JP4640218B2 - Multilayer dielectric resonator and bandpass filter - Google Patents

Description

  The present invention relates to a multilayer dielectric resonator and a bandpass filter.

  With the diversification of wireless communication systems such as terrestrial TV broadcasting, mobile phones, and mobile phones with televisions, laminated dielectrics that form resonant circuits in the microwave band of several hundred MHz to several GHz, such as bandpass filters and duplexers Regarding the resonator, a small-sized and low-loss resonator is desired.

  In order to reduce the loss of the multilayer dielectric resonator, it is necessary to improve the Q value (= 1 / tan δ). The Q value of the resonance circuit is mainly determined by the loss due to the dielectric of the dielectric substrate (dielectric loss) and the loss due to the internal electrodes constituting the resonance circuit (conductor loss). In general, in a low frequency band below the microwave band, the conductor loss is more dominant than the dielectric loss than the dielectric loss.

  Therefore, in order to realize a reduction in loss of the multilayer dielectric resonator and improve the Q value, it is necessary to reduce the specific resistance of the conductor material forming the internal electrode constituting the resonance circuit, and to reduce the width of the internal electrode. It is conceivable to increase the thickness.

  However, reducing the specific resistance of the internal electrode may cause limitations in terms of material and cost, and increasing the width and thickness of the internal electrode means that the electronic component having the multilayer dielectric resonator is large. There is a problem of becoming.

  Therefore, as means for improving the Q value without increasing the size of the multilayer dielectric resonator, a plurality of internal electrodes (longitudinal patterns) are formed on the surface as shown in Patent Documents 1 and 2 below. It has been proposed to stack a large number of dielectric layers.

  In the multilayer dielectric resonator having such a structure, as a method of adjusting the resonance frequency, there is a method of changing the electrode area of the capacitor portion. For example, at present, it is necessary to increase the electrode area of the capacitor in order to make the resonance frequency of the resonator corresponding to 2.7 GHz correspond to 2.4 GHz. However, this method increases the size of the multilayer dielectric resonator.

  Further, as another method for adjusting the resonance frequency, it is conceivable to uniformly reduce the width of the internal electrode pattern constituting the inductor section. However, in this method, the resonance frequency can be changed, but the Q value becomes low.

Therefore, the present inventors have proposed a multilayer dielectric resonator in which the width of the internal electrode pattern constituting the inductor portion is narrowed in a step shape as shown in Patent Document 3. However, as the inventors proceed further development, if the width of the internal electrode pattern is narrowed in a step shape, electric field concentration may occur, and conductor loss may increase at that portion. I found more.
JP-A-4-43703 JP 2001-237619 A Japanese Patent Application No. 2005-346875

  The present invention has been made in view of such a situation, and an object of the present invention is to change the resonance frequency while maintaining a high Q value, and to achieve a low-loss and small-sized multilayer dielectric resonance. Is to provide a vessel.

In order to achieve the above object, a laminated dielectric resonator according to the present invention includes:
A multilayer dielectric resonator in which a plurality of internal electrode layers are laminated via a dielectric layer, and a capacitor part and an inductor part are formed by a pattern and a laminated structure of these internal electrode layers,
The inductor part is constituted by a longitudinal pattern;
A part of the longitudinal pattern has a width change adjusting portion whose width gradually becomes narrower than other main parts.

  In the multilayer dielectric resonator according to the present invention, without changing the size of the internal electrode layer constituting the capacitor unit, a width change adjusting unit having a width narrower than other main parts is formed in a part of the longitudinal pattern. Since it is formed, the resonator can be miniaturized.

  In addition, in the present invention, since the width of the longitudinal pattern is not uniformly narrowed, but a width change adjusting portion whose width is narrower than other main portions is formed only in a part thereof, the Q value is reduced. It is possible to adjust the resonance frequency by reducing the resonance frequency without reducing the resonance frequency. In this manner, the Q value is lowered by forming a width change adjusting portion whose width is narrower than other main portions only in a part of the longitudinal pattern instead of uniformly narrowing the entire longitudinal pattern. Without change, the resonance frequency can be changed (decreased). The present inventors have found this for the first time.

  In particular, in the present invention, since the width change adjustment portion whose width is gradually narrower than other main portions is formed in a part of the longitudinal pattern, the electric field is compared with the case where the width is narrowed stepwise. Concentration hardly occurs, conductor loss is reduced, and a high Q value can be obtained.

  Preferably, a capacitor electrode part to be one electrode of the capacitor part is formed at an end of the longitudinal pattern, and the width change adjusting part is formed at a part away from the capacitor electrode part. is there. In the case of such a pattern, the Q value is improved.

  Preferably, the longitudinal pattern is a linear pattern, and in the middle of the linear pattern, the width is tapered from both sides or one side, and the width change adjusting portion is formed. In the case of such a pattern, the resonance frequency can be changed (decreased) without reducing the Q value.

  Preferably, an adjustment linear pattern having a width smaller than that of the main portion is continuously formed at the tip of the width change adjustment portion in the longitudinal pattern. Even when the adjustment linear pattern having a narrow width is formed, the resonance frequency can be changed (decreased) without lowering the Q value.

  In the present invention, a plurality of width change adjusting portions in the longitudinal pattern may be formed along the longitudinal direction of the longitudinal pattern. For example, a width change adjusting unit may be formed in which the width is gradually narrowed once along the longitudinal direction of the longitudinal pattern, becomes a linear pattern at the tip, and further widens at the tip. In this case, it is possible to slightly change the resonance frequency without reducing the Q value.

  Preferably, the longitudinal pattern of 2 to 5 layers is laminated via the dielectric layer so as to overlap when viewed from the plane side, and constitutes the inductor section. By configuring the inductor section with a plurality of longitudinal patterns stacked at the end via a dielectric layer, the Q value can be set high and the loss is low. That is, in this aspect, it is possible to pass more current than in the conventional structure, and the insertion loss is small.

  More preferably, the longitudinal pattern of three or five layers is laminated via a dielectric layer so as to overlap when viewed from the plane side, and constitutes the inductor section.

  The longitudinal pattern constituting the inductor portion has three layers in the laminating direction than the first layer and the second layer, and the Q value is higher. In the fourth layer, the Q value is slightly lower than the third layer. The Q value is the highest, and in the 6th layer, the Q value tends to be lower than that in the 5th layer. This has been confirmed by experiments by the inventors.

  In the present invention, among the longitudinal patterns laminated via the dielectric layer, the longitudinal pattern located at the center in the laminating direction has the widest width and is separated from the longitudinal pattern located at the center in the laminating direction. As shown, the width of the longitudinal pattern is reduced. According to such an electrode pattern structure, there is little characteristic variation even when a stacking deviation occurs during manufacturing.

  Preferably, among the longitudinal patterns stacked via the dielectric layer, the width change adjustment is performed on the longitudinal pattern disposed at the position farthest in the stacking direction from the longitudinal pattern positioned at the center in the stacking direction. The part is formed. According to such an electrode pattern structure, even if a stacking deviation occurs at the time of manufacture, the characteristic variation is small, and the effect of changing (decreasing) the resonance frequency without reducing the Q value is great.

  Preferably, a pair of longitudinal patterns having the same shape are formed on the surface of the same dielectric layer at line-symmetric positions. According to such an electrode pattern structure, the Q value can be set high.

  Preferably, a lead pattern connected to the input / output terminal is connected to each of the pair of longitudinal patterns formed on the surface of the same dielectric layer. According to such an electrode pattern structure, it is easy to configure a resonator circuit.

  Preferably, the tip of the width change adjusting portion of the longitudinal pattern is connected to the ground terminal electrode. According to such an electrode pattern structure, the effect of changing (decreasing) the resonance frequency without reducing the Q value is great. In the present invention, the width change adjusting portion may be directly connected to the ground terminal electrode, or a narrow linear pattern formed at the tip of the width change adjusting portion is connected to the ground terminal electrode. May be.

  The multilayer dielectric resonator according to the present invention can be used as a band-pass filter or a duplexer, but is preferably used as a band-pass filter.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is an overall perspective view of a multilayer bandpass filter according to an embodiment of the present invention.
2 is a sectional view taken along line II-II shown in FIG.
3 is a sectional view taken along line III-III shown in FIG.
4 to 12 are plan views of the internal electrode layers shown in FIGS.
FIG. 13 is an equivalent circuit diagram of the multilayer bandpass filter shown in FIGS.
14 (A) to 14 (C) are schematic diagrams showing examples of deformation patterns of the inductor portion in the multilayer bandpass filter according to another embodiment of the present invention.
First embodiment

  As shown in FIGS. 1 to 3, the multilayer bandpass filter 2 as an example of the multilayer dielectric resonator according to the present embodiment includes an element body 4. Inside the element body 4, a plurality of internal electrode layers 20 to 36 are laminated via a dielectric layer 40. Capacitor portions C1 to C3 and inductor portions L1 and L2 shown in FIG. 13 are formed by the pattern and laminated structure of these internal electrode layers 20 to 36, and constitute a band-pass filter circuit.

  As shown in FIG. 1, the element body 4 has a rectangular parallelepiped shape, and the size thereof is not particularly limited, but is vertical (X-axis direction) 1.0 to 3.0 mm, horizontal (Y-axis direction) 0. The height is about 5 to 2.5 mm and the height (corresponding to the stacking direction Z) is about 0.6 to 1.0 mm.

  Ground terminal electrodes 10 and 12 are formed on the two side surfaces 4c and 4d facing the Y-axis direction of the element body 4, and the input terminal electrode 6 and the two side surfaces 4a and 4b facing the X-axis direction are formed. An output terminal electrode 8 is formed. Although the material of these terminal electrodes 6-12 is not specifically limited, For example, Au, Ag, Cu, the alloy which has them as a main component, etc. are used.

As shown in FIGS. 2 and 3, internal electrode layers 20 to 36 are stacked on the element body 4 via a dielectric layer 40 from the top to the bottom in the stacking direction Z. The dielectric layer 40 is obtained, for example, by firing a dielectric green sheet after laminating. The material of the dielectric layer 40 is not particularly limited, and for example, a dielectric material such as a BaTiO ₃ system, a BaZrO ₃ system, a BaNdTi system, or a BaSnTi system is used. The thickness of each dielectric layer 40 is not particularly limited, and is 10 to 200 μm.

  The internal electrode layers 20 to 36 formed on each dielectric layer 40 are formed on the surface of the dielectric green sheet to be the dielectric layer 40 by a printing method or the like, and are baked together with the green sheet to become internal electrodes. . It does not specifically limit as a metal which comprises the internal electrode layers 20-36, Au, Ag, Cu, an alloy which has them as a main component, etc. are illustrated.

  The space between internal electrode layers 20 and 22 and the space between internal electrode layers 34 and 36 are larger than the thickness of other dielectric layers 40. The thick dielectric layer 40 is obtained by laminating and firing a plurality of green sheets that do not form an electrode pattern constituting the internal electrode layer.

  As shown in FIG. 4, the internal electrode layer 20 located on the uppermost side in the stacking direction Z-axis of the element body 4 includes a pair of linear patterns 20a and 20a extending in parallel with the Y-axis direction, and these linear patterns 20a, And a rectangular pattern 20b that widely connects the central portion of 20a. The internal electrode layer 20 is an H-shaped pattern as a whole, and is an electrode pattern that is axisymmetric with respect to a center line extending in the Y-axis direction when viewed from the plane arrow side.

  The linear patterns 20a and 20a extend so as to connect the side surfaces 4c and 4b, and are electrically connected to the terminal electrodes 10 and 12 shown in FIG. The rectangular pattern 20b is not directly connected to the terminal electrodes 10 and 12, but is electrically connected to the terminal electrodes 10 and 12 because it is connected to the linear patterns 20a and 20a.

  The internal electrode layer 22 positioned below the internal electrode layer 20 through the thick dielectric layer 40 shown in FIGS. 2 and 3 includes a linear pattern 22b extending in the X-axis direction, as shown in FIG. It is formed on both sides of the linear pattern 22b and has a pair of linear patterns 22a and 22a extending in the Y-axis direction. As shown in FIG. 5, the internal electrode layer 22 has an isolated pattern that is not exposed on any of the side surfaces 4a to 4d, and serves as a floating electrode of the capacitor portion C2 shown in FIG. The internal electrode layer 22 is formed on the surface of the dielectric layer 40 at the center position in the X-axis direction at a position close to the side surface 4c, and with respect to the center line extending in the Y-axis direction when viewed from the plane arrow side This is a line-symmetric electrode pattern.

  As shown in FIG. 6, the internal electrode layer 24 located below the internal electrode layer 22 through the thin dielectric layer 40 shown in FIGS. 2 and 3 has a pair of linear patterns extending in parallel to the Y-axis direction ( 1 type of longitudinal pattern) 24a, 24a. Capacitor electrode portions 24c and 24c mainly constituting one electrode of the capacitor portions C1, C2 and C3 shown in FIG. 13 are integrally formed at the ends of the linear patterns 24a and 24a.

  These capacitor electrode portions 24c, 24c are not exposed on the side surface 4c of the element body 4, and constitute the capacitor portion C2 via the dielectric layer 40 and the internal electrode layer 22 shown in FIG. These capacitor electrode portions 24c, 24c are connected to the capacitor portion C1 and the capacitor electrode portion 28c of the internal electrode layer 28 shown in FIG. Configure C3.

An adjustment linear pattern 24a1 having a width W2 narrower than the width W1 of the other main portion is formed at an end portion of each linear pattern 24a away from the capacitor electrode portion 24c. The width W2 of the adjustment linear pattern 24a1 is narrower to about 50 to 100 μm than the width W1 of the main part of the linear pattern 24a.
The width W1 of the main part is not particularly limited, but is 200 to 400 μm in the present embodiment. The width W2 of the adjustment linear pattern 24a1 is preferably 100 to 350 μm.

  Between the main part in each linear pattern 24a and the linear pattern 24a1 for adjustment, the taper width change adjustment part 24a2 in which a width | variety becomes narrow gradually from both sides rather than a main part is formed.

The total length D2 of each adjustment linear pattern 24a1 and the taper width change adjusting portion 24a2 is preferably 80 to 10%, more preferably 60 to 40% of the total length D1 of the linear pattern 24a. is there. The total length D1 of the linear pattern 24a is not particularly limited with respect to the length D0 of the element body in the Y-axis direction, but is 70 to 90%. The length D3 in the longitudinal direction of the tapered width change adjusting portion 24a2 is preferably 100 μm or more and not more than the total length D2. If the length D3 is too short, electric field concentration tends to occur, and the Q value may be reduced. Moreover, it is desirable to satisfy the following relational expression.
D3 ≧ (W1-W2) / 2

  In this embodiment, in the middle of the linear pattern 24a, the width is tapered from both sides and the adjustment linear pattern 24a1 is formed, but in the present invention, the width is tapered in only one side, The tapered width change adjusting portion 24a2 and the adjusting linear pattern 24a1 may be formed. In the present invention, only the tapered width change adjusting portion 24a2 may be formed within the length D2 without forming the adjustment linear pattern 24a1.

  The end of each adjustment linear pattern 24a1 is exposed to the side surface 4d of the element body 4 and is connected to the terminal electrode 12 shown in FIG. The linear pattern 24a including the tapered width change adjusting unit 24a2 and the adjusting linear pattern 24a1 respectively constitute part of the inductor units L1 and L2 shown in FIG.

  Lead patterns 24b are connected to the side surfaces 4c somewhat from the approximate center of each linear pattern 24a. Each lead pattern 24b extends so as to be exposed on the side surfaces 4a and 4b, and is connected to the input / output terminals 6 and 8 shown in FIG. As shown in FIG. 6, the internal electrode layer 24 is an electrode pattern that is line-symmetric with respect to a center line extending in the Y-axis direction when viewed from the plane arrow side.

  As shown in FIG. 7, the internal electrode layer 26 located below the internal electrode layer 24 through the thin dielectric layer 40 shown in FIGS. 2 and 3 has a pair of linear patterns extending in parallel to the Y-axis direction ( A kind of longitudinal pattern) 26a, 26a. The width W3 of each linear pattern 26a is about 50-100 μm wider than the width W1 of the main part in the linear pattern 24a shown in FIG.

  Each linear pattern 26a is formed at a position where the linear pattern 24a shown in FIG. 6 does not protrude in the X-axis direction when viewed from the plane arrow side. However, the length of each linear pattern 26a in the Y-axis direction is shorter than the length D1 of the linear pattern 24a in the Y-axis direction, and the end of the linear pattern 24a protrudes in the direction of the side surface 4c when viewed from the plane arrow side. It is like that.

  Each linear pattern 26a is exposed on the side surface 4d of the element body 4 and connected to the terminal electrode 12 shown in FIG. 1, and constitutes the inductor portions L1 and L2 shown in FIG.

  A lead pattern 26b is connected to each linear pattern 26a. Each lead pattern 26b extends so as to be exposed on the side surfaces 4a and 4b, and is connected to the input / output terminals 6 and 8 shown in FIG. The lead pattern 26b is the same pattern as the lead pattern 24b shown in FIG. The internal electrode layer 26 shown in FIG. 7 is also an electrode pattern that is line-symmetric with respect to a center line extending in the Y-axis direction when viewed from the plane arrow side.

  As shown in FIG. 8, the internal electrode layer 28 located below the internal electrode layer 26 via the thin dielectric layer 40 shown in FIGS. 2 and 3 has a pair of linear patterns extending in parallel to the Y-axis direction ( 1 type of longitudinal pattern) 28a, 28a. The width W4 of each linear pattern 28a is preferably about 0 to 100 μm wider than the width W3 of the linear pattern 26a shown in FIG. 7, but W4 does not necessarily need to be wide.

  Each linear pattern 28a is formed at a position where the linear pattern 26a shown in FIG. 7 does not protrude in the X-axis direction when viewed from the plane arrow side. However, the length of each linear pattern 28a in the Y-axis direction is substantially the same as the length of the linear pattern 26a in the Y-axis direction.

  Each linear pattern 28a is exposed on the side surface 4d of the element body 4 and connected to the terminal electrode 12 shown in FIG. 1, and constitutes the inductor portions L1 and L2 shown in FIG.

  A lead pattern 28b is connected to each linear pattern 28a. Each lead pattern 28b extends so as to be exposed on the side surfaces 4a and 4b, and is connected to the input / output terminals 6 and 8 shown in FIG. The lead pattern 28b is the same pattern as the lead pattern 24b shown in FIG.

  As shown in FIG. 8, a rectangular capacitor electrode portion 28c is formed at a position away from the end portions of the linear patterns 28a, 28a by a predetermined distance. The capacitor electrode portion 28c is formed with an area that completely covers the pair of capacitor electrode portions 24c and 24c shown in FIG. 6 when viewed from the plane arrow side. The capacitor portions C1 and C2 are formed together with these electrode portions. Form.

  The capacitor electrode portion 28c shown in FIG. 8 is exposed on the side surface 4c of the element body 4 and connected to the terminal electrode 10 shown in FIG. The internal electrode layer 28 shown in FIG. 8 is also an electrode pattern that is axisymmetric with respect to a center line extending in the Y-axis direction when viewed from the plane arrow side.

  As shown in FIG. 9, the internal electrode layer 30 located below the internal electrode layer 28 via the thin dielectric layer 40 shown in FIGS. 2 and 3 has a pair of linear patterns extending in parallel to the Y-axis direction ( 1 type of longitudinal pattern) 30a, 30a and lead pattern 30b. The internal electrode layer 30 has the same electrode pattern as the internal electrode layer 26 shown in FIG.

  As shown in FIG. 10, the internal electrode layer 32 located below the internal electrode layer 30 through the thin dielectric layer 40 shown in FIGS. 2 and 3 has a pair of linear patterns extending in parallel to the Y-axis direction ( One type of longitudinal pattern) 32a, 32a, a linear pattern for adjustment 32a1, a lead pattern 32b, and a capacitor electrode portion 32c. The internal electrode layer 32 has the same electrode pattern as the internal electrode layer 24 shown in FIG.

  The internal electrode layer 34 located below the internal electrode layer 32 through the thin dielectric layer 40 shown in FIGS. 2 and 3 has a pair of linear patterns 34a extending parallel to the Y-axis direction, as shown in FIG. , 34a and a linear pattern 34b extending in the X-axis direction so as to connect them. The internal electrode layer 34 has the same electrode pattern as the internal electrode layer 22 shown in FIG.

  As shown in FIG. 12, the internal electrode layer 36 located below the internal electrode layer 34 via the thick dielectric layer 40 shown in FIGS. 2 and 3 has a pair of linear patterns 36a extending parallel to the Y-axis direction. , 36a and a rectangular pattern 36b extending in the X-axis direction so as to connect them. The internal electrode layer 36 has the same electrode pattern as that of the internal electrode layer 20 shown in FIG.

  In the present embodiment, the inductor portions L1 and L2 shown in FIG. 13 are configured by the respective linear patterns 24a to 32a of the internal electrode layers 24 to 32 shown in FIGS. That is, each of the inductor portions L1 and L2 is configured by five layers of linear patterns 24a to 32a with the dielectric layer 40 interposed therebetween.

  In the multilayer dielectric resonator 2 according to the present embodiment, the inductor portions L1 and L2 are configured by a plurality of layers of linear patterns 24a to 32a that are stacked via the dielectric layer 40 and connected at the ends. Therefore, the Q value can be set high and the loss is low. That is, in this embodiment, it is possible to pass a larger amount of current and the insertion loss is smaller than in the conventional structure.

  Further, in the present embodiment, an adjustment straight line having a width narrower than that of the other main part is formed in a part of the linear patterns 24a and 32a without changing the size of the internal electrode layers constituting the capacitor parts C1, C2, and C3. Since the patterns 24a1 and 32a1 are formed, the size of the resonator can be reduced.

  In addition, in the present embodiment, the entire linear patterns 24a to 32a are not uniformly narrowed, but the adjusting linear patterns 24a1 and 32a1 having a width smaller than that of the other main portions are formed only on a part thereof. For this reason, the resonance frequency can be lowered and adjusted without lowering the Q value.

  Particularly, in the present embodiment, as shown in FIGS. 6 and 10, tapered width change adjusting portions 24a2 and 32a2 are formed between the main portions of the linear patterns 24a and 32a and the adjusting linear patterns 24a1 and 32a1. For this reason, electric field concentration is less likely to occur, conductor loss is reduced, and a high Q value can be obtained as compared with the case where the width is narrowed stepwise.

  Furthermore, in the present embodiment, the inductor portion is constituted by the five linear patterns 24a to 32a via the dielectric layer, so that the Q value can be maximized.

  Furthermore, in the present embodiment, among the linear patterns 24a to 32a stacked via the dielectric layer 40, the width W4 of the linear pattern 28a positioned at the center in the stacking direction is the widest, and the straight line positioned at the center thereof. The linear patterns 24a, 26a, 30a, and 32a that are separated from the pattern 28a in the stacking direction Z are configured such that the pattern widths W3 and W1 become narrower. For this reason, even if electrode pattern stacking misalignment or the like occurs at the time of manufacture, the characteristic variation is small.

Moreover, in the present embodiment, among the linear patterns 24a to 32a stacked via the dielectric layer 40, the linear pattern 28 located at the center in the stacking direction is disposed at a position farthest in the stacking direction Z. Adjustment linear patterns 24a1 and 32a1 are formed on the linear patterns 24a and 32a. According to such an electrode pattern structure, even if a stacking deviation occurs at the time of manufacture, the characteristic variation is small, and the effect of changing (decreasing) the resonance frequency without reducing the Q value is great.
Second embodiment

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  For example, in the embodiment described above, the pattern shapes of the linear patterns 24a and 32a can be variously modified, and may be configured as shown in FIGS. 14 (A) to 14 (C). In FIGS. 14A to 14C, only the linear pattern 24a is shown, but the same applies to the linear pattern 32a.

  In the embodiment shown in FIG. 14A, a tapered width change adjusting portion 24a2 is formed at the tip of the main portion of the linear pattern 24a, and an adjusting linear pattern 24a1 is formed at the tip thereof. First, the tapered width change adjusting portion 24a3 is formed again.

  The minimum values of the longitudinal lengths D3a and D3b of the tapered width change adjusting portions 24a2 and 24a3 are the same as the minimum values of the length D3 of the tapered width change adjusting portion 24a2 shown in FIG. The maximum value is (D2-D3b) or (D2-D3a). These lengths D3a and D3b may be the same or different, but are preferably the same. This is because the symmetry of the pattern can be maintained.

  Further, the maximum width W1a of the tapered width change adjusting portion 24a3 is preferably about the same as the maximum width W1 of the tapered width change adjusting portion 24a3, but it is not necessarily the same. In this embodiment, since the tapered width change adjusting portion 24a3 is formed at the tip of the adjustment linear pattern 24a1, in addition to the function and effect of the embodiment shown in FIGS. 1 to 13, the resonance frequency is slightly changed. Can be made. In addition, in this embodiment, the grounding terminal electrode 12 shown in FIG. 1 can be connected with the maximum width W1 of the tapered width change adjusting portion 24a3, so that the connection resistance can be reduced.

  The embodiment shown in FIG. 14 (B) is a further modification of the embodiment shown in FIG. 14 (A), and both side edge shapes of the tapered width change adjusting parts 24a2 and 24a3 are not straight lines but concave curves. . Also in this embodiment, the same effect as that of the embodiment shown in FIG. 14A can be obtained, and the electric field concentration can be further reduced.

The embodiment shown in FIG. 14C is a further modification of the embodiment shown in FIGS. 1 to 13, and the both-side edge shape of the tapered width change adjusting portion 24a2 is not a straight line but a concave curve. Also in this embodiment, the same effect as that of the embodiment shown in FIGS. 1 to 13 can be obtained, and the electric field concentration can be further reduced.
Other embodiments

  In the above-described embodiment, each of the inductor portions L1 and L2 is configured by five layers of linear patterns 24a to 32a via the dielectric layer 40. However, the present invention is not limited to this. In the present invention, the internal electrode layers 26 and 30 shown in FIGS. 7 and 9 are omitted, and each of the inductor portions L1 and L2 is formed by the linear patterns 24a, 28a, and 32a formed in the three electrode layers 24, 28, and 32. May be configured.

  Alternatively, the linear patterns 26a and 30a of the internal electrode layers 26 and 30 shown in FIGS. 7 and 9 are similar to the width change adjusting units 24a2 and 32a2 and the adjusting linear patterns 24a1 and 32a1 shown in FIGS. It may be formed.

  Further, the multilayer dielectric resonator according to the present invention can be used not only as a band-pass filter but also as a resonator for other purposes.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

Example 1

  A plurality of samples of the multilayer bandpass filter shown in FIGS. 1 to 13 were actually manufactured, and the average value of the resonance frequency and the Q value was obtained. The average value of the resonance frequency was about 2.4 GHz, and the Q value The average value of was 89.5. In addition, the width W1 of the main part in the linear patterns 24a and 32a is 300 μm, the total length D1 is 1200 μm, the width W2 of the adjustment linear pattern 32a1 is 260 μm, and the length D2 is the length D1. The length D3 of the tapered width change adjusting portion 24a2 was 100 μm. The vertical and horizontal dimensions of the element body 4 were 2.5 mm × 2.0 mm, and the height in the Z-axis direction was 1.0 mm.

Comparative Example 1

  The linear patterns 24a and 32a are not provided with the adjusting linear patterns 24a1 and 32a1 and the tapered width change adjusting portions 24a2 and 32a2, and are laminated in the same manner as in Example 1 except that the width W1 is 300 μm over the entire length. A plurality of samples of the type band-pass filter were actually manufactured, and the average values of the resonance frequency and the Q value were obtained. The average value of the resonance frequency was about 2.7 GHz, and the average value of the Q value was 90.04. In Comparative Example 1, the target frequency region could not be obtained.

Comparative Example 2

  The linear patterns 24a and 32a are not provided with the adjustment linear patterns 24a1 and 32a1 and the tapered width change adjusting portions 24a2 and 32a2, and are laminated in the same manner as in Example 1 except that the width W1 is 280 μm over the entire length. A plurality of samples of the type band-pass filter were actually manufactured, and the average values of the resonance frequency and the Q value were obtained. The average value of the resonance frequency was about 2.4 GHz, and the average value of the Q value was 84.1. In Comparative Example 2, the target frequency region could be obtained, but the Q value was lowered.

FIG. 1 is an overall perspective view of a multilayer bandpass filter according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II shown in FIG. FIG. 3 is a sectional view taken along line III-III shown in FIG. FIG. 4 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 5 is a plan view of one of the internal electrode layers shown in FIGS. 6 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 7 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 8 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 9 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 10 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 11 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 12 is a plan view of one of the internal electrode layers shown in FIGS. FIG. 13 is an equivalent circuit diagram of the multilayer bandpass filter shown in FIGS. 14 (A) to 14 (C) are schematic diagrams showing examples of modification patterns of the inductor portion in the multilayer bandpass filter according to another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Laminated band pass filter 4 ... Element main body 6 ... Input terminal electrode 8 ... Output terminal electrode 10, 12 ... Grounding terminal electrode 20-36 ... Internal electrode layer 24a-32a ... Linear pattern 24a1, 32a1 ... Adjustment linear pattern 24a2, 32a2, 24a3... Width change adjusting section 24b to 32b ... Lead pattern 24c, 32c ... Capacitor electrode section C1, C2, C3 ... Capacitor section L1, L2 ... Inductor section

Claims (7)

A multilayer dielectric resonator in which a plurality of internal electrode layers are laminated via a dielectric layer, and a capacitor part and an inductor part are formed by a pattern and a laminated structure of these internal electrode layers,
Three or five longitudinal patterns are stacked via the dielectric layers so as to overlap when viewed from the plane side , and the first ends of these longitudinal patterns are connected to the first ground terminal electrode. The inductor part is configured,
Wherein one of said longitudinal pattern with the dielectric layer are laminated in three layers or five layers, the width of the center longitudinal pattern located in the center of the stacking direction is the most widely longitudinal away in the stacking direction from the center position longitudinal pattern The longer the pattern , the shorter the width of the longitudinal pattern,
Among the longitudinal patterns laminated in 3 layers or 5 layers through the dielectric layer, a pair of outer positions arranged at positions farthest in the laminating direction from the central position longitudinal pattern located at the center in the laminating direction A capacitor electrode portion serving as one electrode of the capacitor portion is formed at each second end portion of the longitudinal pattern opposite to the first end portion along the outer position longitudinal pattern, and the capacitor A width that gradually becomes smaller than the width of the outer position longitudinal pattern formed by the capacitor electrode portion in a portion separated along the outer position longitudinal pattern from the electrode portion toward the first end. A change adjustment part is formed,
The other electrode of the capacitor portion is located at a predetermined distance along the longitudinal direction of the central position longitudinal pattern from the second end opposite to the first end of the central position longitudinal pattern. A multilayer dielectric resonator , wherein a capacitor electrode portion is formed, and the capacitor electrode portion is connected to a second ground terminal electrode different from the first ground terminal electrode . 2. The stacked type according to claim 1, wherein the pair of outer position longitudinal patterns is a linear pattern, and the width thereof is tapered from both sides or one side in the middle of the linear pattern, and the width change adjusting portion is formed. Dielectric resonator. The first end portion side of the width change adjustment portion in the pair of said outer position the longitudinal pattern, wherein the width than the outer position the longitudinal pattern of the second end side is narrow adjustment linear pattern continuously The multilayer dielectric resonator according to claim 2, which is formed. Respectively with respect to the surface of said same dielectric layer, forming a pair in said longitudinal pattern is line-symmetrical position with the same shape of said longitudinal pattern of said three layers are laminated through the dielectric layer or 5-layer The laminated dielectric resonator according to any one of claims 1 to 3 . With respect to each of the three or five layers of the longitudinal pattern laminated via the dielectric layer , one of the longitudinal patterns formed in a pair on the surface of the same dielectric layer is connected to the input terminal. Yes and lead pattern for connecting connects to the other of said longitudinal pattern is formed with a pair on the surface of said same dielectric layer, according to claim 4, lead pattern connected to the output terminal is connected laminated dielectric resonator. The stacked dielectric resonator according to claim 1 , wherein the pair of outer position longitudinal patterns are formed longer in the longitudinal direction than the center position longitudinal pattern.   A band-pass filter having the multilayer dielectric resonator according to claim 1.

Images