JP2016225964A - Resonator, bandpass filter and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact resonator excellent in electrical characteristics, and a bandpass filter and a communication device using the same.SOLUTION: A resonator includes a dielectric substrate 10 having a first principal surface 11, a second principal surface 12, and a side face 13, a dual mode resonator 30 constituted of a first conductor 21 provided on the first principal surface 11 of the dielectric substrate, and having first and second orthogonal resonance modes not degenerated, a shield conductor 23 in contact with the second principal surface 12 and side face 13, and surrounding the dielectric substrate 10 while spaced apart from the first principal surface 11, thus forming a resonance cavity 41, and a second conductor 22 provided on the first principal surface 11 of the dielectric substrate 10 so as to surround the first conductor 21 while spaced apart therefrom, and having the circumference connected with shield conductor 23. The resonator resonates in three modes, i.e., a third mode TMoccurring in the resonance cavity 41, the first mode and second mode.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a small resonator having excellent electrical characteristics, and a bandpass filter and a communication device using the resonator.

  As a small-sized resonator having excellent electrical characteristics, a dual-mode resonator that resonates in two non-degenerate resonance modes orthogonal to each other is known (see, for example, Patent Document 1). In such a dual mode resonator, one flat conductor resonates in two resonance modes, so that a small resonator having excellent electrical characteristics can be realized.

Japanese Patent No. 3165445

  However, since the conventional resonator proposed in Patent Document 1 has only two resonance modes, it is necessary to prepare a plurality of resonators and couple them together when manufacturing a broadband filter. There was a problem that it would increase in size.

  The present invention has been devised in view of such problems in the prior art, and an object thereof is a small resonator having excellent electrical characteristics, and a bandpass filter and a communication device using the resonator. , To provide.

The resonator according to the present invention includes a first main surface, a second main surface opposite to the first main surface, and one or more side surfaces connecting the first main surface and the second main surface. A dual-mode resonance comprising a dielectric substrate having a first resonance mode and a second resonance mode which are composed of a dielectric substrate and a first conductor provided on the first main surface of the dielectric substrate and are not degenerate. And a shield conductor that is in contact with the second main surface and the side surface and that is spaced from the first main surface and surrounds the dielectric substrate to form a resonant cavity; and the first conductor that is spaced from the first main surface. And a second conductor having a peripheral edge connected to the shield conductor, and a TM ₀₁₀ mode generated inside the resonant cavity. A third resonance mode, and the first resonance mode, It resonates in three modes, the second resonance mode.

  The band-pass filter of the present invention includes a resonator, a first coupling electrode coupled to the first resonance mode and the second resonance mode, and a second coupling coupled to the first resonance mode and the second resonance mode. An electrode; a third coupling electrode coupled to the third resonance mode; a fourth coupling electrode coupled to the third resonance mode; a first terminal connected to the first coupling electrode and the third coupling electrode; A second terminal connected to the second coupling electrode and the fourth coupling electrode, and using the first resonance mode, the second resonance mode, and the third resonance mode. And forming a passband.

  A communication apparatus according to the present invention includes a communication circuit, an antenna, and the communication circuit and the bandpass filter connected to the antenna.

  According to the resonator of the present invention, a small resonator having excellent electrical characteristics can be obtained. According to the bandpass filter of the present invention, a small bandpass filter having excellent electrical characteristics can be obtained. According to the communication device of the present invention, a small and high-performance communication device can be obtained.

1 is a perspective view schematically showing a resonator according to a first embodiment of the present invention. It is the sectional view on the AA line of FIG. It is a perspective view which shows typically the resonator of 2nd Embodiment of this invention. It is a perspective view which shows typically the resonator of 3rd Embodiment of this invention. It is the BB sectional view taken on the line of FIG. It is a perspective view which shows typically the band pass filter of 4th Embodiment of this invention. It is CC sectional view taken on the line of FIG. It is the DD sectional view taken on the line of FIG. It is a top view which shows typically the band pass filter of 4th Embodiment of this invention. It is a perspective view which shows typically the band pass filter of 5th Embodiment of this invention. It is the EE sectional view taken on the line of FIG. It is the FF sectional view taken on the line of FIG. It is a top view which shows typically the band pass filter of 5th Embodiment of this invention. It is a block diagram which shows typically the communication apparatus of 6th Embodiment of this invention. It is a graph which shows the simulation result of the electrical property of the band pass filter of 4th Embodiment of this invention. It is a graph which shows the simulation result of the electrical property of the band pass filter of 5th Embodiment of this invention.

  Hereinafter, a resonator of the present invention and a bandpass filter and a communication device using the resonator will be described in detail with reference to the accompanying drawings. In the drawings, directions are indicated by an x-axis, a y-axis and a z-axis that are orthogonal to each other.

(First embodiment)
FIG. 1 is a perspective view schematically showing a resonator according to a first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. FIG. 1 shows a state where the shield conductor 23 is seen through. As shown in FIGS. 1 and 2, the resonator of the present embodiment includes a dielectric substrate 10, a dual mode resonator 30, a second conductor 22, and a shield conductor 23.

The dielectric substrate 10 has a square plate shape, and includes a first main surface 11 located on the + z direction side, a second main surface 12 located on the −z direction side, and four side surfaces 13. have. As a material of the dielectric substrate 10, a known dielectric material such as dielectric ceramics can be used, and in some cases, a resin such as an epoxy resin can be used. However, since it is desirable that the dielectric constant is high in order to reduce the size, for example, a dielectric ceramic material containing BaTiO ₃ , Pb ₄ Fe ₂ Nb ₂ O ₁₂ , TiO ₂ or the like can be preferably used. The planar shape of the dielectric substrate 10 (the shape when viewed in plan from the thickness direction (z-axis direction) of the dielectric substrate 10) is another shape such as another polygonal shape, a circular shape, or an elliptical shape. It does not matter. The dimensions of the dielectric substrate 10 are appropriately set according to desired electrical characteristics.

The dual mode resonator 30 includes a first conductor 21 disposed in the center of the first main surface 11 of the dielectric substrate 10, and resonates in the first resonance mode and the second resonance mode. The first resonance mode and the second resonance mode are orthogonal to each other and are not degenerated. For example, the first resonance mode is a mode having an electric field in the x-axis direction, and the second resonance mode is a mode having an electric field in the y-axis direction. The first conductor 21 has a disk-like shape, and includes a minute protrusion 21a protruding in the −x direction and a minute protrusion 21b protruding in the + x direction. The degeneration of the first resonance mode and the second resonance mode is solved by the protrusion 21a and the protrusion 21b. The shape dimensions of the protrusion 21a and the protrusion 21b are appropriately set according to how much the resonance frequency of the first resonance mode and the resonance frequency of the second resonance mode are different. The degeneration may be solved by forming a notch instead of the protrusion, and the degeneration may be solved by making the dimension of the first conductor 21 in the x-axis direction different from the dimension in the y-axis direction. You may solve the degeneracy by the method. The planar shape of the first conductor 21 is not limited to a circular shape or an elliptical shape, and may be other shapes such as a square shape or a rectangular shape. The dimension of the 1st conductor 21 is suitably set according to the resonant frequency of a 1st resonance mode and a 2nd resonance mode.

  The shield conductor 23 has a rectangular parallelepiped box shape, and forms a resonance cavity 41 surrounded by the shield conductor 23. The shield conductor 23 surrounds the dielectric substrate 10 and accommodates the dielectric substrate 10 in the resonance cavity 41. The shield conductor 23 is in contact with the second main surface 12 and the four side surfaces 13 of the dielectric substrate 10, and is spaced from the first main surface 11. That is, there is a space between the first main surface 11 of the dielectric substrate 10 and the inner surface of the shield conductor 23 facing (opposing) the first main surface 11 of the dielectric substrate 10. The shield conductor 23 is also spaced from the first conductor 21 and the second conductor 22. The space between the first main surface 11 of the dielectric substrate 10 and the shield conductor 23 only needs to have a smaller dielectric constant than the material constituting the dielectric substrate 10, and may be filled with a gas or liquid such as air. It may be a vacuum. The shield conductor 23 is connected to a reference potential (referred to as a ground potential or an earth potential). Note that the shape of the shield conductor 23 is not limited to a rectangular parallelepiped shape, and may be another shape such as a columnar shape or a spherical shape.

The second conductor 22 has a thin plate shape, and has a frame-like planar shape in which the outer edge and the inner edge have a square shape (when viewed in plan from the thickness direction (z-axis direction) of the second conductor 22). Shape). The second conductor 22 is provided on the peripheral edge portion of the first main surface 11 of the dielectric substrate 10 and is provided so as to surround the first conductor 21 with a gap therebetween. The outer edge of the second conductor 22 is connected to the shield conductor 23. Such a second conductor 22 can confine the TM ₀₁₀ mode electric field to the inside of the dielectric substrate 10 to some extent, and can greatly reduce the resonance frequency of the TM ₀₁₀ mode. The planar shape of the shield conductor 23 is not limited to a rectangular frame shape (annular shape), and may be another shape such as an annular shape. Since the TM ₀₁₀ mode resonance frequency decreases as the area of the second conductor 22 increases, the dimension of the second conductor 22 is appropriately set according to the TM ₀₁₀ mode resonance frequency and the like.

  The first conductor 21, the second conductor 22, and the shield conductor 23 can be formed using various known conductive materials such as metals and non-metallic conductive materials. In order to improve the electrical characteristics of the resonator, it is desirable to use a material having high conductivity. For example, a conductive material mainly composed of an Ag alloy such as Ag, Ag—Pd, or Ag—Pt, a Cu-based material, It is desirable to use W-based, Mo-based, Pd-based conductive materials and the like. The second conductor 22 and the shield conductor 23 are electrically connected. The second conductor 22 and the shield conductor 23 may be connected via various known conductive joining members such as solder and conductive adhesive.

As described above, the resonator according to the present embodiment includes the dielectric substrate 10, the dual mode resonator 30, the second conductor 22, and the shield conductor 23. The dielectric substrate 10 includes a first main surface 11, a second main surface 12 opposite to the first main surface 11, and one or more side surfaces 13 connecting the first main surface 11 and the second main surface 12. ,have. The dual mode resonator 30 includes the dielectric substrate 10.
The first main surface 11 is provided with a first conductor 21, and has a first resonance mode and a second resonance mode that are not degenerated perpendicular to each other. The shield conductor 23 is in contact with the second main surface 12 and the side surface 13 and is spaced from the first main surface 11 so as to surround the dielectric substrate 10 and form a resonant cavity 41. The second conductor 22 is provided on the first main surface 11 of the dielectric substrate 10 so as to surround the first conductor 21 with a space therebetween, and the periphery thereof is connected to the shield conductor 23. The resonator of the present embodiment having such a configuration is a first resonance mode, a second resonance mode, and a TM ₀₁₀ mode generated inside the resonance cavity 41, despite having a small and simple structure. It resonates in three modes, the third resonance mode. That is, the resonator according to the present embodiment is a small resonator having excellent electrical characteristics.

  In addition, since the resonator according to the present embodiment includes the second conductor 22, the electric field in the third resonance mode can be confined within the dielectric substrate 10 to some extent. As a result, the resonance frequency of the third resonance mode can be lowered to approach the resonance frequencies of the first resonance mode and the second resonance mode. Therefore, a wide band-pass filter that forms a pass band using the three resonances of the first resonance mode, the second resonance mode, and the third resonance mode is configured by using one resonator of the present embodiment. be able to.

  Further, in the resonator according to the present embodiment, when viewed in plan from the + z direction side, the shape of the first conductor 21 is circular (a shape in which the minute protrusions 21a and the protrusions 21b are added in a circle), and the second The inner shape of the conductor 22 is rectangular. Thus, by changing the shape of the four corners of the second conductor 22, the area of the second conductor 22 can be changed without changing the distance between the portions where the first conductor 21 and the second conductor 22 are close to each other. Therefore, the resonance frequency of the third resonance mode can be changed without substantially affecting the first resonance mode and the second resonance mode. Thereby, an easily designed resonator can be obtained.

(Second Embodiment)
FIG. 3 is a perspective view schematically showing a resonator according to the second embodiment of the present invention. FIG. 3 shows a state where the shield conductor 23 is seen through. Moreover, in this embodiment, a different part from 1st Embodiment mentioned above is demonstrated, the same code | symbol is attached | subjected to the same component, and the overlapping description is abbreviate | omitted.

  In the resonator of this embodiment, as shown in FIG. 3, the planar shape of the first conductor 21 (the shape when viewed in plan from the thickness direction (z-axis direction) of the first conductor 21) is a square shape (protrusion). 21a and protrusions 21b are added to a square). Other configurations are the same as those of the resonator according to the first embodiment. The resonator according to the present embodiment having such a configuration also functions in the same manner as the resonator according to the first embodiment.

(Third embodiment)
FIG. 4 is a perspective view schematically showing a resonator according to the third embodiment of the invention. 5 is a cross-sectional view taken along line BB in FIG. FIG. 4 shows a state seen through the second shield conductor 23b. Further, in the present embodiment, parts different from those of the first embodiment described above will be described, and the same constituent elements will be denoted by the same reference numerals and redundant description will be omitted. In the resonator according to the present embodiment, the shield conductor 23 is constituted by the first shield conductor 23a and the second shield conductor 23b.

  The first shield conductor 23 a is provided on the second main surface 12 and the side surface 13 of the dielectric substrate 10 and covers the entire second main surface 12 and side surface 13 of the dielectric substrate 10. The second main surface 12 and the side surface 13 are in contact.

The second shield conductor 23b has a rectangular parallelepiped box shape, and the second shield conductor 23
A resonant cavity 41 that is a space surrounded by b is formed. The dielectric substrate 10, the first conductor 21, the second conductor 22, and the first shield conductor 23 a are arranged inside the second shield conductor 23 b and are accommodated in the resonance cavity 41. That is, the second shield conductor 23b surrounds the first conductor 21, the second conductor 22, and the first shield conductor 23a.

  Further, the surface (the surface in the −z direction) opposite to the second main surface 12 of the portion disposed on the second main surface 12 of the dielectric substrate 10 in the first shield conductor 23a is a conductive junction (not shown). It is connected to the second shield conductor 23b via a member. The first main surface 11, the first conductor 21, and the second conductor 22 of the dielectric substrate 10 are spaced from the second shield conductor 23b.

  As described above, in the resonator according to the present embodiment, the shield conductor 23 is connected to the first shield conductor 23a and the first shield conductor 23a provided so as to be in contact with the second main surface 12 and the side surface 13 of the dielectric substrate 10. The second shield conductor 23b is connected and surrounds the dielectric substrate 10 at a distance from the first main surface 11 and forms a resonant cavity 41. Therefore, for example, the first shield conductor 23a is configured by applying and hardening (sintering) a conductive paste on the second main surface 12 and the side surface 13 of the dielectric substrate 10, and the second shield is formed by a metal box. Since the conductor 23b can be configured, the resonator can be easily manufactured.

(Fourth embodiment)
FIG. 6 is a perspective view schematically showing a bandpass filter according to the fourth embodiment of the present invention, and shows a state where the shield conductor 23 is seen through. 7 is a cross-sectional view taken along the line CC of FIG. 8 is a cross-sectional view taken along the line DD of FIG. FIG. 9 is a plan view schematically showing the bandpass filter according to the fourth embodiment of the present invention, and shows a state viewed from the −z direction side.

  In the present embodiment, parts different from those of the first embodiment described above will be described, and the same constituent elements will be denoted by the same reference numerals and redundant description will be omitted. The bandpass filter of the present embodiment includes the resonator 1, the first coupling electrode 51, the second coupling electrode 52, the third coupling electrode 53, the fourth coupling electrode 54, the first terminal 61, the second Terminal 62. The resonator 1 has the same configuration as the resonator of the first embodiment described above.

  Each of the first coupling electrode 51 and the second coupling electrode 52 is composed of a flat conductor, and is provided on the first main surface 11 of the dielectric substrate 10. The first coupling electrode 51 is provided between the first conductor 21 and the second conductor 22 with a gap from both the first conductor 21 and the second conductor 22. The second coupling electrode 52 is provided between the first conductor 21 and the second conductor 22 and spaced from the first conductor 21, the second conductor 22, and the first coupling electrode 51. The distance between the first coupling electrode 51 and the first conductor 21 is equal to the distance between the second coupling electrode 52 and the first conductor 21.

  When the first coupling electrode 51 is viewed in a plan view from the z-axis direction, a straight line connecting the central portion of the first coupling electrode 51 and the central portion of the first conductor 21 represents the electric field of the first resonance mode and the second resonance mode. Is provided at a position that forms an angle of 45 ° with the electric field, and is coupled to the first resonance mode and the second resonance mode.

  When the second coupling electrode 52 is viewed in plan from the z-axis direction, the straight line connecting the center portion of the second coupling electrode 52 and the center portion of the first conductor 21 is the electric field of the first resonance mode and the second resonance mode. Is provided at a position that forms an angle of 45 ° with the electric field, and is coupled to the first resonance mode and the second resonance mode.

The planar shapes of the first coupling electrode 51 and the second coupling electrode 52 are not limited at all, and may be various shapes. The dimension of the 1st coupling electrode 51 and the 2nd coupling electrode 52, and the space | interval of the 1st coupling electrode 51 and the 2nd coupling electrode 52, and the 1st conductor 21 are set suitably according to the desired electrical property.

  Each of the first terminal 61 and the second terminal 62 is made of a flat conductor and is provided on the second main surface 12 of the dielectric substrate 10. The periphery of the first terminal 61 and the periphery of the second terminal 62 are areas where the shield conductor 23 does not exist, and the first terminal 61 and the second terminal 62 are arranged at a distance from the shield conductor 23. . A shield conductor 23 is also provided between the first terminal 61 and the second terminal 62. The first terminal 61 and the second terminal 62 are exposed to the outside, and electric signals are input and output through the first terminal 61 and the second terminal 62.

  The third coupling electrode 53 is composed of a columnar conductor extending from the first coupling electrode 51 in the −z direction, and is coupled to the third resonance mode. The third coupling electrode 53 is provided through the dielectric substrate 10, and has one end connected to the first coupling electrode 51 and the other end connected to the first terminal 61. Thereby, the third coupling electrode 53 also has a function of electrically connecting the first coupling electrode 51 and the first terminal 61.

  The fourth coupling electrode 54 is composed of a columnar conductor extending from the second coupling electrode 52 in the −z direction, and is coupled to the third resonance mode. The fourth coupling electrode 54 is provided through the dielectric substrate 10, and has one end connected to the second coupling electrode 52 and the other end connected to the second terminal 62. Thereby, the fourth coupling electrode 54 also has a function of electrically connecting the second coupling electrode 52 and the second terminal 62.

  The third coupling electrode 53 and the fourth coupling electrode 54 extend in the direction from the first major surface 11 to the second major surface 12 of the dielectric substrate 10 (including the direction inclined with respect to the z-axis direction). It only needs to have a portion, thereby coupling to the third resonance mode. The third coupling electrode 53 and the fourth coupling electrode 54 do not have to penetrate in the thickness direction of the dielectric substrate 10 and may be bent in the middle.

  For example, when an electric signal is input to the first terminal 61, the bandpass filter of the present embodiment having such a configuration receives the first resonance mode via the third coupling electrode 53 and the first coupling electrode 51. Three resonance modes of the second resonance mode and the third resonance mode are excited, and an electric signal is output from the second terminal 62 via the second coupling electrode 52 and the fourth coupling electrode 54. At this time, an electrical signal in a frequency range including the resonance frequency of the first resonance mode, the resonance frequency of the second resonance mode, and the resonance frequency of the third resonance mode selectively passes, and functions as a bandpass filter.

  As described above, the bandpass filter of the present embodiment includes the resonator 1 that is the resonator of the first embodiment described above, the first coupling electrode 51 coupled to the first resonance mode and the second resonance mode, and the first A second coupling electrode 52 coupled to the resonance mode and the second resonance mode, a third coupling electrode 53 coupled to the third resonance mode, a fourth coupling electrode 54 coupled to the third resonance mode, and a first coupling electrode 51. And a first terminal 61 connected to the third coupling electrode 53, and a second terminal 62 connected to the second coupling electrode 52 and the fourth coupling electrode 54, the first resonance mode, A pass band is formed using the second resonance mode and the third resonance mode. Therefore, although the band pass filter of this embodiment has a small and simple structure, the pass band can be widened and an electric signal in a wide frequency range can be passed. That is, the bandpass filter of this embodiment can realize a small bandpass filter with excellent electrical characteristics.

In addition, the first coupling electrode 51 is spaced from both the first conductor 21 and the second conductor 22 and between the first conductor 21 and the second conductor 22 on the first main surface 11 of the dielectric substrate 10. Is provided. The second coupling electrode 52 is spaced apart from the first conductor 21, the second conductor 22, and the first coupling electrode 51, and is formed between the first conductor 21 and the second conductor 22 on the first main surface 11 of the dielectric substrate 10. It is provided in between. The third coupling electrode 53 has one end connected to the first coupling electrode 51 and the other end connected to the first terminal 61, and is directed from the first main surface 11 of the dielectric substrate 10 to the second main surface 12. It has a stretched part. The fourth coupling electrode 54 has one end connected to the second coupling electrode 52 and the other end connected to the second terminal 62, and is directed from the first main surface 11 to the second main surface 12 of the dielectric substrate 10. It has a stretched part. With such a configuration, the first resonance mode, the second resonance mode, and the third resonance mode can be excited and used with a simple structure, so that a bandpass filter that is simple in structure and easy to design and manufacture is obtained. I can do it.

(Fifth embodiment)
FIG. 10 is a perspective view schematically showing a bandpass filter according to the fifth embodiment of the present invention, and shows a state where the second shield conductor 23b is seen through. 11 is a cross-sectional view taken along line EE in FIG. 12 is a cross-sectional view taken along line FF in FIG. FIG. 13 is a plan view schematically showing the bandpass filter according to the fourth embodiment of the present invention, and shows a state viewed from the −z direction side. In the present embodiment, parts different from the above-described fourth embodiment will be described, and the same components are denoted by the same reference numerals, and redundant description will be omitted.

  In the present embodiment, as shown in FIGS. 10 to 13, as a resonator, the third embodiment shown in FIGS. 4 and 5 is used instead of the resonator of the first embodiment shown in FIGS. 1 and 2. This resonator is used. That is, the shield conductor 23 is constituted by the first shield conductor 23a and the second shield conductor 23b.

  In the present embodiment, the second shield conductor 23 b has a through hole 24 and a through hole 25. The first terminal 61 is exposed to the outside through the through hole 24, and the second terminal 62 is exposed to the outside through the through hole 25. Further, the first coupling electrode 51 and the second coupling electrode 52 have a pentagonal planar shape instead of a square shape.

  The bandpass filter of this embodiment having such a configuration also functions in the same manner as the bandpass filter of the fourth embodiment described above. In addition, the bandpass filter of the present embodiment can be easily manufactured as compared with the bandpass filter of the fourth embodiment.

(Sixth embodiment)
FIG. 14 is a block diagram schematically showing a communication device according to the sixth embodiment of the present invention. The communication device of this embodiment includes a communication circuit 81, an antenna 82, and a bandpass filter 80 connected to the communication circuit 81 and the antenna 82. The band pass filter 80 is the band pass filter of the fourth embodiment described above. The communication circuit 81 and the antenna 82 are well-known conventional ones.

  The communication apparatus of this embodiment having such a configuration removes unnecessary electric signals using the bandpass filter of the fourth embodiment having a small size and excellent electrical characteristics. A device can be realized. In the present embodiment, the band-pass filter 80 is the band-pass filter of the fourth embodiment. However, the band-pass filter of the fifth embodiment may be used. I do not care.

(First embodiment)
First, the electrical characteristics of the resonator according to the first embodiment shown in FIGS. 1 and 2 were calculated by simulation. In this simulation, the resonance cavity 41 (the space inside the shield conductor 23) has a rectangular parallelepiped shape with a length in the x-axis direction and a y-axis direction of 10 mm and a length in the z-axis direction of 4 mm. The dielectric substrate 10 was a rectangular parallelepiped having a length in the x-axis direction and a y-axis direction of 10 mm and a length in the z-axis direction of 2 mm. The dielectric substrate 10 was disposed inside the resonant cavity 41 so that the second main surface 12 and the four side surfaces 13 were in contact with the shield conductor 23. That is, the dielectric substrate 10 occupies half of the resonance cavity 41 on the −z direction side, and air occupies half of the resonance cavity 41 on the + z direction side. The first conductor 21 has a shape in which a protrusion 21a and a protrusion 21b are added to a disk having a diameter of 4 mm and a thickness of 0.1 mm. The thickness of the second conductor 22 was 0.1 mm, and the inner edge of the second conductor 22 was in a square shape with a side length of 8.1 mm. The conductivity of the first conductor 21, the second conductor 22, and the shield conductor 23 is 4.2 × 10 ⁶ S / m, the relative dielectric constant of the dielectric substrate 10 is 40, and the dielectric loss tangent of the dielectric substrate 10 is 7 5 × 10 ⁻⁵ .

  The simulation results are shown in Table 1. The resonance frequency of the first resonance mode was 5.780 GHz, the resonance frequency of the second resonance mode was 5.781 GHz, and the resonance frequency of the third resonance mode was 5.797 GHz. The Q value in the first resonance mode was 1420, the Q value in the second resonance mode was 1419, and the Q value in the third resonance mode was 1196. From this simulation, it was confirmed that the resonator according to the first embodiment resonates in three resonance modes, ie, the first resonance mode, the second resonance mode, and the third resonance mode, while being small. It was also confirmed that the resonance frequency of the third resonance mode can be brought close to the resonance frequencies of the first resonance mode and the second resonance mode. In this simulation, the projection 21a and the projection 21b are very small because the difference between the resonance frequency of the first resonance mode and the resonance frequency of the second resonance mode is not intended to be large.

(Second embodiment)
Next, the electrical characteristics of the resonator according to the second embodiment shown in FIG. 3 were calculated by simulation. In this simulation, the planar shape of the first conductor 21 was a square shape with one side of 3.4 mm. In addition, the inner edge of the second conductor 22 has a shape in which a protrusion 21a and a protrusion 21b are added to a square having a side length of 8 mm. The other conditions were the same as in the first example.

  The simulation results are shown in Table 2. The resonance frequency of the first resonance mode was 5.720 GHz, the resonance frequency of the second resonance mode was 5.771 GHz, and the resonance frequency of the third resonance mode was 5.779 GHz. The Q value of the first resonance mode was 1179, the Q value of the second resonance mode was 1318, and the Q value of the third resonance mode was 1318. From this simulation, it was confirmed that the resonator according to the second embodiment also has substantially the same function as the resonator according to the first embodiment.

(Third embodiment)
Next, the electrical characteristics of the bandpass filter of the fourth embodiment shown in FIGS. 6 to 9 were calculated by simulation. In this simulation, the inner edge of the second conductor 22 has a square shape with a side length of 6.29 mm. The first coupling electrode 51 and the second coupling electrode 52 have a plate shape with a thickness of 0.1 mm and a square planar shape with one side of 1 mm. Further, the first coupling electrode 51 and the second coupling electrode 52 were arranged with a spacing of 1.78 mm from the first conductor 21. The third coupling electrode 53 and the fourth coupling electrode 54 have a cylindrical shape with a diameter of 0.3 mm and a length of 2 mm. The shapes of the protrusions 21a and 21b were also slightly changed. The other conditions were the same as in the first example.

  The result of the simulation is shown in the graph of FIG. In the graph, the horizontal axis represents frequency and the vertical axis represents attenuation. Further, the transmission characteristic is indicated by a solid line, and the reflection characteristic is indicated by a broken line. It can be confirmed from the transmission characteristics that good filter characteristics are obtained. In addition, it can be confirmed from the reflection characteristics that a pass band is formed using three resonances. In this embodiment, the design is made so that the interval between the resonance frequencies of the three resonance modes is not so wide, so the pass bandwidth is not so wide, but the design is to increase the interval between the resonance frequencies of the three resonance modes. Thus, it goes without saying that the pass bandwidth can be greatly widened.

(Fourth embodiment)
Next, the electrical characteristics of the bandpass filter of the fifth embodiment shown in FIGS. 10 to 13 were calculated by simulation. In this simulation, the shape of the space (resonance cavity 41) inside the second shield conductor 23b was a rectangular parallelepiped having a length of 11 mm in the x-axis direction and the y-axis direction and a length of 4 mm in the z-axis direction. The surface on the −z direction side of the first shield conductor 23 a disposed over the entire second main surface 12 and the side surface 13 of the dielectric substrate 10 is the inner surface on the −z direction side of the second shield conductor 23 b. The dielectric substrate 10 was disposed in the resonance cavity 41 so as to be in contact with the center. The inner edge of the second conductor 22 has a square shape with a side length of 8.373 mm. The first conductor 21 has a shape in which a protrusion 21a and a protrusion 21b are added to a disk having a diameter of 3.84 mm and a thickness of 0.1 mm. The protrusion 21a and the protrusion 21b have a width of 0.5 mm and a protrusion amount of 0.196 mm. The planar shape of the first coupling electrode 51 and the second coupling electrode 52 was a pentagon having a width of 1 mm and a length of 2.58 mm. Further, the first coupling electrode 51 and the second coupling electrode 52 were arranged with a spacing of 0.958 mm from the first conductor 21. The other conditions were the same as in the third example.

  The result of the simulation is shown in the graph of FIG. In the graph, the horizontal axis represents frequency and the vertical axis represents attenuation. Further, the transmission characteristic is indicated by a solid line, and the reflection characteristic is indicated by a broken line. It can be confirmed from the transmission characteristics that good filter characteristics are obtained. In addition, it can be confirmed from the reflection characteristics that a pass band is formed using three resonances. In the present embodiment, the design is made by widening the interval between the resonance frequencies of the three resonance modes, so that a very wide pass bandwidth can be realized. The effectiveness of the present invention was confirmed by the results of the first to fourth examples.

10: Dielectric substrate 11: First main surface 12: Second main surface 13: Side surface 21: First conductor 22: Second conductor 23: Shield conductor 23a: First shield conductor 23b: Second shield conductor 30: Dual mode Resonator 41: Resonant cavity 51: First coupling electrode 52: Second coupling electrode 53: Third coupling electrode 54: Fourth coupling electrode 61: First terminal 62: Second terminal 80: Band pass filter 81: Communication circuit 82 :antenna

Claims (6)

A dielectric substrate having a first main surface, a second main surface opposite to the first main surface, and one or more side surfaces connecting the first main surface and the second main surface;
A dual-mode resonator comprising a first conductor provided on the first main surface of the dielectric substrate and having a first resonance mode and a second resonance mode that are not degenerated perpendicular to each other;
A shield conductor which is in contact with the second main surface and the side surface and which is spaced from the first main surface to surround the dielectric substrate and form a resonant cavity;
A second conductor that is provided on the first main surface of the dielectric substrate so as to surround the first conductor with a space therebetween, and has a peripheral edge connected to the shield conductor;
Have
A resonator that resonates in three modes: a third resonance mode that is a TM ₀₁₀ mode generated inside the resonance cavity, the first resonance mode, and the second resonance mode.   2. The resonator according to claim 1, wherein when viewed in a plan view, the shape of the first conductor is circular, and the shape inside the second conductor is rectangular. The shield conductor is
A first shield conductor provided in contact with the second main surface and the side surface of the dielectric substrate;
A second shield conductor connected to the first shield conductor and surrounding the dielectric substrate at a distance from the first main surface to form the resonant cavity;
The resonator according to claim 1, wherein the resonator is provided. A resonator according to any one of claims 1 to 3,
A first coupling electrode coupled to the first resonance mode and the second resonance mode;
A second coupling electrode coupled to the first resonance mode and the second resonance mode;
A third coupling electrode coupled to the third resonance mode;
A fourth coupling electrode coupled to the third resonance mode;
A first terminal connected to the first coupling electrode and the third coupling electrode;
A second terminal connected to the second coupling electrode and the fourth coupling electrode;
Have
A band-pass filter that forms a passband using the first resonance mode, the second resonance mode, and the third resonance mode. The first coupling electrode is provided between the first conductor and the second conductor on the first main surface of the dielectric substrate, spaced from both the first conductor and the second conductor. The second coupling electrode is spaced apart from the first conductor, the second conductor, and the first coupling electrode, and the first conductor and the second conductor on the first main surface of the dielectric substrate. Provided between the conductor and
The third coupling electrode has one end connected to the first coupling electrode and the other end connected to the first terminal, and is directed from the first main surface of the dielectric substrate to the second main surface. Has a stretched part,
The fourth coupling electrode has one end connected to the second coupling electrode and the other end connected to the second terminal, and is directed from the first main surface of the dielectric substrate to the second main surface. The band-pass filter according to claim 4, wherein the band-pass filter has an extended portion.   A communication apparatus comprising: a communication circuit; an antenna; and the bandpass filter according to claim 4 connected to the communication circuit and the antenna.

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