CN106450602B - TE mode multi-pass band dielectric filter - Google Patents

Abstract

The invention discloses a TE mode multi-pass band dielectric filter, which mainly solves the problems of complex design and low out-of-band suppression of the traditional multi-pass band filter. It includes six TE mode dielectric resonators (5) and support columns (20), dielectric tuning rods (8) and tuning discs (6), metal arcs (2) for controlling port coupling and input and output interfaces (3), A cavity (1) and an inter-cavity coupling structure (13). Realize the multi-pass band response by setting the height of the dielectric tuning rod (8) and the tuning disc (6); the TE mode dielectric resonator (5) performs inter-resonator coupling through an inter-cavity coupling structure (13), Feed coupling via metal arc (2). In combination with the dielectric filter out-of-band suppression method provided by the present invention, the difference in the arrangement of the metal arcs (2) can set transmission zero points on the left and right sides of the frequency band to improve the out-of-band suppression of the filter. The invention has the advantages of high Q value, convenient design and processing, and high out-of-band suppression.

Description

TE mode multi-pass band dielectric filter

technical field

The invention relates to the technical field of radio frequency communication filtering, in particular to a TE mode multi-passband dielectric filter.

Background technique

With the rapid development of mobile communication, communication spectrum resources are becoming more and more crowded, and communication systems often work in multiple frequency bands. This requires a high-performance multi-passband filter to increase the capacity of the communication system and avoid interference between adjacent channels. At the same time, people's requirements for communication transmission quality are getting higher and higher, which also puts forward higher requirements for filter performance indicators in communication systems, such as lower insertion loss requirements and smaller volume requirements. Dielectric resonators have the characteristics of high unloaded Q value, small size and high dielectric constant, which meet the needs of the development of communication systems, so they have developed rapidly and are widely used in wireless base stations and aerospace and other fields.

In 2014, TV Pidhurska and AA Trubin published an article entitled "Dual-bandpass filter built on rectangulardielectric resonators" on Radioelectronics and Communications Systems. A rectangular dielectric resonator is used to obtain a dual passband by exciting the two modes of the fundamental mode TE _01δ and the secondary mode TE _02δ , but the stop band does not generate transmission zeros, resulting in insufficient frequency selectivity.

In 2015, Seema Awasthi, Animesh Biswas and others published an article entitled "Dual-band dielectric cresonator bandstop filters" on the International Journal of RF and Microwave Computer-Aided Engineering. Adopting the TE mode dielectric resonator structure, combined with the source-load coupling produces a transmission zero point, but also causes the increase of the cavity size.

Contents of the invention

The purpose of the present invention is to address the above-mentioned deficiencies in the prior art, and propose a TE mode multi-passband dielectric filter to generate transmission zeros, simplify the design of the multi-passband filter, improve the out-of-band rejection of the filter and increase the frequency of the filter selective.

To achieve the above purpose, the present invention adopts at least one of the following technical solutions.

TE mode three-pass band dielectric filter, including a cavity, six TE mode dielectric resonators arranged in two rows in the cavity, six support columns, six dielectric tuning rods and six dielectric tuning discs, control port coupling The first metal arc, the second metal arc, two input and output interfaces, and the intercavity coupling structure; the first metal arc is connected to the first input and output interface, and the second metal arc is connected to the second input and output interface ; Each of the six TE mode dielectric resonators is provided with a support column, and the arrangement relationship between the six dielectric tuning disks and the six TE mode dielectric resonators is one-to-one correspondence and concentric on the orthographic projection; The dielectric tuning rods are respectively located on the six dielectric tuning discs in one-to-one correspondence; among the six TE mode dielectric resonators, the first TE mode dielectric resonator, the second TE mode dielectric resonator, the third TE mode dielectric resonator, The fourth TE mode dielectric resonator, the fifth TE mode dielectric resonator, and the sixth TE mode dielectric resonator;

Wherein the height of the first medium tuning disc is the same as that of the second medium tuning disc, the height of the third medium tuning disc is the same as that of the fourth medium tuning disc, the height of the fifth medium tuning disc is the same as that of the sixth medium tuning disc, and the height of the first medium tuning disc is the same as that of the sixth medium tuning disc. The disk, the fourth medium tuning disk, and the sixth medium tuning disk are located in the same row and their heights increase sequentially;

The height of the first medium tuning rod is the same as that of the second medium tuning rod, the height of the third medium tuning rod is the same as that of the fourth medium tuning rod, the height of the fifth medium tuning rod is the same as that of the sixth medium tuning rod, the height of the first medium tuning rod, the fourth The medium tuning rod and the sixth medium tuning rod are located in the same row and their heights are raised successively;

The six TE mode dielectric resonators are coupled between resonators through the inter-cavity coupling structure, and at the same time, input and output feed coupling is performed through the first metal arc and the second metal arc; the cavities are arranged in the two rows and share Six resonant cavities;

The first input and output interface is located on the upper side of the upper left resonant cavity in the cavity, and the second input and output interface is located on the right side of the upper right resonant cavity in the cavity; the first metal arc is located on the left side of the first input and output interface , the second metal arc is located above the input and output interfaces. The difference in the way of setting the metal arc can set the transmission zero point on the left and right sides of the frequency band.

Further, the supporting pillars, dielectric tuning rods, and dielectric tuning disks in each resonant cavity are arranged concentrically with the TE mode dielectric resonator.

Further, both the first metal arc and the second metal arc are concentric with the dielectric tuning disk in the resonant cavity.

Further, each support column is fixed in the cavity by screws, and the TE mode dielectric resonators correspond to the support columns one by one and are fixed by bonding.

Further, the length and width of the first metal arc are equal to the length and width of the second metal arc, and the metal arc is welded with the corresponding input and output interfaces to form a filter feed structure.

Further, the two input and output interfaces are located at the center of the cavity wall of the corresponding resonant cavity.

Further, the coupling window formed by the inter-cavity coupling structure is located between any two adjacent TE mode dielectric resonators, and the width of the coupling window between the third TE mode dielectric resonator and the fourth TE mode dielectric resonator is 0; the coupling window width between the sixth TE mode dielectric resonator and the fifth TE mode dielectric resonator is also 0.

Compared with the prior art, the present invention has the following advantages:

1. The present invention adopts 6 TE mode dielectric resonators, and holes are drilled to avoid the interference of high-order modes, the Q value is high and the processing and manufacturing of the filter is convenient;

2. The present invention can achieve multi-passband response by setting the height of the tuning plate and tuning rod of the dielectric resonator, which simplifies the design complexity;

3. The present invention obtains the controllable transmission zero point based on changing the feeding mode, so that both design schemes have a symmetrical transmission zero point, which improves the frequency selectivity and avoids the complex port coupling structure of the source-load coupling, or the hybrid electromagnetic coupling complex tuning structures.

Description of drawings

Fig. 1 is the top view schematic diagram after the cover plate is removed from the TE mode tee band dielectric filter of the embodiment;

Fig. 2 is a B-B sectional schematic diagram of Fig. 1;

Fig. 3 is the transmission characteristic |S ₂₁ | and return loss |S ₁₁ | simulation and test curves of the embodiment.

Detailed ways

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, but the scope of protection claimed by the present invention is not limited to the scope described in the following examples.

As shown in Figure 1 and Figure 2, the TE mode three-pass dielectric filter includes a cavity 1, which is divided into two rows of six TE mode dielectric resonators (5, 19, 16, 12, 33), six support columns (only 20, 22, 34 are shown in the figure), six media tuning rods (8, 17, 14, 10, 31, 28) and six media tuning discs (6, 18, 15, 11, 32 , 29), the first metal arc 2, the second metal arc 4, two input and output interfaces (3, 7), and the inter-cavity coupling structure; the first metal arc 2 and the first input and output The interface 3 is connected, and the second metal arc 4 is connected to the second input and output interface 7; each of the six TE mode dielectric resonators is provided with a support column, and the six dielectric tuning plates are connected to the six TE mode dielectric resonators. The arrangement relationship among them is a one-to-one correspondence from top to bottom and is concentric on the orthographic projection; the six dielectric tuning rods are located on the six dielectric tuning disks in one-to-one correspondence; among the six TE mode dielectric resonators, the first TE mode dielectric resonator is sequentially 5, the second TE mode dielectric resonator 19, the third TE mode dielectric resonator 16, the fourth TE mode dielectric resonator 12, the fifth TE mode dielectric resonator 33, and the sixth TE mode dielectric resonator 30; The first medium tuning disc 6 and the second medium tuning disc 18 have the same height, the third medium tuning disc 15 and the fourth medium tuning disc 11 have the same height, the fifth medium tuning disc 32 and the sixth medium tuning disc 29 have the same height, and The first medium tuning disk 6, the fourth medium tuning disk 11, and the sixth medium tuning disk 29 are located in the same row and their heights are raised successively; the first medium tuning rod 8 and the second medium tuning rod 17 have the same height, and the third medium tuning rod 14 and the fourth medium tuning rod 10 have the same height, the fifth medium tuning rod 31 and the sixth medium tuning rod 28 have the same height, and the first medium tuning rod 8, the fourth medium tuning rod 10, and the sixth medium tuning rod 28 are located in the same row And the height is increased in turn; the six TE mode dielectric resonators are coupled between the resonators through the inter-cavity coupling structure, and at the same time, the input and output feed coupling is performed through the first metal arc 2 and the second metal arc 4; the cavity The body 1 has six resonant cavities arranged in two rows; the first input and output interface 3 is located on the upper side of the upper left resonant cavity in the cavity 1, and the second input and output interface 7 is located on the right side of the upper right resonant cavity in the cavity 1. Side; the first metal arc 2 is located on the left side of the first input and output interface 3 , and the second metal arc 4 is located above the input and output interface 7 . Different ways of setting the metal arcs (2, 4) can set the transmission zero point on the left and right sides of the frequency band. The support pillars, dielectric tuning rods, dielectric tuning disks and TE mode dielectric resonator 5 in each resonant cavity are arranged concentrically. Both the first metal arc 2 and the second metal arc 4 are concentric with the dielectric tuning disk in the resonant cavity. Each support column is fixed in the cavity 1 by a screw 21, and the TE mode dielectric resonator corresponds to the support column one by one and is fixed by bonding. The length and width of the first metal arc 2 are equal to the length and width of the second metal arc 4 , and the metal arc is welded with the corresponding input and output interfaces to form a filter feed structure.

The two input and output interfaces (3, 7) are located at the center of the cavity wall of the corresponding resonant cavity. The coupling window formed by the intercavity coupling structure 13 is located between any two adjacent TE mode dielectric resonators, and the width of the coupling window between the third TE mode dielectric resonator 16 and the fourth TE mode dielectric resonator 12 is 0; the width of the coupling window between the sixth TE mode dielectric resonator 30 and the fifth TE mode dielectric resonator 33 is also 0.

Hereinafter, an embodiment will be further illustrated to illustrate a three-pass band filter with six resonators.

Referring to Fig. 1 and Fig. 2, the three-pass bandpass filter of the present invention mainly consists of six TE mode dielectric resonators (5, 12, 16, 19, 30, 33), supporting columns (20, 22, 24), Media tuning levers (8, 10, 14, 17, 28, 31), 1st media tuning discs (6, 11, 15, 18, 29, 32), metal arcs for control port coupling (2, 4), input The output interface (3, 7), the cavity body 1 and the inter-cavity coupling structure 13 are composed. in:

The TE mode dielectric resonator adopts a dielectric material, its dielectric constant is εr=37, and the loss tangent angle tanδ=0.0002; as shown in Figure 2, its height is 13mm, its outer diameter is 32mm, and its inner hole diameter is 8mm. Support column bonding. The support column is made of aluminum oxide material, with a height of 7 mm and an outer diameter of 19.5 mm. The inner hole of the upper layer has a diameter of 13.5 mm and a height of 4 mm. The inner hole of the lower layer is a threaded hole with a diameter of 3 mm. Through metal screws (21, 23, 26) fixed in the cavity.

The length of the dielectric tuning rod is 35 mm and the diameter is 6 mm; the length of the dielectric tuning disc is 2 mm and the diameter is 25 mm; the dielectric tuning disc and the tuning rod are made of the same dielectric material, the dielectric constant is ε _r =10, and the loss tangent angle tan δ =0.0002.

The radians of the metal arcs (2, 4) are both 130 degrees, and the input and output interfaces (3, 7) are located at the center of the resonant cavity walls to which they belong, and their heights are both 27 mm.

The side length of the bottom surface of the metal cavity is 140mm, the height is 50mm, and the chamfer is set to R2 (radius is 2mm); as shown in Figure 3, the thickness of the inter-cavity coupling structure is 4mm, and the height is 40mm, wherein the inter-cavity coupling The window width of the vertical part of structure 13 is 40mm, the width of the upper left window of the horizontal part is 29mm, the width of the lower left window of the horizontal part is 26mm, the width of the upper right window of the horizontal part is 26mm, and the lower right side of the horizontal part The window width is 26mm.

The height of the medium tuning discs (6, 18) is 30mm, the height of the medium tuning discs (11, 15) is 35mm, and the height of the medium tuning discs (29, 32) is 40mm; the medium tuning rod The heights of (8, 17) are both 32 mm, the heights of the medium tuning rods (10, 14) are both 37 mm, and the heights of the medium tuning rods (28, 31) are both 42 mm.

Effect of the present invention can be further illustrated by following simulation and test experiment:

The second embodiment of the present invention is simulated in the three-dimensional electromagnetic simulation software HFSS, and the response curve of the three-pass band filter obtained is shown in dotted line in FIG. 3 .

The processed three-pass band filter is tested with a vector network analyzer, and the obtained three-pass band filter response curve is shown in Figure 3 as a solid line.

As can be seen from the response curve diagram of the three-pass band filter of Fig. 3, the center frequencies of the three sub-pass bands in the three-pass band filter of the second embodiment are respectively 1.788GHz, 1.816 GHz and 1.845GHz, and the corresponding relative bandwidths They are 0.9%, 1.3% and 1.1% respectively, the insertion loss is 0.57dB, 0.4dB and 0.3dB respectively, the in-band return loss is over 18dB, and has a symmetrical transmission zero point, which makes the filter have good frequency selectivity.

The above examples are preferred embodiments of the present invention and do not constitute any limitation to the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Claims (2)

1. TE mode three-pass band dielectric filter, characterized in that it includes a cavity (1), and six TE mode dielectric resonators (5, 19, 16, 12, 33, 30) arranged in two rows in the cavity , six support posts, six media tuning rods (8, 17, 14, 10, 31, 28) and six media tuning discs (6, 18, 15, 11, 32, 29), the first of the control port couplings A metal arc (2), a second metal arc (4), two input and output interfaces (3, 7), and an intercavity coupling structure; the first metal arc (2) and the first input and output interface (3) connection, the second metal arc (4) is connected to the second input and output interface (7); each of the six TE mode dielectric resonators has a supporting column, and the six dielectric tuning plates resonate with the six TE mode dielectrics The arrangement relationship between the resonators is one-to-one correspondence from top to bottom and is concentric on the orthographic projection; the six dielectric tuning rods are respectively located on the six dielectric tuning disks in one-to-one correspondence; among the six TE mode dielectric resonators, the first TE mode Dielectric resonator (5), second TE mode dielectric resonator (19), third TE mode dielectric resonator (16), fourth TE mode dielectric resonator (12), fifth TE mode dielectric resonator (33) , the sixth TE mode dielectric resonator (30); Wherein the first medium tuning disc (6) and the second medium tuning disc (18) have the same height, the third medium tuning disc (15) and the fourth medium tuning disc (11) have the same height, and the fifth medium tuning disc (32) ) and the sixth medium tuning plate (29) have the same height, and the first medium tuning plate (6), the fourth medium tuning plate (11), and the sixth medium tuning plate (29) are located in the same row and their heights are increased in sequence; The first medium tuning rod (8) is the same height as the second medium tuning rod (17), the third medium tuning rod (14) is the same height as the fourth medium tuning rod (10), and the fifth medium tuning rod (31) is the same as the second medium tuning rod (17). The six medium tuning rods (28) have the same height, and the first medium tuning rod (8), the fourth medium tuning rod (10), and the sixth medium tuning rod (28) are located in the same row and their heights increase sequentially; The six TE mode dielectric resonators are coupled between resonators through the inter-cavity coupling structure, and at the same time, input and output feed coupling is performed through the first metal arc (2) and the second metal arc (4); the cavity ( 1) A total of six resonant cavities are arranged according to the two rows; The first input and output interface (3) is located on the upper side of the upper left resonant cavity in the cavity (1), and the second input and output interface (7) is located on the right side of the upper right resonant cavity in the cavity (1); the first The metal arc (2) is located on the left side of the first input and output interface (3), and the second metal arc (4) is located above the second input and output interface (7); the length and width of the first metal arc (2) The length and width of the second metal arc (4) are equal, and the metal arc is welded with the corresponding input and output interfaces to form a filter feed structure; the two input and output interfaces (3, 7) are located in the cavity of the corresponding resonant cavity The center of the wall; the coupling window formed by the intercavity coupling structure (13) is located between any two adjacent TE mode dielectric resonators, and the third TE mode dielectric resonator (16) and the fourth TE mode dielectric resonator The width of the coupling window between (12) is 0; the width of the coupling window between the sixth TE mode dielectric resonator (30) and the fifth TE mode dielectric resonator (33) is also 0; the support columns in each resonator , the dielectric tuning rod, the dielectric tuning disk and the TE mode dielectric resonator (5) are arranged concentrically; the first metal arc (2) and the second metal arc (4) are concentric with the dielectric tuning disk in the resonant cavity. 2. TE mode tee-band dielectric filter according to claim 1, is characterized in that: each support column is all fixed in the cavity (1) by screw (21), and described TE mode dielectric resonator and support The columns are in one-to-one correspondence and fixed by bonding.