2 jointly form an upper surface capacitance enhanced array loading area.
To better understand the characteristics of the proposed slow wave dielectric integrated waveguide structure, reference is made to fig. 4, where C1, C3 represent the mesh grid and the parasitic capacitance between the inner metal patch 2 and the underlying ground, respectively, C2 represents the enhanced capacitance between the inner metal patch 2 to 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 summary, 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 by the embodiment is significantly reduced, so that a good miniaturization effect is obtained.
In order to verify the filtering performance of the integrated waveguide filter based on the quarter-mode slow wave medium, the proposed filter structure is simulated by the present embodiment, and the simulation results are shown with reference to fig. 4 and 5. It can be seen from fig. 4 that the in-band group delay of the filter is relatively flat in the middle passband, and slightly worsens near the upper and lower roll-off edges, and the group delay in the passband is less than 1.1 ns. As can be seen from FIG. 5, the S parameter simulation curve has two poles, which are respectively 3.54GHz and 3.73GHz, the in-band return loss is lower than 23dB, the insertion loss is lower than 0.92dB, and simultaneously, the S21 curves of the upper and lower stop bands are steeper, the overall out-of-band suppression degree within the range of 4.2-9.0 GHz is lower than 13dB, and two transmission zeros are realized at 4.35GHz and 7.0GHz, and the suppression degrees are respectively 25dB and 50dB, which indicates that the out-of-band suppression effect and the frequency selectivity are good.
In summary, the technical scheme of the embodiment of the utility model at least has the following advantages and beneficial effects: the slow wave dielectric integrated waveguide filter provided by the utility model has good performance in the aspects of out-of-band rejection performance and frequency selectivity. Meanwhile, as the quarter-mode slow wave medium integrated waveguide structure is adopted, the volume is reduced, and the cost is saved; meanwhile, the resonant frequency and the coupling strength of the two resonant cavities can be adjusted by increasing or decreasing the number or geometric parameters of the grounding metalized through holes shared between the two slow-wave resonant cavities so as to achieve the purposes of improving the performance of the filter and compressing the size of the filter.
The present invention has been described in terms of the preferred embodiment, and it is not intended to be limited to the embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should 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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| CN202220193515.8U CN216529289U (en) | 2022-01-24 | 2022-01-24 | Quarter-mode slow wave dielectric integrated waveguide filter for wireless data transmission |
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| CN202220193515.8U CN216529289U (en) | 2022-01-24 | 2022-01-24 | Quarter-mode slow wave dielectric integrated waveguide filter for wireless data transmission |
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