KR100858915B1 - Radio frequency filter - Google Patents

Abstract

A radio frequency filter is provided to design a planar structure freely by using a DR(Dielectric Resonator), thereby improving the degree of freedom in designing a size or a shape. A radio frequency filter includes a DR. The DR is provided at one of a plurality of receiving spaces at least and includes a dielectric disk(422) and a DR support unit(421). The dielectric disk is vertically formed to face a front and rear side surface or a left and right side surface of the corresponding receiving space. The DR support unit is installed between a side surface of the dielectric disk and at least one surface inside the corresponding receiving space and fixes the dielectric disk. A resonance bar(420') is installed at one of the plurality of receiving spaces at least and is vertically installed to be fixed to a bottom surface of the corresponding receiving space.

Description

High Frequency Filter {RADIO FREQUENCY FILTER}

1A, 1B, and 1C are structural diagrams of an RF filter using a DR (Dielectric Resonator)

2A, 2B, and 2C are structural diagrams of a high frequency (RF) filter using a metal resonant rod

3A and 3B are structural diagrams of an RF filter in the case of combining DR and a resonance rod

4 is a structural diagram of an RF filter combining a DR and a resonance rod according to an embodiment of the present invention;

5 is a structural diagram of an RF filter using DR according to another embodiment of the present invention

The present invention relates to a radio frequency (RF) filter.

The high frequency filter (DR filter, cavity filter, wave guide filter, etc.) has a kind of circuit cylinder structure for resonating high frequency, especially ultra high frequency. Resonant circuits by common coils and capacitors are not suitable for forming very high frequencies due to their large radiation losses. The RF filter forms a cavity of a metallic cylinder or cuboid surrounded by a conductor, and includes a resonator rod of a metal (DR) or a metal inside thereof, so that only an electromagnetic field of a natural frequency exists, so that high frequency resonance It has a structure that makes it possible.

These RF filters have low insertion loss and are advantageous for high output, so they are applied to almost all transmission / reception communication equipments such as mobile communication base stations, repeaters, broadcast repeaters, and satellite communication systems, and also for duplexers and bandpass filters. Are employed. Hereinafter, the configuration and operation of the RF filter will be described in detail with reference to the accompanying drawings.

FIG. 1A is an overall perspective view showing the structure of an RF filter using a general DR, FIG. 1B is a partially cutaway perspective view of FIG. 1A, and FIG. 1C is a cutaway perspective view along a dashed-dotted line B in FIG. 1A. 1A to 1C, the RF filter 100 using DR first includes a housing 110 forming a body and a cover 160 coupled to an upper surface of the housing 110 to shield the inside thereof. The interior of the housing 110 is divided into a plurality of receiving spaces (6 in the example of FIG. 1) by the diaphragm 130, for example, a disk having a hollow portion formed to resonate and pass a desired frequency in each receiving space. A dielectric resonator DR 120 of the type is mounted. Input and output connectors 111 and 113 for inputting and outputting wireless signals are provided on the side surface of the housing 110 (the same side in the example of FIG. 1A), and dielectric resonators (DRs) 120 provided in accommodation spaces of the installed positions, respectively. ) Is connected by a coupling copper wire 115 (FIG. 1C). The diaphragm 130 is provided with coupling windows 131, 132, 133, 134 and 135 which connect the accommodation spaces in series from the accommodation space to which the input connector 111 is connected to the accommodation space to which the output connector 113 is connected. do.

When the DR 120 is mounted in each accommodation space of the housing 110, the upper end of the housing 110 is sealed by the cover 160. As shown in FIG. 1A, the cover 160 and the housing 110 are mutually connected by screw 179 fastened to a screw fastening hole 169 and a fastening tab 180 formed in a plurality of appropriately corresponding positions, respectively. Can be combined.

The DR 120 may include a DR support 121 extending from the bottom of the housing 110 (there may be an alumina support for supporting the DR support 121 at the center), and a top outer peripheral surface of the DR support 121. A dielectric disk 122 extending in the radial direction. The resonant frequency is determined by the capacitance value and the inductance value formed between the capacitive component and the inductive component, that is, the housing 110, the diaphragm 130, the DR 120, and the cover 160. In order to form the required filtering characteristics, the shape and size of the accommodation space of the housing 110, the shape, material and size of the DR 120, etc. are appropriately designed.

As described above, after the DR 120 is mounted in each accommodation space of the housing 110, the cover 160 and the housing 110 are combined to manufacture the RF filter 100, and then an error occurred in the manufacturing process. And correcting an error portion caused by an error on the manufactured part. To this end, a plurality of tuning screws 170 and 175 for fastening the resonance characteristic and the coupling characteristic of the RF filter 100 are fastened to a screw hole (not shown) in the upper cover 160 of the RF filter 100. do.

The tuning screws 170 and 175 are fastened to a position corresponding to the DR 120 and are coupled to a position corresponding to the resonance tuning screw 170 used to adjust the resonance characteristics and the coupling windows 131 to 135. The coupling tuning screw 175 used to adjust the characteristics can be divided. Tightening or loosening the tuning screws 170 and 175 adjusts the corresponding resonance characteristics (ie, center frequency) and coupling characteristics (ie, frequency band).

2A is an overall perspective view showing the structure of an RF filter using a general metal resonant rod, and FIGS. 2B and 2C are cutaway perspective views taken along dashed lines B and C of FIG. 2A, respectively. 2A to 2C, the RF filter 100 using the metal resonant rod has a housing 210 forming a body similar to the RF filter using the DR shown in FIGS. An accommodation space may be formed. However, there is a difference in that the metal resonance rod 220 is provided instead of the DR 120 shown in FIGS. 1A to 1C.

The RF filter technology using such DR or metal resonant rod is disclosed in Korea Patent Application No. 2002-84938 (name: radio frequency filter having a dielectric having a high dielectric constant and high selectivity, Applicant: KM Double Oil Co., Ltd.) , Inventor: Jong-kyu Park et al., Application date: December 27, 2002 and Patent Application No. 2002-52352 (name: radio frequency filter with a spring nut, Applicant: KM Double Oil Co., Ltd., inventor: Jong-gyu Park et al., 2002: 2002) August 31, etc.).

The RF filter using such a DR or metal resonant rod is provided in a base station or repeater for transmitting, receiving or relaying an RF signal for wireless communication or broadcasting, and is applied to suppress signal interference between transmission and reception signals or other systems. Various forms and structures have been developed according to the filtering characteristics required.

Accordingly, an object of the present invention is to provide a high frequency filter which can have an efficient and simple structure while satisfying the required filtering characteristics.

Another object of the present invention is to provide a high frequency filter for allowing a relatively free shape design such as size or size.

In order to achieve the above object, the present invention provides a high frequency (RF) filter having a plurality of accommodation spaces in the housing, wherein at least one of the plurality of accommodation spaces is provided with a dielectric resonator (DR), The dielectric resonator is provided with a dielectric disk formed in a form facing the front, rear, left and right sides of the receiving space, and a DR support portion installed between the side of the dielectric disk and the inner bottom of the receiving space to secure the dielectric disk. Characterized by including.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, specific details of the structure and tuning process of the RF filter are shown, which are provided to help a more general understanding of the present invention, and these specific details may be modified or changed within the scope of the present invention. It will be obvious to those of ordinary skill in the art.

3A and 3B are structural diagrams of an RF filter in the case of a combination of a DR and a resonator rod, and FIG. 3A shows a side cross section of the RF filter, and FIG. 3B shows a partial plane cutaway of the RF filter. The RF filter illustrated in FIGS. 3A and 3B has a structure in which a disk-type dielectric resonator (DR) 302 and a metal resonator rod 320 'are mixed. The basic structure of the RF filter including other tuning screws 370 and 375 can adopt the conventional structure as it is.

As such, the mixture of the DR and the resonator rod may be appropriately designed in consideration of the required filtering characteristics, the size of the filter, or the manufacturing cost. For example, metal resonant rods typically have a low Spurious (Q) value compared to DR, which requires less manufacturing cost. In the case of using a metal resonant rod, the size of the accommodation space is relatively free, but in the case of DR, the size is limited. This is because, when the area 320 and the diameter d of the dielectric disk 322 are designed in accordance with the resonant frequency in the DR 320, the shape and size of the optimum accommodation space are determined accordingly (in detail, The distance between the side and the corresponding receiving space is an important factor). Therefore, in consideration of the filtering characteristics, shape, and cost required when fabricating an RF filter, a method of designing a structure of the RF filter by mixing DR and resonator rods has been studied.

As shown in FIGS. 3A and 3B, in the case of designing an RF filter by mixing the DR 320 and the resonator rod 320 ′, the DR 320 is disposed inside the accommodation space of the housing through the DR support 321. Compared to being fixed to the bottom surface, it can be seen that the resonator rod 320 'is installed in the horizontal direction to be fixed to the side wall of the receiving space of the housing. This is to allow the coupling between the two to match the electric field direction between the DR (320) and the resonator rod 320 'as shown by the dashed-dotted arrow in Figure 3a (in Figure 3a as shown by the arrow in one direction However, this is for convenience of explanation and it should be noted that in the AC signal such as the RF signal, the electric field directions are alternately shown in both directions).

As shown in Figure 3a, 3b, when designing the RF filter can be used in combination with the DR and resonator rod, there may be the following problems. First, there are still significant constraints on the size of the receiving space and the housing depending on the diameter of the dielectric disk 322 of the DR 320. In addition, since the resonator rod 320 'must be installed on the inner sidewall of the housing in the horizontal direction, there is a considerable difficulty in a process such as screw assembly when installing the resonator rod 320'. In particular, when the RF filter has six 2x3 shaped spaces as shown in FIGS. 1A and 2A, a screw assembly process may be possible to the outer side, but in addition, if the RF filter has a 3x3 shaped space, The screw assembly process is almost impossible in the accommodating space (ie accommodating space with no side facing the outside of the housing). Therefore, even when the DR and the resonator rods are used in combination, a simple assembly process is possible, and the structure of the RF filter that can be relatively freely designed in size or shape is required.

4 is a structural diagram of an RF filter combining a DR and a resonant rod according to an embodiment of the present invention, and FIG. 5 is a structural diagram of an RF filter using a DR according to another embodiment of the present invention. 4 and 5, the RF filter according to embodiments of the present invention may be configured using the DR 420 and / or the resonator rod 420 ′, and other tuning screws 470 and 475. The basic structure of the RF filter including the above can adopt the conventional structure as it is.

At this time, in the RF filter according to the embodiments of the present invention, the DR 420 is provided in a form that is set up as compared to the conventional so that the dielectric disk 422 faces (front, rear, left and right) side of the housing, the DR support 421 Is installed between the side of the dielectric disk 422 and the inner bottom surface of the accommodation space of the housing to fix the dielectric disk 422. Accordingly, the metal resonator rod 420 ′ may be installed in the longitudinal direction to be fixed to the bottom of the accommodation space of the housing. That is, as shown by the dashed-dotted arrow in FIG. 4, bilateral coupling may be performed by adjusting the electric field direction between the DR 420 having the dielectric disk 422 arranged in a vertical shape and the resonator rod 420 ′. Will be.

In the case of using the DR 420 according to the features of the present invention as shown in FIG. 4, the resonator rod 420 ′ is installed in the vertical direction to be attached to the bottom surface of the housing like the DR 420. Since the process of assembling the screw is very easy when installing '), the resonator rod 420' may have a very easy structure. Accordingly, the RF filter in the case of having six accommodating spaces in the form of 2x3, as shown in FIGS. 1A, 2A, etc., in which the DR 420 and the resonator rod 420 'having such a structure are used, as well as in the form of 3x3, etc. Even if it has an accommodation space, the resonance rod 420 'and the DR 420 can be easily installed at any position.

In addition, the distance between the sidewall and the corresponding sidewall of the accommodation space according to the diameter of the dielectric disk in the DR may be limited in design as described above, but the top and bottom surfaces of the dielectric disk 422 and the corresponding sidewall of the accommodation space may be used as described above. The distance between them is relatively free to design. Therefore, in the case of using the DR 420 according to the present invention, the accommodation space of the DR 420 may have a planar structure of rectangular behavior, deviating from the structure of the conventional planar structure. Accordingly, in the case of using the DR 420 according to the present invention, it is possible to design a planar structure, which is an important design matter in an RF filter, more freely.

In the RF filter shown in FIG. 5, only DRs 420 and 420 ″ are shown. In this case, the DRs 420 are not formed as shown in FIG. 4. It can be seen that the upper and lower surfaces of the dielectric disk 422 of the dielectric disk 422 are installed to face each other. In addition, the specific DR 420 "is installed with the DR support 421 rotated 90 degrees relative to the other DR 420. May be Even when installed in this manner, electric field coupling between the DRs can be made, so that the design of the corresponding RF filter can be more free.

As described above, a variable RF filter according to an embodiment of the present invention may be configured. Meanwhile, in the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. . Therefore, the scope of the present invention should not be defined by the described embodiments, but by the claims and equivalents of the claims.

As described above, the high frequency filter can have an efficient and simple structure while satisfying the required filtering characteristics, and can freely design shapes such as size and size.

Claims (7)

In the high frequency (RF) filter having a plurality of accommodation spaces in the housing, At least one of the plurality of accommodation spaces is provided with a dielectric resonator (DR), The dielectric resonator is provided with a dielectric disk which is formed to face the front, rear, left and right sides of the receiving space; And a DR support installed between the side of the dielectric disk and at least one surface inside the accommodation space to fix the dielectric disk. A resonator rod is installed in at least one of the plurality of accommodation spaces, and the resonance rod is installed in a vertical direction to be fixed to the bottom of the accommodation space. The high frequency filter according to claim 1, wherein at least one surface of the inside of the accommodation space in which the DR support is installed is a bottom surface of the interior of the accommodation space. delete In the high frequency (RF) filter having a plurality of accommodation spaces in the housing, At least one of the plurality of accommodation spaces is provided with a dielectric resonator (DR), The dielectric resonator is provided with a dielectric disk which is formed to face the front, rear, left and right sides of the receiving space; And a DR support installed between the side of the dielectric disk and at least one surface inside the accommodation space to fix the dielectric disk. When the plurality of dielectric resonators are installed in succession in the receiving space, at least a portion of the high frequency filter, characterized in that the side of the adjacent dielectric disk is installed so as to face each other. In the high frequency (RF) filter having a plurality of accommodation spaces in the housing, At least one of the plurality of accommodation spaces is provided with a dielectric resonator (DR), The dielectric resonator is provided with a dielectric disk which is formed to face the front, rear, left and right sides of the receiving space; And a DR support installed between the side of the dielectric disk and at least one surface inside the accommodation space to fix the dielectric disk. When the plurality of dielectric resonators are provided in succession in the receiving space, at least a portion of the high frequency filter, characterized in that the upper and lower surfaces of neighboring dielectric disks are installed to face each other. In the high frequency (RF) filter having a plurality of accommodation spaces in the housing, At least one of the plurality of accommodation spaces is provided with a dielectric resonator (DR), The dielectric resonator is provided with a dielectric disk which is formed to face the front, rear, left and right sides of the receiving space; And a DR support installed between the side of the dielectric disk and at least one surface inside the accommodation space to fix the dielectric disk. When the plurality of dielectric resonators are provided in succession in the receiving space, at least a portion of the high frequency filter, characterized in that the top / bottom and side surfaces of the neighboring dielectric disks are installed to face each other. The high frequency filter according to any one of claims 4 to 6, wherein at least one of the plurality of accommodation spaces is provided with a resonance rod, and the resonance rod is installed in a vertical direction to be fixed to a bottom of the accommodation space.

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