JP3480897B2 - Energy trap type piezoelectric filter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy trap type piezoelectric filter having a piezoelectric substrate having a plurality of vibrating portions.

[0002]

2. Description of the Related Art Various types of energy trapping type piezoelectric filters have been proposed in Japanese Patent Laid-Open No. 7-263999. As shown in FIGS. 12 and 13, this piezoelectric filter F is provided with a single piezoelectric substrate a, and one side of the piezoelectric substrate a (see FIG. 13A) has two pairs of left and right vibrating electrodes b, c is arranged so that the vibrating electrodes b, b are respectively connected to the capacitor electrodes d formed in the central portion, and the left and right sides facing the vibrating electrode pairs b, c in the thickness direction on the other surface (see FIG. 13B). Two common electrodes e, e are formed, and a central capacitor electrode f connected to the common electrodes e, e is formed so as to face the capacitor electrode d in the thickness direction. As a result, the two vibrating electrode pairs b and c and the common electrode e constitute two vibrating portions v and v, and the capacitor electrodes f and
The coupling capacitor C is configured by d. That is, one piezoelectric substrate a carries two left and right vibrating portions v, v and a central coupling capacitor C, respectively. FIG. 14 shows an equivalent circuit of this piezoelectric filter F.

[0003]

In the above-mentioned conventional structure, however, a single piezoelectric substrate a carries two left and right vibrating parts v, v, and an intermediate part carries a coupling capacitor C, respectively. Therefore, there is a problem that the shape of the piezoelectric substrate a becomes a relatively large rectangular shape, and the mounting area of the piezoelectric filter becomes large. Further, since the single coupling capacitor C is provided, it is limited by the shape and thickness of the piezoelectric substrate, the region of the vibrating portion, etc., and the variability of capacitance is limited.

Therefore, in Japanese Patent Application No. 9-231741, a pair of vibrating electrodes facing each other in the surface direction and a capacitor electrode on one side are provided on one side, and one vibrating electrode is connected to the capacitor electrode and the other vibrating electrode is connected. A single-sided electrode pattern is formed by connecting a vibrating electrode to an input / output connecting end located at a side edge deviation portion, and a common electrode facing the vibrating electrode pair in the thickness direction is formed on the other surface, and the single-sided capacitor. The other surface side capacitor electrode facing the electrode in the thickness direction is provided, and the other surface side electrode pattern formed by connecting the capacitor electrode and the common electrode is formed, whereby the vibrating electrode pair and the common electrode vibrate. To
1st which forms a coupling capacitor with a pair of capacitor electrodes
Piezoelectric substrate and second piezoelectric substrate, the first piezoelectric substrate and the second piezoelectric substrate are opposed to each other, the positions of the capacitor electrode pairs are vertically aligned, and the respective input / output connection terminals are mutually connected. Are separated from each other on the same side so as not to disturb the vibration of each vibrating portion, and the first piezoelectric substrate and the second piezoelectric substrate are laminated.
The one-sided capacitor electrodes of the piezoelectric substrate and the other-sided capacitor electrodes of the first substrate are connected to each other, and they are arranged at positions vertically opposed to the input / output connection ends of the first piezoelectric substrate.
The input electrode connected to the connection end and the output electrode connected to the connection end in a position vertically opposed to the input / output connection end of the second piezoelectric substrate, and the other surface side similarly. An energy trapping type piezoelectric filter has been proposed in which an insulating exterior plate formed by exposing an electrode pattern and a grounding electrode to be exposed on the outer surface is laminated on the piezoelectric substrate pair.

In such a structure, since the first piezoelectric substrate and the second piezoelectric substrate each having a single vibrating portion are laminated, the flat area of about half of the conventional structure as a whole. Therefore, there is an advantage that the area of the piezoelectric substrate can be reduced and the mounting area can be reduced. Further, since the first piezoelectric substrate and the second piezoelectric substrate each carry a coupling capacitor and are connected in parallel, as compared with the conventional configuration having a single coupling capacitor C, There is an advantage that the coupling capacitance can be set arbitrarily and circuit design becomes easy.

By the way, in such a structure, the first piezoelectric substrate and the second piezoelectric substrate are vertically overlapped with each other. Therefore, compared with the conventional structure shown in FIGS. The distance between the input / output connection ends of the piezoelectric substrate or the distance between the input electrode and the output electrode formed on the insulating exterior plate is shortened, and mutual electromagnetic field coupling is likely to occur, resulting in impaired attenuation characteristics. I understand. In order to solve this problem, they may be formed separately from each other, but if this is done, the area of the piezoelectric substrate becomes large, and the significance of the above configuration is halved. An object of the present invention is to solve the above problems without increasing the size of the piezoelectric substrate.

[0007]

The present invention has a constitution using the above-mentioned two piezoelectric substrates, and includes a first piezoelectric substrate and a second piezoelectric substrate.
On the other side electrode pattern of the piezoelectric substrate, in a laminated state, so as to cross the input / output connection end of the first piezoelectric substrate and the input / output connection end of the second piezoelectric substrate which are separated on the same side. It is characterized in that each of the shield electrode portions to be formed is extended.

In such a structure, the shield electrode portion is interposed between the input / output connection end of the first piezoelectric substrate and the input / output connection end of the second piezoelectric substrate, and therefore the shield electrode is formed. Since the part is grounded through the grounding electrode of the exterior plate connected to the electrode pattern on the other surface side, it is formed between the input / output connection ends and on the insulating exterior plate that is vertically opposed to the input / output connection end. The electromagnetic field coupling between the input electrode and the output electrode is blocked by the shield electrode section. Therefore, the damping characteristic is improved.

Further, a shield electrode portion located between the input electrode and the output electrode of the insulating outer plate may be extended to the ground electrode.

In this structure, the shield electrode portion of the ground electrode is interposed between the input electrode and the output electrode formed on the insulating exterior plate, and therefore, between the input electrode and the output electrode and the first electrode. The electromagnetic field coupling between the input / output connection end of the piezoelectric substrate and the input / output connection end of the second piezoelectric substrate is blocked, and the damping characteristic is improved in the same manner as above. The configuration using both the shield electrode portion of the other-side electrode pattern and the shield electrode portion of the ground electrode described above will further improve the attenuation characteristics.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of an energy trap type piezoelectric filter F ₁ according to an embodiment of the present invention will be described with reference to FIGS.

This piezoelectric filter F ₁ has the same structure as the first filter.
The piezoelectric substrate 1a and the second piezoelectric substrate 1b of
0a, and the insulating exterior plates 30 and 32 are attached to the upper and lower sides thereof with the same spacers 20b and 20c interposed therebetween.

Here, referring to FIG. 3, the piezoelectric substrates 1a and 1b are arranged.
Will be explained. The piezoelectric substrates 1a and 1b are made of PbTiO
_{It is made of} a piezoelectric ceramic material such as ₃ system, PbZrO ₃ system, PbTiO ₃ —PbZrO ₃ system, and electrode patterns 2 and 3 are formed on the front and back surfaces thereof. The electrode patterns 2 and 3 formed on the front and back surfaces of the piezoelectric substrates 1a and 1b are formed by vapor deposition of silver or by screen printing.

The form of the electrode pattern 2 formed on one side of the piezoelectric substrates 1a and 1b will be described. The vibrating electrode 4 and the vibrating electrode 5 are provided on one side of the piezoelectric substrate 1a, 1b so as to face each other at the front and rear positions. Is formed. The vibrating electrode 4 extends obliquely to the corner ends of the piezoelectric substrates 1a and 1b, and the input / output connection ends 6 are formed at the corner ends (side edge deviation portions). That is, the input / output connection end 6 is formed at a side edge displacement portion which is displaced from the center at the side edge thereof, and when one of the piezoelectric substrates is inverted back and forth, the input / output of the piezoelectric substrates 1a and 1b is performed, as described later. The connection ends 6 and 6 do not coincide with each other in the vertical direction and do not interfere with each other.

On the other side edge opposite to the input / output connection end 6, the one-sided capacitor electrode 7 having a narrow width is formed over the entire front and rear width.
Are formed and are connected to the vibrating electrode 5. The one-sided capacitor electrode 7 has both ends extending to the front and rear edges, and connecting edges 9, 9 are formed at the front and rear ends. Since the two connection edges 9 and 9 are formed in this way, the connection edges 9 and 9 of the piezoelectric substrates 1a and 1b are mutually connected when one of the piezoelectric substrates is inverted back and forth, as will be described later. Be sure to agree.

Next, the form of the other surface side electrode pattern 3 will be described. On the other surface side of the piezoelectric substrates 1a and 1b, the electrode pattern 3 includes a common electrode 10 facing the vibrating electrode pairs 4 and 5 in the thickness direction and a common electrode 10 facing the single-sided capacitor electrode 7 in the thickness direction. The other side capacitor electrode 1 long in the direction
1 and the common electrode 10 and the capacitor electrode 11 are connected to each other. Further, the capacitor electrode 11 projects to the side edge and serves as a ground connection end 12.

Thus, the vibrating electrode pairs 4, 5 and the common electrode 10 constitute the vibrating portion V, and the capacitor electrodes 7, 11 constitute the coupling capacitors C ₁ , C ₂ . .

Here, the first piezoelectric substrate 1a and the second piezoelectric substrate 1b are arranged so that the front and back sides of the first piezoelectric substrate 1a and the second piezoelectric substrate 1b are reversed in the front-rear direction, and the positions of the capacitor electrode pairs 7 and 11 are vertically aligned. ing. For this reason, the connection ends 12 are vertically aligned on one side edge, and the front and rear edges are connected to each other.
Since they match, the connection becomes easy. On the other hand, in such an arrangement mode, the corner edge positions (side edge deviation parts) where the input / output connection ends 6 and 6 exist are opposite positions in the front and rear,
It does not match up and down. Therefore, the input / output connection end 6 of the piezoelectric substrate 1a serves as an input end and serves as an input electrode 33 described later.
And the other input / output connection end 6 of the piezoelectric substrate 1b is
Since it is connected to an output electrode 34 described later as an output end,
It is not allowed to short-circuit each other, but since the input / output connection ends 6 and 6 do not vertically overlap with each other, it is easy to ensure mutual insulation.

The piezoelectric substrates 1a and 1b are provided with a spacer 20.
Layered via a, and similar spacers 20b and 20c are arranged on the upper and lower sides thereof. This spacer 20a, 2
Each of 0b and 20c is formed of an insulating plate, and a circular opening 21 is formed in the center thereof so that the vibration of the vibrating portion V is not disturbed.

An insulating exterior plate 30 is attached to the upper surface of the spacer 20b, and an insulating exterior plate 32 is attached to the lower surface of the spacer 20c, so that the members are integrally laminated. An input electrode 33, an output electrode 34, and a ground electrode 35 are formed on the lower surface of the insulating exterior plate 32.
The input electrode 33 and the output electrode 34 are circuit-symmetrical and therefore compatible with each other.

In the above-mentioned laminated structure, the single-sided capacitor electrodes 7 of the first piezoelectric substrate 1a and the second piezoelectric substrate 1b,
7 connecting end edges 9 and 9 and the other surface side capacitor electrode 1
The connection ends 12 and 12 of 1 and 11 are connected to each other. The input / output connection end 6 of the first piezoelectric substrate 1a is connected to the input electrode 3
3 and the input / output connection end 6 of the second piezoelectric substrate 1b are connected to the output electrode 34, respectively, and similarly, the other surface side electrode pattern 3 is connected to the ground electrode 35.

Next, the conducting means for connecting the electrodes to each other will be described. Recesses 22a to 22c are formed at required positions on the periphery of the spacers 20a to 20c, respectively.
Then, after being integrally laminated, the conductive material 38 is embedded in each of the recesses 22a to 22c, so that the electrodes are connected via the conductive material 38. That is,
By the conductive material 38 embedded in the recesses 22a to 22c,
A conductive path for connecting each electrode will be formed.

Here, as described above, the piezoelectric substrates 1a,
1b is an electrode pattern 2 and an electrode pattern 3 by reversing one side.
The front and back positions are different from each other, and the connection end edges 9 and 9 of the respective capacitor electrodes 7 and 7, the connection end 12 of the capacitor electrodes 11 and 11 and the like are vertically aligned.

The connection edges 9 and 9 of the capacitor electrodes 7 and 7 are connected to each other via the recesses 22a and 22a at the front and rear right ends of the spacer 20a (referred to FIG. 2, hereinafter the same), as described above. , And are connected by the conductive material 38. Similarly, the connection ends 12, 12 of the capacitor electrodes 11, 11 are
Recess 2 formed at the center of the right end of the spacers 20b and 20c
A conductive material 38 is connected to the ground electrode 35 via 2b and 22c. Further, the input / output connection end 6 of the piezoelectric substrate 1a is formed in the recess 2 formed at the rear left corner end of the spacer 20a.
2a (not shown) is connected to the input electrode 33 by the conductive material 38, and the input / output connection end 6 of the piezoelectric substrate 1b is connected to the conductive material 38 via the recess 22a formed at the front left corner of the spacer 20a. Is connected to the output electrode 34. The input electrode 33 is connected to the input-side external electric path, and the output electrode 34 is connected to the output-side external electric path.

In the piezoelectric filter F ₁ having such a structure, the plane can be formed into a substantially square shape which is half of the conventional structure, and the mounting area can be reduced to about half. In addition, the upper and lower insulating exterior plates 30 and 32 are adhered, and mechanically and electrically
The electrode patterns 2 and 3 are protected, and the conductive material 38 and the electrodes 33, 34, and 35 are exposed only on the peripheral surface and the lower surface thereof, which facilitates handling.

By providing such a conducting means, the equivalent circuit of FIG. 11 is constructed. Here, in this configuration, two coupling capacitors C ₁ and C ₂ different from the conventional configuration are connected in parallel, and the coupling capacitance is the sum thereof. Therefore, since the two coupling capacitors C ₁ and C ₂ are used, the coupling capacitance can be arbitrarily and sufficiently secured as compared with the conventional configuration, and the circuit design becomes easy.

Next, the essential part of the present invention will be described. In the above-mentioned configuration, the other surface-side electrode pattern 3 of the first piezoelectric substrate 1a and the second piezoelectric substrate 1b is in the laminated state, and the first and second electrodes located on the same side are spaced apart from each other. The linear shield electrode portions 40, 40 which are vertically positioned between the input / output connecting end 6 of the piezoelectric substrate 1a and the input / output connecting end 6 of the second piezoelectric substrate 1b and cross the space (FIG. 3B, (See Figure 7B)
Have been extended respectively. As a result, the shield electrode portions 40, 40 are interposed between the input / output connection end 6 of the first piezoelectric substrate 1a and the input / output connection end 6 of the second piezoelectric substrate 1b in the stacked state. The shield electrode portions 40, 40 are grounded via a ground electrode 35 connected to the other surface side electrode pattern 3. Therefore, the first and second piezoelectric substrates 1a,
Electromagnetic field coupling between the input / output connection ends 6 and 6 of 1b is blocked by the shield electrode portions 40 and 40 which are grounded. Further, since the input electrode 33 and the output electrode 34 are located at positions vertically opposed to the input / output connection ends 6 and 6, the shield electrode portions 40 and 40 are provided in the input electrode 33 and the output electrode 3.
By interposing between the four electrodes, it is possible to prevent the electromagnetic field coupling between the input electrode 33 and the output electrode 34.

Further, on the lower surface of the insulating exterior plate 32, the ground electrode 35 shields the input electrode 33 and the output electrode 34 so that the shield electrode portion 41 (FIG. 5C, FIG. 7).
(See C) is extended. Therefore, the input electrodes 33,
Electromagnetic field coupling between the output electrodes 34 is blocked by the shield electrode portion 41 integrated with the ground electrode. Further, since the input / output connection ends 6 and 6 are located at positions vertically opposed to the input electrode 33 and the output electrode 34, the shield electrode portion 41 is provided.
Can also prevent electromagnetic field coupling between the input / output connecting ends 6 and 6.

Shielding electrode portion 4 of the other surface side electrode pattern 3
0 and 40 and the shield electrode portion 41 of the ground electrode 35 can prevent electromagnetic field coupling even if only one of them is formed, but by using both together, there is a further effect.

3, 5 and 7 show shield electrode portions 40 and 4 respectively.
1 shows an example of arrangement, and FIGS. 4, 6 and 8 show the relationship between the example of arrangement and the damping characteristics. Further, FIG. 9 relates to the prior invention in which the shield electrode portions 40 and 41 are not provided. Here, in this prior invention, as shown in FIG. 10, the attenuation amount was 32 dB.

Here, FIG. 3 shows that the shield electrode portion 40 is formed only on the other surface side electrode pattern 3 of the piezoelectric substrates 1a and 1b, and as a result, the attenuation characteristic of FIG. 4 can be obtained,
The amount of attenuation was 38 dB, and improvement in attenuation characteristics was observed as compared with the prior invention.

FIG. 5 shows the ground electrode 35 of the insulating exterior plate 32.
The shield electrode portion 41 is formed only on the above, and as a result, the attenuation characteristic of FIG. 6 can be obtained, and the attenuation amount is 34d.
B, which is an improvement in damping characteristics as compared with the prior invention.

Further, FIG. 7 shows that the shield electrode portion 40 is formed on the other surface side electrode pattern 3 and the ground electrode 35 of the insulating exterior plate 32 is formed, respectively, and as a result, the attenuation characteristic of FIG. 8 can be obtained. The amount of attenuation was 45 dB, and the attenuation characteristics were remarkably improved as compared with the prior invention.

As described above, by providing either of the shield electrode portions 40 and 41, the attenuation characteristic can be improved, and by using both in combination, further improvement can be achieved. Thus, the shield electrode portions 40 and 41 can obtain the required attenuation characteristics while reducing the planar shape of the piezoelectric filter F ₁ to half that of the conventional _one .

[0035]

As described above, the energy trapping type piezoelectric filter F _{1 according} to the present invention has the electrode patterns 2 and 3 formed on the front and back surfaces of two piezoelectric substrates, which are laminated and the exterior plate 32 is formed. In the outermost one,
A shield electrode portion 40 is formed on the other surface side electrode pattern 3 of the piezoelectric substrates 1a and 1b, and / or a shield electrode portion 41 is formed on the ground electrode 35 of the insulating exterior plate 32. The electromagnetic field coupling between the output terminal 33 and the output electrode 34 and between the input / output connection ends 6 and 6 is cut off, so that the attenuation characteristic is improved. Therefore, the required characteristics can be obtained without increasing the area of the piezoelectric substrate, and the piezoelectric substrate 1a,
There is an excellent effect that the area reduction due to the laminated structure of 1b can be enjoyed without impairing the characteristics.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of an energy trap type piezoelectric filter F _{1 according to} the present invention.

FIG. 2 is an exploded perspective view of the piezoelectric filter F ₁ .

3A is a plan view of piezoelectric substrates 1a and 1b, FIG. 3B is a rear view thereof, and FIG.

FIG. 4 is a waveform diagram showing an attenuation characteristic of an example including only the shield electrode section 40.

5A is a plan view of piezoelectric substrates 1a and 1b, FIG. 5B is a rear view thereof, and FIG.

FIG. 6 is a waveform diagram showing an attenuation characteristic of an example including only the shield electrode portion 41.

7A is a plan view of piezoelectric substrates 1a and 1b, FIG. 7B is a rear view thereof, and FIG.

FIG. 8 is a waveform diagram showing an attenuation characteristic of an example including shield electrode portions 40 and 41.

9A is a plan view of a piezoelectric substrate 1a, 1b of a comparative example, FIG.

FIG. 10 is a waveform diagram showing an attenuation characteristic of a comparative example.

FIG. 11 is an equivalent circuit diagram of the piezoelectric filter F ₁ .

FIG. 12 is a partially cutaway perspective view of a piezoelectric filter F having a conventional configuration.

13A is a plan view and FIG. 13B is a rear view of a piezoelectric substrate a having a conventional configuration.

FIG. 14 is an equivalent circuit diagram of a piezoelectric filter F having a conventional configuration.

[Explanation of symbols]

F ₁ Energy trapping type piezoelectric filter V Vibrating part C ₁ , C ₂ Coupling capacitors 1a, 1b Piezoelectric substrates 2, 3 Electrode patterns 4, 5 Vibrating electrode 6 Input / output connection end 10 Common electrode 7, 11 Capacitor electrode 9, 12 Connection end Edges 20a to 20c Spacer 32 Insulating exterior plate 33 Input electrode 34 Output electrode 35 Earth electrode 40 Shielding electrode part 41 Shielding electrode part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-55639 (JP, A) JP-A-9-18275 (JP, A) JP-A-5-315885 (JP, A) JP-A-4- 29312 (JP, A) JP 3-97314 (JP, A) JP 62-14512 (JP, A) JP 63-107307 (JP, A) Jitsuhei 6-38489 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H03H 9/00-9/215 H03H 9/54-9/60

Claims (3)

(57) [Claims] 1. A pair of vibrating electrodes facing each other in the surface direction and a single-sided capacitor electrode are provided on one surface, one vibrating electrode is connected to the capacitor electrode, and the other vibrating electrode is used as a side edge deviation portion. A single-sided electrode pattern formed by connecting to the located input / output connection ends is formed, and a common electrode facing the vibrating electrode pair in the thickness direction on the other surface and another surface facing the one-sided capacitor electrode in the thickness direction. The other side electrode pattern is formed by connecting the capacitor electrode and the common electrode to form the other-side electrode pattern, whereby the vibrating portion is formed by the vibrating electrode pair and the common electrode, and the coupling capacitor is formed by the capacitor electrode pair. The first piezoelectric substrate and the second piezoelectric substrate formed are provided, and the front and back of the first piezoelectric substrate and the second piezoelectric substrate are opposite to each other,
The positions of the capacitor electrode pairs are vertically aligned, and the input / output connection ends are separated from each other on the same side so that they are laminated so as not to disturb the vibration of each vibrating part, and the first piezoelectric substrate and The capacitor electrodes on one side of the second piezoelectric substrate,
And the other surface side capacitor electrodes are respectively connected to each other, and the second piezoelectric element and the input electrode which is arranged at a position vertically opposed to the input / output connection end of the first piezoelectric substrate and is connected to the connection end. An output electrode connected to the input / output connection end of the substrate at the upper and lower sides and connected to the connection end, and a ground electrode connected to the other side electrode pattern are exposed on the outer surface. An insulating exterior plate that is formed is laminated on the piezoelectric substrate pair, and is formed on the other side electrode pattern of the first piezoelectric substrate and the second piezoelectric substrate on the same side in a laminated state. An energy trapping type characterized in that a shield electrode portion which is positioned so as to cross the input / output connection end of the first piezoelectric substrate and the input / output connection end of the second piezoelectric substrate, which are separated from each other, is extended. Piezoelectric filter. 2. A pair of vibrating electrodes facing each other in the surface direction and a single-sided capacitor electrode are provided on one surface, one vibrating electrode is connected to the capacitor electrode, and the other vibrating electrode is a side edge displacement portion. A single-sided electrode pattern formed by connecting to the located input / output connection ends is formed, and a common electrode facing the vibrating electrode pair in the thickness direction on the other surface and another surface facing the one-sided capacitor electrode in the thickness direction. The other side electrode pattern is formed by connecting the capacitor electrode and the common electrode to form the other-side electrode pattern, whereby the vibrating portion is formed by the vibrating electrode pair and the common electrode, and the coupling capacitor is formed by the capacitor electrode pair. The first piezoelectric substrate and the second piezoelectric substrate formed are provided, and the front and back of the first piezoelectric substrate and the second piezoelectric substrate are opposite to each other,
The positions of the capacitor electrode pairs are vertically aligned, and the input / output connection ends are separated from each other on the same side so that they are laminated so as not to disturb the vibration of each vibrating part, and the first piezoelectric substrate and The capacitor electrodes on one side of the second piezoelectric substrate,
And the other surface side capacitor electrodes are respectively connected to each other, and the second piezoelectric element and the input electrode which is arranged at a position vertically opposed to the input / output connection end of the first piezoelectric substrate and is connected to the connection end. An output electrode connected to the input / output connection end of the substrate at the upper and lower sides and connected to the connection end, and a ground electrode connected to the other side electrode pattern are exposed on the outer surface. The insulating exterior plate formed is laminated on the piezoelectric substrate pair, and a shield electrode portion located between the input electrode and the output electrode is extended to the ground electrode of the insulating exterior plate. An energy confinement type piezoelectric filter characterized by the following. 3. A pair of vibrating electrodes facing each other in the surface direction and a single-sided capacitor electrode are provided on one surface, one vibrating electrode is connected to the capacitor electrode, and the other vibrating electrode is a side edge deviation portion. A single-sided electrode pattern formed by connecting to the located input / output connection ends is formed, and a common electrode facing the vibrating electrode pair in the thickness direction on the other surface and another surface facing the one-sided capacitor electrode in the thickness direction. The other side electrode pattern is formed by connecting the capacitor electrode and the common electrode to form the other-side electrode pattern, whereby the vibrating portion is formed by the vibrating electrode pair and the common electrode, and the coupling capacitor is formed by the capacitor electrode pair. The first piezoelectric substrate and the second piezoelectric substrate formed are provided, and the front and back of the first piezoelectric substrate and the second piezoelectric substrate are opposite to each other,
The positions of the capacitor electrode pairs are vertically aligned, and the input / output connection ends are separated from each other on the same side so that they are laminated so as not to disturb the vibration of each vibrating part, and the first piezoelectric substrate and The capacitor electrodes on one side of the second piezoelectric substrate,
And the other surface side capacitor electrodes are respectively connected to each other, and the second piezoelectric element and the input electrode which is arranged at a position vertically opposed to the input / output connection end of the first piezoelectric substrate and is connected to the connection end. An output electrode connected to the input / output connection end of the substrate at the upper and lower sides and connected to the connection end, and a ground electrode connected to the other side electrode pattern are exposed on the outer surface. An insulating exterior plate that is formed is laminated on the piezoelectric substrate pair, and is formed on the other side electrode pattern of the first piezoelectric substrate and the second piezoelectric substrate on the same side in a laminated state. The shield electrode portions that are positioned so as to traverse between the input / output connection ends of the first piezoelectric substrate and the input / output connection ends of the second piezoelectric substrate, which are spaced apart from each other, are extended, and the insulating exterior plate is further provided. To the ground electrode of
An energy trapping piezoelectric filter characterized in that a shield electrode portion located between the input electrode and the output electrode is extended. An energy confinement type piezoelectric filter characterized by the above.