JP4284151B2 - Filter device - Google Patents

Description

  The present invention relates to a filter device used in, for example, a wireless communication device such as a mobile phone and a wireless LAN, and other various communication devices.

  2. Description of the Related Art In recent years, filter devices used in mobile communication devices such as mobile phones have been distributed from a filter using a dielectric coaxial resonator to meet demands for thinning and miniaturization of mobile communication devices. Progress has been made in laminated stripline filters used in resonators.

  As such a conventional multilayer stripline filter, Patent Document 1 proposes a configuration having a perspective view shown in FIG. 6 and a perspective plan view shown in FIG.

  6 and 7, reference numeral 71 is a first dielectric layer, 72 is a second dielectric layer laminated on the first dielectric layer 71, and 73 is on the second dielectric layer 72. The laminated third dielectric layer, 81 is a first ground electrode disposed on the lower surface of the first dielectric layer 71, and 82 is a second ground disposed on the upper surface of the third dielectric layer 73. The electrodes 83 and 84 are a first one-end open rectangular resonance electrode and a first one-end short-circuited rectangular resonance electrode 85 and 86 disposed between the first dielectric layer 71 and the second dielectric layer 72, respectively. Are a second one-end open rectangular resonance electrode and a second one-end short-circuited rectangular resonance electrode arranged between the second dielectric layer 72 and the third dielectric layer 73.

  The first and second one-end open rectangular resonance electrodes 83 and 85 have substantially the same shape, are parallel in plan view, and part of the first one-end open rectangular resonance electrode 83 and the second one-end open. A part of the rectangular resonance electrode 85 is arranged so as to overlap each other with the second dielectric layer 72 interposed therebetween.

  The first and second one-end short-circuited rectangular resonance electrodes 84 and 86 have substantially the same shape, are parallel to each other in plan view, and a part of the first one-end short-circuited rectangular resonance electrode 84 and the second A part of the one-end short-circuited rectangular resonance electrode 86 is arranged to overlap each other with the second dielectric layer 72 interposed therebetween.

  Further, the end portion of the first one-end open rectangular resonance electrode 83 opposite to the open end 90 and the end portion of the first one-end short-circuit rectangular resonance electrode 84 opposite to the short-circuit end 91 are electrically connected. The end of the second one-end open rectangular resonant electrode 85 opposite to the open end 90 and the end of the second one-end short-circuited rectangular resonant electrode 86 opposite to the short-circuited end 91 are electrically connected. It became the composition to be. In FIG. 7, the first and second ground electrodes 81 and 82 are not shown.

Then, the width W1 of the first and second one-end open rectangular resonance electrodes 83 and 85, the width W2 of the first and second one-end short-circuited rectangular resonance electrodes 84 and 86, and the first one-end open rectangular resonance electrode 83. And the second one-end open rectangular resonance electrode 85 and the second dielectric layer 72 so as to overlap each other, the width W3, and the first one-end short-circuited rectangular resonance electrode 84 and the second one-end short-circuited rectangular resonance electrode 86. By adjusting the width W4 that overlaps each other with the second dielectric layer 72 in between, the first and second one-end open rectangular resonance electrodes 83 and 85 and the first and second one-end short-circuited rectangular resonances When capacitive coupling is dominant as the coupling formed between the electrodes 84 and 86, a filter characteristic having one attenuation pole on the low band side with respect to the pass band is obtained, and conversely, inductive coupling is dominant. If the It was realized filter characteristic having one pole.
JP-A-9-331201

  However, in such a conventional multilayer stripline filter, the first one-end open rectangular resonance electrode 83 and the second one are caused by the stacking deviation that occurs in the process of stacking the first to third dielectric layers 71 to 73. The one end open rectangular resonant electrode 85 overlaps with the second dielectric layer 72 and the width W3, and the first one end shorted rectangular resonant electrode 84 and the second one end shorted rectangular resonant electrode 86 are the first. The width W4 that overlaps with each other across the two dielectric layers 72 changes, so that the electromagnetic field coupling amount between the first and second one-end open rectangular resonance electrodes 83 and 85, and the first and second one-end short-circuits The amount of electromagnetic field coupling between the rectangular resonance electrodes 84 and 86 changes, which causes a problem that the attenuation pole varies greatly with respect to the desired filter characteristics.

  The present invention has been completed in view of the above problems, and an object of the present invention is to provide a filter device that can reduce fluctuations in attenuation poles of filter characteristics due to misalignment caused in a process of laminating a plurality of dielectric layers. Is to provide.

Filter apparatus according to the present invention, the first and third one-end open rectangular resonant electrodes, as the second dielectric layer each of the at least a portion sandwiching overlap in plan view, the first, second disposed in parallel in the stacking direction of the third dielectric layer, the second and fourth one-end open rectangular resonant electrodes, so sandwiching the second dielectric layer each of at least some overlap in plan view Are arranged in parallel in the stacking direction of the first to third dielectric layers ,
Wherein the first and third one end shorted rectangular resonant electrodes, the so second dielectric layer each of the at least a portion sandwiching overlap in plan view, the lamination of the first to third dielectric layers disposed in parallel in the direction, the second and fourth one end shorted rectangular resonant electrodes, as across the second dielectric layer each of at least some overlap in plan view, the first, second 3 dielectric layers are arranged in parallel in the stacking direction ,
It said first and second ground electrodes are disposed so as to cover the first to fourth one-end open rectangular resonant electrode and the first to fourth one end shorted rectangular resonator electrode in plan view,
An end portion of the first one-end open rectangular resonance electrode opposite to the open end and an end portion of the first one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to each other. Form a resonator of
An end of the second one-end open rectangular resonance electrode opposite to the open end and an end opposite to the short-circuit end of the second one-end short-circuited rectangular resonance electrode are electrically connected to each other. Form a resonator of
An end of the third one-end open rectangular resonance electrode opposite to the open end and an end opposite to the short-circuit end of the third one-end short-circuited rectangular resonance electrode are electrically connected to form a third. Form a resonator of
An end of the fourth one-end open rectangular resonant electrode opposite to the open end and an end opposite to the short-circuited end of the fourth single-ended short-circuited rectangular resonant electrode are electrically connected to form a fourth. Form a resonator of
The first to fourth resonators have parallel length directions.
With respect to the plane of said first and second resonators and the third and fourth resonator, perpendicular to the main surface of said each dielectric layer in parallel to the first to the length direction of the fourth resonator together are arranged in plane symmetry, the first to fourth respective first to fourth in the resonator of the input and output terminals are electrically connected, said second input and said first output terminal A terminal is electrically connected, and the third input / output terminal and the fourth input / output terminal are electrically connected.

  In the filter device according to the present invention, preferably, each ground electrode or each short-circuited end of each short-circuited rectangular resonance electrode and each ground electrode are formed in the dielectric layer in the above-described configuration. And a side conductor formed on at least one of the side surfaces.

  According to the filter device (first filter device) of the present invention, the first and second resonators and the third and fourth resonators are parallel to the length direction of the first to fourth resonators. The first and third resonators are arranged in plane symmetry with respect to a plane orthogonal to the main surface of each dielectric layer, so that even when a stacking deviation occurs in the step of stacking a plurality of dielectric layers, The rate of increase / decrease between the electromagnetic field coupling formed between them and the electromagnetic field coupling formed between the second and fourth resonators is constant. As a result, fluctuations in the attenuation pole of the filter characteristics due to increase / decrease in the electromagnetic field coupling formed between the first and third resonators and the electromagnetic field coupling formed between the second and fourth resonators are offset each other. Therefore, the fluctuation of the attenuation pole of the filter characteristic can be reduced.

  The filter device of the present invention (second filter device) includes a ground conductor or a short-circuited end of each short-circuited rectangular resonance electrode and each ground electrode at least of a through conductor and a side surface formed inside the dielectric layer. When electrically connected by a side conductor formed on one side, the degree of freedom in designing a filter device formed inside a plurality of stacked dielectric layers is improved, and a small and high-performance filter device is provided. can do.

  The filter device of the present invention will be described in detail below. 1 is a see-through perspective view showing an example of an embodiment of the present invention, FIG. 2 is a see-through plan view of the filter device of FIG. 1 (viewed from the stacking direction), and FIG. 3 is a in FIG. FIG. 1 to 3, reference numeral 21 denotes a first dielectric layer, 22 denotes a second dielectric layer laminated on the first dielectric layer 21, and 23 denotes a second dielectric layer 22. The laminated third dielectric layer, 15 is a first ground electrode disposed on the lower surface of the first dielectric layer 21, and 16 is a second ground disposed on the upper surface of the third dielectric layer. Electrodes 31 and 32 are first and second open-ended rectangular resonant electrodes disposed between first and second dielectric layers 21 and 22, respectively, and 41 and 42 are first and second dielectrics, respectively. First and second one-end short-circuited rectangular resonant electrodes 33 and 34 disposed between the layers 21 and 22, respectively, are third and fourth layers disposed between the second and third dielectric layers 22 and 23, respectively. One-end open rectangular resonance electrodes 43 and 44 are disposed between the second and third dielectric layers 22 and 23, respectively. 3 and fourth one-end short-circuited rectangular resonance electrodes, 50 is an open end of each of the first to fourth one-end open rectangular resonance electrodes 31 to 34, and 51 is a first to fourth one-end short-circuited rectangular resonance electrode 41. It is a short-circuit end of each of -44.

  As shown in FIGS. 1 to 3, the first and third one-end open rectangular resonance electrodes 31 and 33 are arranged so that at least a part of each of them overlaps in plan view with the second dielectric layer 22 in between. The second and fourth one-end open rectangular resonance electrodes 32 and 34 are arranged in parallel so that at least a part of each of them overlaps in plan view with the second dielectric layer 22 in between. Further, the first and third one-end short-circuited rectangular resonance electrodes 41 and 43 are arranged in parallel so that at least a part of each of the first and third short-circuited rectangular resonance electrodes 41 and 43 overlap with each other in plan view. These one-end short-circuited rectangular resonance electrodes 42 and 44 are arranged in parallel so that at least a part of each of them overlaps in plan view with the second dielectric layer 22 in between. The first and second ground electrodes 15 and 16 cover the first to fourth one-end open rectangular resonance electrodes 31 to 34 and the first to fourth one-end short-circuited rectangular resonance electrodes 41 to 44 in plan view. Is arranged.

  Then, the end of the first one-end open rectangular resonance electrode 31 opposite to the open end 50 is electrically connected to the end of the first one-end short-circuited rectangular resonance electrode 41 opposite to the short-circuit end 51. Thus, the first resonator 11 is formed, and the end opposite to the open end 50 of the second one-end open rectangular resonant electrode 32 and the short-circuited end 51 of the second single-ended short-circuited rectangular resonant electrode 42 are opposite to each other. The second resonator 12 is formed by electrically connecting the end on the side, the end on the opposite side of the open end 50 of the third one-end open rectangular resonance electrode 33, and the third one-end short-circuited rectangle. The third resonator 13 is formed by electrically connecting the short-circuited end 51 and the opposite end of the shape resonant electrode 43, and is opposite to the open end 50 of the fourth open-ended rectangular resonant electrode 34. The fourth resonator 14 is formed by electrically connecting the end and the end opposite to the short-circuited end 51 of the fourth one-end short-circuited rectangular resonance electrode 44. It is.

  Further, the first and second resonators 11 and 12 and the third and fourth resonators 13 and 14 are parallel to each other in the longitudinal direction of the first to fourth resonators 11 to 14. The first to fourth input / output terminals 61a, 61b, 62a, 62b are electrically connected to the first to fourth resonators 11-14, respectively, with respect to a plane orthogonal to the main surface of the layer. The first input / output terminal 61a and the second input / output terminal 61b are electrically connected, and the third input / output terminal 62a and the fourth input / output terminal 62b are electrically connected. And it is electrically connected to an external circuit via a transmission line, and a high frequency signal is input / output.

  The filter device of the present invention having such a structure is provided between the first and second ground electrodes 15 and 16, or the first and second ground electrodes 40 and 41 and the first to fourth one-end short-circuited rectangular resonance electrodes. At least a ground connection conductor that electrically connects the short-circuit ends 51 of 41 to 44 in the stacking direction, a through conductor (not shown) formed inside the dielectric layer as a connection conductor, and a side conductor formed on the side surface By using one of them, a three-dimensional wiring design is possible, and the degree of freedom in designing a filter device formed inside a plurality of stacked dielectric layers is improved. It becomes.

  In constructing the filter device of the present invention, the first to third dielectric layers 21 to 23, the first and second ground electrodes 15 and 16, the first to fourth one-end open rectangular resonance electrodes 31 to 34 are provided. The first to fourth one-end short-circuited rectangular resonance electrodes 41 to 44 can be made of various materials and forms used for known high-frequency wiring boards.

  Examples of the first to third dielectric layers 21 to 23 used in the filter device of the present invention include ceramic materials such as alumina ceramics and mullite ceramics, inorganic materials such as glass ceramics, or ethylene tetrafluoride resin (polytetra PTFE), tetrafluoroethylene-ethylene copolymer resin (tetrafluoroethylene-ethylene copolymer resin; ETFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (tetrafluoroethylene-perfluteroalkyl vinyl ether) Fluorine resin such as copolymer resin (PFA), glass epoxy resin, resin material such as polyimide, or the like is used. The shapes and dimensions (thickness, width, length) of the first to third dielectric layers 21 to 23 made of these materials are set according to the frequency used, the application, and the like.

First and second ground electrodes 15 and 16, first to fourth one-end open rectangular resonance electrodes 31 to 34, first to fourth one-end short-circuited rectangular resonance electrodes 41 to 44 in the filter device of the present invention, The through conductor is a conductive layer made of a metal material for high-frequency signal transmission, such as a Cu layer, a Mo-Mn metallization layer coated with a Ni plating layer and an Au plating layer, or a W metallization layer with a Ni plating layer. And an Au plated layer deposited thereon, a Cr—Cu alloy layer, a Ni plated layer and an Au plated layer deposited on the Cr—Cu alloy layer, a Ni—Cr alloy layer on the Ta ₂ N layer, and Using an Au plating layer, a Ti layer with a Pt layer and an Au plating layer, or a Ni-Cr alloy layer with a Pt layer and an Au plating layer Thick film printing method or each It is formed by a thin film forming method or a plating method or the like. The thickness and width are also set according to the frequency and application of the high-frequency signal transmitted.

  In forming the first to third dielectric layers 21 to 23 used in the filter device of the present invention, for example, if the dielectric layer is made of glass ceramics, first, a glass ceramic green sheet to be a dielectric layer is used. After preparing a predetermined punching process to form a through hole to be a through conductor, 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 conductor layers The pattern is printed and applied. 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.

  The filter device of the present invention having the configuration shown in FIGS. 1 to 3 and the conventional filter device shown in FIGS. 6 and 7 can realize the same filter characteristics, and FIG. 4 shows typical filter characteristics thereof. is there. In FIG. 4, the horizontal axis represents frequency (unit: GHz), the vertical axis represents insertion loss (unit: dB), and fr represents the attenuation pole.

  FIG. 5 shows a structural model of the filter device of the present invention having the configuration shown in FIGS. 1 to 3 and the conventional filter device shown in FIGS. Are graphs (graphs) showing the amount of change of the attenuation pole fr in the simulation result when ± 100 μm is taken into account.

  For example, in the case of simulation in the filter device of the present invention having the configuration shown in FIGS. 1 to 3, the thicknesses of the first to third dielectric layers 21 to 22 are 0.1 to 0.2 mm and the first to fourth, respectively. The width W1 and the length L1 of each resonance electrode of the one end open rectangular resonance electrodes 31 to 34 are respectively W1 = 0.7 to 1.4 mm, L1 = 4 to 6 mm, and the first and third one end open rectangular resonances. The width W2 of the portion where the electrodes 31 and 33 and the second and fourth one-end open rectangular resonance electrodes 32 and 34 overlap in plan view is W2 = 0.4 to 0.8 mm, and the first to fourth one-end short-circuited rectangular shapes. The width W3 and length L2 of each resonance electrode of the resonance electrodes 41 to 44 are respectively W3 = 0.7 to 1.4 mm, L2 = 4 to 6 mm, the first and third one-end short-circuited rectangular resonance electrodes 41 and 43, and The second and fourth one-end short-circuited rectangular resonance electrodes 42 and 44 are seen in a plan view. The width W4 of the portion that overlaps are the W4 = 0.2~0.4mm. Then, a simulation is performed for a case where ± 100 μm is taken into account as an amount of stacking deviation in the width direction between the surface where the first and second resonators 11 and 12 are present and the surface where the third and fourth resonators 13 and 14 are present. Carried out. Also, in the conventional balanced multilayer stripline filter shown in FIGS. 6 and 7, a similar structural model is created by a three-dimensional electromagnetic field analysis simulator, and simulation is performed in the case where ± 100 μm is taken into account as the stacking misalignment in the width direction. Carried out.

  In FIG. 5, the horizontal axis represents the stacking misalignment in the width direction (unit: μm), the vertical axis represents the amount of change in the attenuation pole fr (unit: GHz), and each characteristic curve is shown in FIG. B shows the result in the filter device of the present invention shown, and B shows the result in the conventional filter device shown in FIGS.

  As is apparent from the results shown in FIG. 5, according to the filter device of the present invention, it is possible to reduce the fluctuation of the attenuation pole of the filter characteristics due to the stacking deviation that occurs in the step of stacking the plurality of dielectric layers.

  For example, regarding the amount of change in the attenuation pole fr when the stacking shift amount is −100 μm and +100 μm, A in FIG. 5 is 0.01 GHz, and B is 0.17 GHz in the attenuation pole fr. It can be seen that the result A in the filter device of the present invention can reduce the amount of change in the attenuation pole fr compared to the result B in the conventional filter device.

  In the filter device according to the present invention, preferably, the first and second ground electrodes 15 and 16 are electrically connected in the stacking direction and the first to fourth one-end short-circuited rectangular resonances in the above configuration. The connection conductor that electrically connects the short-circuit ends 51 of the electrodes 41 to 44 in the stacking direction is at least one of a through conductor formed inside the dielectric layer and a side conductor formed on the side surface. As a result, the degree of freedom in designing a filter device formed inside a plurality of stacked dielectric layers is improved, and a small and high-performance filter device is obtained.

  It should be noted that the present invention is not limited to the above embodiments, and various modifications and improvements can be made without departing from the scope of the present invention.

It is a see-through | perspective perspective view which shows an example of embodiment of the filter apparatus of this invention. It is a see-through plan view showing an example of an embodiment of a filter device of the present invention. FIG. 3 is a cross-sectional view taken along the line a-a ′ in FIG. 2, showing an example of the embodiment of the filter device of the present invention. It is a diagram which shows the example of the insertion loss in the filter apparatus of this invention, and the conventional filter apparatus. It is a diagram which shows the example of the variation | change_quantity of the attenuation pole with respect to the lamination | stacking deviation | shift amount of the width direction in the filter apparatus of this invention, and the conventional filter apparatus. It is a see-through | perspective perspective view which shows the example of the conventional filter apparatus. It is sectional drawing which shows the example of the conventional filter apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... 1st resonator 12 ... 2nd resonator 13 ... 3rd resonator 14 ... 4th resonator 21 ... 1st dielectric material layer 22 ... 2nd dielectric layer 23 ... 3rd dielectric layer 15 ... 1st ground electrode 16 ... 2nd ground electrode 31 ... 1st one end open rectangular resonance electrode 32 ... Second open-end rectangular resonance electrode 33 ... Third open-end rectangular resonance electrode 34 ... Fourth open-end rectangular resonance electrode 41 ... First short-cut rectangular resonance electrode 42 2nd single-ended short-circuited rectangular resonant electrode 43 3rd single-ended short-circuited rectangular resonant electrode 44 4th single-ended short-circuited rectangular resonant electrode 50 Open end 51 Short-circuited end 61a ... first input / output terminal 61b ... second input / output terminal 62a ... third input / output terminal 62b ... fourth input / output terminal

Claims (2)

A first dielectric layer; a second dielectric layer stacked on the first dielectric layer; a third dielectric layer stacked on the second dielectric layer; A first ground electrode disposed on a lower surface of the first dielectric layer; first and second one-end open rectangular resonant electrodes disposed between the first and second dielectric layers; First and second one-end short-circuited rectangular resonant electrodes; third and fourth one-end open rectangular resonant electrodes disposed between the second and third dielectric layers; and third and fourth single-ended short-circuits A rectangular resonance electrode and a second ground electrode disposed on the upper surface of the third dielectric layer;
Wherein the first and third one-end open rectangular resonant electrodes, the so second dielectric layer each of the at least a portion sandwiching overlap in plan view, the lamination of the first to third dielectric layers disposed in parallel in the direction, the second and fourth one-end open rectangular resonant electrodes, as across the second dielectric layer each of at least some overlap in plan view, the first, second 3 dielectric layers are arranged in parallel in the stacking direction ,
Wherein the first and third one end shorted rectangular resonant electrodes, the so second dielectric layer each of the at least a portion sandwiching overlap in plan view, the lamination of the first to third dielectric layers disposed in parallel in the direction, the second and fourth one end shorted rectangular resonant electrodes, as across the second dielectric layer each of at least some overlap in plan view, the first, second 3 dielectric layers are arranged in parallel in the stacking direction ,
It said first and second ground electrodes are disposed so as to cover the first to fourth one-end open rectangular resonant electrode and the first to fourth one end shorted rectangular resonator electrode in plan view,
An end portion of the first one-end open rectangular resonance electrode opposite to the open end and an end portion of the first one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to each other. Form a resonator of
An end of the second one-end open rectangular resonance electrode opposite to the open end and an end opposite to the short-circuit end of the second one-end short-circuited rectangular resonance electrode are electrically connected to each other. Form a resonator of
An end of the third one-end open rectangular resonance electrode opposite to the open end and an end opposite to the short-circuit end of the third one-end short-circuited rectangular resonance electrode are electrically connected to form a third. Form a resonator of
An end of the fourth one-end open rectangular resonant electrode opposite to the open end and an end opposite to the short-circuited end of the fourth single-ended short-circuited rectangular resonant electrode are electrically connected to form a fourth. Form a resonator of
The first to fourth resonators have parallel length directions.
With respect to the plane of said first and second resonators and the third and fourth resonator, perpendicular to the main surface of said each dielectric layer in parallel to the first to the length direction of the fourth resonator together are arranged in plane symmetry, the first to fourth respective first to fourth in the resonator of the input and output terminals are electrically connected, said second input and said first output terminal A filter device, wherein a terminal is electrically connected, and the third input / output terminal and the fourth input / output terminal are electrically connected.   Each ground electrode or each short-circuited end of each one-sided short-circuited rectangular resonance electrode and each ground electrode are electrically connected by a through conductor formed inside the dielectric layer and a side conductor formed on at least one of the side surfaces. The filter device according to claim 1, wherein the filter device is connected in a mechanical manner.

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