KR102785616B1 - Multi type filter assembly - Google Patents

Abstract

The present invention relates to a composite filter, and more particularly, to a composite filter, comprising: a cavity filter provided in one of a plurality of cavities (hereinafter referred to as a 'reference cavity') formed to be open on one side in a housing; and dielectric resonant filters provided in at least two cavities (hereinafter referred to as 'adjacent cavities') adjacent to the reference cavity, wherein the notch characteristics between the cavity filter and the at least two dielectric resonant filters are adjusted according to a window in which a portion of a partition between the reference cavity and the adjacent cavities is cut out and communicated with each other, and the windows are designed at different positions, thereby providing an advantage in that the design of cross coupling is very easy without the need for a metal cross bar, etc. for forming a separate notch.

Description

{MULTI TYPE FILTER ASSEMBLY}

The present invention relates to a composite filter assembly, and more specifically, to a composite filter assembly capable of presenting a standard for filter layout design while maximizing notch characteristics.

In general, filters applied to base station devices are represented by cavity filters and dielectric resonator filters (DR filters).

A typical example of a cavity filter is a notch filter, which is a bandpass filter using a notch. It is a component used in various wireless communication base stations and RF (Radio Frequency) bands, and is a passive element that has the characteristic of passing only a specific band of frequencies and attenuating the remaining frequency signals. Among the important characteristics of such bandpass filters, the insertion loss within the pass band and the attenuation characteristics in the stop band are important factors indicating the performance of the filter. In particular, among these attenuation characteristics, the attenuation characteristics in a specific band must be good in order to reduce interference between adjacent channels or transmission and reception bands.

Meanwhile, the dielectric resonance filter, like the cavity filter, has the function of filtering the input frequency with the minimum loss by its unique high Q (Quality Factor) value and outputting only the frequency of a desired specific band to the output terminal. The dielectric resonance filter adjusts the gap between the dielectric resonator installed for each cavity and the tuning screw arranged on the upper side thereof, the window formed in the partition located between the cavities, and the gap between the tuning screw installed on the upper side of the window and the window, thereby controlling the electromagnetic field characteristics of the cavity, thereby controlling the resonance characteristics (i.e., center frequency) and coupling characteristics (i.e., frequency band).

The above-mentioned dielectric resonance filters are being further developed due to their compactness and low loss.

However, up to now, the methods for enhancing the characteristics of each skirt of the cavity filter and the dielectric resonance filter have been different, so they could not be applied in combination to a single filter.

Republic of Korea Patent No. 10-1357027 (announced on February 4, 2014)

The present invention has been made to solve the above-mentioned technical problem, and its purpose is to provide a composite filter assembly in which a cavity filter and a dielectric resonance filter are applied in combination, and in which the opening direction of a window between cavities in which each filter is positioned can be designed.

In addition, another object of the present invention is to provide a composite filter assembly capable of implementing desired skirt characteristics without having a separate cross metal bar for reinforcing the skirt characteristics between cavity filters.

One embodiment of a composite filter assembly according to the present invention comprises a cavity filter provided in one of a plurality of cavities (hereinafter referred to as a 'reference cavity') formed to be open on one side in a housing, and dielectric resonant filters provided in at least two cavities (hereinafter referred to as 'adjacent cavities') adjacent to the reference cavity, wherein a notch characteristic between the cavity filter and the at least two dielectric resonant filters is adjusted according to a window that is formed by cutting a portion of a partition between the reference cavity and the adjacent cavities and communicating with each other, and the window is designed to be eccentric to different left and right positions centered on the center so that the window is adjusted.

Here, the window may have a predetermined height from the bottom surface of the reference cavity and the adjacent cavity.

In addition, assuming that the dielectric resonance filters are provided in two units and are provided adjacent to each other, and the dielectric filters are defined as a first dielectric filter and a second dielectric filter, respectively, the window may include a first window formed in a partition between the cavity filter and the first dielectric filter, and a second window formed in a partition between the cavity filter and the second dielectric filter.

Additionally, in order to create a C-notch between the cavity filter and the first dielectric filter, the first window may be cut eccentrically inwardly at the boundary between the first dielectric filter and the second dielectric filter.

Additionally, in order to create an L-notch between the cavity filter and the first dielectric filter, the first window may be cut eccentrically outwardly opposite to the boundary between the first dielectric filter and the second dielectric filter.

In addition, assuming that the dielectric resonance filters are provided in three units and are provided adjacent to each other around the reference cavity, and a dielectric filter located in the middle of the dielectric filters is defined as a first dielectric filter, a dielectric filter located on one side of the first dielectric filter is defined as a second dielectric filter, and a dielectric filter located on the other side of the first dielectric filter is defined as a third dielectric filter, the window may include a first window formed in a partition between the cavity filter and the first dielectric filter, a second window formed in a partition between the cavity filter and the second dielectric filter, and a third window formed in a partition between the cavity filter and the third dielectric filter.

In addition, in order to create a multi-C-notch between the cavity filter and the first dielectric filter, the first window may be formed by cutting it eccentrically inwardly at a boundary between the first dielectric filter and the third dielectric filter, and the second window may be formed eccentrically inwardly or outwardly at a boundary between the first dielectric filter and the second dielectric filter.

In addition, in order to create a multi-L-notch between the cavity filter and the first dielectric filter, the first window may be formed by cutting it eccentrically outwardly opposite to the boundary between the first dielectric filter and the third dielectric filter, and the second window may be formed by cutting it eccentrically inwardly or outwardly opposite to the boundary between the first dielectric filter and the second dielectric filter.

Additionally, the third window may be cut eccentrically inwardly or outwardly at the boundary between the first dielectric filter and the third dielectric filter.

In addition, assuming that the dielectric resonance filters are provided in three units and are provided adjacent to each other around the reference cavity, and a dielectric filter located in the middle of the dielectric filters is defined as a first dielectric filter, a dielectric filter located on one side of the first dielectric filter is defined as a second dielectric filter, and a dielectric filter located on the other side of the first dielectric filter is defined as a third dielectric filter, the window may include a second window formed in a partition between the cavity filter and the second dielectric filter and a third window formed in a partition between the cavity filter and the third dielectric filter, but not formed between the cavity filter and the first dielectric filter.

Additionally, in order to create a C-notch between the cavity filter and the second dielectric filter, the second window may be cut eccentrically toward the inside where the first dielectric filter is provided.

According to one embodiment of the composite filter assembly according to the present invention, the following various effects can be achieved.

First, it has the effect of allowing a cavity filter and a dielectric filter to be applied in combination in a single filter.

Second, it has the effect of eliminating the need for a separate cross metal bar-like configuration in forming cross coupling between each cavity equipped with a cavity filter and a dielectric filter.

Third, it has the effect of enabling the designer to implement the skirt characteristics desired by changing the position of the window formed in the inter-cavity partition.

FIG. 1 is a perspective view and a partially enlarged view showing a composite filter assembly according to one embodiment of the present invention.
FIG. 2 is a plan view and a partially enlarged view showing a composite filter assembly according to one embodiment of the present invention.
Figures 3a to 3d are conceptual diagrams and result tables for explaining the notch generation principle for each cross coupling structure.
Figures 4a to 5c are perspective views and field formation diagrams for explaining the L-coupling and C-coupling induction principles according to window shape.
Figures 6a to 7b are a design plan for generating a C-notch according to the window position between one cavity filter and two adjacent dielectric resonant filters and a graph of the results.
Figures 8a to 9b are a design plan for generating an L-notch according to the window position between one cavity filter and two adjacent dielectric resonant filters and a graph of the results.
Figures 10a to 10c are a first design of notch generation according to the window position between one cavity filter and three adjacent dielectric resonant filters and a graph of the results.
Figures 11a to 11c are a second design of notch generation according to the window position between one cavity filter and three adjacent dielectric resonant filters and the resulting graphs.
Figures 12a to 12c are a third design of notch generation according to the window position between one cavity filter and three adjacent dielectric resonant filters and the resulting graphs.

Hereinafter, embodiments of the composite filter assembly according to the present invention will be described in detail with reference to the attached drawings. When adding reference numerals to components in each drawing, it should be noted that the same components are given the same numerals as much as possible even if they are shown in different drawings. In addition, when describing embodiments of the present invention, if it is determined that a specific description of a related known configuration or function hinders understanding of the embodiments of the present invention, the detailed description thereof will be omitted.

In describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by these terms. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person having ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an ideal or overly formal sense, unless explicitly defined in this application.

FIG. 1 is a perspective view and a partially enlarged view showing a composite filter assembly according to one embodiment of the present invention, and FIG. 2 is a plan view and a partially enlarged view showing a composite filter assembly according to one embodiment of the present invention.

A composite filter assembly according to one embodiment of the present invention includes a housing (1) having a plurality of cavities formed therein that are open on one side, as shown in FIGS. 1 and 2. In the housing (1), a plurality of cavities (see reference numerals 10, 21, 22, and 23 of FIGS. 1 and 2), in which at least one of a cavity filter (100) and a dielectric resonance filter (210, 220, and 230) can be installed, can be formed to be open on one side, as described above.

Inside a plurality of cavities, a cavity filter (100) equipped with a metal resonator for TEM (Transverse Electric and Magnetic) mode resonance and a dielectric resonance filter (210, 220, 230) equipped with a dielectric resonator for TE (Transverse Electric) mode resonance may be respectively equipped.

A composite filter assembly according to one embodiment of the present invention is a combination of a plurality of RF filters. As is well known, an RF filter is a device that passes only signals of a preset specific frequency band, and can be classified into a low pass filter, a band pass filter, a high pass filter, and a band stop filter, depending on the frequency band to be filtered.

Important characteristics of a filter include insertion loss and skirt characteristics. Insertion loss refers to the power lost when a signal passes through the filter, and skirt characteristics refer to the steepness of the passband and stopband of the filter.

The above insertion loss and skirt characteristics are in a trade-off relationship depending on the order of the filter. That is, as the order of the filter increases, the skirt characteristics improve, but the insertion loss worsens.

In order to improve the skirt characteristics of a filter while maintaining the insertion loss of the filter, a method of forming a notch (attenuation pole) is mainly used. This is a method of strengthening the skirt characteristics of a filter while maintaining the insertion loss of the filter by forming a notch in a specific frequency band.

It is well known that a cross-coupling method is generally used for forming a notch. Cross-coupling is usually implemented using a coupling metal bar, which is installed by penetrating the inner wall (or bulkhead) defining the cavity and causes a coupling phenomenon between the associated resonators.

FIGS. 3a to 3d are conceptual diagrams and result tables for explaining the notch generation principle for each cross coupling structure, and FIGS. 4a to 4c are perspective views and field formation diagrams for explaining the L-coupling and C-coupling induction principles according to window shapes.

The composite filter assembly according to one embodiment of the present invention is designed to generate cross-coupling between a cavity filter (100) equipped with a resonator made of a general metal material and a dielectric resonance filter (210, 220, 230) equipped with a dielectric resonator without adding a separate configuration, so that it is necessary to first understand the principle of generating cross-coupling.

As referenced in FIGS. 3a and 3b, in the L-Cross Coupling structure or the C-Cross Coupling structure, when the second resonance is at a 90 degree phase or a -90 degree phase, if the phase of the L-Coupling or the phase of the C-Coupling for forming the cross coupling is the same as the phase passing through the 1-2-3 path and the phase passing through the 1-3 path, no notch is generated, whereas a notch is generated if a 180 degree phase difference occurs. Accordingly, in the case of FIG. 3a, no notch is generated in the In phase case, but an L-notch is generated in the Out of phase case, and in the case of FIG. 3b, no notch is generated in the In phase case, but a C-notch is generated in the Out of phase case.

Meanwhile, as referenced in FIGS. 3c and 3d, in the Multi L-Cross Coupling structure or the Multi C-Cross Coupling structure, when the second resonance is at a 90 degree phase or a -90 degree phase, if the phase of the L-Coupling or the phase of the C-Coupling for forming the cross coupling is the same as the phase that passed through the 1-2-3 path and the phase that passed through the 1-3 path, no notch is generated, whereas a notch is generated if a 180 degree phase difference occurs. In addition, if the phase that passed through the 1-3-4 path and the phase that passed through the 1-4 path are the same, no notch is generated, whereas a notch is generated if a 180 degree phase difference occurs. Accordingly, in the case of FIG. 3c, no notch is generated in the In phase case, but Multi L-notches are generated in the Out of phase case, and in the case of FIG. 3d, no notch is generated in the In phase case, but Multi C-notches are generated in the Out of phase case.

Here, the coupling between cavity filters (100) using metal resonators generally occurs in the longitudinal direction and is implemented as an Even mode having the same phase, and the coupling between dielectric resonance filters (210, 220, 230) using dielectric resonators generally occurs in the transverse direction and is implemented as an Even mode having the same phase. That is, the coupling mode between the same type of filters is implemented as an Even mode having the same phase, but, as in the case of the composite filter assembly according to one embodiment of the present invention, the coupling mode induction method for the coupling mode between different types of filters is different.

Referring to FIGS. 4A to 4C, a cavity filter (100) and a dielectric resonance filter (210) are respectively provided in adjacent cavities. Hereinafter, for convenience of explanation, a cavity provided with a cavity filter (100) is referred to as a 'reference cavity (10)', and a cavity provided with a dielectric resonance filter (210) is referred to as an 'adjacent cavity (21)'.

A partition wall (300) is formed between the reference cavity (10) and the adjacent cavity (21). A portion of the partition wall (300) may be cut to provide a window (300a) that allows the reference cavity (10) and the adjacent cavity (21) to communicate with each other.

In the case of FIGS. 4a to 4c, when the window (300a) is formed to be eccentrically connected to one side (the upper side in the drawing of FIG. 4c), and the direction of the electric field (E-field) of the cavity filter (100) faces upward in the drawing, referring to FIG. 4c, it can be seen that the direction of the electric field (E-field) formed in the dielectric resonance filter (210) in the adjacent cavity (21) is the Even mode direction in the drawing, that is, the clockwise direction.

Meanwhile, in the case of FIGS. 5A to 5C, when the window (300) is formed to be eccentrically connected to the other side (the lower side in the drawing of FIG. 5C), and the direction of the electric field (E-field) of the cavity filter (100) faces upward in the drawing, referring to FIG. 5C, it can be seen that the direction of the electric field (E-field) formed in the dielectric resonance filter (210) in the adjacent cavity (21) is in the Odd mode direction in the drawing, that is, counterclockwise.

In this way, the transverse mode of the dielectric resonance filter (210) can generate coupling that changes in conjunction with the longitudinal mode of the cavity filter (100) depending on the change (or position) of the shape of the window (300a). At this time, as described above, when a 180-degree phase difference is generated by using the mode direction of the dielectric resonance filter (210), that is, the Even mode and the Odd mode, cross coupling can be generated.

That is, the embodiments of the composite filter assembly of the present invention described below include a cavity filter (100) provided in a reference cavity (10) among a plurality of cavities formed to be open on one side in a housing (1), and dielectric resonance filters (210,220 or 210,220,230) provided in at least two adjacent cavities (21,22 or 21,22,23) adjacent to the reference cavity (10), and a notch characteristic between the cavity filter (100) and the at least two dielectric resonance filters (210,220,230) is such that a portion of a partition (310,320 or 310,320,330) between the reference cavity (10) and the adjacent cavities (21,22,23) is cut out and connected to each other by a window (310a,320a or In order to be adjusted according to the window (310a, 320a or 310a, 320a, 330a), the window (310a, 320a or 310a, 320a, 330a) can be designed to be eccentrically formed to different positions on the left and right with the center as the center. Here, the window ((310a, 320a or 310a, 320a, 330a)) is preferably formed by cutting so as to have a predetermined height from the bottom surface of the reference cavity (10) and the adjacent cavity (21, 22 or 21, 22, 23). According to an embodiment, the window (310a, 320a or 310a, 320a, 330a) can be formed by cutting so as to have a deeper or higher height than the middle height of the reference cavity (10) and the adjacent cavity (21, 22 or 21, 22, 23).

FIGS. 6a to 7b are graphs of a design for generating a C-notch according to the window position between one cavity filter and two adjacent dielectric resonant filters and the resulting design, and FIGS. 8a to 9b are graphs of a design for generating an L-notch according to the window position between one cavity filter and two adjacent dielectric resonant filters and the resulting design.

According to one embodiment of the present invention, as shown in FIGS. 6A to 7B , a composite filter assembly is provided with two dielectric resonance filters (210, 220) that are provided adjacent to each other, and when the dielectric filters are defined as a first dielectric filter (210) and a second dielectric filter (220), the windows (310a, 320a) may include a first window (310a) formed in a partition wall (310) between a cavity filter (100) and the first dielectric filter (210), and a second window (320a) formed in a partition wall (310) between the cavity filter (100) and the second dielectric filter (220).

Here, in order to create a C-notch between the cavity filter (100) and the first dielectric filter (210), the first window (310a) may be formed by cutting eccentrically inwardly at the boundary between the first dielectric filter (210) and the second dielectric filter (220), as shown in FIG. 6a. At this time, as shown in the graph of FIG. 6b, a C-notch is formed on the left side of the pass band by the first window (310a) between the cavity filter (100) and the first dielectric filter (210).

At this time, even if the formation location of the second window (320a) is changed from the original inwardly eccentrically cut portion, which is the boundary portion between the first dielectric filter (210) and the second dielectric filter (220), to the outer portion, which is the opposite side of the boundary portion between the first dielectric filter (210) and the second dielectric filter (220), as shown in FIG. 7a, it can be confirmed that the C-notch previously created on the left side of the pass band by the first window (310a) of the cavity filter (100) and the first dielectric filter (210) is not affected, as shown in FIG. 7b.

In addition, as referenced in FIG. 8a, in order to create an L-notch between the cavity filter (100) and the first dielectric filter (210), the first window (310a) may be cut eccentrically outwardly opposite to the boundary between the first dielectric filter (210) and the second dielectric filter (220). At this time, referring to FIG. 8b, an L-notch is formed on the right side of the pass band by the first window (310a) between the cavity filter (100) and the first dielectric filter (210).

Here too, even if the formation location of the second window (320a) is changed from the original inwardly eccentrically cut portion, which is the boundary portion between the first dielectric filter (210) and the second dielectric filter (220), to the outer portion, which is the opposite side of the boundary portion between the first dielectric filter (210) and the second dielectric filter (220), as shown in FIG. 9a, it can be confirmed that this does not affect the L-notch previously created on the right side of the pass band by the first window (310a) of the cavity filter (100) and the first dielectric filter (210), as shown in FIG. 9b.

FIGS. 10A to 10C are graphs of a first design for notch generation according to the window position between one cavity filter and three adjacent dielectric resonant filters and the results thereof, and FIGS. 11A to 11C are graphs of a second design for notch generation according to the window position between one cavity filter and three adjacent dielectric resonant filters and the results thereof.

According to another embodiment of the present invention, a composite filter assembly is provided with three dielectric resonance filters (210, 220, 230) as shown in FIGS. 10A and 10B and FIGS. 11A and 11B, and it is assumed that the dielectric resonance filters (210, 220, 230) are provided adjacent to each other around a reference cavity (10), and a dielectric filter located in the middle of the dielectric filters is defined as a first dielectric filter (210), a dielectric filter located on one side of the first dielectric filter (210) is defined as a second dielectric filter (220), and a dielectric filter located on the other side of the first dielectric filter (210) is defined as a third dielectric filter (230). A window (300) is formed in a first window (310a) formed in a partition (310) between the cavity filter (100) and the first dielectric filter (210), and a third dielectric filter (230) formed in a partition (310) between the cavity filter (100) and the second dielectric filter (220). It may include a second window (320a) formed in the partition wall (320) and a third window (330a) formed in the partition wall (330) between the cavity filter (100) and the third dielectric filter (230).

Here, in order to create a multi-C-notch between the cavity filter (100) and the first dielectric filter (210), as shown in FIGS. 10a and 10b, the first window (310a) may be cut eccentrically inwardly at the boundary between the first dielectric filter (210) and the third dielectric filter (230). In addition, the second window (320a) may be cut eccentrically inwardly or outwardly at the boundary between the first dielectric filter (210) and the second dielectric filter (220).

Conversely, in order to create a multi-L-notch between the cavity filter (100) and the first dielectric filter (210), as shown in FIGS. 11a and 11b, the first window (310a) may be cut eccentrically outwardly opposite to the boundary between the first dielectric filter (210) and the third dielectric filter (230). Here, the second window (320a) may be cut eccentrically inwardly or outwardly relative to the boundary between the first dielectric filter (210) and the second dielectric filter (220).

In this way, a multi C-notch or a multi L-notch can be easily formed between the cavity filter (100) and the first dielectric filter (210), which is a dielectric filter located in the center among the multiple dielectric filters, and the second dielectric filter (220) located on one side.

FIGS. 12A to 12C are a third design of notch generation according to the position of a window (300) between one cavity filter (100) and three adjacent dielectric resonance filters (210, 220, 230) and the resulting graphs.

According to another embodiment of the present invention, a composite filter assembly is provided with three dielectric resonance filters (210, 220, 230) as shown in FIGS. 12A and 12B, and assuming that they are provided adjacent to each other around a reference cavity (10), a dielectric filter located in the middle of the dielectric filters is defined as a first dielectric filter (210), a dielectric filter located on one side of the first dielectric filter (210) is defined as a second dielectric filter (220), and a dielectric filter located on the other side of the first dielectric filter (210) is defined as a third dielectric filter (230), a window (300) is not formed between the cavity filter (100) and the first dielectric filter (210), but is formed in a second window (320a) formed in a partition (320) between the cavity filter (100) and the second dielectric filter (220) and a cavity filter (300). It includes a third window (330a) formed in a partition (330) between the filter (100) and the third dielectric filter (230).

Here, in order to create a C-notch between the cavity filter (100) and the second dielectric filter (220), as shown in FIGS. 12a and 12b, the second window (320a) may be cut eccentrically inwardly where the first dielectric filter (210) is provided. At this time, referring to FIG. 12c, it can be confirmed that the cut position of the third window (330a) does not affect the C-notch formed through the second window (320a) at all.

In this way, the composite filter assembly embodiments according to the present invention have the advantage of being able to present a standard between filters applied in a composite form, since various designs are possible without the use of a separate coupling metal bar or the like, in strengthening the cross-coupling characteristic between the reference cavity (10) and the adjacent cavities (21, 22, 23).

Above, embodiments of the composite filter assembly according to the present invention have been described in detail with reference to the attached drawings. However, the embodiments of the present invention are not necessarily limited to the embodiments described above, and it will be understood that various modifications and implementations within an equivalent scope are possible by those skilled in the art to which the present invention pertains. Therefore, the true scope of the present invention will be determined by the claims described below.

1: Housing 10: Reference cavity
21,22,23: Adjacent cavities 100: Cavity filter
210: First genetic filter 220: Second genetic filter
230: 3rd Genome Filter 300a: Windows
310a: 1st window 320a: 2nd window
330a: 3rd window

Claims (11)

A cavity filter provided in one of a number of cavities formed to be open on one side of the housing (hereinafter referred to as a 'reference cavity'); and
A dielectric resonance filter is provided in each of at least two cavities (hereinafter referred to as 'adjacent cavities') adjacent to the above-mentioned reference cavity;
The window is designed to be eccentrically positioned to different left and right with respect to the center so that the notch characteristic between the cavity filter and the at least two dielectric resonant filters is adjusted according to a window in which a part of the partition between the reference cavity and the adjacent cavity is cut out and communicates with each other,
Assuming that the above dielectric resonance filters are provided in two units and are provided adjacent to each other, and the dielectric resonance filters are defined as the first dielectric filter and the second dielectric filter, respectively,
The above window is,
A first window formed in a partition between the cavity filter and the first dielectric filter; and
A second window formed in a partition between the cavity filter and the second dielectric filter;
In order to create a C-notch between the cavity filter and the first dielectric filter, the first window is cut eccentrically inwardly at the boundary between the first dielectric filter and the second dielectric filter.
A composite filter assembly, wherein the first window is cut eccentrically outwardly opposite to the boundary between the first dielectric filter and the second dielectric filter, to create an L-notch between the cavity filter and the first dielectric filter. In claim 1,
A composite filter assembly, wherein the first window and the second window have a predetermined height from the bottom surface of the reference cavity and the adjacent cavity. delete delete delete A cavity filter provided in one of a number of cavities formed to be open on one side of the housing (hereinafter referred to as a 'reference cavity'); and
A dielectric resonance filter is provided in each of at least two cavities (hereinafter referred to as 'adjacent cavities') adjacent to the above-mentioned reference cavity;
The window is designed to be eccentrically positioned to different left and right with respect to the center so that the notch characteristic between the cavity filter and the at least two dielectric resonant filters is adjusted according to a window in which a part of the partition between the reference cavity and the adjacent cavity is cut out and communicates with each other,
Assuming that the dielectric resonance filters are provided in three units and are provided adjacent to each other around the reference cavity, and the dielectric resonance filter located in the middle of the dielectric resonance filters is defined as the first dielectric filter, the dielectric resonance filter located on one side of the first dielectric filter is defined as the second dielectric filter, and the dielectric resonance filter located on the other side of the first dielectric filter is defined as the third dielectric filter,
The above window is,
A first window formed in a partition between the cavity filter and the first dielectric filter;
A second window formed in a partition between the cavity filter and the second dielectric filter; and
A third window formed in a partition between the cavity filter and the third dielectric filter;
In order to create a multi-C-notch between the cavity filter and the first dielectric filter, the first window is formed by cutting eccentrically inwardly at the boundary between the first dielectric filter and the third dielectric filter, and the second window is formed by cutting eccentrically inwardly or outwardly at the boundary between the first dielectric filter and the second dielectric filter.
A composite filter assembly, wherein the first window is formed by cutting eccentrically toward the outside opposite to the boundary between the first dielectric filter and the third dielectric filter, to create a multi-L-notch between the cavity filter and the first dielectric filter, and the second window is formed by cutting eccentrically toward the inside or outside of the boundary between the first dielectric filter and the second dielectric filter. delete delete In claim 6,
The above third window is a composite filter assembly formed by cutting eccentrically inwardly or outwardly at the boundary between the first dielectric filter and the third dielectric filter.
delete delete

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