JP2006262396A - Microwave resonator couple, microwave filter, and microwave filter group - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend the latitude of designing a high frequency member of a communication apparatus by providing various kinds of strong and weak couplings between resonators within the same board. <P>SOLUTION: In the microwave resonator couple, resonators 101 and 102 composed of a microstrip line where a line-shaped electrode is formed on one principal surface of a dielectric layer 11 and a common electrode is formed on the other principal surface, are disposed so as to form a couple. The thickness of the dielectric layer 11 is different between one of the coupled resonators 101 and 102 and the other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a microwave resonator pair using a resonator constituted by a microstrip line, and further to a microwave filter and a group of microwave filters using the resonator pair.

  Communication devices that perform information communication wirelessly or by wire include many high-frequency members that use resonance characteristics. For example, a band pass filter has a function of arranging a plurality of resonant elements and passing only signals in a specific frequency band. This band-pass filter is configured by an excitation line, a resonator, and a coupling formed by each resonator pair.

  A bandpass filter used in a communication system is required to have a skirt characteristic that does not cause interference between adjacent frequency bands. This is because the frequency can be used effectively by using a bandpass filter having a steep skirt characteristic. Here, the skirt characteristic is the degree of attenuation from the end of the pass band to the stop band.

  As a conventional example of an ultra-narrow band-pass filter, there is an example in which a microstrip line structure using a high-temperature superconductor is employed (see, for example, Non-Patent Document 1). Here, in this specification, in the specific band, less than 1% is referred to as an ultra-narrow band, and less than 5% is referred to as a narrow band. The filter of this document is a five-stage Chebyshev type filter, which realizes a relative bandwidth of 0.014%. Such an ultra-narrow band filter requires very small coupling between resonators.

However, since the range of the coupling that can be changed by the distance between the resonator pair and that can obtain a stable coupling is limited, when a filter is configured using this resonator pair, The increase in the number of filter stages necessary for sharp cutting and the narrowing of the band cannot be achieved at the same time. In addition, weak coupling is indispensable in the ultra-narrow band filter. For this reason, if it is multistage, it becomes very large, and there are problems such as warping of the substrate, which makes it very difficult to realize. Furthermore, when trying to create a filter bank using a plurality of ultra-narrow band filters, the filter is originally composed of small coupling, so that weak coupling with another filter is effective and the characteristic is modulated. was there.
IEEE International Microwave Symposium Digest, Vol.3, June 2003., PP1881-4

  In order to realize an ultra narrow band filter as mentioned in the prior art, it is necessary to extremely weaken the coupling between the resonators. The strength of coupling between the resonators is related to the distance between the resonators, and weak coupling can be obtained by separating the distances between the resonators. However, the distance between the resonators is also limited by the substrate size. Therefore, in order to achieve weak coupling with a short inter-resonator distance, it is conceivable to make the substrate thin. If the substrate is made thinner, it is possible to achieve weak coupling at a short distance, but this time, in order to provide strong coupling, the resonators must be very close to each other, which makes manufacturing difficult. come.

  The present invention has been made in consideration of the above circumstances, and the object of the present invention is to provide various couplings between the resonators in the same substrate between the resonators, and to design high-frequency members of communication equipment. An object is to provide a microwave resonator pair, a microwave filter, and a group of microwave filters that can increase the tolerance.

  In order to solve the above problems, the present invention adopts the following configuration.

  That is, according to one aspect of the present invention, the first line-shaped electrode is formed on one main surface of the dielectric layer, and the first is configured by a microstrip line in which a common electrode is formed on the other main surface. And a second line electrode having a structure similar to that of the first resonator, the second line electrode being disposed adjacent to the first line electrode, and the common electrode being shared. A microwave resonator pair including a resonator, wherein one of the first and second resonators is different in thickness from the other dielectric layer.

  Another aspect of the present invention is a resonator including a microstrip line in which a line electrode is formed on one main surface of a dielectric layer and a common electrode is formed on the other main surface. A plurality of microwave filters arranged along one direction, wherein at least one of the resonators is thinner in thickness of the dielectric layer than the other resonators.

  According to still another aspect of the present invention, there is provided a first configuration including a microstrip line in which a line electrode is formed on one main surface of a dielectric layer and a common electrode is formed on the other main surface. A plurality of first microwave filters in which a plurality of resonators are arranged in one direction and a plurality of second resonators having a structure similar to that of the first resonator are arranged in one direction. And a microwave filter group having a second microwave filter arranged in parallel with the first microwave filter, wherein the dielectric layer in the first and second microwave filters has a film thickness. It is characterized by being different.

  According to the present invention, in a microstrip line structure formed on the same substrate, coupling between the adjacent resonators or different filters by changing the thickness of the dielectric layer in the same substrate (dielectric layer) Resonator pairs with different strengths can be arranged. Accordingly, it is possible to widen the design tolerance of the high-frequency member of the communication device, and its usefulness is great.

  Before describing the embodiments, the basic concept of the present invention will be described.

  As shown in FIG. 1, the configuration of the band pass filter is realized by an excitation line 1, a resonator 2, and couplings 3 and 4 formed by respective resonator pairs. As described above, in order to realize an ultra narrow band filter, it is necessary to extremely weaken the coupling between the resonators, and in order to achieve a weak coupling at a short distance between the resonators, a substrate (dielectric layer) is required. It needs to be thin.

  The relationship between the distance between the resonators and the strength of coupling when the substrate is thin is shown in FIG. In FIG. 2, the characteristic when the substrate is thick is also displayed as B so that the effect of thinning the substrate can be seen. From FIG. 2, if the substrate is made thinner, it is possible to achieve a weak coupling at a short distance. However, in this case, in order to have a strong coupling, the resonators must be very close together. Difficulties arise.

  Accordingly, the present inventors have devised a microstrip line structure in which a step is provided in the dielectric layer.

The relationship between the coupling coefficient k and the gap s between the resonators when the dielectric layer is thick and thin is shown in the characteristics A and B of FIG. 2, respectively. The size of the substrate x2, if the smallest gap possible at the time of the conductive pattern formation and x1, physically manufacturable gap s is, x1 <s <x2, and the corresponding to the section X _1-2 The coupling coefficient k is a realizable value of k.

If the thickness of the dielectric layer is uniform, the range of values of the resulting k is the interval when the thickness is thin ka (k _a1 ~k _a2), a thick case section kb (k _b1 to k _b2 ). The structure of the present invention, is spread thick portion and a thin portion, the thickness of the dielectric layer in two ways are present in the same substrate, the range of values of the resulting k is the interval K _ab (k _a1 ~k _b2) It will be.

  In addition, by changing the thickness of the dielectric layer and causing the resonator to have a desired coupling coefficient as described above, a strong and weak coupling coefficient can be realized on the same substrate without increasing the distance between the resonators. Therefore, it is possible to design a narrow-band sharp cut filter within a limited size substrate.

  If one of the two filters is made thinner, the coupling between the filters is weakened. When this is used for independent filters on the same substrate, the parasitic coupling between the filters can be greatly reduced, and the modulation or deterioration due to the parasitic coupling of the characteristics of each filter can be greatly reduced. That is, a plurality of filters can be arranged on the same substrate without affecting each characteristic. As a result, a large number of filters such as filter banks can be formed on the same substrate. Especially in the case of an ultra narrow band filter, the coupling within the filter is very weak and the coupling between the filters is very sensitive. It becomes effective.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
3A and 3B are diagrams for explaining a schematic configuration of the microwave filter according to the first embodiment of the present invention. FIG. 3A is a plan view, and FIG. It is -A 'sectional drawing. This filter is a two-stage filter (resonance frequency 5 GHz, band 2 MHz) using a microstrip line resonator pair.

  Line electrodes 14, 15 and 16 are formed on one main surface (front surface) of the substrate 11 as a dielectric layer, and a common electrode 13 is formed on the other main surface (back surface). The line electrode 14 is formed in an L-shaped pattern and functions as an excitation line. The line electrodes 15 and 16 are formed in a U-shaped pattern and constitute a resonator. That is, the line-shaped electrode 15 and the common electrode 13 constitute a first resonator 101 having a microstrip line structure, and the line-shaped electrode 16 and the common electrode 13 constitute a second resonator 102 having a microstrip line structure. Yes. The resonators 101 and 102 constitute a resonator pair, and the thickness of the substrate in the portion 12 where the resonator 102 is provided is thin.

  Next, the manufacturing procedure of the microstrip line structure will be described. As the dielectric layer, an MgO substrate 11 having a thickness of 0.5 mm and a relative dielectric constant of about 10 was used. On one surface of the substrate 11, a region (recessed region) 12 cut by 0.1 mm by ion milling was provided. And the YBCO thin film which is a superconducting film was formed in the front and back both surfaces of the board | substrate 11 with the laser vapor deposition method. Only the upper surface of this YBCO thin film was cut into the excitation line 14 and the patterns (15, 16) of the resonators 101, 102 by ion milling. The YBCO thin film on the lower surface side of the substrate 11 was used as it is as the common electrode 13. Although not shown in the drawing, Ag and Au layers are formed on the YBCO thin film by sputtering and ion milling at the electrode lead-out portion of the excitation wire 14 in order to make contact with the connector. .

  The characteristics of the two-stage filter of this embodiment are shown in FIG. The solid line in the figure is the characteristic of the element of the present embodiment, and the broken line is the characteristic of the conventional element. Compared to the case of using a conventional dielectric layer having a uniform thickness, the distance between the resonators is the same, but since the coupling between the resonators is small, the filter has a small band. It can be seen that is realized.

Here, YBCO, which is a superconductor, is used as a conductor for forming an electrode. However, in the case of another oxide superconductor, a metal-based superconductor, or a metal such as Au, the coupling is similarly small. A resonator pair can be realized. Further, the same effects as those of the present embodiment can be obtained as long as the substrate is made of a material capable of forming the conductor, such as sapphire and LaAlO ₃ . However, due to the nature of using a resonator, it is preferable to use a conductor with a small conductor loss or a substrate with a small dielectric loss as a component of the resonator.

  As described above, according to the present embodiment, the concave region 12 is provided in one of the adjacent resonators 101 and 102 to reduce the substrate thickness, thereby reducing the coupling between the resonators 101 and 102 and reducing the bandwidth. A smaller filter can be realized. Here, disposing the adjacent resonators 101 and 102 with a step as in the present embodiment can weaken the coupling between the resonators than simply disposing the resonators adjacent to each other on a thin dielectric layer. It is.

(Second Embodiment)
FIGS. 5A and 5B are diagrams for explaining a schematic configuration of a microwave filter according to the second embodiment of the present invention. FIG. 5A is a plan view, and FIG. It is -B 'sectional drawing. This filter is a Chebyshev 8-stage bandpass filter constituted by a microstrip line. In addition, the same code | symbol is attached | subjected to FIG. 3 (a) (b) and an identical part, and the detailed description is abbreviate | omitted.

  The filter of the present embodiment is designed with a center frequency of 5 GHz and a bandwidth of 2.5 MHz, and the coupling between the resonator pairs is reduced by alternately changing the thickness of the substrate. Therefore, an 8-stage ultra-narrow band filter can be realized with a relatively small filter occupation area of 30 mm × 40 mm and a small specific band of 0.05%.

  The manufacturing procedure of this filter structure will be described below. Similar to the first embodiment, an MgO substrate 11 having a thickness of 0.5 mm and a relative dielectric constant of about 10 was used as the dielectric layer. On the surface of the substrate 11, a recessed area 12 was provided by cutting 0.1 mm by ion milling. Then, YBCO thin films were formed on both surfaces of the substrate 11 by laser vapor deposition. The YBCO thin film was cut into patterns of excitation lines 14 and resonators 201, 202 (electrodes 17, 18, 19, 20, 21, 22, 23, 24) by ion milling. As in the first embodiment, Ag and Au are formed by sputtering and ion milling in the electrode lead-out portion of the excitation wire 14. The area occupied by the filter is 30 mm × 40 mm.

  In the pattern of FIG. 5A, the electrodes 17, 19, 21, and 23 constituting the first resonator 201 are formed on the dielectric layer portion having no step, and the electrodes 18, 20, and 22 and 24 are arranged in a stepped portion, that is, a portion 12 where the dielectric layer is 0.1 mm thinner. That is, the first resonator 201 having a thick dielectric layer and the second resonator 202 having a thin dielectric layer are alternately arranged.

  The characteristics of the band pass filter of this embodiment are shown in FIG. The solid line in the figure is the characteristic of the element of the present embodiment, and the broken line is the characteristic of the conventional element. From this figure, it can be seen that the element of this embodiment can realize good characteristics despite the ultra-narrow band.

Here, as described in the first embodiment, other oxide superconductors, metal-based superconductors, or metals such as Au can be used as conductors instead of YBCO. Further, as described in the first embodiment, a substrate on which the conductor such as sapphire and LaAlO ₃ can be formed can be used as the substrate.

  As described above, according to the present embodiment, by providing the recessed regions 12 having a thin dielectric layer thickness alternately in the arrangement direction of the resonators, the coupling between the adjacent resonators can be reduced. The same effects as those of the first embodiment can be obtained.

(Third embodiment)
FIGS. 7A and 7B are views for explaining a schematic configuration of a microwave filter according to the third embodiment of the present invention. FIG. 7A is a plan view, and FIG. It is -C 'sectional drawing. Similar to the second embodiment, this filter is a Chebyshev 8-stage bandpass filter configured by a microstrip line. In addition, the same code | symbol is attached | subjected to FIG. 3 (a) (b) and an identical part, and the detailed description is abbreviate | omitted.

  The filter of the present embodiment realizes a wider band than the second embodiment, with a center frequency of 5 GHz and a band of 10 MHz. In this case, the coupling amount of the resonator pair is set to three from small to relatively large. When a conventional dielectric substrate with a constant plate thickness is used, the distance between the resonators is too large in the case of small coupling, making it difficult to achieve stable coupling. Good coupling could be achieved by changing the dielectric thickness of each vessel.

  The manufacturing procedure of this microstrip line structure will be described below. As in the first embodiment, a MgO substrate 11 having a thickness of 0.5 mm and a relative dielectric constant of about 10 was used as the base dielectric layer. The surface of the substrate 11 was provided with a recessed area 12 cut by 0.1 mm and a recessed area 25 cut by 0.2 mm by ion milling. And the YBCO thin film was formed in the both main surfaces of the board | substrate 11 with the laser vapor deposition method. The YBCO thin film was cut into excitation lines 14 and resonator patterns (electrodes 26, 27, 28, 29, 30, 31, 32, 33) by ion milling. As in the first embodiment, Ag and Au are formed by sputtering and ion milling in the electrode lead-out portion of the excitation wire 14.

  In the pattern of FIG. 7A, the electrodes 26 and 33 are in a dielectric layer portion without a step, the electrodes 27, 28, 31, and 32 are in a portion 12 having a step of 0.1 mm, and the electrodes 29 and 30 have a step of 0. It is arranged in a 2 mm portion 25. Here, the coupling coefficient between the resonator by the electrode 26 and the resonator by the electrode 27 is k1, the coupling coefficient between the resonator by the electrode 27 and the resonator by the electrode 28 is k2, and the resonator and the electrode by the electrode 28 The coupling coefficient between the resonator by the electrode 29 and the resonator by the electrode 31 is k4, the coupling coefficient between the resonator by the electrode 29 and the resonator by the electrode 30 is k4, and the coupling coefficient between the resonator by the electrode 30 and the resonator by the electrode 31. , K5, the coupling coefficient between the resonator by the electrode 31 and the resonator by the electrode 32 is k6, and the coupling coefficient between the resonator by the electrode 32 and the resonator by the electrode 33 is k7. K1 = k7> k2 = k6> k3 = k5> k4.

  The characteristics of the bandpass filter of this embodiment are shown in FIG. The solid line in the figure is the characteristic of the element of the present embodiment, and the wavy line is the characteristic of the conventional element. From this figure, compared with the conventional element in which the plate thickness of the dielectric substrate is constant and the plate thickness is determined to obtain a large inter-resonator coupling, this embodiment element has a small to large coupling between the resonators. It can be seen that good characteristics can be realized as the existing filter.

As described in the first embodiment, other oxide superconductors, metal superconductors, or metals such as Au can be used as conductors instead of YBCO. Further, as described in the first embodiment, a substrate on which the conductor such as sapphire and LaAlO ₃ can be formed can be used as the substrate.

  As described above, according to the present embodiment, the concave region 12 is provided in the dielectric substrate 11 and the portions 25 having different film thicknesses are provided in the concave region 12, so that various couplings can be made between the resonators in the same substrate. Can have. For this reason, the tolerance of design of the high frequency member of a communication apparatus can be expanded greatly. Therefore, the degree of freedom in designing a microwave component using a resonator can be greatly increased, and integration of an ultra-narrow band sharp cut filter, which has been impossible in the past, and a filter having greatly different bands on the same substrate can be realized. .

(Fourth embodiment)
FIGS. 9A and 9B are diagrams for explaining a schematic configuration of a microwave filter group according to the fourth embodiment of the present invention. FIG. 9A is a plan view, and FIG. 9B is a plan view. It is DD 'sectional drawing of. This filter group is two types of 8-stage bandpass filters. In addition, the same code | symbol is attached | subjected to the part same as FIG. 3 (a) (b), and the detailed description is abbreviate | omitted.

  Two types of 8-stage bandpass filters are formed on the same substrate made of a dielectric layer. That is, a first filter having a center frequency of 4.92 GHz and a band of 10 MHz and a second filter having a center frequency of 4.94 GHz and a band of 5 MHz are arranged on the same substrate.

  Isolation between filters is very important in integrating filters used for filter banks and the like. This isolation becomes a problem particularly in a narrow band filter having a small coupling. In the present embodiment, the present invention is applied to a pair of resonators belonging to different filters to configure a narrowband filter group in which the interaction between the filters is sufficiently reduced.

  In production, as in the first embodiment, a MgO substrate 11 having a thickness of 0.5 mm and a relative dielectric constant of about 10 was used as a substrate as a dielectric layer serving as a base. A concave region 25 having a step of 0.2 mm was formed on the surface of the substrate 11 by ion milling. Then, YBCO thin films were formed on both surfaces of the substrate 11 by laser vapor deposition. The YBCO thin film was cut into excitation lines 14 and resonator patterns (electrodes 34 and 35) by ion milling. That is, as the first filter 401, the electrode 34 is disposed in the dielectric layer portion having no step, and as the second filter 402, the electrode 35 is disposed in the portion 25 having the step, that is, the portion 25 where the dielectric layer is 0.2 mm thin. did. The excitation line 14 was formed in a portion having no step in any of the filters 401 and 402.

  The characteristics of the microwave filter group (both bandpass filters) of this embodiment are shown in FIG. From this figure, it can be seen that the modulation of the characteristic due to the mutual interference is not seen and the filter is realized as an independent filter.

As described in the first embodiment, other oxide superconductors, metal superconductors, or metals such as Au can be used as conductors instead of YBCO. Further, as described in the first embodiment, a substrate on which the conductor such as sapphire and LaAlO ₃ can be formed can be used as the substrate.

  As described above, according to the present embodiment, the first and second filters 401 and 402 formed on the same substrate 11 are formed on the same substrate 11 by changing the film thicknesses of the dielectric layers in the respective filters. Filters 401 and 402 having different characteristics can be realized. That is, by simply changing the film thickness of the dielectric layer, two filters having different couplings between the resonators can be easily manufactured in the same substrate. Therefore, the degree of freedom in designing a microwave component using a resonator can be greatly increased, and integration of an ultra-narrow band sharp cut filter, which has been impossible in the past, and a filter having greatly different bands on the same substrate can be realized. .

(Fifth embodiment)
FIGS. 11A and 11B are views for explaining a schematic configuration of a microwave filter group according to the fifth embodiment of the present invention. FIG. 11A is a plan view, and FIG. It is DD 'sectional drawing. This group of filters is three types of eight-stage bandpass filters having different bandwidths. In addition, the same code | symbol is attached | subjected to FIG. 3 (a) (b) and an identical part, and the detailed description is abbreviate | omitted.

  Three types of eight-stage bandpass filters are formed on the same substrate made of a dielectric layer. That is, three filters having a common center frequency of 5 GHz and bandwidths of 5 MHz, 7 MHz, and 10 MHz are integrated on a single substrate. As described above, even when the coupling value to be used varies greatly due to the different bands, the present embodiment enables integration on the same substrate.

  In manufacturing, as in the first embodiment, a MgO substrate 11 having a thickness of 0.5 mm and a relative dielectric constant of about 10 was used as a substrate as a dielectric layer serving as a base. On the surface of the substrate 11, a step was formed between the recessed region 12 cut by 0.1 mm and the recessed region 25 cut by 0.2 mm by ion milling. And the YBCO thin film was formed in the both main surfaces of the board | substrate 11 with the laser vapor deposition method. The YBCO thin film was cut into excitation lines 14 and resonator patterns (electrodes 36, 37, 38) by ion milling. That is, as the first filter (broadband bandpass filter) 501, the electrode 37 is disposed on the dielectric layer portion without a step, and as the second filter (intermediate bandpass filter) 502, the dielectric layer has a thickness of 0.1 mm. The electrode 38 is disposed on the thin portion 12, and the resonator 36 is disposed on the portion 25 where the dielectric layer is 0.2 mm thin as a third filter (narrow bandwidth bandpass filter) 503. The excitation line 14 was formed in a portion having no step in any filter.

  The characteristics of the microwave filter group of this embodiment are shown in FIG. In the figure, the dotted line indicates the characteristics of the first filter 501, the broken line indicates the characteristics of the second filter 502, and the solid line indicates the characteristics of the third filter 503. As can be seen from the figure, bandpass filters with different bandwidths on the same substrate were fabricated, which were difficult to achieve with a conventional microstrip line structure with no characteristic modulation and a uniform dielectric layer thickness. did it.

In this filter group, the thinnest dielectric layer portion is arranged at the center so that the band-pass filters are separated from each other. In addition, as described in the first embodiment, other oxide superconductors, metal-based superconductors, or metals such as Au can be used as conductors instead of YBCO. Further, as described in the first embodiment, a substrate on which the conductor such as sapphire and LaAlO ₃ can be formed can be used as the substrate.

  As described above, according to the present embodiment, in the first to third filters 501 to 503 formed on the same substrate 11, the film thickness of the dielectric layer in each filter is made different, so that the same substrate 11 is formed. Filters 501 to 503 having different characteristics can be realized. That is, only by changing the film thickness of the dielectric layer, three filters having different couplings between the resonators can be easily manufactured in the same substrate. Therefore, the same effect as in the fourth embodiment can be obtained.

(Modification)
The present invention is not limited to the above-described embodiments. Various modifications can be made to the conductor and the dielectric layer constituting the microstrip line as described above. Furthermore, conditions such as the number of arranged resonators, the type of the thin portion of the dielectric layer, the arrangement method, and the like can be appropriately changed according to the specifications. Moreover, although the example applied to the filter was described in the embodiment, the present invention is not necessarily limited to the filter, and can be applied to various devices using a resonator.

  In addition, various modifications can be made without departing from the scope of the present invention.

The schematic diagram which shows the basic composition of a bandpass filter. The characteristic view which shows the relationship between the gap of the microstrip line resonator pair comprised in the dielectric material layer from which thickness differs, and a coupling coefficient. The top view and sectional view showing the schematic structure of the microwave filter concerning a 1st embodiment. The figure which shows the characteristic of the microwave filter concerning 1st Embodiment. The top view and sectional drawing which show schematic structure of the microwave filter concerning 2nd Embodiment. The figure which shows the characteristic of the microwave filter concerning 2nd Embodiment. The top view and sectional drawing which show schematic structure of the microwave filter concerning 3rd Embodiment. The figure which shows the characteristic of the microwave filter concerning 3rd Embodiment. The top view and sectional drawing which show schematic structure of the microwave filter group concerning 4th Embodiment. The figure which shows the characteristic of the microwave filter group concerning 4th Embodiment. The top view and sectional drawing which show schematic structure of the microwave filter group concerning 5th Embodiment. The figure which shows the characteristic of the microwave filter group concerning 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Excitation line 2 ... Resonator 3 ... Coupling between excitation line and resonator 4 ... Coupling between resonators 11 ... Substrate (dielectric layer)
12 ... recessed area 13 ... common electrode 14 ... line electrode (excitation line)
15 to 24, 26 to 38 ... line electrode 25 ... recessed region 101, 201 ... first resonator 102, 202 ... second resonator 401, 501 ... first microwave filter 402, 502 ... second Microwave filter 503 ... Third microwave filter

Claims (5)

A first resonator constituted by a microstrip line in which a first line-shaped electrode is formed on one main surface of the dielectric layer and a common electrode is formed on the other main surface;
A second resonator having a structure similar to that of the first resonator, the second line electrode being disposed adjacent to the first line electrode, and the common electrode being shared. And
A microwave resonator pair, wherein one of the first and second resonators is different in thickness from the other dielectric layer. A plurality of resonators composed of microstrip lines in which a line electrode is formed on one main surface of the dielectric layer and a common electrode is formed on the other main surface are arranged along one direction. A microwave filter,
At least one of the resonators is characterized in that the dielectric layer is thinner than the other resonators.   3. The microwave filter according to claim 2, wherein the resonators are adjacent to each other and have different thicknesses of the dielectric layer.   The resonator includes a first resonator in which the dielectric layer is thick and a second resonator in which the dielectric layer is thin, and the first and second resonators are alternately arranged. The microwave filter according to claim 3, wherein the microwave filter is provided. A plurality of first resonators including a microstrip line in which a line electrode is formed on one main surface of the dielectric layer and a common electrode is formed on the other main surface are provided along one direction. A first microwave filter arranged;
A plurality of second resonators having a structure similar to that of the first resonator, and a second microwave filter arranged in parallel with the first microwave filter; And
A group of microwave filters, wherein the dielectric layers of the first and second microwave filters have different thicknesses.

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