JP2006067221A - Laminated dielectric filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated dielectric filter in which attenuation characteristics near a pass band are improved. <P>SOLUTION: The laminated dielectric filter is provided with first and second planar electrode arranged on a first plane; a first strip line resonator arranged on a second plane in approximately parallel and capacitively coupled to the first planar electrode; a second strip line resonator capacitively coupled to both the first and second planar electrodes; a third strip line resonator capacitively coupled to the second planar electrodes; a third planar electrode arranged on a third plane and capacitively coupled to the first, second, and third strip line resonators; and fourth and fifth planar electrodes arranged on a fourth plane, each opposing the third planar electrode and arranged so as to have a gap exceeding the width of the second strip line resonator. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filter, and more particularly to a multilayer dielectric filter.

2. Description of the Related Art Multilayer dielectric filters in which dielectric materials such as dielectric ceramics are laminated are used in communication devices such as cellular phones and wireless LANs. This multilayer dielectric filter can be formed, for example, by laminating dielectric substrates on which stripline transmission lines are arranged (see Patent Documents 1 and 2).
Japanese Patent No. 2551966 Japanese Patent No. 2963835

However, it is not always easy to impart desired characteristics to the multilayer dielectric filter. For example, it is difficult to ensure a wide passband.
In view of the above, an object of the present invention is to provide a multilayer dielectric filter having a wide passband.

  In order to achieve the above object, a multilayer dielectric filter according to the present invention is disposed in a stacked manner on the first plane and the first and second flat plate electrodes disposed on the first plane. A first stripline resonator that is capacitively coupled to the first plate electrode and disposed in parallel with each other on the second plane, and a second that is capacitively coupled to both the first and second plate electrodes. A stripline resonator, a third stripline resonator capacitively coupled to the second plate electrode, a third plane disposed in a stack on the second plane, and the first plane A third plate electrode capacitively coupled to the first, second, and third stripline resonators; and a third plate electrode on a fourth plane that is stacked on the third plane. A gap that is opposite and exceeds the width of the second stripline resonator 4 which is arranged, characterized by comprising a fifth flat plate electrode.

  According to the present invention, it is possible to provide a multilayer dielectric filter having a wide pass band.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a circuit diagram showing a circuit configuration of a multilayer dielectric filter 100 according to the first embodiment of the present invention.
As shown in FIG. 1, the multilayer dielectric filter 100 includes an input terminal Pi, an output terminal Po, capacitors (capacitors: capacitive elements) C1, C2, C3, Ci, Co, and resonant elements L1 to L3. Among these, the capacitors C 1, C 2, C 3 and the resonant elements L 1 to L 3 are for defining the characteristics of the multilayer dielectric filter 10. The capacitors Ci and Co are for capacitive coupling to the input terminal Pi and the output terminal Po, respectively, and have little influence on the characteristics of the multilayer dielectric filter 10.
The resonant elements L1 to L3 are grounded via a ground terminal (also referred to as “ground terminal”) G for grounding.

  The input terminal Pi is connected to, for example, an antenna and receives a signal. A signal input from the input terminal Pi is output to the output terminal Po according to the frequency. That is, a signal having a frequency within the pass band (for example, 4.9 to 5.9 GHz) is output from the input terminal Pi to the output terminal Po, and a signal having a frequency outside the pass band is attenuated within the multilayer dielectric filter 100. And is not output from the output terminal Po.

FIG. 2 is a perspective view showing the appearance of the multilayer dielectric filter 100.
The multilayer dielectric filter 100 is configured by stacking substrates 110 to 180. As the substrates 110 to 180, for example, a 2012 (2.0 mm × 1.25 mm) type substrate made of glass ceramic (relative permittivity εr = 54, tan δ = 1.6 × 10 ⁻³ ) is used, and thick film printing is performed. An electrode pattern printed with silver paste or the like is formed.
The substrates 110 to 180 may be made of a ceramic material other than glass ceramic.

  Notches 11 to 18 serving as predetermined terminals are formed on the sides of each of the substrates 110 to 180. The notches 11 to 18 are aligned in the stacking direction of the substrates 110 to 180 at the time of stacking and constitute a groove extending in the stacking direction. By printing the silver paste in the groove, it functions as the input terminal Pi, the output terminal Po, and the ground terminal G.

FIG. 3 is an exploded perspective view illustrating a state in which the substrates 110 to 180 constituting the multilayer dielectric filter 100 are separated.
The substrate 110 has a thickness of 90 to 100 μm (95 ± 5 μm), and has land patterns (mounting electrode patterns) 111a to 111h (not shown) connected to the notches 11 to 18 on the lower surface, respectively. . The land patterns 111a and 111b correspond to the input terminal Pi and the output terminal Po, respectively, and the land patterns 111c to 111h correspond to the ground terminal G, respectively.
The substrate 110 has a grounding (ground) plate electrode 112 and electrode patterns of connection portions 113 to 115 on the upper surface. The flat plate electrode 112 is connected to the ground terminal G through the connecting portions 113 to 115, shields flat plate electrodes 121 and 122, which will be described later, from the outside, stabilizes the operation of the multilayer dielectric filter 100, and is described below. The characteristics of the electrodes 131 to 133 as stripline resonators are defined. The plate electrode 112 has a rectangular shape of 750 μm × 1500 μm in the vertical direction (X direction) and the horizontal direction (Y direction).

The substrate 120 has a thickness of 270 to 300 μm (280 ± 10 μm), and has plate electrodes 121 and 122 for the capacitors C1 and C2 on the upper surface. The plate electrodes 121 and 122 function as capacitors C1 and C2 by capacitively coupling with plate electrodes 131 to 133 described later. The plate electrode 121 functions as a capacitor C1 between the plate electrodes 131 and 132 by capacitively coupling with the plate electrodes 131 and 132, respectively. The plate electrode 122 functions as a capacitor C <b> 2 between the plate electrodes 132 and 133 by capacitively coupling with the plate electrodes 132 and 133, respectively.
Each of the plate electrodes 121 and 122 has a rectangular shape of vertical (X direction) and horizontal (Y direction) 350 μm × 675 μm, and is arranged in series in the longitudinal direction (Y direction) of each other.

  The substrate 130 has a thickness of 40 to 50 μm (45 ± 5 μm), and has plate electrodes 131 to 133 for the resonators L1 to L3 on the upper surface. Each of the plate electrodes 131 to 133 is connected to a lower surface of vias 143 to 145 described later in the vicinity of one end and a ground terminal G at the other end. The plate electrodes 131 to 133 each have a rectangular shape of 900 μm × 250 μm, 900 μm × 250 μm, and 900 μm × 250 μm in the vertical direction (X direction) and the horizontal direction (Y direction), and are arranged in parallel in the width direction (Y direction) with a spacing of 375 μm. Is arranged.

The plate electrodes 131 to 133 function as stripline resonators based on the positional relationship with the plate electrode 112 for grounding.
Here, since the plate electrodes 131 to 133 are electrically connected to the plate electrodes 151 to 153 that function as stripline resonators, the characteristics of the resonators L1 to L3 are as follows. It is defined by both plate electrodes 151-153. That is, the resonators L1 to L3 are divided into plate electrodes 131 to 133 and plate electrodes 151 to 153. This is because the wiring length of the plate electrodes 131 to 133 is substantially increased without increasing the area of the substrate 130. It is also possible to configure the resonators L1 to L3 without dividing them into the plate electrodes 131 to 133 and the plate electrodes 151 to 153.

  The substrate 140 has a thickness of 60 to 70 μm (65 ± 5 μm), plate electrodes 141 and 142 for capacitors Ci and Co disposed on the upper surface, and vias 143 to 145 for interlayer connection penetrating vertically on the substrate 140. And have. The plate electrodes 141 and 142 are capacitively coupled to the plate electrodes 131 and 133, respectively, and function as capacitors Ci and Co. The plate electrodes 141 and 142 are connected to the input terminal Pi and the output terminal Po at the connection portions 146 and 147, respectively. The plate electrodes 141 and 142 each have a rectangular shape with a length (X direction) and a width (Y direction) of 500 μm × 500 μm.

The substrate 150 has a thickness of 40 to 50 μm (45 ± 5 μm) and has plate electrodes 151 to 153 for the resonators L1 to L3 on the upper surface. The plate electrodes 151 to 153 are provided with vias 154 to 156 for interlayer connection in the vicinity of one end thereof. Each of the plate electrodes 151 to 153 has a rectangular shape of 600 μm × 250 μm, 700 μm × 250 μm, and 600 μm × 250 μm in the vertical direction (X direction) and the horizontal direction (Y direction), and is arranged in parallel at an interval of 375 μm in the width direction (Y direction). Is arranged.
The plate electrodes 151 to 153 are electrically connected to the plate electrodes 131 to 133 by vias 154 to 156 and vias 143 to 145, respectively. That is, the plate electrode 151 is electrically connected to the plate electrode 131, and constitutes a resonator L1 formed of a 1/4 wavelength strip line between the plate electrodes 112 and 171a. The plate electrode 152 is electrically connected to the plate electrode 132, and constitutes a resonator L2 composed of a 1/4 wavelength strip line between the plate electrodes 112, 171a and 171b. The plate electrode 153 is electrically connected to the plate electrode 133, and constitutes a resonator L3 composed of a 1/4 wavelength strip line between the plate electrodes 112 and 117b.

  The characteristics of the flat plate electrodes 151 to 153 as strip lines are defined based on the arrangement relationship with the flat plate electrodes 1171a and 171b for grounding. That is, the characteristics of the plate electrode 151 as a strip line are mainly defined by the arrangement with the plate electrode 171a. The characteristics of the plate electrode 153 as a strip line are mainly defined by the arrangement with the plate electrode 171b. The characteristics of the plate electrode 152 as a strip line are mainly defined by the arrangement with the plate electrodes 171a and 171b. Since the plate electrode 152 is disposed above and below both of the plate electrodes 171a and 171b, the characteristics are affected by both, for example, the width of the gap between the plate electrodes 171a and 171b.

The substrate 160 has a thickness of 90 to 100 μm (95 ± 5 μm), and has a plate electrode 161 for the capacitor C3 on the upper surface. The plate electrode 161 is capacitively coupled to each of the plate electrodes 151 to 153 and functions as a capacitor C3. The plate electrode 161 has a rectangular shape with a length (X direction) and a width (Y direction) of 100 μm × 1200 μm.
The plate electrode 161 is closer to the plate electrodes 151 to 153 than the plate electrodes 171a and 171b, but the area of the region overlapping the plate electrodes 151 to 153 is not so large. The influence on the characteristics of the 153 stripline resonator is limited, and it is sufficient to consider it as the capacitor C3.

  The substrate 170 has electrode patterns of grounding plate electrodes 171a and 171b and connection portions 172 and 173 on the upper surface. The plate electrodes 171a and 171b are connected to the ground terminal G by connection portions 172 and 173, respectively. The plate electrodes 171a and 171b shield the plate electrode 161 from the outside, stabilize the operation of the multilayer dielectric filter 100, and define the characteristics of the plate electrodes 151 to 153 as stripline resonators. The plate electrodes 171a and 171b each have a rectangular shape of 750 μm × 650 μm in the vertical direction (X direction) and the horizontal direction (Y direction), and are arranged with an interval Dg = 100 μm. That is, it can be considered that the plate electrodes 171a and 171b are obtained by dividing the plate electrode 171 near the center. As will be described later, this division can improve the characteristics of the multilayer dielectric filter 100 in the vicinity of the pass band.

  The substrate 180 is arranged to protect the inside of the multilayer dielectric filter 100, particularly the plate electrodes 171a and 171b from the outside.

(Relationship between shape and size of flat plate electrodes 171a and 171b and characteristics of multilayer dielectric filter 100)
Hereinafter, the relationship between the shape and size of the plate electrodes 171a and 171b and the characteristics of the multilayer dielectric filter 100 will be described.
First, the shapes and dimensions of the plate electrodes 171a and 171b are shown in FIGS.
FIG. 4 is a plan view showing the plate electrodes 171a and 171b, assuming that a gap having a distance Dg is formed at the center in the Y direction of the plate electrodes 171 having a length (X direction) and a width (Y direction) of Lx and Ly. It is. That is, it may be considered that the plate electrodes 171a and 171b of Lx and (Ly−Dg) / 2 are arranged in the Y direction at intervals of Dg. Note that the connecting portions 172 and 173 have vertical and horizontal Dx and Dy.
In FIG. 4, the arrangement of the plate electrodes 151 to 153 and 161 is indicated by a broken line.

  FIG. 5 is a plan view showing the case where the gap width Dg in FIG. 4 is 0, that is, the plate electrodes 171a and 171b are connected and integrated to form the plate electrode 171. 6 is a plane showing a case where the gap width Dg in FIG. 4 is (Ly−2 × Dy), that is, the widths of the plate electrodes 171a and 171b are the same as the width Dy of the connection portions 172 and 173, respectively. FIG.

A. FIG. 7 shows that the distance Dg is changed from 0 to 1000 μm (specifically, the distance Dg is changed to 0, 5, 10, 20, 30, 60). , 90, 120, 180, 250, 300, 400, 600, 800, 1000 μm) are graphs showing simulation results of frequency characteristics of the multilayer dielectric filter 100. In this graph, the horizontal axis represents the frequency [GHz] of the signal input to the input terminal Pi, and the vertical axis represents the attenuation (transmittance) [dB] of the signal output from the output terminal Po with respect to the signal input from the input terminal Pi. To express.
Here, the vertical (X direction) and horizontal (Y direction) lengths of the plate electrode 171 are Lx = 750 μm and Ly = 1400 μm, and the vertical and horizontal lengths of the connecting portions 172 and 173 are Dx = 150 μm and Dy = 200 μm. Further, the horizontal width (Y direction) of each of the plate electrodes 151 to 153 was 250 μm, and the width of the gap was 375 μm. 5 and 6 correspond to the cases where the distance Dg = 0 and 1000 μm, respectively.

  When the distance Dg is 0 (when the flat plate electrodes 171a and 171b are integrally connected as the flat plate electrode 171), the transmittance increases from a frequency of 3 GHz and has a peak (peak) near the frequency of 4.7 GHz. . The frequency between 4.7 GHz and 5.8 GHz is almost constant (flat) with some undulations (pass band). Thereafter, the transmittance decreases from 5.8 GHz and has a valley in the vicinity of 7.7 GHz. Then, it rises toward a mountain (local maximum) R0 near a frequency of 8.5 GHz and then descends.

When the distance Dg is not 0 (when there is a gap between the flat plate electrodes 171a and 171b), the attenuation pole P is generated between the peaks and valleys, thereby changing the characteristics of the multilayer dielectric filter 100. The attenuation pole P is represented by a white circle corresponding to the value of the interval Dg. For example, P120 represents the attenuation pole P when the distance Dg is 120 μm.
FIG. 8 is a graph showing the correspondence between the position (frequency) of the attenuation pole P in FIG. 7 and the interval Dg. The horizontal axis of the graph is the interval Dg, and the vertical axis represents the frequency of the attenuation pole.

Further, when the interval Dg is increased to some extent, a new peak (maximum) Q is generated in the transmittance. This maximum Q is represented by a white circle corresponding to the value of the interval Dg. For example, Q120 represents the maximum Q when the interval Dg is 120 μm.
The maximum R when the interval Dg is 0 moves corresponding to the interval Dg. For this reason, the maximum R is represented by a white circle corresponding to the value of the interval Dg. For example, R120 represents the maximum R when the distance Dg is 120 μm.

  Here, the distance Dg can be relativized in relation to the width D of the plate electrode 152. That is, the relative width Fg = (Dg / D) can be expressed instead of the interval Dg. For this reason, the space | interval Dg and relative width Fg are written together below.

As shown in FIGS. 7 and 8, the position of the attenuation pole P moves to the high frequency side as the distance Dg increases, and is almost equal to the valley near 7.7 GHz when the distance Dg is about 300 μm (relative width Fg is 1.2). After that, it has moved to the high frequency side as a unit.
In addition, when the distance Dg is 40 μm (relative width Fg is .16) or less, preferably 30 μm (relative width Fg is .12) or less, the passband is narrower than when the distance Dg is 0. That is, it is useful when it is desired to narrow the pass band of the multilayer dielectric filter 100.
On the other hand, when the distance Dg is 50 μm (relative width Fg is .2) or more, preferably 60 μm (relative width Fg is .24) or more, the pass band becomes wider than the case where the distance Dg is 0 and exceeds the pass band. The change in transmission (attenuation) is large. In other words, it is useful when it is desired to widen the pass band of the multilayer dielectric filter 100, and the switching from the pass band to the non-pass band is quick (the change in attenuation is large when the pass is out of the pass band).

The local maximum Q occurs when Dg is about 100 μm (relative width Fg is 0.4) and Dg is present up to about 400 μm (relative width Fg is 1.6), but the presence cannot be clearly confirmed thereafter.
The maximum R moves to the high frequency side as Dg increases.

B. The relationship between the division state of the plate electrode 171 and the characteristics of the multilayer dielectric filter 100 Next, the relationship between the division state of the plate electrode 171 and the characteristics of the multilayer dielectric filter 100 will be described.
FIG. 9 is a plan view showing a state in which the plate electrodes 171a and 171b shown in FIG. 4 are connected by the connecting portion 171c. The plate electrodes 171a and 171b are connected by two connection portions 171c near both ends in the X direction (the plate electrode 171 has an opening). FIG. 10 is a plan view showing a state in which the direction of division of the plate electrode 171 is changed. The plate electrode 171 is divided in the X direction by a gap having a width of Dgx (divided in a direction perpendicular to the length direction of the plate electrode 152), and is divided into plate electrodes 171e and 171f. 9 and 10 are not significantly different from FIG. 4 except for the divided state, and thus detailed description thereof is omitted. These flat plate electrodes 171 shown in FIGS. 9 and 10 can be considered as comparative examples of the present embodiment.

FIG. 11 is a graph showing the correspondence between the division state of the plate electrode 171 and the simulation result of the frequency characteristics of the multilayer dielectric filter 100. In this graph, the horizontal axis represents the frequency [GHz] of the signal input to the input terminal Pi, and the vertical axis represents the attenuation (transmittance) [dB] of the signal output from the output terminal Po with respect to the signal input from the input terminal Pi. To express.
In FIG. 11, (1) when the gap obtained by dividing the plate electrode 171 is along the length direction of the plate electrode 152 (FIG. 4), (2) the divided plate electrodes 171 a and 171 b are connected by the coupling portion 171 c. 9 is a graph in the case where the gap is divided between the flat plate electrodes 171 (FIG. 9), and (3) is perpendicular to the length direction of the flat plate electrode 152 (FIG. 10).
Here, the width Dg of the gap between the plate electrodes 171a and 171b in the cases (1) and (2) is 60 μm. In the case (2), the width L1x of the coupling portion 171c is set to 100 μm. In the case of (3), the width Dgx of the gap between the plate electrodes 171d and 171e is 50 μm in the graph (3) -1 and 100 μm in the graph (3) -2.

As shown in FIG. 11, in the case of (1), an attenuation pole (same as the attenuation pole P60 in FIG. 7) is generated near a frequency of 6.3 GHz. However, in the cases of (2) and (3) Therefore, it can be seen that there is no attenuation pole corresponding to this, and it is difficult to adjust the pass band of the multilayer dielectric filter 100.
In the case of (2), although the opening of the flat plate electrode 171 exists on the flat plate electrode 152, the characteristic is almost the same as that in the case of no opening (when the gap Dg is 0). It was. From this, it can be seen that it is preferable that the flat plate electrodes 171a and 171b are not connected on the flat plate electrode 152 in order to generate the attenuation pole. The presence or absence of connection of the flat plate electrodes 171a and 171b on the flat plate electrode 152 is considered to affect the characteristics of the flat plate electrode 152 as a strip line.

  The fact that the attenuation pole did not appear in the case of (3) indicates that the generation of the attenuation pole corresponds to the direction of the gap between the plate electrodes 171. It is considered that whether or not the gap is arranged along the length direction (X direction) on the plate electrode 152 affects the characteristics of the plate electrode 152 as a strip line.

C. When there are two resonators In the present embodiment, the gap between the plate electrodes 171a and 171b is located at a position corresponding to the resonator L2 at the center of the three resonators L1 to L3.
Here, as a reference example, a multilayer dielectric filter 500 having two resonators is considered. The multilayer dielectric filter 500 is configured by excluding the plate electrode 132 of the substrate 130 and the plate electrode 152 of the substrate 150 in the multilayer dielectric filter 100 shown in FIG.
That is, the multilayer dielectric filter 500 includes a flat plate electrode 530 in which two flat plate electrodes 531 and 532 are arranged instead of the substrate 130, and a flat plate in which two flat plate electrodes 551 and 552 are arranged in place of the substrate 150. Assume that the electrode 550 is disposed. Moreover, it replaces with the board | substrate 170 and the plate electrode 570 in which the plate electrode 571 is arrange | positioned shall be arrange | positioned.

12 to 14 are plan views showing the correspondence between the flat plate electrode 571 on the substrate 570 and the flat plate electrodes 551 and 552 on the substrate 550 of the multilayer dielectric filter 500. The plate electrodes 551 and 552 constitute stripline resonators between the plate electrodes 571 connected to the ground.
In FIG. 12, the flat plate electrode 571 is not divided and has a rectangular shape. The connecting portion 572 connects the flat plate electrode 571 and the ground G. In FIG. 13, the flat plate electrode 571 is divided into flat plate electrodes 571 a and 571 b between the electrodes 551 and 552. In FIG. 14, the plate electrode 571 is divided into plate electrodes 571c, 571d, and 571e on the electrodes 551 and 552, respectively.

  FIG. 15 is a graph showing a correspondence relationship between the division state of the plate electrode 571 and the simulation result of the frequency characteristics of the multilayer dielectric filter 500 when there are two resonators. In this graph, the horizontal axis represents the frequency [GHz] of the signal input to the input terminal Pi, and the vertical axis represents the attenuation (transmittance) [dB] of the signal output from the output terminal Po with respect to the signal input from the input terminal Pi. To express.

In FIG. 15, (4) when the flat plate electrode 571 is not divided (FIG. 12), (5) when the flat plate electrode 571 is divided in the middle of the resonator (FIG. 13), and (6) the flat plate electrode 571 is on the resonator. FIG. 14 shows a graph when divided by (FIG. 14).
In the case of (4) where the flat plate electrode 571 is not divided, the transmittance characteristic has a peak (maximum) near a frequency of 2.4 GHz and a valley (minimum) near 4.5 GHz. The transmittance characteristics in the case of (5) and (6) in which the plate electrode 571 is divided also have peaks and valleys corresponding to these peaks and valleys, and no attenuation pole is generated between these peaks and valleys. That is, in the case of two resonators, even if the flat plate electrode 571 is divided, the position of the peaks and valleys changes, but there is no substantial difference in the transmittance characteristics (the shape of the graph). It turns out that it is the same even if it changes.

D. Relationship between the gap Dg between the plate electrodes 171a and 171b and the characteristics of the multilayer dielectric filter 100 (actual measurement)
The above-mentioned AC have calculated | required the transmittance | permeability characteristic of the division | segmentation of the plate electrode 171 and a laminated dielectric filter by simulation. Here, the results of actually producing and measuring the multilayer dielectric filter 100 will be described.
FIG. 16 is a graph showing the relationship between the gap Dg between the plate electrodes 171 a and 171 b and the frequency characteristics of the multilayer dielectric filter 100.
FIG. 16 shows a graph when the gap Dg between the plate electrodes 171a and 171b is 100, 250, and 300 μm.
The plate electrodes 171a and 171b and other conditions in these cases are as described in FIG. That is, the flat plate electrodes 171a and 171b each have a vertical (X direction) and horizontal (Y direction) rectangular shape of 750 μm × 650 μm, and are arranged with an interval Dg = 100 μm. The plate electrodes 151 to 153 have rectangular shapes of 600 μm × 250 μm, 700 μm × 250 μm, and 600 μm × 250 μm in the vertical direction (X direction) and the horizontal direction (Y direction), and are spaced apart from each other by 375 μm in the width direction (Y direction). And are arranged in parallel.

  Comparing FIG. 16 showing the actual measurement result with FIG. 7 showing the simulation result, it can be seen that the simulation and the actual measurement correspond very well. When the gap Dg is 100 μm (relative width Fg = 0.4)), 250 μm (relative width Fg = 1.0)), 300 μm (relative width Fg = 1.2)), the maximum Q is generated in both simulation and measurement. As the gap Dg increases, the gap moves to the high frequency side. In both simulation and actual measurement, the maximum R moves to the high frequency side as the gap Dg increases.

As described above, the frequency characteristic of the multilayer dielectric filter 100, for example, the width of the pass band can be adjusted by the gap Dg.
The attenuation pole P is confirmed when the gap Dg is 100 μm, and is not confirmed when the gap Dg is 300 μm. This is probably because the valley of the transmittance and the attenuation pole are integrated, and thus the attenuation pole P alone does not appear.

Summarizing the results of the above A to D (FIGS. 7, 11, 15, and 17), the following can be said.
(1) When the flat plate electrode 171 is divided at a position corresponding to the flat plate electrode 152 corresponding to the central resonator with a filter in which three resonators are arranged substantially in parallel, an attenuation pole is generated. This attenuation pole makes it possible to adjust the filter characteristics.
In a filter in which two resonators are arranged substantially in parallel, the division of the plate electrode is not effective for generating an attenuation pole.
(2) A direction along the length direction of the plate electrode 152 is effective as the direction of the divisional break, and it is difficult to effectively generate an attenuation pole in a direction orthogonal to the direction. Further, if the plate electrodes 171a and 171b are connected on the plate electrode 152, the attenuation pole is not effectively generated. Note that the plate electrodes 171a and 171b may be connected to each other. In the above embodiment, both the plate electrodes 171a and 171b are connected to the ground G.

(3) When the distance (gap Dg) between the plate electrodes 171a and 171b is increased, the attenuation pole moves from the low frequency side to the high frequency side. When the gap Dg is about 1.2 times the width of the plate electrode 152, the valley of transmittance matches the position (frequency) of the attenuation pole, and thereafter moves to the high frequency side while keeping the same.
(4) The interval Dg is 40 μm (relative width Fg is .16) or less, preferably 30 μm (relative width Fg is .12) or less, and the pass band is narrower than when the interval Dg is 0, and the interval Dg is 50 μm ( The relative bandwidth Fg is 2) or more, preferably 60 μm (relative width Fg is .24) or more, and the passband is wider than when the distance Dg is zero.

(5) The attenuation pole P generated by dividing the plate electrode 171 is not confirmed when the distance Dg is 250 μm (the relative width Fg is 1.0), that is, the width of the electrode 152 is exceeded. This is considered due to the correspondence between the distance Dg and the width of the plate electrode 152.

(6) Further, when the distance Dg is about 100 μm (0.4 in terms of relative width Fg), the maximum transmittance Q appears, and the distance Dg increases and moves to the high frequency side.
(7) The maximum R moves to the high frequency side as the interval Dg increases.
(8) From the above, for example, by adjusting the interval Dg by 60 to 100 μm, the passband can be set more than when Dg = 0 while the attenuation pole P is generated (in other words, the good attenuation characteristic is maintained). It can be widely used.

(Second Embodiment)
A second embodiment of the present invention will be described.
FIG. 17 is a circuit diagram showing a circuit configuration of a multilayer dielectric filter 200 according to the second embodiment of the present invention.
As shown in FIG. 17, the multilayer dielectric filter 200 includes an input terminal Pi, an output terminal Po, capacitors (capacitors: capacitor elements) C1, C2, C3, inductors Li, L0, and resonant elements L1 to L3. The multilayer dielectric filter 200 is obtained by replacing the capacitors Ci and Co of the multilayer dielectric filter 100 with inductors Li and L0. That is, the multilayer dielectric filter 100 is a C (capacitance) coupling type, whereas the multilayer dielectric filter 200 is an L (inductor) coupling type.

FIG. 18 is an exploded perspective view showing a state in which the substrates 110 to 130, 240, and 150 to 180 constituting the multilayer dielectric filter 200 are separated. The appearance of the multilayer dielectric filter 200 is shown in FIG.
The multilayer dielectric filter 200 is configured by replacing the substrate 140 of the multilayer dielectric filter 100 with a substrate 240.

The substrate 240 has a thickness of 60 to 70 μm (65 ± 5 μm), the plate electrodes 241 and 243 for the inductors Li and Lo disposed on the upper surface, the plate electrode 242 disposed between them, and the plate electrodes 241 and 242. , 243, and vias 154 to 156 for interlayer connection penetrating up and down the substrate 240. The plate electrodes 241 and 243 function as inductors Li and Lo, respectively, and are connected to the input terminal Pi and the output terminal Po through the connection portions 246 and 247, respectively. The plate electrode 242 is disposed to adjust the resonance frequency of the resonance element L2. In the first embodiment as well, the plate electrode corresponding to the plate electrode 242 is arranged between the plate electrodes 141 and 142 on the substrate 140 in FIG. 3, and the resonance frequency of the resonance element L2 can be adjusted. .
The plate electrodes 241, 242, and 243 each have a rectangular shape of 750 μm × 250 μm, 750 μm × 250 μm, and 750 μm × 250 μm in the vertical (X direction) and horizontal (Y direction), and is arranged in parallel at an interval of 375 μm.

  Also in the multilayer dielectric filter 200 according to the present embodiment, it has been confirmed that the attenuation pole P is generated by dividing the electrode 171. That is, whether the input / output is C-coupling or L-coupling does not influence the essential characteristics of the multilayer dielectric filter.

(Other embodiments)
Embodiments of the present invention are not limited to the above-described embodiments, and can be expanded and modified. The expanded and modified embodiments are also included in the technical scope of the present invention.

1 is a circuit diagram illustrating a circuit configuration of a multilayer dielectric filter according to a first embodiment of the present invention. 1 is a perspective view illustrating an appearance of a multilayer dielectric filter according to a first embodiment of the present invention. It is a disassembled perspective view showing the state which isolate | separated the board | substrate which comprises the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a top view showing the shape and dimension of the flat electrode which comprises the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a top view showing the shape and dimension of the flat electrode which comprise the comparative example of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a top view showing the shape and dimension of the flat electrode which comprise the comparative example of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a graph showing the correspondence between the width of the gap and the frequency characteristics of the multilayer dielectric filter. It is a graph showing the correspondence of the position (frequency) of the attenuation pole P of FIG. 7, and a space | interval. It is a top view showing the shape and dimension of the flat electrode which comprise the comparative example of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a top view showing the shape and dimension of the flat electrode which comprise the comparative example of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a graph showing the correspondence of the division | segmentation state of a flat electrode and the frequency characteristic of a laminated dielectric filter. It is a top view showing the shape and dimension of the flat electrode which comprise the comparative example of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a top view showing the shape and dimension of the flat electrode which comprise the comparative example of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a top view showing the shape and dimension of the flat electrode which comprise the comparative example of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a graph showing the frequency characteristic of the laminated dielectric filter which concerns on the 1st Embodiment of this invention. It is a graph showing the relationship between the gap | interval between flat plate electrodes, and the frequency characteristic of a laminated dielectric filter. It is a circuit diagram showing the circuit structure of the laminated dielectric filter which concerns on the 2nd Embodiment of this invention. It is a disassembled perspective view showing the state which isolate | separated the board | substrate which comprises the laminated dielectric filter which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Laminated dielectric filter 11-18 Notch 110-180 Board | substrate 121 Flat plate electrode 131-133 Flat plate electrode 141, 142 Flat plate electrode 143-145 Via 151-153 Flat plate electrode 154-156 Via 161 Flat plate electrode 171a, 171b Flat plate electrode

Claims (7)

First and second flat plate electrodes disposed on a first plane;
A first stripline resonator that is capacitively coupled to the first plate electrode and arranged in parallel with each other on a second plane that is stacked on the first plane; A second stripline resonator capacitively coupled to both of the two plate electrodes; a third stripline resonator capacitively coupled to the second plate electrode;
A third plate electrode disposed on a third plane stacked on the second plane and capacitively coupled to the first, second, and third stripline resonators;
On the fourth plane arranged in a stack on the third plane, each is opposed to the third plate electrode and has a gap exceeding the width of the second stripline resonator. 4th and 5th flat plate electrodes,
A multilayer dielectric filter comprising: 2. The multilayer dielectric filter according to claim 1, wherein the fourth and fifth plate electrodes are grounded. The multilayer dielectric filter according to claim 1, wherein the gap is disposed corresponding to the second stripline resonator. 2. The multilayer dielectric filter according to claim 1, wherein one side of each of the fourth and fifth plate electrodes is disposed substantially parallel to each other. A first electrically connected to the first stripline resonator disposed substantially parallel to each other on a fifth plane disposed in a stacked manner between the first plane and the second plane. 4 stripline resonators, a fifth stripline resonator electrically connected to the second stripline resonator, and a sixth stripline resonator electrically connected to the third stripline resonator. Stripline resonators,
The multilayer dielectric filter according to claim 1, further comprising: A sixth plate electrode capacitively coupled to the first stripline resonator, disposed on a sixth plane disposed in a stacked manner between the first plane and the second plane; A seventh plate electrode capacitively coupled to the third stripline resonator;
The multilayer dielectric filter according to claim 1, further comprising: A sixth plate electrode electrically connected to the first stripline resonator, disposed on a sixth plane disposed in a stacked manner between the first plane and the second plane; And a seventh plate electrode electrically connected to the third stripline resonator,
The multilayer dielectric filter according to claim 1, further comprising:

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