CN210778906U

CN210778906U - H-surface dielectric adjustable waveguide filter

Info

Publication number: CN210778906U
Application number: CN201921439023.7U
Authority: CN
Inventors: 王浩; 邹涌泉; 唐波; 陈勇
Original assignee: Chengdu Spaceon Electronics Co Ltd
Current assignee: Chengdu Spaceon Electronics Co Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2020-06-16
Anticipated expiration: 2029-08-30

Abstract

The utility model belongs to the technical field of the wave filter, concretely relates to adjustable waveguide filter of H face medium. The technical scheme is as follows: an H-plane dielectric tunable waveguide filter comprises a rectangular waveguide body; a coupling structure is arranged in the rectangular waveguide body, and the coupling structure divides the inner cavity of the rectangular waveguide body into a plurality of resonant cavities; at least one adjustable element is arranged in one resonant cavity, a plurality of through holes are formed in the H surface of the rectangular waveguide body, one end of the adjustable element extends into the rectangular waveguide body from the through holes, and the other end of the adjustable element is connected with a driving mechanism. In order to solve the problems existing in the prior art, the utility model provides a tunable filter that adjustable component set up from the H face for compare under the same resonant cavity size have bigger medium motion stroke, tuning range when setting up adjustable component in the E face and be wideer, the motion stroke of adjustable component can be bigger under the same tuning range, have lower tuning sensitivity.

Description

H-surface dielectric adjustable waveguide filter

Technical Field

The utility model belongs to the technical field of the wave filter, concretely relates to adjustable waveguide filter of H face medium.

Background

The tunable filter is a filter whose center frequency can be adjusted within a certain range, is an important component of a microwave communication system, and is widely applied to frequency hopping radio stations, electronic countermeasure, dynamic frequency distribution systems and the like at present. Compared with a single-frequency filter, the tunable filter has many advantages, such as that a single tunable filter can cover many frequency bands, and remote control of working frequency switching can be realized. Therefore, the adjustable filter can effectively reduce material cost and operation cost, furthest utilizes frequency spectrum resources and has wide application prospect.

In recent years, in order to meet the development demand of communication systems, the tunable filter technology of the microwave frequency band is becoming one of the hot points in the field of microwave communication, and intensive research is carried out by each large communication equipment supplier.

The existing tunable filter in the microwave frequency band is mainly realized by adding a tuning mechanism on the basis of a waveguide filter. The main implementation methods include the following: 1. an E-plane rotating dielectric sheet tunable filter (patent No.: WO2010150815a1) of NEC corporation of japan realizes tuning by providing a rotatable dielectric sheet in an E-plane single-iris filter. 2. An E-plane push-flat metal sheet tunable filter (patent number: WO2016095165a1) of hua-shi technology ltd, in which tuning is achieved by changing the size of a resonant cavity by horizontally pushing a group of metal sheets parallel to a metal coupling diaphragm in the length direction of a waveguide. 3. An adjustable filter loaded with an E-plane dielectric sheet of Jiangsu Befude communication technology, Inc. based on an inductive window filter, tuning is achieved by inserting a PCB substrate into a cavity from the center line of the E-plane (patent No. CN 107910624A).

The NEC and hua cheng patents adopt the scheme of an E-film filter, and since the metal coupling diaphragm is thin, it is easy to deform or damage, and the width of the coupling diaphragm in the propagation direction is inversely proportional to the coupling strength. In the case of a certain central frequency, the bandwidth of the filter needs to be increased, the coupling strength needs to be increased, and the width of the coupling diaphragm needs to be necessarily reduced, and the width needs to be increased to a certain extent to ensure the structural reliability, so that the bandwidth of the filter cannot be made very wide. In addition, since the coupling strength is adjusted by the width of the coupling diaphragm in the propagation direction, the length is longer than that of an inductive window filter with a certain window thickness. Meanwhile, the assembly of the filter is more complicated than that of an inductive window filter, and extra errors are easily introduced to cause the electrical performance deterioration. The dielectric sheet in the NEC patent can only rotate within the range of 0-90 degrees, tuning is very sensitive, and in order to meet the requirement of tuning stepping precision, a driving mechanism is complex in structure, large in size and high in cost. The huache patent does not have a coupling compensation device, which may cause obvious bandwidth change in the tuning process and obvious fluctuation of main indexes such as in-band echo, in-band insertion loss, out-of-band rejection and the like in the tuning process. The method of inserting the medium from the E-plane is adopted in the besford patent to realize tuning, the tuning range of the besford patent is in direct proportion to the movement stroke of the medium piece, the movement stroke of the medium piece is limited by the height of the resonant cavity, and the high-height of the resonant cavity can enable high-order harmonics to approach the pass band to influence the out-of-band suppression performance, so that the tuning range of the besford patent is limited by the height of the resonant cavity. Under the condition that the dielectric material and the size are not changed, the tuning range needs to be enlarged, the height of the resonant cavity needs to be increased to enlarge the motion stroke of the medium, and therefore, the height of the filter is high, and the structure is not compact.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems in the prior art, the present invention provides a tunable filter with a tunable element arranged from the H-plane, which has a larger medium motion stroke and a wider tuning range when the tunable element is arranged compared to the E-plane under the same cavity size, and the motion stroke of the tunable element under the same tuning range can be larger and has a lower tuning sensitivity.

The utility model discloses the technical scheme who adopts does:

an H-plane dielectric tunable waveguide filter comprises a rectangular waveguide body; a coupling structure is arranged in the rectangular waveguide body, and the coupling structure divides the inner cavity of the rectangular waveguide body into a plurality of resonant cavities; at least one adjustable element is arranged in one resonant cavity, a plurality of through holes are formed in the H surface on one side of the rectangular waveguide body, one end of the adjustable element is connected with a driving mechanism, and the other end of the adjustable element extends into the resonant cavity from the through holes.

Preferably, the shape of the adjustable element includes, but is not limited to, one of a sheet, a round bar and a rectangular column.

Preferably, at least two adjustable elements are inserted into the resonant cavity of the end portion.

Preferably, the material of the adjustable element is a medium with a certain dielectric constant, including but not limited to one of plastic, PCB substrate, quartz and ceramic.

Preferably, the number of tunable elements in each resonant cavity may be the same or different.

Preferably, the insertion depth of the tunable element in the resonant cavity may be different

Preferably, the coupling structure is a plurality of coupling partition walls, and the coupling partition walls are fixed in the rectangular waveguide body.

Preferably, the rectangular waveguide body includes a bottom groove, an opening is formed in an E surface of the bottom groove, an E panel is connected to the opening of the bottom groove, the through hole is formed in a side edge of the bottom groove, and the coupling partition wall is fixed in the bottom groove.

Preferably, the coupling structure comprises two metal coupling diaphragms, the two metal coupling diaphragms are sleeved in the rectangular waveguide body, and the metal coupling diaphragms are parallel to the H surface of the rectangular waveguide body; the metal coupling diaphragm is provided with a plurality of metal coupling diaphragms, and the resonant cavity is formed by separating the metal coupling diaphragms on the two metal coupling diaphragms.

Preferably, the rectangular waveguide body comprises two H-face grooves, an E-face plate is connected between two ends of each H-face groove, the through hole is formed in one of the H-face grooves, and the two metal coupling diaphragms are sleeved in a space defined by the two H-face grooves and the two E-face plates.

Preferably, the drive mechanism is a linear motor.

The utility model has the advantages that:

1. the width of the waveguide filter in the E surface direction is larger than that of the H surface, and the adjustable element has a longer movement stroke after being inserted from the H surface. Under the same resonant cavity size, compare the filter that the E face set up adjustable element, the utility model discloses have bigger medium motion stroke, tuning range is wideer. Under the same tuning range, the utility model discloses the motion stroke of adjustable component can be bigger, has lower tuning sensitivity, reduces the required precision to actuating mechanism, reduces its complexity and cost. In addition, the height of the resonant cavity is not limited by the tuning range, and the smaller height of the resonant cavity makes the resonant cavity more suitable for application scenes with limited height space.

2. The shape of the adjustable element comprises but is not limited to a sheet shape, a round rod shape and a rectangular column shape, so that the adjustable element has certain strength, is not easy to deform, has higher reliability, and can reduce electrical deterioration caused by vibration.

3. By adjusting the position, size and shape of the dielectric rod, the number of the dielectric rods in the resonant cavity can be reduced to one under the condition of meeting the electrical performance index, the structure is simpler, the debugging is more convenient, and the production cost is also reduced.

4. Compared with the scheme of the tunable filter with the through holes arranged on the two sides, the tunable filter has the advantages that the production cost is reduced, and the movement of the dielectric rod is easier to control. And when the through hole is arranged only on one side, the gap of the rectangular waveguide body is reduced, the electromagnetic leakage condition is correspondingly reduced, and the insertion loss is reduced.

The advantages of the invention are not limited to the description, but rather are described in greater detail in the detailed description for better understanding.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

It will be appreciated by those skilled in the art that the objects and advantages that can be achieved with the present invention are not limited to the details set forth above, and that these and other objects that can be achieved with the present invention will be more clearly understood from the following detailed description.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of the present invention when the adjustable element is in the form of a sheet;

FIG. 2 is a cross-sectional view of the present invention with the adjustable element in the form of a sheet;

FIG. 3 is a schematic structural view of the present invention when the adjustable element is cylindrical;

FIG. 4 is a schematic structural diagram of the present invention when the adjustable element is a rectangular column;

FIG. 5 is a schematic structural diagram of the present invention when the coupling structure includes two metal coupling diaphragms;

fig. 6 is a cross-sectional view of the present invention when the coupling structure includes two metal coupling diaphragms.

In the figure: 1-a rectangular waveguide; 11-E face; 12-H surface; 13-bottom groove; 14-E panels; 15-H face groove; 2-a coupling structure; 21-a coupling partition wall; 22-a metal sheet; 221-a metal coupling diaphragm; 3-a resonant cavity; 4-a coupling window; 5-an adjustable element; 6-driving mechanism.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Example 1:

as shown in fig. 1 to 4, the present invention includes a rectangular waveguide 1, and the side of the rectangular waveguide 1 includes an E-plane 11 and an H-plane 12; a coupling structure 2 is arranged in the rectangular waveguide body 1, the coupling structure 2 divides the inner cavity of the rectangular waveguide body 1 into a plurality of resonant cavities 3, and a coupling window 4 is arranged between every two adjacent resonant cavities 3; the method is characterized in that: at least one adjustable element 5 is inserted into one resonant cavity 3, a plurality of through holes are arranged on the H surface 12 of the rectangular waveguide body 1, one end of the adjustable element 5 extends out of the through holes, and one end of the adjustable element 5 extending out of the through holes is connected with a driving mechanism 6.

The width of the waveguide filter in the direction of the E-plane 11 is greater than the width of the H-plane 12, so that the tunable element 5 has a longer movement stroke after the tunable element 5 is inserted from the H-plane 12. Under the same resonant cavity size, compare E face 11 and set up the wave filter of adjustable component 5, the utility model discloses have bigger medium motion stroke, the tuning range is wideer. Under the same tuning range, the utility model discloses adjustable element 5's motion stroke can be bigger, has lower tuning sensitivity, reduces the required precision to actuating mechanism 6, reduces its complexity and cost.

In addition, the cavity 3 height can be further depressed to optimize distal suppression, with smaller cavity 3 heights making it more suitable for application scenarios with limited height space.

The number of the dielectric rods 5 in each resonant cavity 3 can be reduced to one by skillfully adjusting the shapes, sizes, positions and numbers of the adjustable elements of the dielectric rods 5, so that the structure is simplified, and the production cost is reduced; and meanwhile, the synchronous change of the frequency of each resonant cavity in the tuning process and the normalized coupling coefficient are basically unchanged, so that the stability of electric performance indexes such as bandwidth, return loss, out-of-band rejection and the like in a tuning range is ensured. Because the resonant cavity 3 of head and tail need compensate input-output coupling and middle chamber coupling simultaneously, then insert two at least adjustable components in the resonant cavity 3 of tip, guarantee the utility model discloses stable electrical property has in tuning range.

The coupling structure 2 is a plurality of coupling partition walls 21, and the coupling partition walls 21 are fixed in the rectangular waveguide body 1. The coupling walls 21 are fixed in the rectangular waveguide 1, so that the rectangular waveguide 1 can be divided into a plurality of resonant cavities 3, and tuning can be conveniently performed by adjusting the depth of the adjustable elements 5 inserted into the resonant cavities. The rectangular waveguide 1 comprises a bottom groove 13, an E surface of the bottom groove 13 is open, an E panel 14 is connected to the opening of the bottom groove 13, a through hole is formed in the side edge of the bottom groove 13, and a coupling partition wall 21 is fixed in the bottom groove 13.

As shown in fig. 1, in the present embodiment, the coupling partition 21 is integrally formed with the rectangular waveguide 1. In the present embodiment, a waveguide is used as an input/output port, and the coupling partition wall 21 is used as an input/output coupling device. In practice, the input/output port form can be selected according to actual needs, for example, SMA joints are adopted, and the corresponding input/output coupling device is a probe coupling device. The bottom groove 13 and the E-face plate 14 are formed by splitting the rectangular waveguide 1 in a cavity and a cover plate, and may be split at any position perpendicular to the E-face 11 or the H-face 12 or in an irregular manner according to specific situations, so as to facilitate machining and assembling. It should be noted that electromagnetic leakage is prevented by welding or the like at a large gap that cuts off the surface current of the rectangular waveguide 1, reducing the filter insertion loss.

As shown in fig. 1, 3 and 4, at least one tunable element 5 is disposed in each resonant cavity 3, and the number of tunable elements 5 disposed in each resonant cavity 3 may be the same or different, and is determined according to actual needs. The larger the number of adjustable elements 5, the more design variables, the easier it is to achieve electrical performance specifications, but the more complicated the design. The rectangular waveguide 1 is provided on one side H-face 12 with at least one slit or through-hole having a cross-sectional area that is slightly larger than the cross-sectional area of the tunable element 5 extending therethrough, so that the tunable element 5 can be moved without friction relative to the rectangular waveguide 1. Meanwhile, the cross section area of the slit or the through hole cannot be too large, so that electromagnetic leakage at the slit or the through hole is reduced, and insertion loss is reduced.

The material of the tunable element 5 is a dielectric with a certain dielectric constant, including but not limited to plastic, PCB substrate, quartz and ceramic. The material of the tunable element 5 is selected in consideration of its loss tangent, which is proportional to the dielectric loss and the volume, and the dielectric loss is proportional to the filter insertion loss. As shown in fig. 1, 3 and 4, the shape of the adjustable element 5 may be one of a sheet, a round bar and a rectangular column. The shape of the adjustable element 5 can be one of a sheet shape, a round bar shape and a rectangular column, so that the adjustable element 5 has certain strength, is not easy to deform, and reduces electrical deterioration caused by vibration.

The tunable element 5 is inserted into the rectangular waveguide 1, so that the local dielectric constant of the corresponding resonant cavity 3 is increased, thereby changing the electromagnetic energy distribution inside the resonant cavity 3, so that the resonant frequency of the resonant cavity 3 is reduced, and simultaneously changing the coupling strength between adjacent resonant cavities 3. Wherein the amount of frequency change is proportional to the volume and dielectric constant of the tunable element 5 inserted inside the cavity 3. When the tunable element is positioned away from the center of the cavity 3, the effect on the electromagnetic energy will be less, and thus the frequency reduction for the same insertion volume will be less. When the tunable element 5 is close to the coupling structure 2, the electromagnetic energy distribution at the coupling structure 2 is enhanced, and since the tunable element 5 is deviated from the center of the resonant cavity 3, the frequency of the resonant cavity 3 is also higher, which finally results in enhanced coupling. Therefore, by adjusting the position, size, shape and number of the adjustable element 5, the coupling coefficient can be compensated while adjusting the frequency, so that the normalized coupling coefficient is basically unchanged, and the electrical performance indexes such as bandwidth and the like in the tuning process are kept stable.

One end of each tunable element 5 is fixed to the driving mechanism 6, so that the driving mechanism 6 can drive the tunable elements 5 to move in the rectangular waveguide 1, thereby realizing tuning. The more the tunable element 5 extends into the rectangular waveguide body 1, the lower the filter frequency.

Example 2:

as shown in fig. 5 and 6, the present invention includes a rectangular waveguide 1, the side of the rectangular waveguide 1 includes an E-plane 11 and an H-plane 12; a coupling structure 2 is arranged in the rectangular waveguide body 1, the coupling structure 2 divides the inner cavity of the rectangular waveguide body 1 into a plurality of resonant cavities 3, and a coupling window 4 is arranged between every two adjacent resonant cavities 3; the method is characterized in that: at least one adjustable element 5 is inserted into one resonant cavity 3, a plurality of through holes are arranged on the H surface 12 of the rectangular waveguide body 1, one end of the adjustable element 5 extends out of the through holes, and one end of the adjustable element 5 extending out of the through holes is connected with a driving mechanism 6.

The coupling structure 2 comprises two metal sheets 22, the two metal sheets 22 are sleeved in the rectangular waveguide 1, and the metal sheets 22 are parallel to the H surface 12 of the rectangular waveguide 1; the metal plate 22 is composed of several coupling diaphragms 221 and metal connecting parts parallel up and down, wherein the metal connecting parts are part of the waveguide wall, and the resonant cavity 3 is formed by separating the metal coupling diaphragms 221 on the two metal plates 22. The rectangular waveguide body 1 comprises two H-shaped grooves 15, E panels 14 are connected between two ends of each H-shaped groove 15, a through hole is formed in one H-shaped groove 15, and two metal sheets 22 are sleeved in a space defined by the two H-shaped grooves 15 and the two E panels 14. When the coupling structure 2 comprises the two metal sheets 22, the rectangular waveguide 1 comprises the two H-shaped grooves 15, and the two metal sheets 22 are sleeved in a space surrounded by the two H-shaped grooves 15 and the two E-shaped panels 14, so that the metal sheets 22 can be conveniently installed.

In this embodiment, the resonant cavity 3 is formed by separating the metal coupling membranes 221 on the two metal sheets 22. The metal coupling membrane 221 between the two resonant cavities 3 is used to control the coupling strength between the resonant cavities 3, and the resonant cavity 3 at the end and the end of the metal coupling membrane 221 are used to control the input-output coupling strength. The number of parallel metal sheets 22 can be determined as required, and the more metal sheets 22 are, the more metal coupling membranes 221 are, the more adjustable parameters are, the easier the electrical performance index is to be realized, but the design is more complicated. In this embodiment, a rectangular waveguide is used to implement input and output, and a metal coupling diaphragm 221 is correspondingly used to implement input and output coupling, but in practice, other input and output ports may also be used, for example, an SMA joint is used, and a probe coupling device may be used as a corresponding input and output coupling structure. The tunable element 5 in the form of a dielectric sheet is used in the present embodiment to realize frequency and coupling tuning, but in practice, it may be in the form of a cylindrical dielectric rod and a rectangular cylindrical dielectric block similar to those in fig. 3 and 4.

The present invention is not limited to the above-mentioned optional embodiments, and any other products in various forms can be obtained by anyone under the teaching of the present invention, and any changes in the shape or structure thereof, all the technical solutions falling within the scope of the present invention, are within the protection scope of the present invention.

Claims

1. An H-plane dielectric tunable waveguide filter includes a rectangular waveguide body (1); a coupling structure (2) is arranged in the rectangular waveguide body (1), and the coupling structure (2) divides the inner cavity of the rectangular waveguide body (1) into a plurality of resonant cavities (3); the method is characterized in that: at least one adjustable element (5) is arranged in one resonant cavity (3), a plurality of through holes are formed in the H surface (12) on one side of the rectangular waveguide body (1), one end of the adjustable element (5) is connected with a driving mechanism (6), and the other end of the adjustable element extends into the resonant cavity (3) from the through holes.

2. The H-plane dielectric tunable waveguide filter according to claim 1, wherein: the shape of the adjustable element (5) includes, but is not limited to, one of a sheet, a round bar and a rectangular column.

3. The H-plane dielectric tunable waveguide filter according to claim 1, wherein: at least two adjustable elements (5) are inserted into the resonant cavity (3) at the end part.

4. The H-plane dielectric tunable waveguide filter according to claim 1, wherein: the material of the adjustable element (5) includes but is not limited to one of plastic, PCB substrate, quartz and ceramic.

5. The H-plane dielectric tunable waveguide filter according to claim 1, wherein: the coupling structure (2) is a plurality of coupling partition walls (21), and the coupling partition walls (21) are fixed in the rectangular waveguide body (1).

6. The H-plane dielectric tunable waveguide filter according to claim 5, wherein: the rectangular waveguide body (1) comprises a bottom groove (13), an E surface (11) of the bottom groove (13) is provided with an opening, the opening of the bottom groove (13) is connected with an E panel (14), a through hole is formed in the side edge of the bottom groove (13), and a coupling partition wall (21) is fixed in the bottom groove (13).

7. The H-plane dielectric tunable waveguide filter according to claim 1, wherein: the coupling structure (2) comprises two metal sheets (22), the two metal sheets (22) are sleeved in the rectangular waveguide body (1), and the metal sheets (22) are parallel to the H surface (12) of the rectangular waveguide body (1); the metal sheets (22) are provided with a plurality of metal coupling membranes (221), and the resonant cavity (3) is formed by separating the metal coupling membranes (221) on the two metal sheets (22).

8. The H-plane dielectric tunable waveguide filter according to claim 7, wherein: rectangular wave conductor (1) includes two H face grooves (15), all is connected with E panel (14) between the both ends of two H face grooves (15), and the through-hole sets up on one of them H face groove (15), and two sheetmetals (22) cover are located in the space that two H face grooves (15) and two E panels (14) enclose.

9. The H-plane dielectric tunable waveguide filter according to any one of claims 1 to 8, wherein: the driving mechanism (6) is a linear motor.