JP2008205692A - High-frequency filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-frequency filter of simple structure, which improves attenuation characteristic on the high band side and the low band side of a passband, limiting the increase of both an insertion loss and a unit size. <P>SOLUTION: The high-frequency filter includes a conductive case having semi-coaxial cavity resonators 111-115 and a plurality of cavities corresponding thereto; first coupling windows 155-158 for connecting the plurality of cavities so as to couple the semi-coaxial cavity resonators 111-115 in series by electric field coupling; second coupling windows 159, 160 for connecting both end cavities with a cavity selected in advance among the plurality of connected cavities; and couplers 151a, 152a for coupling, by magnetic field coupling, both end semi-coaxial resonators 111, 115 among semi-coaxial cavity resonators 111-115 coupled in series by electric field coupling, via the semi-coaxial cavity resonator 113 selected in advance. The couplers 151a, 152a are disposed on the second coupling windows 159, 160, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a high-frequency filter including a plurality of resonators.

  Satellite communication, business telephone backup lines, and the like require a high frequency filter that removes signals other than a specific band so as to efficiently receive communication signals in the MHz band to GHz band.

  As shown in FIG. 11, the conventional high-frequency filter has a filter case 1, input / output connectors 3 and 4 attached to both side surfaces of the filter case 1 in the longitudinal direction, and a direction connecting the input / output connectors 3 and 4. And a plurality of inner conductors 11, 12, 13 fixed to the filter case 1 and a frequency adjustment screwed into the mounting hole of the filter case 1 so as to correspond to the inner conductors 11, 12, 13 Screws 14, 15, and 16 and frequency characteristic inclination adjusting members 17 and 18 that shield part of the electric field coupling between the adjacent inner conductors 11, 12, and 13 and adjust the inclination of the frequency characteristic of the filter are provided. .

  In the conventional high-frequency filter configured as described above, the filter case 1 and the plurality of inner conductors 11, 12, and 13 constitute a plurality of semi-coaxial resonators, and the resonance frequencies of the semi-coaxial resonators are frequency adjusted. The degree of coupling between the semi-coaxial resonators is adjusted by the screws 14, 15, and 16, and the frequency characteristic inclination adjusting members 17 and 18 are adjusted.

When improvement of the attenuation characteristics on the high band side and low band side of the pass band is required, it is possible to increase the unloaded Q of each semi-coaxial resonator or increase the number of stages of the semi-coaxial resonator. It was general (see, for example, Patent Document 1).
Japanese Patent Laying-Open No. 2005-311862 (FIG. 1)

  However, the conventional high-frequency filter has a problem that the size of the device increases when it is attempted to improve the attenuation characteristics on the high-frequency side and the low-frequency side of the pass band by increasing the unloaded Q of each semi-coaxial resonator. . On the other hand, if the method of increasing the number of stages of the semi-coaxial resonators is used to improve the attenuation characteristics on the high band side and low band side of the pass band, there is a problem that not only the apparatus is increased in size but also the insertion loss is increased.

  The present invention has been made to solve the conventional problems, and compared with the conventional high-frequency filter, the increase in insertion loss and the increase in size of the device are suppressed, and the high-frequency side and low-passband of the passband can be achieved with a simple configuration. An object of the present invention is to provide a high-frequency filter having improved attenuation characteristics on the band side.

  The high-frequency filter according to the present invention includes a conductive housing in which a plurality of resonators are partially configured, and a plurality of cavities respectively corresponding to the plurality of resonators are formed, and the plurality of resonators are electrically coupled or magnetically coupled. A plurality of first coupling windows for communicating the plurality of cavities so as to be coupled in a row, and a plurality of second coupling windows for communicating the cavities at both ends and the preselected cavities among the plurality of the communicated cavities. And a plurality of coupling portions for coupling the resonators at both ends by magnetic field coupling via the preselected resonators among the plurality of resonators coupled in series by the electric field coupling or the magnetic field coupling. The plurality of coupling portions are respectively disposed in the plurality of second coupling windows.

  With this configuration, an increase in insertion loss and an increase in the size of the apparatus can be suppressed, and the attenuation characteristics on the high frequency side and low frequency side of the passband can be improved with a simple configuration.

  In the high-frequency filter of the present invention, the plurality of resonators are respectively constituted by a plurality of semi-coaxial resonators.

  With this configuration, it is possible to improve the attenuation characteristics on the high frequency side and low frequency side of the pass band with a simple configuration.

  In the high-frequency filter of the present invention, the plurality of resonators are each composed of a plurality of dielectric resonators.

  With this configuration, it is possible to improve the attenuation characteristics on the high frequency side and low frequency side of the pass band with a simple configuration.

  In the high frequency filter according to the aspect of the invention, at least one of the plurality of coupling portions may include a part of the magnetic flux in the cavity of one resonator coupled by the magnetic field coupling and the magnetic flux in the other cavity. A closed circuit that links in the same direction is configured, and the remaining coupling part is configured to chain a part of the magnetic flux in the cavity of one resonator coupled by the magnetic field coupling and the magnetic flux in the other cavity in opposite directions. A closed circuit is formed.

  With this configuration, it is possible to improve the attenuation characteristics on the high-frequency side and the low-frequency side of the pass band using a coupling portion with a simple configuration.

  The high frequency filter of the present invention includes a plurality of holding portions that are electrically connected to the plurality of coupling portions, and the conductive housing holds the plurality of holding portions in a rotatable manner.

  With this configuration, the coupling degree of the magnetic field coupling between the resonators can be adjusted by rotating the coupling portion.

  The high-frequency filter of the present invention includes a plurality of holding portions electrically connected to the plurality of coupling portions, and the conductive housing holds the plurality of holding portions so as to be movable in the axial direction. .

  With this configuration, the coupling degree of magnetic field coupling between the resonators can be adjusted by moving the coupling part in the axial direction of the holding part.

  In the high-frequency filter of the present invention, a cavity corresponding to the resonators at both ends and a cavity corresponding to the preselected resonator are formed adjacent to the conductive housing.

  With this configuration, it is possible to improve the attenuation characteristics on the high frequency side and low frequency side of the pass band with a simple configuration.

  The present invention can provide a high-frequency filter that suppresses an increase in insertion loss and an increase in the size of the device and improves the attenuation characteristics on the high-frequency side and the low-frequency side of the passband with a simple configuration as compared with the conventional high-frequency filter. Is.

  Hereinafter, a high frequency filter according to an embodiment of the present invention will be described with reference to FIGS.

  In addition, the structure of the high frequency filter in embodiment is an illustration, Comprising: It is not limited to this. In particular, the high-frequency filter of the present invention may have any number of stages as long as it is constituted by five or more resonators.

(First embodiment)
As shown in FIGS. 1 to 4, the high-frequency filter 100 according to the present embodiment includes first to fifth semi-coaxial resonators 111 to 115. The first to fifth semi-coaxial resonators 111 to 115 are The first semi-coaxial resonator 111 and the third semi-coaxial resonator 113 and the third semi-coaxial resonator 113 and the fifth semi-coaxial resonator 115 are coupled by magnetic field coupling. Yes.

  The high frequency filter 100 of the present embodiment includes a conductive housing 102, an input terminal 3, an output terminal 4, a plurality of internal conductors 116 to 120, frequency adjusting means 141 to 145, and first coupling degree adjusting means. 146 to 149 and second coupling degree adjusting means 151 and 152 are provided.

  The conductive casing 102 includes a container portion 102a and a lid portion 102b. The container portion 102a includes a plurality of cavities, a plurality of first coupling windows 155 to 158, and a plurality of second coupling windows 159 and 160. Is formed.

  The plurality of cavities formed in the container portion 102a correspond to the cavities of the first to fifth semi-coaxial resonators 111 to 115, respectively.

  The cavity of the first semi-coaxial resonator 111 and the cavity of the second semi-coaxial resonator 112 are the first so that the first semi-coaxial resonator 111 and the second semi-coaxial resonator 112 are coupled by electric field coupling. The connection window 155 communicates with each other. Similarly, the cavity of the second semi-coaxial resonator 112 and the cavity of the third semi-coaxial resonator 113 are coupled so that the second semi-coaxial resonator 112 and the third semi-coaxial resonator 113 are coupled by electric field coupling. Are communicated by the first coupling window 156. Further, the cavity of the third semi-coaxial resonator 113 and the cavity of the fourth semi-coaxial resonator 114 are connected so that the third semi-coaxial resonator 113 and the fourth semi-coaxial resonator 114 are coupled by electric field coupling. The first coupling window 157 communicates. Further, the cavity of the fourth semi-coaxial resonator 114 and the cavity of the fifth semi-coaxial resonator 115 are coupled so that the fourth semi-coaxial resonator 114 and the fifth semi-coaxial resonator 115 are coupled by electric field coupling. The first coupling window 158 communicates.

  Further, the cavity of the first semi-coaxial resonator 111 and the cavity of the third semi-coaxial resonator 113 are communicated by the second coupling window 159, and the cavity of the third semi-coaxial resonator 113 and the fifth semi-coaxial resonator are connected. The cavity of the resonator 115 is communicated by the second coupling window 160.

  The input terminal 3 is provided at one end of the conductive casing 102 and inputs electromagnetic waves (for example, microwaves) from a connected external circuit to the first semi-coaxial resonator 111. On the other hand, the output terminal 4 is provided at the other end of the conductive casing 102 and outputs an electromagnetic wave from the fifth semi-coaxial resonator 115.

  In this embodiment, the input terminal 3 and the output terminal 4 are provided on the side surfaces on one end side and the other end side of the conductive casing 102, respectively, but the input terminal 3 and the output terminal 4 are provided on one end side of the conductive casing 102. May be.

  The inner conductor 116 is disposed in the cavity of the first semi-coaxial resonator 111 so as to be separated from the inner wall. Similarly, the inner conductor 117 is disposed in the cavity of the second semi-coaxial resonator 112 away from the inner wall, and the inner conductor 118 is disposed in the cavity of the third semi-coaxial resonator 113 away from the inner wall. The inner conductor 119 is disposed in the cavity of the fourth semi-coaxial resonator 114 away from the inner wall, and the inner conductor 120 is disposed in the cavity of the fifth semi-coaxial resonator 115 away from the inner wall. .

  The inner conductors 116 to 120 may be formed integrally with the container portion 102a of the conductive casing 102.

  Further, when the cavities of the first to fifth semi-coaxial resonators 111 to 115 are arranged in a staggered manner, the cavities of the first semi-coaxial resonator 111, the third semi-coaxial resonator 113, and the third semi-coaxial resonator 113 are arranged. The cavity of the coaxial resonator 113 and the cavity of the fifth semi-coaxial resonator 115 are adjacent to each other, and the first semi-coaxial resonator 111, the third semi-coaxial resonator 113, the third semi-coaxial resonator 113, and the fifth The semi-coaxial resonator 115 is preferably coupled by magnetic field coupling.

  The frequency adjustment means 141 of the first semi-coaxial resonator 111 includes a frequency adjustment unit 141a that can adjust the resonance frequency of the first semi-coaxial resonator 111, and a fixing unit (not shown) that fixes the frequency adjustment unit 141a. have. Similarly, the frequency adjusting unit 142 of the second semi-coaxial resonator 112 fixes the frequency adjusting unit 142a capable of adjusting the resonance frequency of the second semi-coaxial resonator 112 and the frequency adjusting unit 142a (not shown). ) The frequency adjustment means 143 of the third semi-coaxial resonator 113 includes a frequency adjustment unit 143a that can adjust the resonance frequency of the third semi-coaxial resonator 113, and the frequency adjustment unit 143a. A frequency adjusting means 144 of the fourth semi-coaxial resonator 114, and a frequency adjusting unit 144a capable of adjusting the resonance frequency of the fourth semi-coaxial resonator 114; The frequency adjusting unit 145 of the fifth semi-coaxial resonator 115 includes a fixing unit (not shown) that fixes the frequency adjusting unit 144a. The frequency adjusting unit 145 of the fifth semi-coaxial resonator 115 can adjust the resonance frequency of the fifth semi-coaxial resonator 115. The number and adjustment unit 145a, fixing the frequency adjusting section 145a (not shown) and a fixing portion.

  Each of the frequency adjusting portions 141a to 145a is formed of a rod-like member on which a male screw is formed. The frequency adjusting portions 141a to 145a are respectively screwed into the plurality of mounting holes of the lid portion 102b and partially protrude into the cavity.

  The length of the portion where the frequency adjustment units 141a to 145a protrude into the cavity is defined as “insertion depth”, and the resonance frequencies of the first to fifth semi-coaxial resonators 111 to 115 are the frequency adjustment units 141a to 145a. It is set by adjusting the insertion depth.

  On the other hand, the fixing unit (not shown) maintains the resonance frequency of the first to fifth semi-coaxial resonators 111 to 115 constant by fixing the frequency adjusting units 141a to 145a. Each fixing part may be constituted by a nut or the like.

  The first coupling degree adjusting means 146 provided between the first semi-coaxial resonator 111 and the second semi-coaxial resonator 112 includes the first semi-coaxial resonator 111 and the second semi-coaxial resonator 112. A coupling degree adjusting unit 146a capable of adjusting the coupling degree of the electric field coupling, a holding unit (insertion rod) 146b that holds the coupling degree adjusting unit 146a, and the holding unit 146b are fixed to the lid unit 102b (not shown). It consists of a fixed part. Similarly, the first coupling degree adjusting means 147 provided between the second semi-coaxial resonator 112 and the third semi-coaxial resonator 113 is similar to the second semi-coaxial resonator 112 and the third semi-coaxial resonator. A coupling degree adjustment unit 147a capable of adjusting the coupling degree of the electric field coupling of the resonator 113, a holding unit (insertion rod) 147b that holds the coupling degree adjustment unit 147a, and the holding unit 147b are fixed to the lid 102b ( (Not shown) and a fixed part. The first coupling degree adjusting means 148 provided between the third semi-coaxial resonator 113 and the fourth semi-coaxial resonator 114 includes the third semi-coaxial resonator 113 and the fourth semi-coaxial resonator 114. A coupling degree adjustment unit 148a capable of adjusting the coupling degree of the electric field coupling, a holding unit (insertion rod) 148b that holds the coupling degree adjustment unit 148a, and the holding unit 148b are fixed to the lid portion 102b (not shown). It consists of a fixed part. The first coupling degree adjusting means 149 provided between the fourth semi-coaxial resonator 114 and the fifth semi-coaxial resonator 115 includes the fourth semi-coaxial resonator 114 and the fifth semi-coaxial resonator 115. A coupling degree adjusting unit 149a capable of adjusting the coupling degree of the electric field coupling, a holding unit (insertion rod) 149b that holds the coupling degree adjusting unit 149a, and the holding unit 149b are fixed to the lid unit 102b (not shown). It consists of a fixed part.

  The holding portion 146b is screwed into the mounting hole of the lid portion 102b, and the coupling degree adjusting portion 146a communicates the cavity of the first semi-coaxial resonator 111 and the cavity of the second semi-coaxial resonator 112. One coupling window 155 is partially blocked. Similarly, the holding portion 147b is screwed into the mounting hole of the lid portion 102b, and the coupling degree adjusting portion 147a communicates the cavity of the second semi-coaxial resonator 112 and the cavity of the third semi-coaxial resonator 113. The first coupling window 156 is partially blocked. The holding portion 148b is screwed into the mounting hole of the lid portion 102b, and the coupling degree adjusting portion 148a communicates the cavity of the third semi-coaxial resonator 113 and the cavity of the fourth semi-coaxial resonator 114. The first coupling window 157 is partially blocked. The holding portion 149b is screwed into the mounting hole of the lid portion 102b, and the coupling degree adjusting portion 149a communicates the cavity of the fourth semi-coaxial resonator 114 and the cavity of the fifth semi-coaxial resonator 115. The first coupling window 158 is partially blocked.

  The second coupling degree adjusting means 151 provided between the first semi-coaxial resonator 111 and the third semi-coaxial resonator 113 includes the first semi-coaxial resonator 111 and the third semi-coaxial resonator 113. A coupling portion 151a that magnetically couples the coupling portion 151a, a holding portion 151b that is electrically connected to the coupling portion 151a and holds the coupling portion 151a, and a fixing portion (not shown) that fixes the holding portion 151b to the container portion 102a. It consists of In the coupling portion 151a, a part of the magnetic flux in the cavity of the first semi-coaxial resonator 111 and a part of the magnetic flux in the cavity of the third semi-coaxial resonator 113 are linked in the same direction.

  On the other hand, the second coupling degree adjusting means 152 provided between the third semi-coaxial resonator 113 and the fifth semi-coaxial resonator 115 includes the third semi-coaxial resonator 113 and the fifth semi-coaxial resonator 115. A coupling portion 152a for magnetically coupling the container 115, a holding portion 152b that is electrically connected to the coupling portion 152a, and holds the coupling portion 152a, and a holder (not shown) that fixes the holding portion 152b to the container portion 102a. It consists of parts. In the coupling portion 152a, a part of the magnetic flux in the cavity of the third semi-coaxial resonator 113 and a part of the magnetic flux in the cavity of the fifth semi-coaxial resonator 115 are linked in the opposite direction.

  The holding portion 151b has a rotation axis parallel to the central axis of the cavity of the first semi-coaxial resonator 111 and the central axis of the cavity of the third semi-coaxial resonator 113, and rotates integrally with the coupling portion 151a. The coupling degree of the magnetic coupling between the first semi-coaxial resonator 111 and the third semi-coaxial resonator 113 is set by rotating the holding unit 151b and adjusting the direction of the coupling unit 151a. The Similarly, the holding portion 152b has a rotation axis parallel to the central axis of the cavity of the third semi-coaxial resonator 113 and the central axis of the cavity of the fifth semi-coaxial resonator 115, and is integrated with the coupling portion 152a. The degree of magnetic field coupling between the third semi-coaxial resonator 113 and the fifth semi-coaxial resonator 115 is adjusted by rotating the holding portion 152b and adjusting the direction of the coupling portion 152a. Is set by

  In the present embodiment, the coupling degree of the magnetic coupling between the first semi-coaxial resonator 111 and the third semi-coaxial resonator 113 and the magnetic coupling between the third semi-coaxial resonator 113 and the fifth semi-coaxial resonator 115 are described. The degree of coupling is set by adjusting the direction of the coupling parts 151a and 152a, but may be set by adjusting the position of the coupling parts 151a and 152a in the depth direction.

  The coupling portion 151a has a loop shape so that a part of the magnetic flux in the cavity of the first semi-coaxial resonator 111 and a part of the magnetic flux in the cavity of the third semi-coaxial resonator 113 are linked in the same direction. It is constituted by a conductor. On the other hand, the coupling portion 152a is configured so that a part of the magnetic flux in the cavity of the third semi-coaxial resonator 113 and a part of the magnetic flux in the cavity of the fifth semi-coaxial resonator 115 are linked in the opposite direction. It is comprised by the character-shaped conductor.

  Next, a method for assembling the high frequency filter 100 of the present embodiment will be described.

  The inner conductors 116 to 120, the input terminal 3, and the output terminal 4 are attached to the container portion 102a. Next, probes are attached to the inner conductors of the input terminal 3 and the output terminal 4. Next, a loop-shaped coupling portion 151 a is attached to a second coupling window that connects the cavity of the first semi-coaxial resonator 111 and the cavity of the third semi-coaxial resonator 113, and the third semi-coaxial resonator An 8-shaped coupling portion 152 a is also attached to the second coupling window that communicates the cavity 113 and the cavity of the fifth semi-coaxial resonator 115. Finally, the cover part 102b to which the frequency adjusting means 141 to 145 and the first coupling degree adjusting means 146 to 149 are attached is put on the container part 102a and fixed with screws or a conductive adhesive.

  The assembling method of the high frequency filter 100 described here is an example, and the present invention is not limited to this assembling method.

  Next, the adjustment method of the center frequency with respect to the pass band of the high frequency filter 100 of this Embodiment is demonstrated.

The input terminal 3 and the output terminal 4 are connected to, for example, a network analyzer, and the frequency adjusting units 141a to 145a are rotated by a driver or the like while observing the frequency characteristics displayed on the screen of the network analyzer. The insertion depth is adjusted, and the center frequency of the high frequency filter 100 is set.
Next, an example of a method for adjusting the coupling degree of electric field coupling and magnetic field coupling will be described.
The input terminal 3 and the output terminal 4 of the high-frequency filter of the present embodiment are connected to, for example, a network analyzer, and the first characteristic is observed with a driver or the like while observing the frequency characteristics displayed on the screen of the network analyzer. The holding portions 146b to 149b of the coupling degree adjusting means 146 to 149 are rotated to adjust the insertion depth of the coupling adjusting units 146a to 149a.

  Similarly, while observing the frequency characteristics displayed on the screen of the network analyzer, the holding units 151b and 152b of the second coupling degree adjusting means 151 and 152 are rotated by a driver or the like, and the directions of the coupling units 151a and 152a are rotated. Adjust.

  When the coupling degree of the magnetic field coupling is appropriately adjusted, the high frequency filter 100 of the present embodiment has frequency characteristics as shown in FIG.

  In the present embodiment, the attachment holes of the holding portions 151b and 152b are provided on the bottom of the container portion 102a so that the coupling degree of the magnetic field coupling can be adjusted from the bottom side of the conductive casing 102. The degree of coupling may be adjusted from the lid side of the conductive housing 102.

  When the coupling degree of magnetic field coupling is configured to be adjustable from the lid side of the conductive casing 102, for example, as shown in FIG. 6, the lengths of the holding portions 153b and 154b are increased, and the coupling portions 153a and 154a are increased. Since the attachment to the conductive casing 102 becomes difficult with the attachment, the holding portions 153b and 154b and the coupling portions 153a and 154a may be detachable.

  As described above, the high-frequency filter according to the present embodiment includes a conductive housing in which a plurality of cavities respectively corresponding to a plurality of semi-coaxial resonators and a plurality of semi-coaxial resonators are connected in an electric field coupling. A plurality of first coupling windows for communicating the plurality of cavities so as to be coupled; a plurality of second coupling windows for communicating between the cavities at both ends and a preselected cavity among the plurality of communicated cavities; and an electric field A plurality of semi-coaxial resonators coupled together by coupling, a plurality of coupling portions coupling the semi-coaxial resonators at both ends by magnetic field coupling via a pre-selected semi-coaxial resonator, and Since the coupling part is arranged in each of the plurality of second coupling windows, increase in insertion loss and increase in the size of the device are suppressed, and the attenuation characteristics on the high band side and low band side of the pass band are improved with a simple configuration. it can.

  In the high-frequency filter of the present invention, at least one of the plurality of coupling portions has a part of the magnetic flux in the cavity of one semi-coaxial resonator coupled by magnetic field coupling and the magnetic flux in the other cavity. Construct a closed circuit that links in the same direction, and the remaining coupling part reverses the part of the magnetic flux in the cavity of one semi-coaxial resonator coupled by magnetic field coupling and the magnetic flux in the other cavity. Since the closed circuit to be linked is configured, a transmission zero point (attenuation pole) can be secured on the high band side and low band side of the pass band by using a coupling unit having a simple configuration.

Since the high-frequency filter of this embodiment is formed by adjoining the cavities of the semi-coaxial resonators at both ends and the cavities of the pre-selected semi-coaxial resonators, a simple configuration while suppressing an increase in the size of the device Thus, the attenuation characteristics on the high band side and low band side of the pass band can be improved.
(Second Embodiment)
The configuration of the frequency filter 200 of the present embodiment will be described with reference to FIGS.

  The high-frequency filter 200 according to the present embodiment includes first to fifth dielectric resonators 211 to 215, and the first to fifth dielectric resonators 211 to 215 are coupled in series by electric field coupling or magnetic field coupling. The first dielectric resonator 211, the third dielectric resonator 213, the third dielectric resonator 213, and the fifth dielectric resonator 215 are coupled by magnetic field coupling.

  The high-frequency filter 200 of the present embodiment includes a conductive casing 202, an input terminal 3, an output terminal 4, a plurality of dielectrics 216 to 220, a frequency adjusting unit, a first coupling degree adjusting unit, Two coupling degree adjusting means are provided.

  The conductive casing 202 includes a container portion 202a and a lid portion 202b. The container portion 202a includes a plurality of cavities, a plurality of first coupling windows 255 to 258, and a plurality of second coupling windows 259 and 260. Is formed.

  The plurality of cavities formed in the container portion 202a correspond to the cavities of the first to fifth dielectric resonators 211 to 215, respectively.

  The cavity of the first dielectric resonator 211 and the cavity of the second dielectric resonator 212 so that the first dielectric resonator 211 and the second dielectric resonator 212 are coupled by electric field coupling or magnetic field coupling. Are communicated by the first coupling window 255. Similarly, the cavity of the second dielectric resonator 212 and the third dielectric resonator are coupled so that the second dielectric resonator 212 and the third dielectric resonator 213 are coupled by electric field coupling or magnetic field coupling. The 213 cavities are communicated by a first coupling window 256. Furthermore, the cavity of the third dielectric resonator 213 and the fourth dielectric resonator 214 are coupled so that the third dielectric resonator 213 and the fourth dielectric resonator 214 are coupled by electric field coupling or magnetic field coupling. Are connected by a first coupling window 257. Further, the cavity of the fourth dielectric resonator 214 and the fifth dielectric resonator 215 are connected so that the fourth dielectric resonator 214 and the fifth dielectric resonator 215 are coupled by electric field coupling or magnetic field coupling. Are connected by a first coupling window 258.

  In addition, the cavity of the first dielectric resonator 211 and the cavity of the third dielectric resonator 213 are communicated by the second coupling window 259, and the cavity of the third dielectric resonator 213 and the fifth dielectric The cavity of the resonator 215 is communicated by the second coupling window 260.

  The dielectric 216 is supported by the support member and is disposed in the cavity of the first dielectric resonator 211. Similarly, the dielectric 217 is supported by the support member and disposed in the cavity of the second dielectric resonator 212, and the dielectric 218 is supported by the support member and the cavity of the third dielectric resonator 213. The dielectric 219 is supported by the support member and is disposed in the cavity of the fourth dielectric resonator 214, and the dielectric 220 is supported by the support member and the fifth dielectric resonator 215. Is placed in the cavity.

  Further, when the cavities of the first to fifth dielectric resonators 211 to 215 are arranged in a staggered manner, the cavity of the first dielectric resonator 211, the cavity of the third dielectric resonator 213, and the third dielectric The cavity of the body resonator 213 and the cavity of the fifth dielectric resonator 215 are adjacent to each other, and the first dielectric resonator 211, the third dielectric resonator 213, the third dielectric resonator 213, and the fifth This dielectric resonator 215 is preferably coupled by magnetic field coupling.

  The frequency adjusting means of the first dielectric resonator 211 includes a frequency adjusting unit 241a that can adjust the resonance frequency of the first dielectric resonator 211, and a fixing unit (not shown) that fixes the frequency adjusting unit 241a. Have. Similarly, the frequency adjusting unit of the second dielectric resonator 212 fixes the frequency adjusting unit 242a that can adjust the resonance frequency of the second dielectric resonator 212 and the frequency adjusting unit 242a (not shown). The frequency adjusting means of the third dielectric resonator 213 includes a fixing unit, and a frequency adjusting unit 243a capable of adjusting the resonance frequency of the third dielectric resonator 213 and the frequency adjusting unit 243a are fixed. A frequency adjusting means of the fourth dielectric resonator 214, a frequency adjusting unit 244a capable of adjusting the resonance frequency of the fourth dielectric resonator 214, and the frequency adjusting unit. A frequency adjusting means for adjusting the resonance frequency of the fifth dielectric resonator 215, and a frequency adjusting means for adjusting the resonance frequency of the fifth dielectric resonator 215. This Fixing the frequency adjuster 245a (not shown) and a fixing portion.

  The frequency adjusting portions 241a to 245a are configured by rod-like members formed with male screws, screwed into the plurality of mounting holes of the lid portion 202b, and partially projecting into the cavity.

  The length of the portion where the frequency adjustment units 241a to 245a protrude into the cavity is defined as “insertion depth”, and the resonance frequencies of the first to fifth dielectric resonators 211 to 215 are the frequency adjustment units 241a to 245a. It is set by adjusting the insertion depth.

  On the other hand, the fixing unit (not shown) maintains the resonance frequencies of the first to fifth dielectric resonators 211 to 215 constant by fixing the frequency adjustment units 241a to 245a. Each fixing part may be constituted by a nut or the like.

  The first degree-of-coupling adjusting means provided between the first dielectric resonator 211 and the second dielectric resonator 212 includes the first dielectric resonator 211 and the second dielectric resonator 212. A coupling degree adjusting unit 246a capable of adjusting the coupling degree of electric field coupling or magnetic field coupling, a holding unit (insertion rod) 246b that holds the coupling degree adjusting unit 246a, and the holding unit 246b are fixed to the lid unit 202b (illustrated). Not) It consists of a fixed part. Similarly, the first coupling degree adjusting means provided between the second dielectric resonator 212 and the third dielectric resonator 213 includes the second dielectric resonator 212 and the third dielectric resonance. A coupling degree adjusting unit 247a capable of adjusting the coupling degree of electric field coupling or magnetic field coupling of the device 213, a holding unit (insertion rod) 247b holding the coupling level adjusting unit 247a, and fixing the holding unit 247b to the lid unit 202b. And a first coupling degree adjusting means provided between the third dielectric resonator 213 and the fourth dielectric resonator 214 is configured by a third dielectric resonance. A coupling degree adjusting unit 248a capable of adjusting the coupling degree of electric field coupling or magnetic field coupling between the resonator 213 and the fourth dielectric resonator 214, a holding unit (insertion rod) 248b for holding the coupling degree adjusting unit 248a, The holding portion 248b is fixed to the lid portion 202b (see FIG. And a first coupling degree adjusting means provided between the fourth dielectric resonator 114 and the fifth dielectric resonator 115 is configured with the fourth dielectric resonator 214 and the fourth dielectric resonator 214. Coupling degree adjusting unit 249a capable of adjusting the coupling degree of electric field coupling or magnetic field coupling of fifth dielectric resonator 215, holding unit (insertion rod) 249b holding this coupling degree adjusting unit 249a, and holding unit 249b It is comprised with the fixing | fixed part (not shown) which fixes to the cover part 202b.

  The holding portion 246b is screwed into the mounting hole of the lid portion 202b, and the coupling portion 246a communicates the cavity of the first dielectric resonator 211 and the cavity of the second dielectric resonator 212. The coupling window 255 is partially blocked. Similarly, the holding portion 247b is screwed into the attachment hole of the lid portion 202b, and the coupling portion 247a communicates the cavity of the second dielectric resonator 212 and the cavity of the third dielectric resonator 213. The first coupling window 256 is partially blocked. The holding portion 248b is screwed into the attachment hole of the lid portion 202b, and the coupling portion 249a communicates the cavity of the third dielectric resonator 213 and the cavity of the fourth dielectric resonator 214. One coupling window 257 is partially blocked. The holding portion 249b is screwed into the mounting hole of the lid portion 202b, and the coupling portion 248a communicates the cavity of the fourth dielectric resonator 214 and the cavity of the fifth dielectric resonator 215. One coupling window 258 is partially blocked.

  The second coupling degree adjusting means provided between the first dielectric resonator 211 and the third dielectric resonator 213 includes the first dielectric resonator 211 and the third dielectric resonator 213. A coupling portion 251a for magnetic field coupling, a holding portion 251b that is electrically connected to the coupling portion 251a and holds the coupling portion 251a, and a fixing portion (not shown) that fixes the holding portion 251b to the container portion 202a. It is configured. In the coupling portion 251a, a part of the magnetic flux in the cavity of the first dielectric resonator 211 and a part of the magnetic flux in the cavity of the third dielectric resonator 213 are linked in the same direction.

  On the other hand, the second coupling degree adjusting means provided between the third dielectric resonator 213 and the fifth dielectric resonator 215 includes the third dielectric resonator 213 and the fifth dielectric resonator. A coupling portion 252a that magnetically couples 215, a holding portion 252b that is electrically connected to the coupling portion 252a and holds the coupling portion 252a, and a fixing portion (not shown) that fixes the holding portion 252b to the container portion 202a. It consists of and. In the coupling portion 252a, a part of the magnetic flux in the cavity of the third dielectric resonator 213 and a part of the magnetic flux in the cavity of the fifth dielectric resonator 215 are linked in the opposite direction.

  The holding part 251b has a rotation axis parallel to the central axis of the cavity of the first dielectric resonator 211 and the central axis of the cavity of the third dielectric resonator 213, and rotates integrally with the coupling part 251a. The degree of magnetic field coupling between the first dielectric resonator 211 and the third dielectric resonator 213 is set by rotating the holding unit 251b and adjusting the direction of the coupling unit 251a. The Similarly, the holding part 252b has a rotation axis parallel to the central axis of the cavity of the third dielectric resonator 213 and the central axis of the cavity of the fifth dielectric resonator 115, and is integrated with the coupling part 252a. The degree of magnetic field coupling between the third dielectric resonator 213 and the fifth dielectric resonator 215 can be adjusted by rotating the holding portion 252b and adjusting the direction of the coupling portion 252a. Is set by

  The coupling portion 251a has a loop shape so that a part of the magnetic flux in the cavity of the first dielectric resonator 211 and a part of the magnetic flux in the cavity of the third dielectric resonator 213 are linked in the same direction. It is constituted by a conductor. On the other hand, the coupling portion 252a is configured so that a part of the magnetic flux in the cavity of the third dielectric resonator 213 and a part of the magnetic flux in the cavity of the fifth dielectric resonator 215 are linked in the opposite direction. It is comprised by the character-shaped conductor.

  In the case of the semi-coaxial resonator according to the first embodiment, the electric field and the magnetic field density are different at the upper and lower positions. Therefore, the first coupling window is provided at the upper portion to achieve electric field coupling. However, in the case of the dielectric resonator according to the present embodiment, the density of the electric field and the magnetic field is uniform at the upper and lower positions. Therefore, even if the position of the coupling window is changed up and down, either the electric field or the magnetic field is coupled. Must not. Therefore, in the case where a plurality of dielectric resonators are connected by the first coupling window, they are coupled by both an electric field and a magnetic field, but there is no problem in characteristics. On the other hand, in the second coupling window, coupling portions 251a and 252a having a loop structure as shown in FIGS. 7 and 8 are used so as to achieve magnetic field coupling.

  The coupling portion 251a is disposed horizontally and is rotatably held by the holding portion 251b at the center of this member. The figure-shaped coupling part 252a is also arranged horizontally like the coupling part 251a, and is rotatably held by the holding part 252b so that the intersecting portions do not come into contact with each other. The coupling portions 251a and 252a are grounded to the housing by the holding portions 251b and 252b.

  Similar to the high frequency filter 100 of the first embodiment, when the coupling degree of the magnetic field coupling is appropriately adjusted, the high frequency filter 200 of the present embodiment has frequency characteristics as shown in FIG.

  As described above, the high-frequency filter according to the present embodiment includes the conductive housing in which a plurality of cavities respectively corresponding to a plurality of dielectric resonators are formed, and the plurality of dielectric resonators by electric field coupling or magnetic field coupling. A plurality of first coupling windows for communicating a plurality of cavities so as to be connected in a row, and a plurality of second coupling windows for communicating a cavity at both ends and a preselected cavity among the plurality of cavities communicated And a plurality of coupling portions for coupling the dielectric resonators at both ends by magnetic field coupling via a preselected dielectric resonator among the plurality of dielectric resonators coupled in series by electric field coupling or magnetic field coupling And a plurality of coupling portions are respectively disposed in the plurality of second coupling windows, so that an increase in insertion loss and an increase in the size of the device are suppressed, and the high band side and low band of the pass band with a simple configuration. The side attenuation characteristics can be improved.

  In the high-frequency filter of the present invention, at least one of the plurality of coupling portions includes a part of the magnetic flux in the cavity of one dielectric resonator coupled by magnetic field coupling and the magnetic flux in the other cavity. Construct a closed circuit that links in the same direction, and the remaining coupling part reverses the part of the magnetic flux in the cavity of one dielectric resonator and the magnetic flux in the other cavity that are coupled by magnetic field coupling. Since the closed circuit to be linked is configured, it is possible to improve the attenuation characteristics on the high band side and the low band side of the pass band by using a coupling unit having a simple configuration.

  The high-frequency filter of the present embodiment has a simple configuration while suppressing the enlargement of the device because the cavity of the dielectric resonator at both ends and the cavity of the dielectric resonator selected in advance are formed adjacent to each other. Thus, the attenuation characteristics on the high band side and low band side of the pass band can be improved.

  As described above, the high-frequency filter according to the present invention has a simple configuration on the high-frequency side and the low-frequency side of the passband while suppressing an increase in insertion loss and an increase in the size of the device as compared with the conventional high-frequency filter. It has an effect that the attenuation characteristic can be improved, and is useful as a high frequency filter for removing signals other than a specific band.

It is an external appearance perspective view of the high frequency filter concerning a 1st embodiment of the present invention. It is a top view of the container part of the state which removed the cover part of the high frequency filter which concerns on the 1st Embodiment of this invention. It is AA sectional drawing of the high frequency filter of FIG. It is BB sectional drawing of the high frequency filter of FIG. It is a frequency characteristic figure of the high frequency filter concerning a 1st embodiment of the present invention. In the high frequency filter of the 1st Embodiment of this invention, it is AA sectional drawing of the high frequency filter of the structure which can adjust 2nd coupling degree adjustment means from the cover part side. It is a top view of the container part of the state which removed the cover part of the high frequency filter which concerns on the 2nd Embodiment of this invention. It is AA sectional drawing of the high frequency filter of FIG. It is BB sectional drawing of the high frequency filter of FIG. It is a frequency characteristic figure of the high frequency filter concerning a 2nd embodiment of the present invention. It is a longitudinal cross-sectional view of the conventional high frequency filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 High frequency filter 102 Conductive housing 102a Container part 102b Cover part 3 Input terminal 4 Output terminal 111 thru | or 115 Semi-coaxial resonator 116 thru | or 120 Internal conductor 141 thru | or 145 Frequency adjustment member (frequency adjustment means)
146 thru | or 149 coupling | bond part (1st coupling degree adjustment means)
151a, 152a coupling part (second coupling degree adjusting means)
151b, 152b Holding unit 155 to 158 First coupling window 159, 160 Second coupling window 200 High frequency filter 202 Conductive housing 202a Container unit 202b Lid 211 to 215 Dielectric resonator 216 to 220 Dielectric 241 to 245 Frequency Adjustment member (frequency adjustment means)
246 thru | or 249 coupling | bond part (1st coupling degree adjustment means)
251a, 252a coupling part (second coupling degree adjusting means)
251b, 252b Holding portion 255 to 258 First coupling window 259, 260 Second coupling window

Claims (7)

A plurality of resonators partially configured, and a conductive housing in which a plurality of cavities respectively corresponding to the plurality of resonators are formed;
A plurality of first coupling windows communicating the plurality of cavities such that the plurality of resonators are coupled in series by electric field coupling or magnetic field coupling;
Among the plurality of cavities communicated, a plurality of second coupling windows that communicate cavities at both ends and a preselected cavity;
Among a plurality of resonators connected in series by the electric field coupling or magnetic field coupling, a plurality of coupling portions that couple the resonators at both ends by magnetic field coupling via the preselected resonator,
The high-frequency filter, wherein the plurality of coupling portions are respectively disposed in the plurality of second coupling windows. The high frequency filter according to claim 1, wherein the plurality of resonators are respectively configured by a plurality of semi-coaxial resonators. The high frequency filter according to claim 1, wherein each of the plurality of resonators includes a plurality of dielectric resonators. Among the plurality of coupling portions, at least one coupling portion is a closed structure that links a part of the magnetic flux in the cavity of one resonator coupled by the magnetic field coupling and the magnetic flux in the other cavity in the same direction. The remaining coupling part constitutes a closed circuit that links a part of the magnetic flux in the cavity of one resonator coupled by the magnetic field coupling and the magnetic flux in the other cavity in the opposite direction. The high frequency filter according to any one of claims 1 to 3, wherein the high frequency filter is provided. The plurality of holding portions electrically connected to each of the plurality of coupling portions, and the conductive casing holds each of the plurality of holding portions rotatably. 5. The high frequency filter according to any one of 4 to 4. The plurality of holding portions electrically connected to each of the plurality of coupling portions, and the conductive casing holds the plurality of holding portions so as to be movable in the axial direction. The high frequency filter according to claim 4. The cavity corresponding to the resonators at both ends and the cavity corresponding to the preselected resonator are formed adjacent to the conductive housing, according to any one of claims 1 to 6. The high frequency filter described in 1.

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