JP2004260376A - Laminated strip line filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized laminated strip line filter which can provide filter characteristics having attenuation poles of different frequencies. <P>SOLUTION: The laminated strip line filter has first to third dielectric layers 10-12 that are sequentially laminated. In the layers 10-12, first and second resonators 30, 31 are disposed in parallel with the second dielectric layer 11 inserted between them so that they are at least partly overlapped as seen from the laminating direction, the first and third resonators 30, 32 are disposed in parallel with the second dielectric layer 11 inserted between them so that they are at least partly overlapped as seen from the laminating direction, and rectangular resonance electrodes forming the resonators have different widths and different widths of overlapped portions thereof. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a laminated strip line filter used in a wireless communication device such as a mobile phone and a wireless LAN, and various other communication devices.
[0002]
[Prior art]
In recent years, filters used in mobile communication devices such as mobile phones have been resonating from distributed filters using filters using dielectric coaxial resonators in response to demands for thinner and smaller mobile communication devices. To the multilayer stripline filter used in the vessel.
[0003]
FIG. 4 is a perspective view, FIG. 5 is a perspective plan view, and FIG. 6 is a cross-sectional view taken along line bb ′ in FIG. 5 as such a laminated strip line filter. Reference 1).
[0004]
4 to 6, reference numeral 40 denotes a first dielectric layer, 41 denotes a second dielectric layer laminated on the first dielectric layer 40, and 42 denotes a second dielectric layer on the second dielectric layer 41. The laminated third dielectric layer, 50 is a first ground electrode disposed on the lower surface of the first dielectric layer 40, and 51 is the second ground electrode disposed on the upper surface of the third dielectric layer 42 The electrodes, 52 and 53, are a first one-end open rectangular resonance electrode and a first one-end short-circuit rectangular resonance electrode disposed between the first and second dielectric layers 40, 41. The second one-end open rectangular resonance electrode and the second one-end short-circuit rectangular resonance electrode 56 and 57 disposed between the third dielectric layers 41 and 42 are the second and third dielectric layers 41 and 42. A third one-end open rectangular resonance electrode and a third one-end short-circuited rectangular resonance electrode 58 disposed between the first one end and the third one end Each of the open ends of the rectangular resonant electrode 52, 54, 56 release, 59 is a respective short-circuit ends of the first to third one end shorted rectangular resonant electrode 53, 55, 57.
[0005]
As shown in WA, WB, WC, and WD in FIGS. 5 and 6, the first and second rectangular open-ended resonant electrodes 52 and 54 each have at least one of the respective electrodes sandwiching the second dielectric layer 41. The portions are arranged in parallel so as to overlap by the width of WA when viewed from the laminating direction, and the first and third open-ended rectangular resonant electrodes 52 and 56 are at least each of which sandwiches the second dielectric layer 41. Some are arranged in parallel so that they may overlap with the width of WB when viewed from the laminating direction. Further, the first and second one-end short-circuited rectangular resonance electrodes 53 and 55 are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps with the width WC when viewed from the lamination direction. At the same time, the first and third single-ended short-circuited rectangular resonant electrodes 53 and 57 are arranged in parallel with the second dielectric layer 41 interposed therebetween so that at least a part thereof overlaps with the width of WD when viewed in the laminating direction. Have been.
[0006]
The first and second ground electrodes 50 and 51 are first to third open-ended rectangular resonant electrodes 52, 54 and 56, and first to third single-ended short-circuited rectangular resonant electrodes 53 when viewed from the stacking direction.・ It is arranged to cover 55 and 57.
[0007]
Then, an end of the first one-end open rectangular resonance electrode 52 opposite to the open end 58 and an end of the first one-end short-circuit rectangular resonance electrode 53 opposite to the short-circuit end 59 are electrically connected. To form a first resonator, and an end opposite to the open end 58 of the second one-end open rectangular resonance electrode 54 and an end opposite to the short-circuit end 59 of the second one-end short-circuit rectangular resonance electrode 55. Are electrically connected to each other to form a second resonator, and an end of the third one-end open rectangular resonance electrode 56 opposite to the open end 58 is connected to the third one-end short-circuit rectangular resonance. The third resonator is formed by electrically connecting the short-circuit end 59 of the electrode 57 to the opposite end.
[0008]
The second resonator and the third resonator are arranged at symmetrical positions in a line-symmetric shape with respect to the central axis cc ′, and the first resonator is line-symmetric with respect to the central axis cc ′. It is formed in a suitable shape.
[0009]
Further, an input (output) terminal is electrically connected to the second resonator, and an output (input) terminal is electrically connected to the third resonator.
[0010]
The distance Wopen between the second one-end open rectangular resonance electrode 54 and the third one-end open rectangular resonance electrode 56, or the second one-end open short-circuit resonance electrode 55 and the third one-end short-circuit rectangular resonance electrode 57 By adjusting the distance Wshort with respect to the pass band, a filter characteristic having one attenuation pole on each of the high band side and the low band side with respect to the pass band is realized. Further, by using a plurality of additional resonators, a filter characteristic having two or more attenuation poles having different frequencies has been realized.
[0011]
[Patent Document 1]
JP-A-8-70201
[Problems to be solved by the invention]
However, since such a conventional laminated strip line filter has a line-symmetric structure, the shapes WA, WB, WC, and WD of the overlapping portions of the resonator electrodes are the same on the left and right with respect to the center axis cc ′. I have to be. The attenuation pole of the filter characteristic is generated by the electromagnetic field coupling at the overlapping portion of the respective resonance electrodes. As a result, there is a problem that only a single characteristic is obtained for the frequency of the attenuation pole, and a filter characteristic having a plurality of different attenuation poles cannot be realized. In addition, in order to realize a filter characteristic having a plurality of different attenuation poles, it is necessary to add a resonator having an axially symmetric structure in which overlapping portions have different shapes, resulting in an increase in the overall size of the filter. was there.
[0013]
The present invention has been devised in view of the above problems, and an object of the present invention is to provide a multilayer strip line filter that is small in size and can realize filter characteristics having attenuation poles of different frequencies. To provide.
[0014]
[Means for Solving the Problems]
The laminated strip line filter of the present invention has a first dielectric layer, a second dielectric layer laminated on the first dielectric layer, and a laminated layer on the second dielectric layer. A third dielectric layer, a first ground electrode disposed on a lower surface of the first dielectric layer, and a first open end disposed between the first and second dielectric layers. A rectangular resonant electrode and a first one-end short-circuited rectangular resonant electrode, and a second open-ended rectangular resonant electrode and a second short-circuited one-end rectangular disposed between the second and third dielectric layers A resonance electrode, a third one-end open rectangular resonance electrode, a third one-end short-circuit rectangular resonance electrode, and a second ground electrode disposed on the upper surface of the fourth dielectric layer. And at least part of each of the second one-end open rectangular resonance electrodes is laminated with the second dielectric layer interposed therebetween. And the first and third one-end open rectangular resonance electrodes are overlapped with each other with the second dielectric layer interposed therebetween when viewed from the laminating direction. And the first and second one-end short-circuited rectangular resonance electrodes are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps when viewed from the lamination direction with the second dielectric layer interposed therebetween. The first and third one-end short-circuited rectangular resonance electrodes are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps when viewed from the lamination direction, with the second dielectric layer interposed therebetween. The ground electrode is disposed so as to cover the first to third single-ended rectangular resonant electrodes and the first to third single-ended short-circuited rectangular resonant electrodes when viewed from the lamination direction, and the first single-ended open rectangular shape. Open end of resonance electrode The first end is formed by electrically connecting the end on the side of the first side and the end on the side opposite to the short-circuited end of the first one-end short-circuited rectangular resonance electrode, and the second end-opened rectangular shape is formed. An end opposite to the open end of the resonance electrode and an end opposite to the short-circuit end of the second one-end short-circuited rectangular resonance electrode are electrically connected to form a second resonator; An end opposite to the open end of the third one-end open rectangular resonance electrode and an end opposite to the short-circuit end of the third one-end short-circuit rectangular resonance electrode are electrically connected to each other to form a third end. A resonator is formed, overlapping widths of the first open-ended rectangular resonant electrode and the second and third open-ended rectangular resonant electrodes are different from each other, and the first open-ended rectangular resonant electrode is different from each other. The overlap widths of the shape resonance electrode and the second and third one-end short-circuited rectangular resonance electrodes have different dimensions, respectively. The input terminal of the second resonator and the output terminal of the third resonator are electrically connected, or the output terminal of the second resonator and the input terminal of the third resonator are electrically connected. It is characterized by the fact that the connection is made.
[0015]
According to the laminated strip line filter of the present invention, the overlapping widths of the first open-ended rectangular resonant electrode and the second and third open-ended rectangular resonant electrodes have different dimensions, and The overlapping widths of the first single-ended short-circuited rectangular resonant electrode and the second and third single-ended short-circuited rectangular resonant electrodes have different dimensions, so that the first and second and the first and third resonant electrodes are different. Are different from each other in shape, and as a result, the amount of electromagnetic field coupling between the first and second and first and third resonance electrodes is different, so that attenuation poles having different frequencies are generated. Can be.
[0016]
Further, in the laminated strip line filter of the present invention, in the above-described configuration, each of the ground electrodes, or each of the short-circuited ends of each of the short-circuited rectangular resonance electrodes and each of the ground electrodes is formed inside the dielectric layer. Characterized in that they are electrically connected in the stacking direction by the through conductor and / or the side conductor formed on the side surface.
[0017]
Thereby, the degree of freedom in designing the laminated strip line filter formed inside the plurality of laminated dielectric layers is improved, and a compact and high-performance laminated strip line filter can be provided.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the laminated strip line filter of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 is a perspective view showing an example of an embodiment of the laminated strip line filter of the present invention. FIG. 2 is a perspective plan view of FIG. 1 viewed from the laminating direction. FIG. 3 is a line aa ′ in FIG. It is sectional drawing. 1 to 3, reference numeral 10 denotes a first dielectric layer, 11 denotes a second dielectric layer laminated on the first dielectric layer 10, and 12 denotes a second dielectric layer on the second dielectric layer 11. The laminated third dielectric layer, 20 is a first ground electrode disposed on the lower surface of the first dielectric layer 10, and 21 is the second ground electrode disposed on the upper surface of the third dielectric layer 12. The electrodes, 22 and 23, are a first one-end open rectangular resonance electrode and a first one-end short-circuit rectangular resonance electrode disposed between the first and second dielectric layers 10 and 11, and 24 and 25 are the second and The second one-end open rectangular resonance electrode and the second one-end short-circuit rectangular resonance electrode, 26 and 27, disposed between the third dielectric layers 11 and 12, respectively, are the second and third dielectric layers 11 and 12. A third one-end open rectangular resonance electrode and a third one-end short-circuit rectangular resonance electrode, which are disposed between the first and third pieces Each of the open end of the open rectangular resonant electrode 22, 24, and 26, 29 are each of a short-circuit ends of the first to third one end shorted rectangular resonant electrodes 23, 25 and 27. The first to third one-end short-circuited rectangular resonance electrodes 23, 25, and 27 are electrically connected to the first ground electrode 20 and the second ground electrode 21, and are short-circuited (not shown).
[0020]
Then, as shown in WA, WB, WC, and WD in FIGS. 2 and 3, the first and second rectangular open-ended resonant electrodes 22 and 24 each have at least each of the second dielectric layers 11 interposed therebetween. A part thereof is arranged in parallel with an overlapping width so as to overlap with the width of WA when viewed from the laminating direction, and the first and third open-ended rectangular resonant electrodes 22 and 26 sandwich the second dielectric layer 11 therebetween. Are arranged in parallel with an overlapping width such that at least a part of each overlaps with the width of WB when viewed from the stacking direction. The first and second one-end short-circuited rectangular resonant electrodes 23 and 25 are parallel with an overlapping width such that at least a part of each of the first and second short-circuited rectangular resonant electrodes overlaps with the width of WC when viewed from the laminating direction. And the first and third single-ended short-circuited rectangular resonance electrodes 23 and 27 are arranged such that at least a part of each of the first and third short-circuited rectangular resonance electrodes overlaps with the width of WD when viewed from the lamination direction with the second dielectric layer 11 interposed therebetween. They are arranged in parallel with the overlap width. Further, the first and second ground electrodes 20 and 21 are first to third single-ended rectangular resonant electrodes 22, 24 and 26, and first to third single-ended short-circuited rectangular resonant electrodes 23 when viewed from the lamination direction.・ It is arranged to cover 25 and 27.
[0021]
Then, an end of the first one-end open rectangular resonance electrode 22 opposite to the open end 28 and an end of the first one-end short-circuit rectangular resonance electrode 23 opposite to the short-circuit end 29 are electrically connected. To form a first resonator 30, which is opposite to the end of the second one-end open rectangular resonance electrode 24 opposite to the open end 28 and the short-circuit end 29 of the second one-end short-circuit rectangular resonance electrode 25. The other end is electrically connected to form a second resonator 31, and the end of the third one-end open rectangular resonance electrode 26 opposite to the open end 28 is connected to the third one-end short-circuited rectangular. A third resonator 32 is formed by electrically connecting the short-circuited end 29 of the shape resonance electrode 27 and the opposite end.
[0022]
Further, the width of the portion where the first open-ended rectangular resonant electrode 22 and the second and third open-ended rectangular resonant electrodes 24 and 26 overlap each other when viewed in the laminating direction, that is, the overlapping widths WA and WB are different from each other. The overlapping widths WC and WD of the portions where the first one-end short-circuited rectangular resonance electrode 23 and the second and third one-end short-circuited rectangular resonance electrodes overlap each other when viewed in the laminating direction are different from each other.
[0023]
The widths W22, W24, and W26 of the first to third one-end open rectangular resonance electrodes have different dimensions, and the widths W23, W25, and W27 of the first to third one-end short-circuit rectangular resonance electrodes have different dimensions. By changing the arrangement in the width direction of the first to third one-end open rectangular resonance electrodes and the one-end short-circuit rectangular resonance electrodes 22 to 27, or by combining them, the first The overlapping widths WA and WB of the one-end open rectangular resonance electrode 22 and the second and third one-end open rectangular resonance electrodes 24 and 26 have different dimensions, and the first one-end short-circuit rectangular resonance electrode 23 and the second And the overlapping widths WC and WD with the third single-ended short-circuited rectangular resonant electrodes 25 and 27 can be different in size, so that the overlapping width WA and the overlapping width WC and the overlapping width WB overlap. Ri is the area of the portion to be formed becomes different between the width WD, it can be made to different electromagnetic coupling amount generated in this portion to each other.
[0024]
The overlap width WA of the first one-end open rectangular resonance electrode 22 and the second one-end open rectangular resonance electrode 24, the first one-end short-circuit rectangular resonance electrode 23, and the second one-end short-circuit rectangular resonance electrode 25 Can form a resonance circuit between the first and second resonators 30 and 31 by electromagnetic field coupling, and can generate the first attenuation pole. Also, the overlap width WB of the first open-ended rectangular resonant electrode 22 and the open-ended rectangular resonant electrode 26, the first open-ended rectangular resonant electrode 23, and the open-ended rectangular resonant electrode 27 Another resonance circuit having an electromagnetic field coupling amount different from the previous electromagnetic field coupling can be formed between the first and third resonators 30 and 32 by the overlap width WD of the first and third resonators 30 and 32, and the second attenuation pole is generated. Can be done.
[0025]
The widths W23, W25, and W27 of the first to third single-ended short-circuited rectangular resonant electrodes 23, 25, and 27 with respect to the widths W22, W24, and W26 of the first to third single-ended rectangular electrodes 22, 24, and 26, respectively. And the first one-ended short-circuited rectangular resonance electrode 23 and the second and third electrodes for the overlap width WA / WB of the first one-ended open rectangular resonance electrode 22 and the second and third one-ended open rectangular resonance electrodes 24 and 26. The overlap widths WC and WD with the third one-end short-circuited rectangular resonance electrode are formed to have different dimensions depending on the filter characteristics to be realized.
[0026]
Further, the input terminal 33 is electrically connected to the second resonator 31, and the output terminal 34 is electrically connected to the third resonator 32, and is connected to an external circuit. Note that the input terminal 33 can be an output terminal and the output terminal 34 can be an input terminal as necessary.
[0027]
In the laminated strip line filter of the present invention having such a configuration, the first and second ground electrodes 20 and 21 or the first and second ground electrodes 20 and 21 and the first to third single-ended short-circuited rectangular shapes are provided. The short-circuited ends 29 of the resonance electrodes 23, 25, 27 are formed by through conductors (not shown) formed inside the dielectric layer, or by side conductors (not shown) formed on the side surfaces of the dielectric layer. Alternatively, by using a configuration in which the through conductors and the side conductors are electrically connected in the stacking direction, a three-dimensional wiring design can be appropriately performed for the filter structure to be applied. The design flexibility of the laminated strip line filter formed inside the body layer is improved, and a compact and high-performance laminated strip line filter can be provided.
[0028]
In forming the laminated strip line filter of the present invention, first to third dielectric layers 10 to 12, first and second ground electrodes 20 and 21, first to third open-ended rectangular resonant electrodes 22 24, 26 and the first to third single-ended short-circuited rectangular resonance electrodes 23, 25, 27 can be made of various materials and forms used for known high-frequency wiring boards.
[0029]
As the first to third dielectric layers 10 to 12 used in the laminated strip line filter of the present invention, for example, ceramic materials such as alumina ceramics and mullite ceramics, inorganic materials such as glass ceramics, and ethylene tetrafluoride resin ( Polytetrafluoroethylene; PTFE) / ethylene tetrafluoride-ethylene copolymer resin (tetrafluoroethylene-ethylene copolymer resin; ETFE) / ethylene tetrafluoride-perfluoroalkoxyethylene copolymer resin (tetrafluoroethylene-perfluoroalkyl) Fluororesins such as vinyl ether copolymer resin (PFA) and resin materials such as glass epoxy resin and polyimide are used. The shapes and dimensions (thickness, width, and length) of the first to third dielectric layers 10 to 11 made of these materials are set according to the frequency used, the application, and the like.
[0030]
The first and second ground electrodes 20 and 21, the first to third one-end open rectangular resonant electrodes 22, 24 and 26, and the first to third one-end short-circuit rectangular resonant electrodes in the laminated strip line filter of the present invention. 23, 25, 27, through conductors or side conductors are obtained by applying a Ni plating layer and an Au plating layer on a conductor layer of a metal material for high-frequency signal transmission, for example, a Cu layer / Mo-Mn metallized layer. Ni plating layer and Au plating layer deposited on W metallized layer Cr-Cu alloy layer Ni plating layer and Au plating layer deposited on Cr-Cu alloy layer Ta ₂ N A Ni-Cr alloy layer and an Au plating layer deposited on a layer; a Pt layer and an Au plating layer deposited on a Ti layer; or a Pt layer and an Au plating layer on a Ni-Cr alloy layer Adhere to Using what was the like, and is formed by a thick film printing method or various thin film forming method or a plating method or the like. The thickness and width are also set according to the frequency of the transmitted high-frequency signal, the application, and the like.
[0031]
In producing the first to third dielectric layers 10 to 12 used in the laminated strip line filter of the present invention, for example, when the dielectric layer is made of glass ceramic, first, a green ceramic glass to be a dielectric layer is used. A sheet is prepared, and a predetermined punching process is performed on the sheet to form a through hole serving as a through conductor. Then, the through hole is filled with a conductive paste such as Cu by a screen printing method, and a predetermined transmission line pattern and other Print and apply the conductor layer pattern. Next, baking is performed at 850 to 1000 ° C., and finally Ni plating and Au plating are performed on the conductor layer exposed on the outer surface.
[0032]
【Example】
As an embodiment, in the laminated strip line filter of the present invention having the configuration shown in FIGS. 1 to 3, a structural model for realizing filter characteristics having one attenuation pole on each of a high band side and a low band side with respect to a pass band. Was fabricated on a three-dimensional electromagnetic field analysis simulator, and simulation analysis was performed.
[0033]
For example, in the case of the simulation in the laminated strip line filter of the present invention having the configuration shown in FIGS. 1 to 3, the thickness of each of the first to third dielectric layers 10 to 12 is set to the first dielectric layer h1 = 0.2 mm. , The second dielectric layer h2 = 0.2 mm, the third dielectric layer h3 = 0.2 mm,
The width W22, W24, W26 of each of the first to third one-end open rectangular resonance electrodes 22, 24, 26 and the length L22, L24, L26 of each resonance electrode are W22 = 2.35 mm, W24. = 1.2 mm, W26 = 1.34 mm, L22 = L24 = L26 = 2.367 mm,
The width W23 / W25 / W27 of each of the first to third one-end short-circuited rectangular resonance electrodes 23/25/27 and the length L23 / L25 / L27 of each resonance electrode are W23 = 2.35 mm and W25, respectively. = 1.34 mm, W27 = 1.2 m, L23 = L25 = L27 = 2.367 mm,
The width WA of the portion where the first and second open-ended rectangular resonant electrodes 22 and 24 overlap when viewed in the stacking direction is 0.55 mm, and the first and second short-circuited rectangular resonant electrodes 23 and 25 are stacked from the stacking direction. It is assumed that the overlap width WC of the overlapping portions is 0.22 mm,
The width WB = 0.22 mm of the portion where the first and third one-end open rectangular resonant electrodes 22 and 26 overlap when viewed from the laminating direction, and the first and third one-end short-circuit rectangular resonant electrodes 23 and 27 are from the laminating direction. The overlapping width WD of the overlapping portions is set to 0.55 mm. The relative dielectric constant of each dielectric layer used in the simulation was set to 7.7.
[0034]
FIG. 7 shows a simulation result under the above conditions. In FIG. 7, the horizontal axis represents frequency (unit: GHz), and the vertical axis represents insertion loss (unit: dB). As can be seen from the results shown in FIG. 7, it can be seen that attenuation poles fr1 and fr2 having different frequencies are generated on the low band side and the high band side with respect to the pass band.
[0035]
The attenuation pole is an overlapping portion between the first one-end open (short-circuit) rectangular resonance electrode 22 (23) and the second and third one-end open (short-circuit) rectangular resonance electrodes 24 (25) and 26 (27). The electromagnetic field coupling between the electrodes can be increased by increasing the area of the overlapping portion to obtain a stronger electromagnetic field coupling, or by reducing the area of the overlapping portion to obtain a weaker electromagnetic field coupling. Since the values of L and C, which are distributed constants that form a resonance circuit by coupling, can be changed, the attenuation pole can be changed to a high frequency side or a low frequency side. In the laminated strip line filter of the present invention in this embodiment, filter characteristics having different attenuation poles can be realized by the widths W22 to W27 of the first to third one-end open (short-circuited) rectangular resonance electrodes, and the first to third resonance electrodes. And the second and third single-ended (short-circuited) rectangular resonant electrodes 24 (25) and 26 (27) are formed with different dimensions, respectively. The reason for this is that, because of the arrangement, the shapes of the respective overlapping portions of the resonance electrodes are different, and as a result, the amount of electromagnetic field coupling between the resonance electrodes is also different, so that attenuation poles having different frequencies can be generated. .
[0036]
Further, in the laminated strip line filter of the present invention, in the above-described configuration, the connection conductor for electrically connecting the first and second ground electrodes 20 and 21 in the lamination direction, or the first to third single-ended short-circuited rectangular resonances are provided. Connection conductors for electrically connecting the short-circuited ends 29 of the electrodes 23, 25 and 27 and the first and second ground electrodes 20 and 21 in the laminating direction are provided on the through conductors and / or side surfaces formed inside the dielectric layer. It is characterized by being formed side conductors, thereby improving the design flexibility of a laminated strip line filter formed inside a plurality of laminated dielectric layers, and having a small size and high performance. A laminated stripline filter can be provided.
[0037]
It should be noted that the present invention is not limited to the above-described embodiments, and various changes and improvements may be made without departing from the spirit of the present invention.
[0038]
For example, when it is desired to further generate an attenuation pole, a new resonator having a different shape may be added.
[0039]
【The invention's effect】
According to the laminated strip line filter of the present invention, the overlapping widths of the first one-end open (short-circuit) rectangular resonance electrode and the second and third one-end open (short-circuit) rectangular resonance electrodes are formed with different dimensions. Therefore, the shapes of the overlapping portions of the first and second and first and third resonance electrodes are different from each other. As a result, the electromagnetic field coupling amount between the first and second and first and third resonance electrodes is different. Therefore, attenuation poles having different frequencies can be generated.
[0040]
Further, according to the laminated strip line filter of the present invention, in the above-described configuration, each ground electrode, or the short-circuited end of each one-end short-circuited rectangular resonance electrode and each ground electrode are formed in the through conductor formed inside the dielectric layer. And / or when electrically connected in the laminating direction by side conductors formed on the side surfaces, the degree of freedom in designing a laminated strip line filter formed inside a plurality of laminated dielectric layers is improved, and the size is reduced. And a high-performance laminated strip line can be provided.
[0041]
As described above, according to the present invention, it is possible to provide a multilayer strip line filter that is small and can realize filter characteristics having attenuation poles of different frequencies.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an embodiment of a laminated strip line filter of the present invention.
FIG. 2 is a perspective plan view showing an example of an embodiment of the laminated strip line filter of the present invention.
FIG. 3 is a sectional view taken along line aa ′ in FIG. 2;
FIG. 4 is a perspective view showing an example of a conventional laminated strip line filter.
FIG. 5 is a perspective plan view showing an example of a conventional laminated strip line filter.
FIG. 6 is a sectional view taken along line bb ′ in FIG. 5;
FIG. 7 is a diagram showing an example of insertion loss in the laminated strip line filter of the present invention.
[Explanation of symbols]
Reference Signs List 10 first dielectric layer 11 second dielectric layer 12 third dielectric layer 20 first ground electrode 21 second ground electrode 22 ..First one-end open rectangular resonance electrode 23... First one-end short-circuit rectangular resonance electrode 24... Second one-end open rectangular resonance electrode 25. 26 third third-end open rectangular resonant electrode 27 third third short-circuited rectangular resonant electrode 28 open end 29 short-circuit end 30 first resonator 31 -Second resonator 32 ... Third resonator 33 ... Input terminal (output terminal)
34 output terminal (input terminal)

Claims (2)

A first dielectric layer, a second dielectric layer laminated on the first dielectric layer, a third dielectric layer laminated on the second dielectric layer, A first ground electrode disposed on the lower surface of the first dielectric layer, a first open-ended rectangular resonant electrode disposed between the first and second dielectric layers, and a first end A short-circuit rectangular resonance electrode, a second one-end open rectangular resonance electrode, a second one-end short-circuit rectangular resonance electrode, and a third one-end open disposed between the second and third dielectric layers. A rectangular resonance electrode, a third one-end short-circuited rectangular resonance electrode, and a second ground electrode disposed on the upper surface of the fourth dielectric layer;
The first and second open-ended rectangular resonant electrodes are arranged in parallel so that at least a part of each of the first and second rectangular open-ended resonant electrodes overlaps when viewed from the laminating direction, and the first and second open-ended resonant electrodes are arranged in parallel. 3, the one end open rectangular resonance electrodes are arranged in parallel so that at least a part of each of the two end resonance electrodes overlaps when viewed from the laminating direction, with the second dielectric layer interposed therebetween.
The first and second one-end short-circuited rectangular resonance electrodes are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps when viewed from the laminating direction, with the second dielectric layer interposed therebetween. 3 is arranged in parallel so that at least a part of each of the short-circuited rectangular resonant electrodes overlaps with the second dielectric layer interposed therebetween when viewed from the laminating direction.
The first and second ground electrodes are disposed so as to cover the first to third single-ended rectangular resonant electrodes and the first to third single-ended short-circuited rectangular resonant electrodes when viewed from the lamination direction,
An end opposite to the open end of the first one-end open rectangular resonance electrode and an end opposite to the short-circuit end of the first one-end short-circuit rectangular resonance electrode are electrically connected to each other to form a first end. Forming a resonator of
An end of the second one-end open rectangular resonance electrode opposite to the open end and an end of the second one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to form a second end. Forming a resonator of
An end of the third one-end open rectangular resonance electrode opposite to the open end and an end of the third one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to form a third end. Forming a resonator of
The overlapping widths of the first open-ended rectangular resonant electrode and the second and third open-ended rectangular resonant electrodes have different dimensions, respectively, and the first open-ended rectangular resonant electrode and the first open-ended rectangular resonant electrode have different widths. The overlapping widths of the second and third one-end short-circuited rectangular resonance electrodes are different from each other,
An input terminal is electrically connected to the second resonator and an output terminal is electrically connected to the third resonator, or an output terminal is electrically connected to the second resonator and an input terminal is electrically connected to the third resonator. A laminated strip line filter, which is electrically connected. The respective ground electrodes or the short-circuited ends of the single-ended rectangular resonant electrodes and the respective ground electrodes are laminated by a through conductor formed inside the dielectric layer and / or a side conductor formed on a side surface. 2. The multilayer strip line filter according to claim 1, wherein the filter is electrically connected in the directions.

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