JP2021061475A - Structure - Google Patents

Abstract

To make it less susceptible to the effects of noise that can enter a microstrip line from the outside in a structure that connects a post-wall waveguide and a coplanar line.SOLUTION: In a structure (1), a first conductor layer (11), a first dielectric layer (12), a second conductor layer (13), a second dielectric layer (14), and a third conductor layer (15) are laminated in this order. In the second dielectric layer (14), a first post wall (second post wall 141) constituting a post wall waveguide (140) is formed. A coplanar line (130) is formed in the second conductor layer (13), and the first conductor layer (11) and the third conductor layer (15) cover a strip conductor (131) of the coplanar line (130) in a plan view.SELECTED DRAWING: Figure 1

Description

The present invention relates to a structure that electromagnetically couples a post-wall waveguide and a coplanar line.

When filtering high frequencies contained in the quasi-millimeter wave band (for example, 28 GHz band) and the millimeter wave band (for example, 60 GHz band), a resonator coupling type configured by electromagnetically coupling a plurality of resonators. Filter device is widely used.

Patent Document 1 illustrates a resonator-coupled filter device configured by electromagnetically coupling a plurality of resonators. Each resonator includes a block made of a dielectric material and a wall made of a conductor material covering the surface of the block. The block surrounded by a wall functions as a resonance region of each resonator. Therefore, the plurality of electromagnetically coupled resonators is an aspect of the dielectric waveguide. Further, the filter device described in Patent Document 1 further includes a substrate made of a dielectric material and a coplanar line formed on one main surface of the substrate, and by mounting a plurality of resonators on the substrate. , A plurality of resonators and a coplanar line are electromagnetically coupled.

In Patent Document 1, the plurality of resonators are arranged linearly (one-dimensionally) in a single layer or three-dimensionally (three-dimensionally) in a plurality of layers.

Further, as another aspect of the dielectric waveguide, a post-wall waveguide is known. The post wall waveguide includes a dielectric substrate, a pair of conductor layers formed on a pair of main surfaces of the dielectric substrate, and a post wall formed inside the dielectric substrate. The post wall is formed by arranging a plurality of conductor posts that short-circuit a pair of conductor layers with each other by penetrating a dielectric substrate in a fence shape. The region of the dielectric substrate surrounded by the pair of conductor layers and the post wall functions as a waveguide region of the post wall waveguide.

JP-A-2019-36806

In the filter device described in Patent Document 1, the input / output pattern constituting the coplanar line and the ground pattern sandwiching the input / output pattern (replaced with the strip conductor in the present specification) (replaced with the ground conductor in the present specification). Is formed on one main surface of the substrate.

Since most of the coplanar line configured in this way is not electromagnetically shielded except for the tip connected to the resonator, the high frequency transmitted through the coplanar line is affected by noise. Cheap.

One aspect of the present invention has been made in view of the above-mentioned problems, and an object thereof is to allow the microstrip line to be penetrated from the outside in a structure that electromagnetically couples a post-wall waveguide and a microstrip line. It is to make it less susceptible to noise than before.

In order to solve the above problems, the structure according to the first aspect of the present invention includes at least a first conductor layer, a first dielectric layer, a second conductor layer, a second dielectric layer, and a third conductor layer. Is a structure laminated in this order, and the second dielectric layer is formed with a first post wall that constitutes a post wall waveguide together with the second conductor layer and the third conductor layer. The second conductor layer is formed with a coplanar line that terminates within the waveguide region of the post-wall waveguide when viewed in a plan view, and the first conductor layer and the third conductor layer are the coplanar. A configuration is adopted in which the strip conductor of the line is covered in a plan view.

According to the above configuration, the strip conductor is shielded from the outside of the structure by the first conductor layer and the third conductor layer. Therefore, the structure according to the first aspect is less susceptible to noise than in the past.

In the first aspect described above, the structure according to the second aspect of the present invention includes a terminal post wall in which the first dielectric layer overlaps a region including the end point of the coplanar line in a plan view. We have adopted a structure in which two post walls are formed.

In the conventional filter device, the conductor provided in the vicinity of the strip conductor of the coplanar line is only the ground conductor that sandwiches the strip conductor. Therefore, the high frequency transmitted through the coplanar line forms an electric field between the strip conductor and the ground conductor, and in the latter stage of the coplanar line, it is generally coupled to a resonator (which can be read as a post-wall waveguide in the present specification). Will be done.

On the other hand, when the structure includes the first conductor layer and the third conductor layer as in the first aspect described above, the first conductor layer and the third conductor layer and the third conductor layer are placed in the vicinity of the strip conductor in addition to the second conductor layer. A conductor layer will be provided. Therefore, the high frequency transmitted through the coplanar line forms an electric field between the strip conductor and the third conductor layer and also between the strip conductor and the first conductor layer. It is coupled to the waveguide region of the post-wall waveguide formed in the dielectric layer and also leaks into the inside of the first dielectric layer.

According to the above configuration, since the second post wall including the terminal post wall is formed inside the first dielectric layer, it is possible to prevent the high frequency transmitted through the coplanar line from leaking to the first dielectric layer. can do.

The structure according to the third aspect of the present invention is the structure according to the first aspect or the second aspect described above, wherein the first post wall is a plurality of resonators in which the post wall waveguide is electromagnetically coupled. The configuration is adopted so as to include a resonator group consisting of.

According to the above configuration, the post-wall waveguide functions as a resonator-coupled bandpass filter. Therefore, in the structure according to the third aspect, the high frequency coupled to the post-wall waveguide from the coplanar line is filtered, or the high frequency filtered by passing through the post-wall waveguide is applied to the coplanar. It can be connected to a line.

The structure according to the fourth aspect of the present invention is the third dielectric layer, the fourth conductor layer, ..., The nth conductor layer, the nth dielectric material in the first aspect or the second aspect described above. A third layer formed of the layer, the n + 1 conductor layer, and the i-th dielectric layer (i is an integer satisfying 3 ≦ i ≦ n), which is any of the third dielectric layer to the n-th dielectric layer. The i-post wall further includes an i-post wall that comprises a resonator together with an i-th conductor layer and an i + 1 conductor layer, and the first post wall has one or more post-wall waveguides. The resonators are arranged so as to include the resonators, and among the plurality of resonators provided in the second dielectric layer to the nth dielectric layer, the resonators adjacent to each other in the stacking direction overlap each other in a plan view. , Adopts the configuration.

According to the above configuration, the resonators adjacent to each other in the stacking direction can be easily and electromagnetically coupled to each other. Therefore, the structure according to the fourth aspect functions as a resonator-coupled bandpass filter. On top of that, according to the above configuration, the maximum length when the structure is viewed in a plan view can be shortened as compared with the case where each of the plurality of resonators is arranged in a single layer.

In the structure according to the fifth aspect of the present invention, in the fourth aspect described above, among the second conductor layer to the nth conductor layer, adjacent resonators in the stacking direction overlap each other in a plan view. A structure is adopted in which an opening is formed in the area.

According to the above configuration, the resonators adjacent to each other along the stacking direction can be easily and surely electromagnetically coupled to each other.

In the structure according to the sixth aspect of the present invention, in any one of the first to fifth aspects described above, the capacitance between the strip conductor and the ground conductor of the coplanar line is the strip. A configuration is adopted in which the capacitance between the conductor and the first conductor layer is larger than the capacitance between the strip conductor and the third conductor layer.

According to the above configuration, the strip conductor is not as a signal line of a microstrip line realized with at least one of the first conductor layer and the third conductor layer, but as a signal line of a coplanar line realized with a ground conductor. Can function as. Further, according to the above configuration, the distance between the second conductor layer and the first conductor layer and the distance between the second conductor layer and the third conductor layer can be set wide, so that the post-wall waveguide can be used. The transmission characteristics can be improved.

In the structure according to the seventh aspect of the present invention, in any one of the first to sixth aspects described above, one of the pair of voids between the strip conductor and the ground conductor of the coplanar line is At the end point of the coplanar line, it is bent in the first direction orthogonal to the extending direction of the coplanar line, and the other of the pair of voids is bent in the second direction opposite to the first direction at the end point. The configuration is adopted.

According to the above configuration, it is possible to improve the conversion efficiency from the waveguide mode in which the coplanar line is waveguideed to the waveguide mode in which the post-wall waveguide is guided.

In the structure according to the eighth aspect of the present invention, in the seventh aspect described above, the length of the portion extending in the first direction from the bent portion of one of the pair of voids is the pair. A configuration is adopted in which the length of the other side of the void is equal to the length of the portion extending in the second direction from the bent portion.

According to the above configuration, it is possible to further improve the conversion efficiency from the waveguide mode in which the coplanar line is waveguideed to the waveguide mode in which the post-wall waveguide is guided.

In the structure according to the eighth aspect of the present invention, in the seventh aspect or the eighth aspect described above, the vicinity of one tip of the pair of voids is bent from the first direction to the direction along the extending direction. The vicinity of the other tip of the pair of voids is bent in a direction along the stretching direction from the second direction.

According to the above configuration, the coplanar line and the post-wall waveguide can be coupled by changing the design of the length near the tip of one gap and the length near the tip of the other gap in the pair of gaps. The amount can be varied.

According to one aspect of the present invention, an object of the present invention is to make a structure that electromagnetically couples a post-wall waveguide and a coplanar line less susceptible to noise that may enter the coplanar line from the outside. be able to.

It is an exploded perspective view of the structure which concerns on 1st Embodiment of this invention. It is a plan view of the structure shown in FIG. 1, and is an enlarged plan view near the end point of a coplanar line. It is sectional drawing of the structure shown in FIG. It is an exploded perspective view which shows a part of the structure which concerns on 2nd Embodiment of this invention. It is an exploded perspective view which shows the remaining part of the structure which concerns on 2nd Embodiment of this invention. It is a graph which shows the reflection characteristic and the transmission characteristic in the structure shown in FIG. 4 and FIG.

[First Embodiment]
The structure 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is an exploded perspective view of the structure 1. FIG. 2 is a plan view of the structure 1 and is an enlarged plan view of the vicinity of the end point Pt of the coplanar line 130. FIG. 3 is a cross-sectional view of the structure 1 and is a cross-sectional view taken along the line AA'shown in FIG.

[Structure of structure 1]
As shown in FIG. 1, the structure 1 includes a first conductor layer 11, a first dielectric layer 12, a second conductor layer 13, a second dielectric layer 14, a third conductor layer 15, and a second conductor layer 1. It includes a 1-post wall 121 and a second post wall 141. Each of the first post wall 121 and the second post wall 141 is an aspect of the second post wall and the first post wall described in the claims, respectively. In the claims, the post wall formed in the second dielectric layer is referred to as the first post wall, and the post wall formed in the first dielectric layer is referred to as the second post wall in the defined order. It is called.

In the structure 1, each of the first conductor layer 11, the first dielectric layer 12, the second conductor layer 13, the second dielectric layer 14, and the third conductor layer 15 are laminated in this order.

The conductor constituting each of the first conductor layer 11, the second conductor layer 13, and the third conductor layer 15 is not limited, but is preferably a metal having high conductivity such as copper, aluminum, and an aluminum alloy. .. In the present embodiment, the first conductor layer 11, the second conductor layer 13, and the third conductor layer 15 are made of copper. Further, the thicknesses of the first conductor layer 11, the second conductor layer 13, and the third conductor layer 15 are not limited and can be appropriately determined.

The dielectric constituting each of the first dielectric layer 12 and the second dielectric layer 14 is not limited, but is preferably a dielectric having a small high frequency loss, such as quartz glass or a liquid crystal polymer. In the present embodiment, the first dielectric layer 12 and the second dielectric layer 14 are made of quartz glass. Further, the thicknesses of the first dielectric layer 12 and the second dielectric layer 14 are not limited and can be appropriately determined.

<Terminal area 120>
As shown in FIGS. 1 and 2, the first post wall 121 is a group of conductor posts composed of a plurality of conductor posts formed inside the first dielectric layer 12. The first post wall 121 is composed of a terminal post wall 1211, a first auxiliary post wall 1212, and a second auxiliary post wall 1213.

Each conductor post constituting the terminal post wall 1211, the first auxiliary post wall 1212, and the second auxiliary post wall 1213 of the first post wall 121 is predetermined when the first dielectric layer 12 is viewed in a plan view. It is arranged in a fence shape so that it has a vertical shape. In the present embodiment, the predetermined shape is a shape bordering the T-shape of the alphabet. The T-shape of the alphabet is composed of a first line segment and a second line segment, and has a shape in which one end of the second line segment is connected to the central portion of the first line segment.

Each conductor post of the first post wall 121 penetrates from one main surface of the first dielectric layer 12 to the other main surface. Therefore, the first conductor layer 11 and the second conductor layer 13 are short-circuited by the first post wall 121.

In the present embodiment, each conductor post of the first post wall 121 forms a plurality of through holes at predetermined positions of the first dielectric layer 12, and then a conductor film is formed on the inner wall of each of the through holes. Is obtained by forming (see FIG. 3). However, each conductor post of the first post wall 121 is not limited to the conductor film formed in this way, and may be composed of conductors filled in each of the through holes.

The distance between the conductor posts of the first post wall 121 adjacent to each other is relative to the waveguide mode having a frequency included in a predetermined band (for example, a 62.5 GHz band having a center frequency near 62.5 GHz). It can be appropriately determined within the range in which the first post wall 121 functions as a virtual conductor wall. Further, the diameter of each conductor post of the first post wall 121 can be appropriately determined.

The first post wall 121 functions as a virtual conductor wall. Of the first post wall 121, the terminal post wall 1211 and the second auxiliary post wall 1213 together with the first conductor layer 11 and the second conductor layer 13 surround the vicinity of the terminal point Pt of the coplanar line 130 when viewed in a plan view. It constitutes a terminal area 120.

Of the narrow walls realized by the first post wall 121, the terminal post wall 1211 is arranged linearly when the first dielectric layer 12 is viewed in a plan view. The end post wall 1211 is a narrow wall located orthogonal to the extension direction of the strip conductor 131 of the coplanar line 130, which will be described later, and is located deeper than the end point Pt of the coplanar line 130 when viewed along the extension direction. is there. In other words, the end post wall 1211 is arranged parallel to the T-shaped first line segment and on the opposite side of the first auxiliary post wall 1212 of the first line segment.

Of the narrow walls realized by the first post wall 121, the first auxiliary post wall 1212 is composed of two post walls arranged linearly when the first dielectric layer 12 is viewed in a plan view. .. Each of the two post walls of the first auxiliary post wall 1212 is arranged parallel to each other and sandwiching the strip conductor 131 of the coplanar line 130 described later when the first dielectric layer 12 is viewed in a plan view. ing. In other words, each of the two post walls of the first auxiliary post wall 1212 is arranged parallel to the T-shaped second line segment and on both sides of the second line segment.

Of the narrow walls realized by the first post wall 121, the second auxiliary post wall 1213 is composed of two post walls arranged linearly when the first dielectric layer 12 is viewed in a plan view. .. Each of the two post walls of the second auxiliary post wall 1213 is linear and sandwiches the first auxiliary post wall 1212 parallel to the terminal post wall 1211 when the first dielectric layer 12 is viewed in a plan view. Have been placed. Each of the two post walls of the second auxiliary post wall 1213 is orthogonal to the extending direction of the strip conductor 131 of the coplanar line 130, which will be described later, and when viewed along the extending direction, the end point of the coplanar line 130. It is a narrow wall located in front of Pt. In other words, the terminal post wall 1211 is arranged parallel to the T-shaped first line segment and on the side of the first auxiliary post wall 1212 of the first line segment.

The AA'line shown in FIG. 2 is a straight line passing through the center of each conductor post constituting the second auxiliary post wall 1213. In one aspect of the present invention, the second auxiliary post wall 1213 may be omitted.

<Post wall waveguide 140>
The second post wall 141 is a group of conductor posts composed of a plurality of conductor posts formed inside the second dielectric layer 14. Each conductor post of the second post wall 141 is arranged in a fence shape so as to have a predetermined shape when the second dielectric layer 14 is viewed in a plan view. In the present embodiment, the predetermined shape is based on a rectangular shape, and a portion corresponding to the strip conductor 131 of the coplanar line 130, which will be described later, is projected. Each conductor post of the second post wall 141 penetrates from one main surface of the second dielectric layer 14 to the other main surface. Therefore, the second conductor layer 13 and the third conductor layer 15 are short-circuited by the second post wall 141.

In the present embodiment, each conductor post of the second post wall 141 forms a plurality of through holes at predetermined positions of the second dielectric layer 14, similarly to each conductor post of the first post wall 121. Then, it is obtained by forming a conductor film on the inner wall of each of the through holes. However, each conductor post of the second post wall 141 is not limited to the conductor film formed in this way, and may be composed of conductors filled inside each of the through holes.

The second post wall 141 functions as a virtual conductor wall, and together with the second conductor layer 13 and the third conductor layer 15, constitutes the post wall waveguide 140. That is, the second post wall 141 constitutes a narrow wall of the post wall waveguide 140 and a partition wall for forming a coupling window described later. Of the narrow walls realized by the second post wall 141, the virtual conductor wall of the portion corresponding to the rectangular short side of the base is referred to as a short wall. The second conductor layer 13 and the third conductor layer 15 form a pair of wide walls of the post wall waveguide 140. Further, the second conductor layer 13 is a wide wall common to the terminal region 120 and the post wall waveguide 140.

The waveguide region of the post wall waveguide 140 is a region surrounded by the second post wall 141 when the third conductor layer 15 is viewed in a plan view.

The post-wall waveguide 140 includes a resonator group consisting of M resonators, and adjacent resonators are electromagnetically coupled to each other through a coupling window. M is not limited as long as it is an integer of 2 or more, but in the present embodiment, M = 5. FIG. 1 shows only the resonator 1401 which is the first stage resonator and the resonator 1402 which is the second stage resonator among the five resonators 1401 to 1405, and the third stage to 5 are shown. Resonators 1403 to 1405 in the stage are not shown. The post-wall waveguide 140 configured in this way is a bandpass filter having a single-layer structure, and functions as a resonator-coupled bandpass filter. Therefore, the structure 1 is suitable when it is desired to reduce the length in the stacking direction (that is, the thickness of the structure 1) as compared with the structure 2 described later in the second embodiment.

In the present embodiment, the pass band of the post-wall waveguide 140 is a 62.5 GHz band having a center frequency near 62.5 GHz.

<Coplanar line 130>
As shown in FIG. 1, the second conductor layer 13 is formed with a pair of voids 134 and 135. Each of the voids 134 and the void 135 can be said to be a groove from one main surface of the second conductor layer 13 to the other main surface.

Since the voids 134 and 135 are formed in the second conductor layer 13, a part of the second conductor layer 13 is divided into three regions. In the following, in the second conductor layer 13, the region sandwiched between the gap 134 and the gap 135 is referred to as a strip conductor 131, and each of the regions sandwiching the strip conductor 131 is referred to as a ground conductor 132 and a ground conductor 133, respectively. ..

The strip conductor 131, the ground conductor 132, and the ground conductor 133 configured in this way form the coplanar line 130. The coplanar line 130 is formed in a region sandwiched between the terminal region 120 and the post wall waveguide 140.

The coplanar line 130 functions as one input / output port provided in the resonator 1401 which is one end of the post wall waveguide 140. Although not shown in FIG. 1, the resonator 1405, which is the other end of the post-wall waveguide 140, is provided with a coplanar line having the same configuration as the coplanar line 130. This coplanar line functions as the other input / output port of the post wall waveguide 140.

<Effect of structure 1>
In the structure 1, the strip conductor 131 of the coplanar line 130 is covered with the first conductor layer 11 and the third conductor layer 15 when the second conductor layer 13 is viewed in a plan view.

According to this configuration, the strip conductor 131 is shielded from the outside of the structure 1 by the first conductor layer 11 and the third conductor layer 15. Therefore, the structure 1 is less susceptible to noise than in the past.

Further, as shown in FIG. 2, the coplanar line 130 is extended so as to cross each short wall of the post wall waveguide 140 when the third conductor layer 15 is viewed in a plan view. Hereinafter, the direction in which the strip conductor 131 is stretched is referred to as a stretching direction (see FIG. 2). Therefore, the end point Pt of the coplanar line 130 is located inside the waveguide region of the post-wall waveguide 140 in plan view. That is, the coplanar line 130 is terminated in a region sandwiched between the termination region 120 and the post wall waveguide 140.

According to this configuration, the electromagnetic wave transmitted by the coplanar line 130 can be input to the post wall waveguide 140. Alternatively, the electromagnetic wave transmitted through the post-wall waveguide 140 can be input to the coplanar line 130.

Since the structure 1 includes the first conductor layer 11 and the third conductor layer 15, in addition to the ground conductors 132 and 133 formed by using the second conductor layer 13, in the vicinity of the strip conductor 131, The first conductor layer 11 and the third conductor layer 15 are provided. Therefore, the high frequency transmitted through the coplanar line 130 forms an electric field between the strip conductor 131 and the third conductor layer 15 and also between the strip conductor and the first conductor layer, so that the latter stage of the coplanar line 130 In addition to being coupled to the waveguide region of the post-wall waveguide 140, it also leaks to the terminal region 120 formed inside the first dielectric layer 12.

As described above, the terminal post wall 1211 of the first post wall 121 forming the narrow wall of the terminal region 120 is orthogonal to the extending direction of the strip conductor 131 and is a coplanar line when viewed along the extending direction. It is a terminal post wall located behind the terminal point Pt of 130. Therefore, the structure 1 can prevent the high frequency transmitted through the coplanar line 130 from leaking to the first dielectric layer 22.

As shown in FIG. 1, the widths of the voids 134 and 135 (the lengths in the directions orthogonal to the stretching direction) are the thicknesses of the first dielectric layer 12 and the second dielectric layer 14, respectively. Is significantly below. Therefore, the capacitance generated between the strip conductor 131 and each of the ground conductors 132 and 133 includes the capacitance generated between the strip conductor 131 and the first conductor layer 11 and the strip conductor 131. It is larger than the capacitance generated between the third conductor layer 15 and the third conductor layer 15.

According to this configuration, the strip conductor 131 is realized together with the ground conductors 132, 133, not as a signal line of a microstrip line realized with at least one of the first conductor layer 11 and the third conductor layer 15. It can function as a signal line for a coplanar line. Further, according to this configuration, the distance between the second conductor layer 13 and the third conductor layer 15 (that is, the thickness of the second dielectric layer 14) can be set wide, so that the transmission of the post-wall waveguide 140 can be set. The characteristics can be improved.

The gap 134 is bent at the end point Pt in the first direction orthogonal to the stretching direction. The gap 135 is bent at the end point Pt in the second direction orthogonal to the stretching direction and in the second direction opposite to the first direction.

According to this configuration, it is possible to improve the conversion efficiency from the waveguide mode in which the coplanar line 130 is waveguideed to the waveguide mode in which the post-wall waveguide 140 is guided.

In addition, the length L1 of the portion of the gap 134 extending in the first direction from the bent portion Pt is the length of the portion of the void 135 extending in the second direction from the bent portion Pt. Is equal to L2. That is, each of the voids 134 and 135 is formed so as to be axisymmetric with a straight line parallel to the stretching direction and passing through the middle of each as an axis of symmetry.

According to this configuration, the conversion efficiency from the waveguide mode in which the coplanar line 130 is guided to the waveguide mode in which the post-wall waveguide 140 is guided can be further improved.

Further, the vicinity of the tip of the gap 134 is bent from the first direction in the direction along the stretching direction, and the vicinity of the tip of the gap 135 is bent in the direction along the stretching direction from the second direction.

According to the above configuration, the coupling amount between the coplanar line 130 and the post wall waveguide 140 is changed by changing the design of the length L3 near the tip of the gap 134 and the length L4 near the tip of the gap 135. be able to. In this embodiment, the length L3 and the length L4 are equal. However, in one aspect of the present invention, the length L3 and the length L4 may be different.

[Second Embodiment]
The structure 2 according to the second embodiment of the present invention will be described with reference to FIGS. 4 to 6. FIG. 4 is an exploded perspective view showing an input / output unit 2a which is a part of the structure 2. FIG. 5 is an exploded perspective view showing a filter portion 2b which is a remaining part of the structure 2. FIG. 6 is a graph showing reflection characteristics and transmission characteristics in the structure 2 shown in FIGS. 4 and 5.

[Structure of structure 2]
In the present embodiment, as shown in FIGS. 4 and 5, the structure 2 is divided into an input / output unit 2a and a filter unit 2b, and will be illustrated and described. However, in the actual structure 2, the input / output unit 2a and the filter unit 2b are joined in a laminated state. The third conductor layer 25 shown in each of FIGS. 4 and 5 is a single member, and is only shown in FIGS. 4 and 5 for convenience of explanation.

As shown in FIGS. 4 and 5, the structure 2 includes a first conductor layer 21, a first dielectric layer 22, a second conductor layer 23, a second dielectric layer 24, and a third conductor layer 25. , The third dielectric layer 26, the fourth conductor layer 27, the fourth dielectric layer 28, the fifth conductor layer 29, the first post walls 221a, 221b, and the second post walls 241a, 241b. A third post wall 261a, 261b and a fourth post wall 281 are provided.

In the structure 1 shown in FIG. 1, the post-wall waveguide 140 is a resonator group composed of five resonators 1401 to 1405 formed in the second dielectric layer and electromagnetically coupled. Includes. This resonator group functions as a bandpass filter. That is, the post-wall waveguide 140 of the structure 1 functions as a bandpass filter having a single-layer structure.

On the other hand, in the structure 2, the post-wall waveguide directly or indirectly coupled to the coplanar lines 230a and 230b is formed in the second dielectric layer 24, the third dielectric layer 26, and the fourth dielectric layer 28. It includes a resonator group composed of five resonators 240a, 260a, 280, 260b, 240b, which are electromagnetically coupled. This resonator group functions as a bandpass filter. That is, the post-wall waveguide of the structure 2 functions as a bandpass filter having a multi-layer structure. In this embodiment, these configurations will be described.

The pass band of the post-wall waveguide of the structure 2 is a 62.5 GHz band having a center frequency near 62.5 GHz.

Further, in the structure 2, each of the coplanar lines 230a and 230b adopts the same configuration except that the arranged directions are reversed by 180 °, and each of the terminal regions 220a and 220b has the same configuration. The same configuration is adopted except that the arranged orientation is reversed by 180 °, and each of the resonators 240a and 240b is reversed except that the arranged orientation is reversed by 180 °. The same configuration is adopted. Although these configurations are distinguished by adding "a" and "b" to the end of the reference numerals, they will be collectively described below.

<Terminal areas 220a, 220b>
Each of the terminal regions 220a and 220b is formed inside the first dielectric layer 22, and adopts the same configuration as the terminal region 120 of the structure 1.

That is, the first post wall 221a that functions as a narrow wall of the terminal region 220a is configured in the same manner as the first post wall 121, and includes the terminal post wall 2211, the first auxiliary post wall 2212, and the second auxiliary. It is composed of a post wall 2213. Further, each conductor post constituting the terminal post wall 2211 of the first post wall 221a, the first auxiliary post wall 2212, and the second auxiliary post wall 2213 has a fence shape having a T-shaped alphabet. Is located in.

The end post wall 2211 is a narrow wall that is orthogonal to the extension direction of the strip conductor 231a of the coplanar line 230a, which will be described later, and is located deeper than the end point of the coplanar line 230a when viewed along the extension direction. ..

The first auxiliary post wall 2212 is composed of two post walls arranged linearly when the first dielectric layer 22 is viewed in a plan view. Each of the two post walls of the first auxiliary post wall 2212 is arranged parallel to each other and sandwiching the strip conductor 231a of the coplanar line 230a, which will be described later, when the first dielectric layer 22 is viewed in a plan view. ing.

The second auxiliary post wall 2213 is composed of two post walls arranged linearly when the first dielectric layer 12 is viewed in a plan view. Each of the two post walls of the second auxiliary post wall 1213 is orthogonal to the extending direction of the strip conductor 131 of the coplanar line 130, which will be described later, and when viewed along the extending direction, the end point of the coplanar line 130. It is a narrow wall located in front of Pt.

Further, the first post wall 221b that functions as a narrow wall of the terminal region 220b is arranged in a state where the first post wall 121 is rotated by 180 °. In other words, the first post wall 221b is arranged in a state where the first post wall 221a is rotated by 180 °. Therefore, the stretching direction of the strip conductor 231a and the stretching direction of the strip conductor 231b are parallel but opposite to each other. Therefore, in the present embodiment, the detailed description of the terminal region 220b will be omitted.

<Resonators 240a, 240b>
Each of the second post walls 241a and 241b is a group of conductor posts formed inside the second dielectric layer 24 and composed of a plurality of conductor posts, similarly to the second post wall 141 of the structure 1. Each of the conductor posts of the second post walls 241a and 241b is arranged in a fence shape so as to have a predetermined shape when the second dielectric layer 24 is viewed in a plan view. In the present embodiment, the predetermined shape is based on a rectangular shape, and a portion corresponding to the strip conductors 231a and 231b of the coplanar lines 230a and 230b, which will be described later, is projected. The second post wall 241a and the second post wall 241b share a post wall at a boundary between the resonators 240a and 240b, which will be described later.

Each of the second post walls 241a and 241b functions as a virtual conductor wall like the second post wall 141, and constitutes the resonators 240a and 240b together with the second conductor layer 23 and the third conductor layer 25, respectively. To do.

Since each of the resonators 240a and 240b is separated by the shared portion of the second post wall 241a and 241b described above, they are not directly and electromagnetically coupled. When the coplanar line 230a described later is used as an input port, each of the resonators 240a and 240b is a first-stage resonator and a last-stage resonator among the five-stage resonators that function as bandpass filters. ..

<Resonators 260a, 260b>
Each of the third post walls 261a and 261b is formed inside the third dielectric layer 26, and is a group of conductor posts composed of a plurality of conductor posts, similarly to the second post wall 141 of the structure 1. Each of the conductor posts of the third post walls 261a and 261b is arranged in a fence shape so as to have a predetermined shape when the third dielectric layer 26 is viewed in a plan view. In this embodiment, the predetermined shape is rectangular. The third post wall 261a and the third post wall 261b share a post wall at a boundary between the resonators 260a and 260b, which will be described later.

Each of the third post walls 261a and 261b functions as a virtual conductor wall like the second post wall 141, and constitutes the resonators 260a and 260b together with the third conductor layer 25 and the fourth conductor layer 27, respectively. To do.

Each of the third post walls 261a and 261b is such that at least a part of each of the resonators 260a and 260b overlaps at least a part of the resonators 240a and 240b when the third dielectric layer 26 is viewed in a plan view. , Have been placed.

Since each of the resonators 260a and 260b is separated by the shared portion of the third post wall 261a and 261b described above, they are not directly and electromagnetically coupled. When the coplanar line 230a described later is used as an input port, each of the resonators 260a and 260b is a second-stage resonator and a fourth-stage resonator among the five-stage resonators that function as bandpass filters. Is.

<Resonator 280>
The fourth post wall 281 is a group of conductor posts formed inside the fourth dielectric layer 28 and composed of a plurality of conductor posts, similarly to the second post wall 141 of the structure 1. Each conductor post of the fourth post wall 281 is arranged in a fence shape so as to have a predetermined shape when the fourth dielectric layer 28 is viewed in a plan view. In this embodiment, the predetermined shape is rectangular.

The fourth post wall 281 functions as a virtual conductor wall like the second post wall 141, and constitutes the resonator 280 together with the fourth conductor layer 27 and the fifth conductor layer 29.

The fourth post wall 281 is such that at least a part of the resonator 280 overlaps at least a part of the resonator 260a when the fourth dielectric layer 28 is viewed in a plan view, and at least a part of the resonator 280. Are arranged so as to overlap at least a part of the resonator 260b.

When the coplanar line 230a described later is used as an input port, the resonator 280 is the third-stage resonator of the five-stage resonator that functions as a bandpass filter.

<Third conductor layer 25 and fourth conductor layer 27>
An opening 251a is formed in a region of the third conductor layer 25 in which the resonator 240a and the resonator 260a, which are adjacent to each other in the stacking direction, overlap each other in a plan view. Similarly, in the third conductor layer 25, an opening 251b is formed in a region where the resonator 240b and the resonator 260b, which are adjacent to each other in the stacking direction, overlap each other in a plan view.

An opening 271a is formed in a region of the fourth conductor layer 27 in which the resonator 260a and the resonator 280, which are adjacent to each other in the stacking direction, overlap each other in a plan view. Similarly, in the fourth conductor layer 27, an opening 271b is formed in a region where the resonator 260b and the resonator 280, which are adjacent to each other in the stacking direction, overlap each other in a plan view.

As described above, the openings 251a and 251b are formed in the third conductor layer 25, and the openings 271a and 271b are formed in the fourth conductor layer 27, so that the resonator 240a and the resonator 260a have openings 251a. The resonator 260a and the resonator 280 are electromagnetically coupled via the opening 271a, and the resonator 280 and the resonator 260b are electromagnetically coupled via the opening 271b. The resonator 260b and the resonator 240b are electromagnetically coupled to each other through the opening 251b. Therefore, the post-wall waveguide formed inside the second dielectric layer 24, the third dielectric layer 26, and the fourth dielectric layer 28 is a resonator coupling of a multilayer structure (three-layer structure in this embodiment). Acts as a type bandpass filter.

<Coplanar lines 230a, 230b>
Each of the coplanar lines 230a and 230b adopts the same configuration as the coplanar line 130 of the structure 1. That is, the second conductor layer 23 is formed with a pair of voids 234a and 235a and voids 234b and 235b.

By forming the voids 234a and 235a in the second conductor layer 23, a part of the second conductor layer 23 is divided into a strip conductor 231a and a ground conductor 232a and 233a sandwiching the strip conductor 231a. Further, by forming the voids 234b and 235b in the second conductor layer 23, a part of the second conductor layer 23 is divided into a strip conductor 231b and a ground conductor 232b and 233b sandwiching the strip conductor 231b.

The strip conductor 231a, the ground conductor 232a, and the ground conductor 233a constitute the coplanar line 230a, and the strip conductor 231b, the ground conductor 232b, and the ground conductor 233b constitute the coplanar line 230b. Each of the coplanar lines 230a and 230b is formed in a region sandwiched between the termination regions 220a and 220b and the resonators 240a and 240b, respectively.

Each of the coplanar lines 230a and 230b functions as one input / output port and the other input / output port of the post wall waveguide of the structure 2, respectively.

Further, in the structure 2, each of the coplanar lines 230a and 230b (that is, one input / output port and the other input / output port) is formed in the second conductor layer 23. However, in one aspect of the present invention, one input / output port and the other input / output port may be formed in different conductor layers.

<Effect of structure 2>
In the structure 2, in the coplanar lines 230a and 230b, the strip conductors 231a and 231b are covered with the first conductor layer 21 and the third conductor layer 25 (in other words, they overlap each other) when the second conductor layer 23 is viewed in a plan view. ing.

According to this configuration, the strip conductors 231a and 231b are shielded from the outside of the structure 2 by the first conductor layer 21 and the third conductor layer 25. Therefore, the structure 2 is less susceptible to noise than in the past.

Since the structure 2 includes the first conductor layer 21 and the third conductor layer 25, the ground conductors 232a, 233a, formed by using the second conductor layer 23, are located in the vicinity of the strip conductors 231a and 231b. In addition to 232b and 233b, the first conductor layer 21 and the third conductor layer 25 are provided. Therefore, the high frequency transmitted through the coplanar lines 230a and 230b forms an electric field between the strip conductors 231a and 231b and the third conductor layer 25, and also between the strip conductors 231a and 231b and the first conductor layer 21. Therefore, in the subsequent stage of the coplanar lines 230a and 230b, it is coupled to the resonance region of the resonators 240a and 240b and also leaks to the resonance region of the terminal regions 220a and 220b formed inside the first conductor layer 21.

As described above, the first post walls 221a and 221b forming the narrow walls of the terminal regions 220a and 220b are orthogonal to the stretching direction of the strip conductors 231a and 231b of the coplanar lines 230a and 230b and are along the stretching direction. When viewed, it includes a terminal post wall located behind the terminal points Pt of the coplanar lines 230a and 230b. Therefore, the structure 2 can prevent the high frequency transmitted through the coplanar lines 230a and 230b from leaking to the first dielectric layer 22.

The gaps 234a and 235a shown in FIG. 4 and the gaps 234b and 235b are configured in the same manner as the gaps 134 and 135 shown in FIG. 1, respectively. Therefore, each of the coplanar lines 230a and 230b of the structure 2 has the same effect as the coplanar line 130 of the structure 1.

As described above, the structure 2 is formed on the third dielectric layer 26, the fourth conductor layer 27, the fourth dielectric layer 28, the fifth conductor layer 29, and the third dielectric layer 26. The fourth post walls 261a and 261b, which are the third post walls 261a and 261b forming the resonators 260a and 260b together with the third conductor layer 25 and the fourth conductor layer 27, and the fourth dielectric layer 28 formed on the fourth dielectric layer 28. It is a post wall 281 and further includes a fourth post wall 281 that constitutes a resonator 280 together with a fourth conductor layer 27 and a fifth conductor layer 29. In this embodiment, n = 4.

In the structure 2, the second post wall 241a, 241b is arranged so that the post wall waveguide formed by itself includes the resonators 240a, 240b, and the second dielectric layer to the fourth dielectric layer. Of the plurality of resonators 240a, 260a, 280, 260b, 240b provided in the layer, the resonators adjacent to each other in the stacking direction overlap each other in a plan view. That is, (1) the resonator 240a and the resonator 260a overlap in a plan view, (2) the resonator 260a and the resonator 280 overlap in a plan view, and (3) resonate with the resonator 280. The vessel 260b overlaps in a plan view, and (4) the resonator 260b and the resonator 240b overlap in a plan view.

According to this configuration, the resonators adjacent to each other in the stacking direction (the resonators (1) to (4) described above) can be easily and electromagnetically coupled to each other. Therefore, the structure 2 functions as a resonator-coupled bandpass filter. In addition, the structure 2 can have a shorter maximum length in a plan view as compared with the structure 1 in which each of the plurality of resonators is arranged in a single layer.

In the structure 2, openings 251a, 271a, 271b, and 251b are formed in the regions of the second conductor layer 23 to the fourth conductor layer 27 in which the resonators adjacent to each other in the stacking direction overlap each other in a plan view. ing. Specifically, in the region where (5) the resonator 240a and the resonator 260a overlap in a plan view, an opening 251a is formed in the third conductor layer 25, and (6) the resonator 260a and the resonator 260a. An opening 271a is formed in the fourth conductor layer 27 in the region where the 280 overlaps in the plan view, and (7) in the region where the resonator 280 and the resonator 260b overlap in the plan view, the opening 271a is formed. An opening 271b is formed in the four conductor layer 27, and an opening 251b is formed in the third conductor layer 25 in the region where (8) the resonator 260b and the resonator 240b overlap in a plan view.

According to this configuration, the resonators adjacent to each other along the stacking direction (the resonators (1) to (4) described above) are connected to each other through the openings described in (5) to (8) described above. Therefore, it can be easily and surely coupled electromagnetically.

Each of the coplanar lines 230a and 230b of the structure 2 adopts the same configuration as the coplanar line 130 of the structure 1. Therefore, each of the coplanar lines 230a and 230b has the same effect as the coplanar line 130 described in the first embodiment. Therefore, in the present embodiment, the description of the effects of the coplanar lines 230a and 230b will be omitted.

[Reflection and transmission characteristics]
The reflection characteristics and transmission characteristics of the structure 2 shown in FIGS. 4 and 5 will be described with reference to FIG. FIG. 6 is a graph showing simulation results of reflection characteristics and transmission characteristics in the structure 2. In the structure 2, the end of the strip conductor 231a of the coplanar line 230a is defined as the first port, and the end of the strip conductor 231b of the coplanar line 230b is defined as the second port. In such a port arrangement, the frequency dependence of the S parameter S11 is referred to as a reflection characteristic, and the frequency dependence of the S parameter S21 is referred to as a transmission characteristic. The pass band of the post-wall waveguide of the structure 2 is a 62.5 GHz band.

With reference to FIG. 6, in the 62.5 GHz band, S11 is -10 dB or less and S21 is about 2 dB, so that it was found that the structure 2 functions well as a bandpass filter.

[Additional notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1,2 Structure 11,21 First conductor layer 12,22 First dielectric layer 120, 220a, 220b Termination region 121,221a, 221b First post wall (one of the second post walls described in the claims) Aspect)
1211,22111 Termination post wall 13,23 Second conductor layer 130, 230a, 230b Coplanar line 131,231a, 231b Strip conductor 132, 133,232a, 233a, 232b, 233b Ground conductor 134, 135, 234a, 235a, 234b, 235b voids (a pair of voids)
14,24 Second Dielectric Layer 140 Post Wall Waveguide 240a, 240b Resonator 141,241a, 241b Second Post Wall (one aspect of the first post wall described in the claims)
1401,1402 ... Resonator 15,25 Third conductor layer 251a, 251b Opening 26 Third dielectric layer 261a, 261b Third post wall 260a, 260b Resonator 27 Fourth conductor layer 271a, 271b Opening 28 Fourth Dielectric layer (one aspect of the nth dielectric layer described in the claims)
280 Resonator 281 4th post wall 29 5th conductor layer (one aspect of the n + 1 conductor layer described in the claims)

Claims (9)

A structure in which at least the first conductor layer, the first dielectric layer, the second conductor layer, the second dielectric layer, and the third conductor layer are laminated in this order.
The second dielectric layer is formed with a first post wall that constitutes a post wall waveguide together with the second conductor layer and the third conductor layer.
The second conductor layer is formed with a coplanar line that terminates within the waveguide region of the post-wall waveguide when viewed in a plan view.
The first conductor layer and the third conductor layer cover the strip conductor of the coplanar line in a plan view.
A structure characterized by that. The first dielectric layer is formed with a second post wall including a terminal post wall that overlaps in a plan view with a region including the terminal point of the coplanar line.
The structure according to claim 1. The first post wall is arranged such that the post wall waveguide includes a resonator group consisting of a plurality of electromagnetically coupled resonators.
The structure according to claim 1 or 2. The third dielectric layer, the fourth conductor layer, ..., The nth conductor layer, the nth dielectric layer, and the n + 1th conductor layer,
The i-th post wall formed in the i-th dielectric layer (i is an integer satisfying 3 ≦ i ≦ n) which is any of the third dielectric layer to the n-th dielectric layer, and is a resonator. Further comprises an i-post wall, which comprises the i-th conductor layer and the i + 1-th conductor layer.
The first post wall is arranged such that the post wall waveguide contains one or more resonators.
Of the plurality of resonators provided in the second dielectric layer to the nth dielectric layer, the resonators adjacent to each other in the stacking direction overlap each other in a plan view.
The structure according to claim 1 or 2. An opening is formed in each of the second conductor layer to the nth conductor layer in a region where adjacent resonators in the stacking direction overlap each other in a plan view.
The structure according to claim 4. The capacitance between the strip conductor and the ground conductor of the coplanar line is the capacitance between the strip conductor and the first conductor layer, and between the strip conductor and the third conductor layer. Greater than the capacitance of
The structure according to any one of claims 1 to 5, wherein the structure is characterized by the above. One of the pair of voids between the strip conductor and the ground conductor of the coplanar line is bent in the first direction orthogonal to the extending direction of the coplanar line at the end point of the coplanar line, and the pair of voids The other is bent in the second direction, which is the opposite direction of the first direction, at the end point.
The structure according to any one of claims 1 to 6, wherein the structure is characterized by the above. The length of the portion of one of the pair of voids extending in the first direction from the bent portion is the length of the portion of the other of the pair of voids extending in the second direction from the bent portion. be equivalent to,
The structure according to claim 7. The vicinity of one tip of the pair of voids is bent from the first direction in the direction along the stretching direction, and the vicinity of the other tip of the pair of voids is in the direction from the second direction along the stretching direction. Bent,
The structure according to claim 7 or 8.

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