CN218385689U - Adjustable planar substrate integrated waveguide filter - Google Patents

Abstract

The application provides an adjustable planar substrate integrated waveguide filter, which comprises a dielectric substrate and metal layers respectively arranged on the upper side and the lower side of the dielectric substrate, wherein diagonal metal through holes are formed in diagonal positions of the metal layers, unmetallized through holes are formed in the center of the metal layers, and the adjustment of the center frequency of the filter is realized by adjusting a position relation perturbation electric field between a copper column and the unmetallized through holes. The filter can reduce energy leakage through the diagonal metal through holes, improve the insertion loss of the filter, avoid generating harmonic waves outside the band and improve out-of-band rejection; the electric field in the cavity is disturbed through the position between the copper column and the non-metallized through hole, so that the frequency of the resonator is tuned. The method is simple, the structure is convenient to process, and the method can be widely applied to a multifunctional comprehensive radio frequency system.

Description

Adjustable planar substrate integrated waveguide filter

Technical Field

The application relates to the field of microwave devices, in particular to an adjustable planar substrate integrated waveguide filter.

Background

In modern communication, multiband, multi-standard and multi-mode wireless communication services are widely applied, and in order to support popularization and application of the services, a radio frequency system capable of meeting the standards needs to be designed. The adjustable band-pass or adjustable dual-frequency filter is used as a core component in the transceiver, and can meet the requirements of the current communication system to a certain extent. The research on reconfigurable waveguide filters and microstrip filters has never been interrupted, but the microstrip structures have poor performance at high frequencies and the volume and cost of the traditional waveguides limit the development and application of the microstrip structures, so that the research on tunable filters with planar waveguide structures with high quality factors is a research hotspot of current researchers.

At present, the substrate integrated waveguide tunable filter is mainly an electrically tunable filter, and for example, a tuning method such as a semiconductor varactor and an MEMS (micro electro mechanical system) is adopted to realize the tunable characteristic of the frequency band of the filter. Thus limiting the application scenarios of the filter.

SUMMERY OF THE UTILITY MODEL

In order to solve the defects in the prior art, the application aims to provide an adjustable planar substrate integrated waveguide filter. The application realizes effective regulation of the central frequency of the filter in a more simple and convenient regulation mode by inserting the copper column perturbation electric field into the substrate integrated waveguide cavity.

To achieve the above object, the present application provides an adjustable planar substrate integrated waveguide filter, comprising: a dielectric substrate; the top metal layer is fixedly attached to and covered on the top of the medium substrate; the bottom metal layer is fixedly attached to and covers the bottom of the medium substrate and has the same plane structure as the top metal layer; diagonal metal through holes are symmetrically arranged at diagonal positions of the dielectric substrate, and the diagonal metal through holes vertically penetrate through the top metal layer and the bottom metal layer; unmetallized vias symmetrically arranged in an array at a center of the dielectric substrate, the unmetallized vias vertically penetrating the top metal layer and the bottom metal layer; and the copper column is inserted into the unmetallized through hole, perturbs the electric field and adjusts the central frequency of the filter.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein edge metal through holes are further disposed at edges of the top metal layer and the bottom metal layer, and are arranged at equal intervals along an edge of the dielectric substrate, and the edge metal through holes vertically penetrate through the top metal layer and the bottom metal layer.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein the top metal layer and the bottom metal layer are further connected to an input terminal and an output terminal, and the input terminal and the output terminal are coupled to the top metal layer and the bottom metal layer at right angles and have extending directions perpendicular to each other.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein the top metal layer, the bottom metal layer, and the dielectric substrate are all configured as a rectangle, the diagonal metal through holes are disposed at two ends of a diagonal on the same side of the rectangle, and the input terminal and the output terminal are disposed on the same side of a connection line of the diagonal metal through holes.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein the matrix in which the unmetallized through holes and the copper pillars are arranged at equal intervals as 3 × 3 is disposed at a central position of the rectangle, and the depth of each copper pillar extending into the unmetallized through hole is independently adjusted.

Optionally, the adjustable planar substrate integrated waveguide filter as described in any of the above, wherein the top metal layer, the bottom metal layer, and the dielectric substrate are all configured as right-angled isosceles triangles, the diagonal metal through holes are disposed at the edges of the long sides of the right-angled isosceles triangles, the edge metal through holes are equidistantly arranged at the edges of the right-angled sides of the right-angled isosceles triangles, and the input terminal and the output terminal are disposed at the middle positions of the right-angled sides of the right-angled isosceles triangles.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein the unmetallized through holes are rectangular strips symmetrically formed along the long edge and the central axis of the right-angled isosceles triangle.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein the rectangular strips are arranged in a T shape, the length and width dimensions of each rectangular strip are the same, and a copper pillar is inserted into each rectangular strip.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein the copper pillars in each rectangular bar slide along the unmetallized via holes with long sides of right-angled isosceles triangles centrosymmetrically.

Optionally, the tunable planar substrate integrated waveguide filter as described in any of the above, wherein the unmetallized via has a dielectric hollowed out for only the copper pillar to move.

Compared with the prior scheme, the method has the following technical effects:

the application provides an adjustable planar substrate integrated waveguide filter, which comprises a dielectric substrate and metal layers respectively arranged on the upper side and the lower side of the dielectric substrate, wherein diagonal metal through holes are formed in diagonal positions of the metal layers, unmetallized through holes are formed in the center of the metal layers, and the adjustment of the center frequency of the filter is realized by adjusting a position relation perturbation electric field between a copper column and the unmetallized through holes. The filter can reduce energy leakage through the diagonal metal through holes, improve the insertion loss of the filter, avoid generating harmonic waves outside the band and improve out-of-band rejection; the electric field in the cavity is disturbed through the position between the copper column and the unmetallized through hole, so that the frequency of the resonator is tuned. The method is simple, the structure is convenient to process, the method can be widely applied to a multifunctional comprehensive radio frequency system, and the problems of serious electromagnetic interference, poor equipment stealth, difficulty in maintenance and the like caused by increasing of electronic equipment on the naval vessel horizontal launch due to the fact that the number of antennas is more and more are effectively solved. The method and the device can greatly improve the information fusion and the information sharing degree of the comprehensive radio frequency system, are favorable for electromagnetic compatibility of ship electronic equipment, and effectively improve the stealth performance of the ship electronic equipment.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application.

Drawings

The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application and not limit the application. In the drawings:

fig. 1 is a schematic plan view of a first tunable planar substrate integrated waveguide filter according to the present application;

FIG. 2 is a graph of the electric field distribution of the principal mode TM10 of the cavity obtained by intrinsic mode simulation of the filter of FIG. 1;

FIG. 3 is a graph of the electric field distribution of the TE102 mode obtained by eigen-simulation of the filter of FIG. 1;

FIG. 4 is a graph of the electric field distribution of the TE201 mode obtained by eigen-simulation of the filter of FIG. 1;

FIG. 5 shows the reflection coefficients obtained by simulation of the filter of FIG. 1 when different numbers of copper pillars are inserted respectively;

FIG. 6 is a diagram of forward transmission coefficients obtained by simulation of the filter of FIG. 1 when different numbers of copper pillars are inserted respectively;

FIG. 7 is a schematic plan view of a second tunable planar substrate integrated waveguide filter according to the present application;

FIG. 8 is a graph of the electric field distribution of the TE101 mode obtained by eigen-simulation of the filter of FIG. 7;

FIG. 9 is a graph of the electric field distribution of the TE102 mode obtained by eigen-simulation of the filter of FIG. 7;

FIG. 10 is a simulation result of S-parameters obtained by the filter of FIG. 7 when the copper pillars are slid to different positions, respectively

In the figure, 1 denotes a top metal layer; 2 denotes an output terminal; 3 denotes an edge metal via; 4 denotes diagonal metal vias; and 5 denotes an unmetallized via.

Detailed Description

The preferred embodiments of the present application will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein only to illustrate and explain the present application and not to limit the present application.

The meaning of "and/or" as used herein is intended to include both the individual components or both.

The meaning of "inside and outside" in this application means that the direction from the metal layer of the planar substrate integrated waveguide filter to the center of the dielectric substrate is inside and vice versa, with respect to the filter itself; and not as a specific limitation on the mechanism of the device of the present application.

The terms "left and right" as used herein refer to the user facing the planar substrate integrated waveguide filter with the user's left side being left and the user's right side being right, and are not intended to limit the mechanism of the apparatus of the present application.

The term "connected" as used herein may mean either a direct connection between components or an indirect connection between components through other components.

The term "up and down" as used herein means that when a user is facing the planar substrate integrated waveguide filter, the direction from the bottom metal layer to the top metal layer is up, and vice versa, not specifically limited to the device mechanism of the present application.

Referring to fig. 1, the present application provides a tunable planar substrate integrated waveguide filter, comprising:

a dielectric substrate;

the top metal layer 1 is fixedly attached to and covered on the top of the medium substrate;

the bottom metal layer is fixedly attached to and covers the bottom of the medium substrate and has the same plane structure as the top metal layer 1;

diagonal metal through holes 4 symmetrically arranged at diagonal positions of the dielectric substrate, wherein the diagonal metal through holes 4 vertically penetrate through the top metal layer 1 and the bottom metal layer;

unmetallized vias 5 symmetrically arranged in an array at a center of the dielectric substrate, the unmetallized vias 5 vertically penetrating the top metal layer 1 and the bottom metal layer;

and the copper column is inserted into the unmetallized through hole 5 to perturb the electric field and adjust the central frequency of the filter.

Therefore, the method for tuning the frequency of the cavity resonator is creatively applied to the planar substrate integrated waveguide circuit in the planar substrate integrated waveguide filter according to the electric field perturbation theory by means of the traditional rectangular waveguide resonator and the idea of disturbing the electric field in the cavity by inserting the pin at the position with the highest field strength. The unmetallized through hole array is arranged at the central position of the substrate integrated waveguide, and the through hole copper column perturbation electric field is inserted to realize the tuning of the central frequency of the substrate integrated waveguide filter, thereby realizing the adjustable planar substrate integrated waveguide filter.

In the planar substrate integrated waveguide filter provided by the present application, the edges of the top metal layer 1 and the bottom metal layer may also be generally provided with edge metal vias 3 arranged at equal intervals along the edge of the dielectric substrate. The edge metal vias 3 may be disposed to vertically penetrate the top metal layer 1 and the bottom metal layer.

In the planar substrate integrated waveguide filter, the top metal layer 1 and the bottom metal layer can be provided with input and output terminals coupled at right angles. Wherein the input terminal and the output terminal 2 are arranged perpendicular to each other and extend outward from the groove at the middle position of the edges of the top metal layer 1 and the bottom metal layer, so as to generate zero points in the second passband between the TE102 and the TE 201.

The side length a of the filter cavity in the planar substrate integrated waveguide filter can be set to be 30mm, the dielectric substrate can be set to be based on Rogers 5880, the thickness of the dielectric substrate can be selected to be 0.508mm, the relative dielectric constant is 2.2, and the loss tangent is 0.0009. The eigenmode simulation can be performed to obtain the simulation results shown in fig. 2 to 6.

In this embodiment, the top metal layer 1, the bottom metal layer and the dielectric substrate may be simultaneously configured as a rectangle, and the diagonal metal vias 4 are disposed at two ends of a diagonal on the same side of the rectangle to perturb the TE102 mode, so as to separate the TE102 resonant frequency from the TE201 resonant frequency, thereby implementing a second dual-band dual-mode band-pass. In this implementation, the input terminal and the output terminal 2 are disposed on the same side of the line connecting the diagonal metal vias 4. Because TE102 and TE201 are 90 degrees out of phase, plus input-output right angle coupling, a transmission zero is generated on each side of the second passband.

In order to realize the tuning of the central frequency of the filter, in the present application, the unmetallized via holes 5 and the copper pillars may be specifically set as a matrix of 3 × 3 arranged at equal intervals, and symmetrically arranged at the central position of the rectangle, and each copper pillar independently adjusts the depth of the unmetallized via hole 5. Thus, the simulation results of fig. 5 can be used to obtain: the filter structure can realize the filtering effect of different frequency bands when no copper column is inserted, a single copper column is inserted or other copper columns are inserted, and the central frequency of the filter is adjusted.

In another implementation manner shown in fig. 7, on the basis of the research on the substrate integrated waveguide dual-band tunable filter, the top metal layer 1, the bottom metal layer, and the dielectric substrate may be all configured as right-angled isosceles triangles to form a half-mode substrate integrated waveguide tunable band-pass filter. In the filter, diagonal metal through holes 4 are arranged on the long edge of a right-angled isosceles triangle, edge metal through holes 3 are arranged on the right-angled edge of the right-angled isosceles triangle at equal intervals, and an input terminal and an output terminal 2 are vertically arranged in the middle of the right-angled edge of the right-angled isosceles triangle.

On this half module substrate integrated waveguide structure unmetallized through-hole 5 sets up to the rectangle strip of seting up along right angle isosceles triangle's long limit edge and axis symmetry, and the medium substrate is drawn empty and is formed the rectangular channel and replace the through-hole that inserts the copper post in the rectangle strip, and the copper post can make a round trip to slide along the groove, realizes the continuous regulation to wave filter central frequency, has effectively increased the tunable frequency band of wave filter.

The half-mode substrate integrated waveguide is obtained by cutting along the diagonal line of the square substrate integrated waveguide, the size of the half-mode substrate integrated waveguide is only half of the original size, and the transmission characteristic and frequency calculation are the same as those of the square substrate integrated waveguide. Cooperate in triangle-shaped medium substrate and metal level structure, the rectangle strip that this application will supply to adjust copper post tuning position arranges for the T font, and the length and width size of each rectangle strip sets up the same, sets up and inserts a copper post in each rectangle strip respectively, and each copper post adjusts its position apart from T font center node according to unified index. In the half-mode substrate integrated waveguide filter, the odd-mode electric field will not be excited, and only the even-mode exists. The modes transmitted in the filter passband of the half-mode structure are the TE101 and TE102 modes, and the TE101 and TE102 eigen-mimic true electric field distributions are shown in fig. 8-10.

When the copper pillar embedded in the rectangular bar moves, the electric fields of the TE101 and TE102 modes will be disturbed and their resonant frequencies will both move. The structure of the tunable filter is shown in fig. 8 and 9. The opposite corners of the filter are not provided with additional metalized through holes, the input and the output of the filter all adopt a coplanar waveguide structure, rectangular groove media in the cavity are hollowed, the groove width is the same as the diameter of the copper column, and the embedded copper column can be conveniently moved. The right center of the T-shaped structure of the rectangular strip is provided with a metallized through hole at the position corresponding to the middle point of the bottom edge of the metal layer of the isosceles right triangle, a movable copper metal cylinder is embedded in a groove formed by the rectangular strip, the distance ds between the copper cylinder and the center of the cavity can be correspondingly adjusted and moved according to the filtering frequency band, and the three copper cylinders respectively slide for the same distance along the unmetallized through hole 5 in a symmetrical mode with the center of the long edge of the right-angled isosceles triangle every time. The results of S parameter simulation are shown in FIG. 10, which is based on a board with a thickness of 0.508mm and a dielectric constant of 2.2, modeled and simulated by HFSS software based on Rogers 5880. According to simulation results, extra metalized through holes are not added to opposite corners in the structure, energy can cause leakage, and the insertion loss of the filter is poor; and meanwhile, harmonic waves are generated outside the band, so that the out-of-band rejection is poor. As can be seen from the electric field distribution of the TE202, out-of-band harmonics are generated by TE202 resonance.

The application has the advantages that:

energy leakage can be reduced through the diagonal metal through holes, the insertion loss of the filter is improved, harmonic waves generated outside the band are avoided, and out-of-band rejection is improved; the electric field in the cavity is disturbed through the position between the copper column and the unmetallized through hole, so that the frequency of the resonator is tuned. Compared with other adjustable filter structures, the frequency band adjusting mode is simple, the structure processing is convenient, the filter can be widely applied to a multifunctional comprehensive radio frequency system, and the problems that electromagnetic interference is serious, equipment stealth is poor, maintenance is difficult and the like due to the fact that electronic equipment is increased on the navy ship horizontal launch and the number of antennas is more and more are caused are effectively solved. The method and the system can greatly improve the information fusion and the information sharing degree of the comprehensive radio frequency system, are favorable for the electromagnetic compatibility of the electronic equipment of ships and effectively improve the stealth performance of the electronic equipment.

Those of ordinary skill in the art will understand that: although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. An adjustable planar substrate integrated waveguide filter comprising:

a dielectric substrate;

the top metal layer (1) is fixedly attached to and covered on the top of the medium substrate;

the bottom metal layer is fixedly attached to and covers the bottom of the medium substrate and has the same plane structure as the top metal layer (1);

diagonal metal through holes (4) symmetrically arranged at diagonal positions of the dielectric substrate, wherein the diagonal metal through holes (4) vertically penetrate through the top metal layer (1) and the bottom metal layer;

unmetallized vias (5) symmetrically arranged in an array at a central position of the dielectric substrate, the unmetallized vias (5) vertically penetrating the top metal layer (1) and the bottom metal layer; the copper column is inserted into the unmetallized through hole (5) and perturbs the electric field to adjust the center frequency of the filter.

2. The tunable planar substrate integrated waveguide filter according to claim 1, wherein the top metal layer (1) and the bottom metal layer are further provided with edge metal vias (3) at their edges, which are arranged at equal intervals along the edge of the dielectric substrate, and the edge metal vias (3) vertically penetrate through the top metal layer (1) and the bottom metal layer.

3. Tunable planar substrate integrated waveguide filter according to claim 2, characterized in that the top metal layer (1) and the bottom metal layer are further connected with input and output terminals (2), the input and output terminals (2) being coupled with the top metal layer (1) and the bottom metal layer at right angles and having mutually perpendicular directions of extension.

4. The tunable planar substrate integrated waveguide filter according to claim 3, wherein the top metal layer (1), the bottom metal layer and the dielectric substrate are rectangular, the diagonal metal vias (4) are disposed at two ends of the diagonal on the same side of the rectangle, and the input terminal and the output terminal (2) are disposed on the same side of the line connecting the diagonal metal vias (4).

5. An adjustable waveguide filter on a planar substrate as claimed in claim 4, wherein the unmetallized vias (5) and the copper pillars are arranged in a 3 x 3 matrix at the center of the rectangle, each pillar having an independently adjustable depth extending into the unmetallized via (5).

6. The tunable planar substrate integrated waveguide filter according to claim 3, wherein the top metal layer (1), the bottom metal layer and the dielectric substrate are all arranged as a right-angled isosceles triangle, the diagonal metal vias (4) are arranged at the long edge of the right-angled isosceles triangle, the edge metal vias (3) are arranged at equal intervals at the right-angled edge of the right-angled isosceles triangle, and the input terminal and the output terminal (2) are arranged at the middle position of the right-angled edge of the right-angled isosceles triangle.

7. An adjustable planar substrate integrated waveguide filter according to claim 6, characterized in that the unmetallized vias (5) are arranged as rectangular strips symmetrically arranged along the long edges and the central axis of a right-angled isosceles triangle.

8. The tunable planar substrate integrated waveguide filter according to claim 7, wherein the rectangular strips are arranged in a T-shape, the length and width dimensions of each rectangular strip are the same, and a copper pillar is inserted into each rectangular strip.

9. An adjustable planar substrate integrated waveguide filter according to claim 8, characterized in that the copper posts in each rectangular bar slide centrally symmetrically along the non-metallized through holes (5) with the long side of the right isosceles triangle respectively.

10. The tunable planar substrate integrated waveguide filter according to claim 1, wherein the unmetallized via (5) is hollowed out of the dielectric for copper pillar movement only.

Images