JPH10290109A - Dielectric multilayer substrate, microwave and/or milliwave filter and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate production by making mutually different the refractive index of mutually adjacent two dielectric layers at least among plural dielectric layers, respectively providing both mutually practically parallel main surfaces on the respective plural dielectric layers and mutually laminating both the main surfaces each other. SOLUTION: On a dielectric substrate 25 having dielectric constant εr2 , refractive index N2 and thickness t2 , a dielectric substrate 14 having dielectric constant εr1 , refractive index N1 and thickness t1 is laminated and on that substrate 14, a dielectric substrate 14 having dielectric constant εr2 , refractive index N2 and thickness t2 is laminated. On that substrate 14, dielectric substrates 14 and 24 are alternately laminated. No conductor is included in the dielectric substrates 14, 24 and 25 and no conductor is included among the dielectric substrates 14, 24 and 25, either. Thus, a dielectric multilayer substrate can be easily produced without providing any slit requesting high working accuracy and a filter for selectively transmitting or reflecting the electromagnetic waves of wide frequency bands can be easily produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a dielectric multilayer substrate,
The present invention relates to a filter for microwaves and / or millimeter waves and a method for manufacturing the same, particularly to a microwave band (frequency:
3 to 30 GHz) or millimeter wave band (frequency: 30 to 300)
(GHz), and a method of manufacturing the short-circuit device (short plunger).

[0002]

2. Description of the Related Art In a microwave band or a millimeter wave band, a waveguide, a microstrip line, a coplanar line, a coaxial line, and the like are usually widely used as transmission lines for electromagnetic waves.

[0003] Among them, a waveguide is particularly suitable for low-loss and high-power transmission because an electromagnetic wave propagates in a closed space as compared with an open line. Therefore, it is often used as a part of a microwave or millimeter wave transmission / reception system or a feeder line for an antenna.

Conventionally, in such a waveguide, as an element for short-circuiting the end of the line by changing the line length,
The variable short-circuit device (short plunger) shown in FIGS. 7 and 8 is frequently used. When such a variable short-circuit device is used, a slight gap is provided between the variable short-circuit device and the inner wall of the waveguide in order to have mobility in the waveguide. The presence of the air gap results in transmission (leakage) of electromagnetic waves. Therefore, as shown in FIGS. 7 and 8, a groove (slit) 82 whose width is 幅 of the wavelength of the electromagnetic wave propagating in the waveguide 83.
Is provided on the surface of the variable short-circuit device 80 to form a λ / 4 transformer, and by converting the characteristic impedance in the waveguide 83, a state close to an electrical short is created, thereby transmitting (leaking) electromagnetic waves. Is suppressed. The equivalent circuit of the variable short circuit is as shown in FIG. 9, Z for electromagnetic waves having a wavelength lambda _g
in becomes almost 0.

[0005]

However, the present inventors have found that the following problems mainly exist in the above prior art.

That is, as the frequency of the electromagnetic wave becomes higher (as the wavelength becomes shorter), the width of the slit 82 naturally becomes smaller, and extremely high processing accuracy is required.
For example, when the frequency of the electromagnetic wave is 100 GHz, λ / 4
Is 0.75 mm, and a processing accuracy of ± several tens μm is required. Therefore, the higher the frequency, the higher the manufacturing cost of the short circuit.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and does not require the provision of slits requiring extremely high processing accuracy, and can be easily manufactured by using a dielectric multilayer substrate for microwave and / or millimeter wave. It is a main object to provide filters and methods for their manufacture.

[0008]

First, the principle of the present invention devised by the present inventors will be described.

Lossless dielectric constant ε _r (refractive index n 2
It is assumed that a dielectric substrate 2 having a very high degree of parallelism and a thickness t is placed in a medium 1 having a refractive index n ′. As shown in FIG. 1, when an electromagnetic wave (plane wave) enters the dielectric substrate 2 from the medium 1 at an incident angle θ ′, the refraction angle in the dielectric substrate 2 is changed to θ.
The path difference Δ between the partial waves A1 and A2 of the plane wave
L can be expressed by equation (1). That is,

ΔL = n (AC + CE) −n′AB

Here, since the optical path lengths between the wavefronts AD and BE are equal,

## EQU2 ## nDE = n'AB

Therefore,

ΔL = n (AC + CD) = n [t ｛cos (2θ) / cosθ｝ + (t / cosθ)] = 2ntcosθ (1)

Accordingly, if the wavelength of the incident wave in vacuum is λ ₀ , the phase difference δ with respect to the equation (1) can be expressed by the equation (2).

[0013]

Δ = (2πΔL) / λ ₀ = 4πnt (cos θ) / λ ₀ (2)

The intensity ratio (transmittance) of the electromagnetic wave transmitted through the dielectric substrate 2 to the intensity of the electromagnetic wave incident on the dielectric substrate 2
T is represented by equation (3).

[0015]

T = 1 / {1 + Csin ² (δ / 2)} (3)

Here, C = 4R / (1-R) ² ,
C is the contrast, and R is the intensity reflectance.

[0017] When δ is 2mπ of (m is an arbitrary integer), 1 next to the transmittance maximum value, indicating the condition at the frequency f _m, the c ₀ as a high-speed in a vacuum formula (4) is obtained .

[0018]

F _m = mc ₀ / (2 nt cos θ) (4)

That is, given the refractive index n, the thickness t of the substrate, and the incident angle θ, the frequency (resonance frequency) at which the transmittance becomes maximum is determined. Interval Delta] f _m mutual resonant frequency equation (5)

Δf _m = f _{m + 1} −f _m = c ₀ / (2 nt cos θ) (5)

Further, when δ is (2m + 1) π (m is an arbitrary integer), the transmittance becomes the minimum (the reflectance becomes the maximum value), indicating this condition at the frequency f _m ', and c ₀ Equation (6) is obtained as a high speed in vacuum.

[0021]

F _m ′ = (2m + 1) c ₀ / (4 nt cos θ) (6)

That is, given the refractive index n, the thickness t of the substrate, and the incident angle θ, the frequency at which the transmittance becomes minimum (the reflectance becomes maximum) is determined.

Further, considering the case of normal incidence (θ = 0), equations (4) and (5) are

Equation 9] _{f m = mc 0 / (2ntcosθ} ) = mc 0 / (2nt) ··· (7) Δf m = f m + 1 -f m = c 0 / (2nt) ··· (8) becomes And equation (6)

F _m ′ = (2m + 1) c ₀ / (4 nt) (9)

Here, from equation (9),

Equation 11] _{f m '= 2mc 0 / (} 4nt) + c 0 / (4nt) = mc 0 / (2nt) + {(1/2) × c 0} / (2nt) = f m + 1 / 2Δf m ·・ ・ (10)

Thus, the frequency at which the transmittance becomes minimum (the frequency at which the reflectance becomes maximum) is located at the center between adjacent frequencies at which the transmittance becomes maximum. Therefore, the transmission characteristics of the electromagnetic wave are as shown in FIG.

Here, from equation (9),

Equation 12] nt = (2m + 1) × (1/4) × c 0 / f m '= (2m + 1) × (1/4) λ 0 ··· (11)

That is, when the product of the refractive index n and the thickness t of the substrate is set to an odd multiple of 1/4 of the wavelength of the incident electromagnetic wave, the transmittance becomes minimum, that is, the reflectance becomes maximum.

The above is a description of the case where the dielectric substrate 2 is placed in the medium 1 having a refractive index of n '. However, a plurality of dielectric substrates have a refractive index between adjacent dielectric substrates. The same applies to the case where they are arranged so as to be different from each other.

That is, the refractive index n _q (q = 1, 2,..., P) and the thickness t _q (q = 1, 2,. Product n _q · t _q with p)
The if respectively (lambda _0/4) of the (2m + 1) times (m is an arbitrary integer), the formula (9), the equation (11), the frequency c
_For an electromagnetic wave of ₀ / λ _0, the transmittance is minimum, ie, the reflectance is maximum, and the transmittance is minimum, ie, the reflectance is maximum, for each of the plurality of dielectric substrates. Since a plurality of dielectric substrates are stacked, the reflectance is higher than that of a single layer, and the frequency band in which the reflectance is close to 1 is:
It becomes wider with it. Therefore, it is possible to maximize the reflectance (minimize the transmittance) over a wide band around the electromagnetic wave of the frequency c ₀ / λ ₀ .

On the other hand, in the above-described conventional short-circuit device 80, since the width of the slit 82 is fixed, it is effective only for an electromagnetic wave of a specific frequency (single frequency) and has a wide bandwidth. It is not suitable as a short circuit for electromagnetic waves.

As described above, by using the dielectric multilayer substrate, the reflectance can be maximized (substantially 1) over a much wider band, as compared with a conventional short circuiter manufactured by machining. A short circuiter (short plunger) having a function of a band rejection filter (BRF: band rejection filter) that selectively reflects an electromagnetic wave in a desired frequency band can be obtained.

Further, when a dielectric multilayer substrate is used as such a short-circuit device, it is not necessary to provide a slit which requires high processing accuracy as in the conventional case, and it is manufactured at a lower cost as compared with the conventional short-circuit device. can do.

On the other hand, from the equation (7),

Equation 13] nt = (m / 2) × c 0 / f m = m × 1 / (2λ 0) ··· (12)

That is, it can be seen that the transmittance becomes maximum when the product of the refractive index n and the thickness t of the substrate is set to an integral multiple of 1/2 of the wavelength of the incident electromagnetic wave.

Accordingly, the refractive index n _q (q = 1, 2,..., P) and the thickness t _q (q = 1, 2,. product with p) n _q
By slightly shifting each of _tq , the frequency at which the transmittance becomes maximum can be shifted slightly, so that a band-pass filter (BPF: band-pass filter) that selectively transmits electromagnetic waves in a desired frequency band can be obtained. ) Function can also be obtained.

In order to provide the above characteristics, a conductor does not exist in each dielectric substrate constituting the dielectric multilayer substrate, and a conductor does not exist between the dielectric multilayer substrates. Preferably not.

The adjacent dielectric layers may be in close contact with each other, and an intermediate layer composed of an air layer or a dielectric layer may be present between the adjacent dielectric layers. However, it is preferable that the product n · t of the refractive index n of the intermediate layer and the thickness in the laminating direction is about 1/40 or less of the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate. This is because, even if the intermediate layer exists, the product n · t of the refractive index n and the thickness becomes very small, and has little effect on the filter characteristics as a short circuiter or the like. Further, the refractive index of the intermediate layer is preferably smaller than 3. If an adhesive is used as the intermediate layer, the dielectric layers adjacent to each other can be bonded to each other.

The present invention has been made based on such principles and knowledge. According to claim 1, there is provided a dielectric multilayer substrate in which a plurality of dielectric layers are laminated. The refractive indexes of at least two of the dielectric layers adjacent to each other are different from each other, and each of the plurality of dielectric layers has two main surfaces substantially parallel to each other, and between the plurality of dielectric layers. The plurality of dielectric layers are stacked such that the two main surfaces are substantially parallel to each other,
There is provided a dielectric multilayer substrate, wherein no conductor is provided in the dielectric layer and between the dielectric layers.

This dielectric multilayer substrate can be effectively used as a microwave and / or millimeter wave filter. Further, since the structure is such that the dielectric layers are stacked, the manufacture thereof is also easy.

According to a second aspect of the present invention, there is provided the dielectric multilayer substrate according to the first aspect, wherein the plurality of dielectric layers have different refractive indexes between adjacent dielectric layers. You.

According to the third aspect, a dielectric layer made of one dielectric material and a dielectric layer made of the other dielectric material are alternately laminated out of two dielectric materials having different refractive indexes. The dielectric multilayer substrate according to claim 2, wherein:

According to a fourth aspect of the present invention, in each of the plurality of dielectric layers, a product of a distance t ₁ between the two main surfaces and a refractive index n ₁ of a dielectric material constituting the dielectric layer. n ₁
4. The dielectric multilayer substrate according to claim ₁ , wherein t ₁ has a value that is substantially an odd multiple of a predetermined first common value.

According to the fifth aspect, the predetermined first
5. The dielectric multilayer substrate according to claim 4, wherein the common value of is １ ／ of the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate.

The predetermined first common value is １ ／ of the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate, and the dielectric multilayer substrate functions as a short circuit.

According to a sixth aspect of the present invention, the distance t ₂ between the two main surfaces of at least one of the plurality of dielectric layers and the dielectric constituting the at least one dielectric layer The product n ₂ · t ₂ of the material and the refractive index n ₂ is equal to a predetermined first value.
And a distance t ₃ between the main surfaces of at least one other dielectric layer of the plurality of dielectric layers and the at least one other dielectric layer. is the product n ₃ · t ₃ between the refractive index n ₃ of the dielectric material constituting claim 1, characterized in that it comprises a substantially integral multiple of the value of said first value predetermined second value which is different from the 4. A dielectric multilayer substrate according to any one of the above aspects.

By using this dielectric multilayer substrate, a filter obtained by combining at least two filters having different characteristics can be obtained. As a result, filters having various characteristics are obtained, and the degree of freedom in design increases.

According to the seventh aspect, the predetermined first
Is a predetermined third value to a value of に of the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate, and the third value is smaller than a value of の of the wavelength. The predetermined second value is １ ／ of the wavelength.
7. The dielectric multilayer substrate according to claim 6, wherein the value is a value obtained by subtracting the third value from the value.

By using this dielectric multilayer substrate, a bandpass filter having a desired bandwidth can be obtained.

According to a eighth aspect of the present invention, there is provided the dielectric multilayer substrate according to any one of the first to seventh aspects, wherein the adjacent dielectric layers are in close contact with each other.

According to a ninth aspect of the present invention, there is provided the dielectric multi-layer substrate according to any one of the first to seventh aspects, wherein a layer made of an adhesive is present between the adjacent dielectric layers. Provided.

According to a tenth aspect, an intermediate layer made of an air layer or a dielectric layer exists between the dielectric layers adjacent to each other, and the refractive index n _{4 of the} intermediate layer and the intermediate layer in the laminating direction. product n ₄ · t ₄ between the thickness t ₄ of the layer, said dielectric claim, wherein the multilayer substrate is about 1/40 or less of the wavelength of microwave or millimeter wave incident on 1-7 and 9 The dielectric multilayer substrate according to any one of the above is provided.

[0052] the product n ₄ of the intermediate layer of such a thickness may be present in the dielectric layers, and the refractive index n ₄ and the thickness t ₄ of the intermediate layer
Since · t ₄ is smaller than the wavelength, when using a dielectric multi-layer substrate as a filter, little effect on the filter characteristics. Note that an adhesive is preferably used as the intermediate layer.

According to the eleventh aspect, there is provided a microwave and / or millimeter wave filter including a dielectric multilayer substrate in which a plurality of dielectric layers are stacked, wherein the plurality of dielectric layers are adjacent to each other. The refractive indices of at least two of the dielectric layers are different from each other, each of the plurality of dielectric layers has two main surfaces substantially parallel to each other, and the two main layers are disposed between the plurality of dielectric layers. A microwave and / or millimeter wave filter is provided, wherein the plurality of dielectric layers are stacked such that the surfaces are substantially parallel to each other.

Since this dielectric multilayer substrate has a structure in which dielectric layers are laminated, its manufacture is also easy.

According to a twelfth aspect of the present invention, a conductor is not provided in the dielectric layer and between the dielectric layers.
Alternatively, a millimeter wave filter is provided.

According to a thirteenth aspect of the present invention, the plurality of dielectric layers have different refractive indices between adjacent dielectric layers. A millimeter wave filter is provided.

According to the fourteenth aspect, a dielectric layer made of one of the two dielectric materials having different refractive indices and a dielectric layer made of the other dielectric material are alternately laminated. A microwave and / or millimeter wave filter according to any one of claims 11 to 13, wherein the filter is provided.

[0058] Also, according to claim 15, in each of said plurality of dielectric layers, wherein the product of the refractive index n ₅ of the dielectric material constituting the dielectric layer and the distance t ₅ between the two main surfaces n ₅
· T ₅ is substantially microwave and / or millimeter wave filter according to any one of claims 11 to 14, characterized in that it has an odd multiple value, respectively are provided in the predetermined second common value You.

According to a sixteenth aspect of the present invention, the predetermined second common value is ま た は of a wavelength of a microwave or a millimeter wave incident on the dielectric multilayer substrate. Item 15. A microwave and / or millimeter wave filter according to item 15 is provided.

A predetermined second common value is １ ／ of the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate, and this filter functions as a short circuit.

According to claim 17, the microwave and / or millimeter wave filter is a microwave and / or millimeter wave short circuit. , A microwave and / or millimeter wave filter.

As described above, the microwave and / or millimeter wave filter using the dielectric multilayer substrate of the present invention is a short circuiter, particularly a band rejection filter (BRF) that selectively reflects an electromagnetic wave in a desired frequency band. : Band rejection filter), which is preferably used as a short-circuit device (short plunger) having a function.

According to the eighteenth aspect, in each of the plurality of dielectric layers, the product of the distance t ₅ between the main surfaces and the refractive index n ₅ of the dielectric material forming the dielectric layer is provided. n ₅
· T ₅ is provided microwave and / or millimeter wave filter according to claim 17, wherein it is almost an odd multiple of a quarter of the wavelength of microwave or millimeter-wave reflected by the short circuit Is done.

According to a nineteenth aspect, a distance t ₆ between the main surfaces of at least one of the plurality of dielectric layers and a dielectric constituting the at least one dielectric layer are set. The product n ₆ · t _{6 of the} material and the refractive index n ₆ has a value that is substantially an integral multiple of a predetermined fourth value, and the product n ₆ · t ₆ of at least one other dielectric layer of the plurality of dielectric layers. The product n ₇ · t ₇ of the distance t ₇ between the two main surfaces and the refractive index n ₇ of the dielectric material constituting the at least one other dielectric layer is the fourth product.
The microwave and / or millimeter wave filter according to any one of claims 11 to 14, wherein the filter has a value that is substantially an integral multiple of a predetermined fifth value different from the value of the fifth value.

Since this filter is a filter obtained by combining at least two filters having different characteristics,
The filter characteristics can be variously changed, and the degree of freedom in design increases.

According to a twentieth aspect, the predetermined fourth value is a predetermined sixth value equal to a half of the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate. And a value obtained by adding the sixth value smaller than a value of 波長 of the wavelength, and the predetermined fifth value is 1 / の of the wavelength.
The microwave and / or millimeter wave filter according to claim 19, wherein the filter is a value obtained by subtracting the sixth value from the value of 2.

In this way, a band-pass filter having a desired bandwidth can be obtained.

The microwave and / or millimeter wave filter according to any one of claims 11 to 20, wherein the dielectric layers adjacent to each other are in close contact with each other. Is provided.

According to a twenty-second aspect of the present invention, there is provided a method as set forth in any one of the eleventh to twentieth aspects, wherein a layer made of an adhesive is present between the adjacent dielectric layers. A millimeter wave filter is provided.

According to a twenty-third aspect, an intermediate layer made of an air layer or a dielectric layer exists between the dielectric layers adjacent to each other, and the refractive index n _{8 of the} intermediate layer and the intermediate layer in the laminating direction. claim product n ₈ · t ₈ the thickness t ₈ layers, wherein the dielectric is about 1/40 or less of the wavelength of microwave or millimeter-wave incident on the multilayer substrate 11
30. A microwave and / or millimeter wave filter according to any one of claims 20 to 22. Note that an adhesive is preferably used as the intermediate layer.

[0071] the product n ₄ of the intermediate layer of such a thickness may be present in the dielectric layers, and the refractive index n ₄ and the thickness t ₄ of the intermediate layer
Since · t ₄ is smaller than the wavelength, little influence on the filter characteristic. Note that an adhesive is preferably used as the intermediate layer.

According to claim 24, claim 16,
24. A transmission line comprising the microwave and / or millimeter wave filter according to 18, 20, or 23, wherein the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate or the microwave reflected by the short circuiter A transmission line is provided, wherein the wavelength of the millimeter wave is the wavelength of a microwave or a millimeter wave transmitted through the transmission line.

According to a twenty-fifth aspect, the plurality of sintered bodies are made of a plurality of dielectric materials each having a different refractive index from each other and do not include a conductor therein. Forming a plurality of dielectric substrates, each of which has a predetermined thickness, and both main surfaces of which are parallel to each other, forming a plurality of dielectric substrates, including a conductor between the plurality of dielectric substrates And bonding the plurality of dielectric substrates with an adhesive made of an insulating material without performing the method.

According to a twenty-sixth aspect, the plurality of sintered bodies are made of a plurality of dielectric materials each having a different refractive index from each other and do not include a conductor therein. Forming a plurality of dielectric substrates, each of which has a predetermined thickness, and both main surfaces of which are parallel to each other, forming a plurality of dielectric substrates, including a conductor between the plurality of dielectric substrates Bonding the plurality of dielectric substrates with an adhesive made of an insulating material to form a dielectric multi-layer substrate without performing the method. Is provided.

According to a twenty-seventh aspect, a step of producing a plurality of raw sheets using a plurality of dielectric materials each having a different refractive index from each other and not including a conductor. And forming a laminate by laminating the plurality of raw sheets in a predetermined order without including a conductor between the plurality of raw sheets, and sintering the laminate. A method for manufacturing a dielectric multilayer substrate is provided.

According to a twenty-eighth aspect, a step of producing a plurality of raw sheets using a plurality of dielectric materials each having a different refractive index from each other and not including a conductor. Forming a laminate by laminating the plurality of raw sheets in a predetermined order without including a conductor between the plurality of raw sheets; and sintering the laminate to form a dielectric multilayer substrate. And a method of manufacturing a filter for microwaves and / or millimeter waves.

[0077]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 shows a short-circuit device 5 according to an embodiment of the present invention.
FIG. 2 is a schematic perspective view for explaining the case of the reference numeral 0; A dielectric substrate 14 having a relative dielectric constant of ε _r1 , a refractive index of n ₁ and a thickness of t ₁ is laminated on a dielectric substrate 25 having a relative dielectric constant of ε _r2 , a refractive index of n ₂ and a thickness of t ₃ , A dielectric substrate 24 having a relative dielectric constant of ε _r2 , a refractive index of n ₂ , and a thickness of t ₂ is stacked thereon, and the dielectric substrates 14 and 24 are alternately stacked thereon. .

No conductor is contained in the dielectric substrates 14, 24, 25, and no conductor is contained between the dielectric substrates 14, 24, 25.

The dielectric substrates 14, 24, and 25 are bonded together with an adhesive (not shown). As the adhesive, for example, a dielectric constant ε _r <5, Q> 5000 (at,
A low dielectric constant and a low loss of 1 GHz) and a thickness of several tens μm or less are desirable.

Next, a method of manufacturing the short circuit device 50 according to the present embodiment will be described with reference to FIG.

Here, a case where dielectric ceramics are used as the material of the dielectric substrates 14, 24 and 25 will be described as an example.

First, raw material powders 11 and 21 of two types of dielectric substrates (ceramic substrates) 14 and 24 (25) are granulated by a spray drier or the like (step 1).

Next, each of them is molded into a block shape by a hydraulic press or the like to form molded bodies 12 and 22 (step 2).

Next, the blocks of the compacts 12 and 22 are fired in the air through a binder removing step to obtain dense sintered bodies 13 and 23 (step 3).

Next, these sintered bodies 13 and 23 are sliced into a plate shape, and further polished to a desired thickness to form dielectric substrates (ceramic substrates) 14, 24 and 25 (step 4). .

Next, an adhesive is uniformly applied on the surfaces of the dielectric substrates 14, 24 and 25 using a spin coater or the like.
Further, the respective dielectric substrates 14, 24 (25) are alternately stacked (step 5).

Next, in order to enhance the adhesion between the substrates, the adhesive is sufficiently dried while pressing in a direction perpendicular to the substrate surface with a weight 40 or the like to obtain the dielectric multilayer substrate 30 (Step 6). The dielectric multilayer substrate 30 thus obtained can be used as a short circuit device 50.

In this embodiment, the dielectric multilayer substrate 30
As a method for manufacturing the dielectric block, the sintered dielectric blocks 13 and 23
However, the method for manufacturing the dielectric multilayer substrate is not limited to this, and a plurality of dielectric layers each having a certain thickness and each having any one of at least two different refractive indexes are provided. Any method can be used as long as the layers can be stacked in a predetermined order. For example, a raw multi-layer substrate may be formed by preparing raw sheets of a predetermined thickness for a plurality of dielectric materials, laminating them in a predetermined order, and firing them simultaneously. In this case, the combination of dielectric materials that can be co-fired is limited. However, the above-described manufacturing method of the present embodiment, that is, a dielectric substrate is cut out from a sintered dielectric block, and then these are pasted. According to the matching method, the range of choice of the dielectric material to be laminated is greatly increased.

[0090]

Next, as an embodiment of the present invention, a short circuiter formed by using two kinds of dielectric ceramics will be described.

The short-circuit device 50 of this embodiment has the structure shown in FIG. 3, and has a dielectric constant ε _r of 21.5, a refractive index n of 4.59, and a thickness t of 1630 μm. The relative dielectric constant ε _r is 117, the refractive index n is 10.59, and the thickness t is
Is laminated, and a dielectric substrate 24 having a relative dielectric constant ε _r of 21.5, a refractive index n of 4.59, and a thickness t of 330 μm is laminated thereon. The body substrate 14, the dielectric substrate 24, and the dielectric substrate 14 are alternately stacked in this order.

[0092] If the refractive index n of the dielectric layer 14 is 10.59, and a thickness t is 140 .mu.m, the millimeter-wave refractive index × thickness incident 1.5mm next wavelengths (50 GHz) and lambda _1, the lambda ₁ / 4. Refractive index n 4.59 of the dielectric layer 24, a thickness t of 330 [mu] m, refractive index × thickness 1.5mm next and also the wavelength of the millimeter wave incident to lambda _1, is its lambda _1/4 ing. The refractive index n is 4.59 of the dielectric layer 25, the thickness t is 1630Myuemu, refractive index × thickness 7.5mm, and the and the wavelength of the millimeter wave incident to lambda _1, the λ _1/4 ( 2m + 1)
(In this case, m = 2). In this way, although the thick thickness of the dielectric layer 25 is for mechanical retention of the short circuit 50, even when such thick, the refractive index × thickness of lambda _1/4 (2m + 1) times (m =
0, 1, 2,...), So that it also has a function of reflecting the incident millimeter wave, and the reflectance is maximized as a short-circuit device.

No conductor is contained in the dielectric substrates 14, 24, 25, and no conductor is contained between the dielectric substrates 14, 24, 25.

The dielectric substrates 14, 24, and 25 are bonded to each other with an adhesive (not shown). An epoxy adhesive was used as the adhesive, and its dielectric constant ε _r was 4, refractive index n was 2, Q (at 1 GHz) was 3000, and thickness was 12 μm. Since the thickness is small and n is small, the refractive index × thickness is very small as 24 μm, and a low-loss adhesive is used.
It hardly affects the frequency characteristics of the transmittance of the short-circuit device 50.

The short-circuit device 50 was manufactured by the manufacturing method of the embodiment described with reference to FIG.

The short-circuit device 50 was provided in the waveguide 60, and the reflection characteristics (transmission characteristics) of electromagnetic waves in the 30 to 70 GHz band were measured using a network analyzer (HP8510C) 70 in accordance with the measurement system of FIG. The result is shown by a solid line in FIG. At 40 to 60 GHz, the reflectivity of the electromagnetic wave is almost 1, that is, the transmittance is almost 0, and the effective performance as a short-circuit device (short plunger) is exhibited in a wide bandwidth of 20 GHz. As a comparative example, the reflection characteristics (transmission characteristics) of electromagnetic waves in the conventional short-circuit plate 80 (short plunger provided with a slit) shown in FIGS. In this case, the performance as a short-circuiting plate (short plunger) has a bandwidth of about 4 GHz (48 to 52 G).
Hz), but the effective bandwidth as a short-circuit (short plunger) is 1 / compared to the case of the short-circuit device 50 of the present embodiment using a dielectric multilayer substrate.
It turns out that there are only five.

As described above, without providing slits requiring high processing accuracy, electromagnetic waves in a desired frequency band can be selectively reflected at a lower cost than in the prior art and having a much wider effective bandwidth. A short-circuit device (short plunger) having a function of a band rejection filter can be realized.

[0098]

According to the present invention, there is provided a dielectric multilayer substrate, a filter for microwave and / or millimeter wave which can be easily manufactured without providing a slit which requires extremely high processing accuracy, and a method for manufacturing the same. Provided.

Then, if this dielectric multilayer substrate is used,
A filter capable of selectively transmitting or reflecting electromagnetic waves in a wide frequency band can be easily formed.

The filter using this dielectric multilayer substrate is:
In particular, it is preferably used as a short circuiter (short plunger) having a function of a band rejection filter (BRF: band rejection filter) that selectively reflects an electromagnetic wave in a desired frequency band.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view for explaining the principle of the present invention.

FIG. 2 is a diagram illustrating frequency characteristics of transmittance of the optical system of FIG. 1;

FIG. 3 is a schematic perspective view illustrating a short circuiter according to an embodiment of the present invention.

FIG. 4 is a diagram for explaining a method of manufacturing a short circuiter according to one embodiment of the present invention.

FIG. 5 is a diagram for explaining a measurement system used in one embodiment of the present invention.

FIG. 6 shows the transmittance (reflectance) of the short-circuit device according to one embodiment of the present invention.
FIG. 4 is a diagram showing frequency characteristics of the multiplexed signal;

FIG. 7 is a perspective view illustrating a conventional variable short circuit device.

FIG. 8 is a cross-sectional view illustrating a conventional variable short-circuit device.

FIG. 9 is an equivalent circuit diagram of a conventional variable short-circuit device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Medium 2 ... Dielectric substrate 11, 21 ... Raw material powder 12, 22 ... Molded body 13, 23 ... Sintered body 14, 24, 25 ... Dielectric substrate 30 ... Dielectric multilayer substrate 40 ... Weight 50 ... Short circuit (Short plunger) 60: Waveguide 70: Network analyzer 80: Short circuiter 82: Slit (groove) 83: Waveguide

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G02B 5/28 G02B 5/28

Claims (28)

[Claims] 1. A dielectric multilayer substrate in which a plurality of dielectric layers are stacked, wherein at least two of the plurality of dielectric layers are adjacent to each other.
The refractive indices of the two dielectric layers are different from each other, each of the plurality of dielectric layers has two main surfaces substantially parallel to each other, and the two main surfaces are mutually between the plurality of dielectric layers. The dielectric multilayer substrate, wherein the plurality of dielectric layers are stacked so as to be substantially parallel to each other, and no conductor is provided in the dielectric layers and between the dielectric layers. 2. The dielectric multilayer substrate according to claim 1, wherein said plurality of dielectric layers have different refractive indices between adjacent dielectric layers. 3. The method according to claim 1, wherein a dielectric layer made of one of the two dielectric materials having different refractive indices and a dielectric layer made of the other dielectric material are alternately laminated. The dielectric multilayer substrate according to claim 2. 4. In each of the plurality of dielectric layers, a product n ₁ · t _{1 of} a distance t ₁ between the two main surfaces and a refractive index n ₁ of a dielectric material constituting the dielectric layer is defined as: 4. The dielectric multilayer substrate according to claim 1, wherein each of said dielectric multilayer substrates has a value which is substantially an odd multiple of a predetermined first common value. 5. The method according to claim 1, wherein the predetermined first common value is one of a wavelength of a microwave or a millimeter wave incident on the dielectric multilayer substrate.
The dielectric multilayer substrate according to claim 4, wherein the ratio is / 4. 6. At least one of said plurality of dielectric layers.
The product n ₂ · t ₂ of the distance t ₂ between the two main surfaces of the two dielectric layers and the refractive index n ₂ of the dielectric material forming the at least one dielectric layer is a predetermined first value. A distance t ₃ between the main surfaces of at least one other dielectric layer of the plurality of dielectric layers and the other at least one
The product n ₃ · t ₃ of the two dielectric layers and the refractive index n ₃ of the dielectric material has a value substantially equal to an integral multiple of a predetermined second value different from the first value. The dielectric multilayer substrate according to any one of claims 1 to 3, wherein 7. The method according to claim 1, wherein the predetermined first value is a predetermined third value equal to a half of the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate, and A value obtained by adding the third value smaller than the value of 2, and the predetermined second value is a value obtained by subtracting the third value from a value of １ ／ of the wavelength. The dielectric multilayer substrate according to claim 6, wherein 8. The dielectric multilayer substrate according to claim 1, wherein said dielectric layers adjacent to each other are in close contact with each other. 9. A method according to claim 1, wherein a layer made of an adhesive is present between said dielectric layers adjacent to each other.
The dielectric multilayer substrate according to any one of the above. 10. An intermediate layer comprising an air layer or a dielectric layer is present between said dielectric layers adjacent to each other, and a difference between a refractive index n ₄ of said intermediate layer and a thickness t ₄ of said intermediate layer in said laminating direction. 10. The dielectric according to claim 1, wherein a product n ₄ · t ₄ is about 1/40 or less of a wavelength of a microwave or a millimeter wave incident on the dielectric multilayer substrate. Body multilayer board. 11. A microwave and / or millimeter wave filter comprising a dielectric multilayer substrate on which a plurality of dielectric layers are stacked, wherein at least two of the plurality of dielectric layers are adjacent to each other.
The refractive indices of the two dielectric layers are different from each other, each of the plurality of dielectric layers has two main surfaces substantially parallel to each other, and the two main surfaces are mutually between the plurality of dielectric layers. A microwave and / or millimeter wave filter, wherein the plurality of dielectric layers are stacked so as to be substantially parallel to each other. 12. The semiconductor device according to claim 1, wherein no conductor is provided in said dielectric layer and between said dielectric layers.
2. The filter for microwaves and / or millimeter waves according to 1. 13. The microwave and / or millimeter wave filter according to claim 11, wherein the plurality of dielectric layers have different refractive indices between adjacent dielectric layers. 14. A method according to claim 1, wherein a dielectric layer made of one of the two dielectric materials having different refractive indexes and a dielectric layer made of the other dielectric material are alternately laminated. The microwave and / or millimeter wave filter according to any one of claims 11 to 13. 15. In each of the plurality of dielectric layers, a product n ₅ · t _{5 of} a distance t ₅ between the two main surfaces and a refractive index n ₅ of a dielectric material forming the dielectric layer is: The microwave and / or millimeter wave filter according to any one of claims 11 to 14, wherein the filter has a value substantially equal to an odd multiple of a predetermined second common value. 16. A microwave and a microwave according to claim 15, wherein said predetermined second common value is １ ／ of a wavelength of a microwave or a millimeter wave incident on said dielectric multilayer substrate. And / or millimeter wave filters. 17. The microwave and / or millimeter-wave filter according to claim 11, wherein said microwave and / or millimeter-wave filter is a microwave and / or millimeter-wave short circuit. Wave filter. 18. In each of the plurality of dielectric layers, a product n ₅ · t _{5 of} a distance t ₅ between the two main surfaces and a refractive index n ₅ of a dielectric material forming the dielectric layer is: 18. The microwave and / or millimeter wave filter according to claim 17, wherein the filter is substantially an odd multiple of 1/4 of the wavelength of the microwave or millimeter wave reflected by the short circuit. 19. A distance t ₆ between said main surfaces of at least one dielectric layer of said plurality of dielectric layers and a refractive index n ₆ of a dielectric material forming said at least one dielectric layer.
N ₆ · t ₆ has a value that is substantially an integral multiple of a predetermined fourth value, and the distance between the two main surfaces of at least one other dielectric layer of the plurality of dielectric layers is The distance t ₇ and the other at least one
The product n ₇ · t _{7 of} the dielectric material constituting the two dielectric layers and the refractive index n ₇ has a value that is substantially an integral multiple of a predetermined fifth value different from the fourth value. The microwave and / or millimeter wave filter according to any one of claims 11 to 14, wherein: 20. The method according to claim 17, wherein the predetermined fourth value is a half of a wavelength of a microwave or a millimeter wave incident on the dielectric multilayer substrate.
Is a value obtained by adding the sixth value which is a predetermined sixth value which is smaller than the value of 1/2 of the wavelength to the value of the above, and the predetermined fifth value is 1/2 of the wavelength. 20. The microwave and / or millimeter wave filter according to claim 19, wherein the value is a value obtained by subtracting the sixth value from the value. 21. The microwave and / or millimeter wave filter according to claim 11, wherein the adjacent dielectric layers are in close contact with each other. 22. The microwave and / or millimeter wave filter according to claim 11, wherein a layer made of an adhesive is present between said dielectric layers adjacent to each other. The said dielectric layers 23. adjoining exists an intermediate layer consisting of an air layer or a dielectric layer, the thickness t ₈ of the intermediate layer in the stacking direction and the refractive index n ₈ of the intermediate layer product n ₈ · t ₈ is, micro according to any one of claims 11 to 20 and 22, wherein the dielectric is about 1/40 or less of the wavelength of microwave or millimeter-wave incident on the multilayer substrate Wave and / or millimeter wave filters. 24. A transmission line comprising the microwave and / or millimeter wave filter according to claim 16, 18, 20 or 23, wherein the wavelength of the microwave or millimeter wave incident on the dielectric multilayer substrate or A transmission line, wherein the wavelength of the microwave or millimeter wave reflected by the short circuiter is the wavelength of the microwave or millimeter wave transmitted through the transmission line. 25. A plurality of dielectric substrates each comprising a plurality of sintered bodies each comprising a plurality of dielectric materials each having a different refractive index from each other and containing no conductor therein. A step of creating the plurality of dielectric substrates having a predetermined thickness and both main surfaces parallel to each other, without including a conductor between the plurality of dielectric substrates,
Bonding the plurality of dielectric substrates with an adhesive made of an insulating material. 26. A plurality of dielectric substrates, each comprising a plurality of sintered bodies each comprising a plurality of dielectric materials each having a different refractive index from each other and containing no conductor therein. A step of creating the plurality of dielectric substrates having a predetermined thickness and both main surfaces parallel to each other, without including a conductor between the plurality of dielectric substrates,
Bonding the plurality of dielectric substrates with an adhesive made of an insulating material to form a dielectric multilayer substrate, and a method for manufacturing a microwave and / or millimeter wave filter. 27. A step of preparing a plurality of raw sheets each using a plurality of dielectric materials each having a different refractive index from each other and not including a conductor; and A step of forming a laminate by laminating the plurality of raw sheets in a predetermined order without including a conductor therebetween; and a step of sintering the laminate. A method for manufacturing a multilayer substrate. 28. A step of producing a plurality of raw sheets each using a plurality of dielectric materials each having a different refractive index from each other and not including a conductor; and A step of forming a laminate by laminating the plurality of raw sheets in a predetermined order without including a conductor therebetween; and a step of sintering the laminate to form a dielectric multilayer substrate. A method for manufacturing a microwave and / or millimeter wave filter, comprising: