WO2020143045A1

WO2020143045A1 - Split-type resonator

Info

Publication number: WO2020143045A1
Application number: PCT/CN2019/071430
Authority: WO
Inventors: 张孟伦; 庞慰; 孙晨
Original assignee: 天津大学; 诺思(天津)微系统有限责任公司
Priority date: 2019-01-11
Filing date: 2019-01-11
Publication date: 2020-07-16

Abstract

Disclosed is a split-type resonator, which is a resonator group constituted by connecting a plurality of sub-resonators in parallel, wherein each sub-resonator is of a polygonal shape. The split-type resonator is provided with two pins, wherein the two pins respectively occupy a first potential and a second potential. By means of increasing a perimeter-area ratio of the resonator, heat dissipation performance of the resonator, and overall power capacity of an electronic device are improved.

Description

Split resonator

Technical field

The invention relates to a resonator, in particular to a split resonator.

Background technique

Thin film bulk wave resonators made by longitudinal resonance of piezoelectric films in the thickness direction have become a viable alternative to surface acoustic wave devices and quartz crystal resonators in mobile phone communications and high-speed serial data applications. The RF front-end bulk wave filter/duplexer provides superior filtering characteristics, such as low insertion loss, steep transition band, and strong anti-static discharge (ESD) capability. With the continuous improvement of the power capacity requirements of electronic devices such as filters and resonators in the fields of communication and the like, the heat generation of filters and resonators has increased significantly. The high temperature caused by high heat will cause the device Q value and electromechanical coupling coefficient to decrease greatly; in addition, the high temperature will cause the frequency of the resonator to drift; in addition, the high temperature will also reduce the overall life of the device. The above problems ultimately lead to serious deterioration of the performance parameters of the filter composed of resonators such as bandwidth, insertion loss, roll-off characteristics, and out-of-band suppression.

The traditional way to deal with the problem of heating is to increase the area of the resonator. This method can effectively reduce the power density in the resonator within a certain power range, thereby reducing the operating temperature of the resonator. However, relying solely on the method of increasing the area can no longer meet the current power requirements of the resonator, and further improvement of the traditional structure is needed.

Summary of the invention

The object of the present invention is to provide a split resonator, which not only increases the perimeter area ratio of the thin film bulk acoustic resonator, thereby improving the heat dissipation performance of the resonator and the overall power capacity of the electronic device; but also can improve the rational layout of the resonator It effectively suppresses high-order harmonics and improves the stability of the circuit.

To achieve the above objectives, the present invention provides the following technical solutions:

A split resonator, the split resonator is a resonator group composed of multiple sub-resonators connected in parallel, the shape of the sub-resonators is polygon; the split resonator has 2 pins, the The two pins occupy the first potential and the second potential, respectively.

Optionally, each of the sub-resonators has the first potential on one side and the second potential on the other side. That is, each split resonator contains only two sets of equipotential connections.

Optionally, the C axis of the piezoelectric layer of each of the sub-resonators is directed from the first potential to the second potential, or from the second potential to the first potential.

Alternatively, the piezoelectric layers of all sub-resonators in the split resonator may have the same C-axis orientation.

Optionally, the C-axis of the piezoelectric layer of at least one sub-resonator is opposite to the C-axis of the piezoelectric layer of at least one of the remaining sub-resonators. That is to say, not all the sub-resonator piezoelectric layer C-axis directions are all the same.

In the case where the C-axis directions of the piezoelectric layers of all sub-resonators are not all the same, optionally, there are more than two of the sub-resonators spatially arranged as axisymmetric, and/or more than three of the sub-resonators The spatial arrangement of the resonators is center-symmetric, and the symmetry of the sub-resonator arrangement at this time helps to suppress and cancel higher harmonics in the circuit and improve circuit stability.

Optionally, the split resonator according to claim 1, wherein each sub-resonator of the plurality of sub-resonators maintains acoustic isolation. At least one place between the upper electrode-upper electrode, the lower electrode-lower electrode, and the piezoelectric layer-piezoelectric layer of two adjacent sub-resonators is not connected, the two sub-resonators maintain acoustic isolation. For example, when there is an electrical connection between the upper electrode-upper electrode and the lower electrode-lower electrode, the piezoelectric layer-piezoelectric layer should be disconnected.

The gap width of the upper electrode or the lower electrode or the piezoelectric layer of two adjacent sub-resonators is not less than half an acoustic wave wavelength, or not less than 2 acoustic wave wavelengths.

Optionally, the split resonator is provided with 2 sets of equipotential interconnection, wherein the first set of equipotential interconnection is composed of the electrodes of the sub-resonator at the first potential and the electrical connections between these electrodes, the second set, etc. The potential interconnection is composed of the electrodes of the sub-resonator at the second potential and the electrical connections between these electrodes.

Optionally, the structure of the equipotential interconnection is serial and/or branched.

Optionally, the upper electrode and the lower electrode are made of metal, a metal multilayer composite material or alloy.

Optionally, the metal includes at least one of the following: molybdenum, ruthenium, gold, magnesium, aluminum, tungsten, titanium, chromium, iridium, osmium, platinum, gallium, germanium.

Optionally, the piezoelectric layer material includes aluminum nitride, zinc oxide, lead titanium zirconate, lithium niobate, and the above-mentioned materials doped with a certain proportion of rare earth elements.

The beneficial effect of the present invention is that the present invention splits a traditional single resonator in an electronic device into a polygon resonator group composed of several polygon sub-resonators. This structure can increase the perimeter area ratio of the resonator, thereby improving the resonator Heat dissipation performance and overall power capacity of electronic devices. In addition, another advantage of the split resonator is to help make the resonator layout more compact, so as to rationally use space and reduce device size.

BRIEF DESCRIPTION

The drawings are used to better understand the present invention and do not constitute an undue limitation on the present invention. among them:

Figure 1 is a split connection layout of the present invention;

2 is another split connection layout of the present invention;

3 is another split connection layout of the present invention;

4 is another split connection layout of the present invention;

5 is another split connection layout of the present invention;

6 is another split connection layout of the present invention;

7 is another split connection layout of the present invention;

8 is another split connection layout of the present invention;

9 is another split connection layout of the present invention;

10 is an explanatory diagram of the relationship between the equipotential connection and the direction of the C axis related to the present invention;

11A and 11B are respectively a top view and a cross-sectional view of a split resonator according to an embodiment of the present invention.

detailed description

The following is a preferred embodiment of the thin film bulk wave resonator of the present invention, but it does not limit the protection scope of the present invention.

Example 1:

This embodiment provides a split pentagonal resonator, as shown in FIG. 1, which shows the splitting method of the resonator and the connection method of the equipotential electrode: the upper electrode of the resonator R401 has a pin C400 C401-C405 are electrically connected, and the upper electrodes (solid lines) of the sub-resonators R401, R402, R403, R404, R405, and R406 are serially connected in the order shown by the arrows in the figure. The above serial connection method is only an example, and other serial sequences can also be used. The lower electrode (dotted line part) can be connected in the same way, or other prescribed ways can be used to traverse the equipotential electrodes connected to each sub-resonator one by one. In addition, the illustrations and specific descriptions corresponding to the embodiments only involve one set of equipotential connections in the split resonator, while omitting another set of equipotential connections (this description method is applicable to all the embodiments of the present invention. Not repeated in the examples).

It should be noted that in each embodiment of the present invention, serial connection does not refer to the series connection in series and parallel, but refers to the connection sequence of the same set of equipotential electrodes of each sub-resonator, that is, for example, as shown in Figs. , 7, 8, each sub-resonator is only connected to one other sub-resonator, which is different from the radial type connection, that is, it is different from R606 in FIG. 2, R701, R706 in FIG. 3 and so on.

The electrical connection between the sub-resonators is in the form of parallel connection. For example, for one sub-resonator and another sub-resonator, the upper electrode and the lower electrode of the two are interconnected. Each drawing can be understood as a top view, because the above-mentioned parallel state is not shown.

In addition, the “upper electrode” involved in the embodiments is only one possible combination of equipotential electrodes, and the electrode combination of equipotential connection can still have other ways (this principle applies to all embodiments in the present invention) For example, a certain electrical connection may be changed to connect the upper electrode of a certain sub-resonator (such as R401) and the lower electrode of another sub-resonator (such as R402), and so on.

In order to ensure the acoustic isolation of the two adjacent sub-resonators, the gap width of the upper electrode or the lower electrode or the piezoelectric layer of the two adjacent sub-resonators is set to not less than half of the sound wave wavelength, preferably not less than 2 sound waves wavelength.

It should be noted here that the above-mentioned upper electrode and the lower electrode may be made of a multi-layer composite material of platinum or gallium material; there is at most only an electrical connection between each two adjacent resonators, while maintaining acoustic isolation.

The above method requires that the final equivalent impedance remains unchanged.

Example 2:

An example of a split pentagonal resonator is given, and the splitting method of the resonator and the connection method of the upper electrode are shown in FIG. 2: The upper electrode of the resonator R601 has a pin C600, first the upper electrode of R601 (Solid line part) is connected to the upper electrode of R606 (solid line part) through C601, and then the upper electrode of R606 is radially connected to the upper electrode (solid line part) of R602-R605 through C602-C605. The above radial connection method is only an example, and other radial types may also be used. The lower electrode (dotted line) can be connected in the same way, or in other ways.

In addition, an electrical connection may be changed to connect the upper electrode of a sub-resonator (such as R601) and the lower electrode of another sub-resonator (such as R606).

Example 3:

As shown in FIG. 7, the pentagonal resonator is split into two sub-resonators R101 and R102, the input electrode of the upper electrode of C100, wherein the two upper electrodes of the sub-resonator are electrically connected through the conductor C101. The lower electrodes of similar sub-resonators can also be electrically connected in this way. In addition, the upper electrode of R101 may be connected to the lower electrode of R102. Similarly, the lower electrode of R101 may be connected to the upper electrode of R102.

At the same time, ensure that the sub-resonators R101 and R102 maintain acoustic isolation: That is, at least one of the electrode bodies or piezoelectric layers corresponding to the two resonators is not connected. And in order to ensure a good acoustic isolation state, the width of the gap between the electrodes or the piezoelectric layers of adjacent sub-resonators is ensured to be not less than half an acoustic wave wavelength, and the preferred range is not less than two acoustic wave wavelengths.

Example 4:

As shown in FIG. 4, a pentagonal resonator is split into 6 sub-resonators: R801, R802, R803, R804, R805, and R806. And through C801-C810, the upper electrode of each resonator is electrically connected, and a connection is established between each two equipotential electrodes of all sub-resonators, that is, each sub-resonator and all adjacent sub-resonators There is a connection. In addition, the upper electrode of a resonator (such as R801) can be connected to the lower electrode of the adjacent resonator (R802); the lower electrode of a resonator (such as R801) can also be connected to the phase The upper electrode of the adjacent resonator (R802), while ensuring acoustic isolation between adjacent sub-resonators.

Other connection methods can also be used. As shown in FIG. 3, the pentagonal resonator is split into 6 sub-resonators R701-R706 and connected as shown in the figure, wherein, from R701, they are respectively connected to adjacent sub-radiators The resonator, and from R706, are connected to adjacent sub-resonators radially.

Example 5:

As shown in Figure 5, the hexagonal resonator is split into 8 pentagonal sub-resonators R901-R908, the two sub-resonators located in the middle are axisymmetric, and the surrounding 6 sub-resonators are center-symmetrical, as shown in the figure Connect the upper electrode of the resonator. In addition, other splitting methods and traversing connection methods can be selected.

Example 6:

As shown in Figures 8 and 9, the pentagonal resonator is split into sub-resonators R201-R203 and connected to its upper electrode by a single path traversal; or split into sub-resonators R301-R303 and connected respectively by the electrodes on R301 radially The upper electrodes of R302 and R303.

Example 7:

Further, as shown in FIG. 6, the resonator splitting method of the present invention can also be expanded as described in FIG. 6, that is, the present invention can be used to split resonators of any shape during implementation, and the splitting trajectory can be TR1 in the above figure. The straight line shown can also be a polyline shown by TR2, an arc shown by TR3, or other mathematical or irregular curves shown by TR4; a combination of the above split trajectories can also be used, so the above The sides of the polygon may be straight lines and/or curved lines. Regardless of whether it is a straight line or a curved line, the two sides at the boundary of the adjacent sub-resonators (that is, the sides on both sides of the split trajectory in the figure) are preferably parallel, which helps reduce the area of the split resonator.

The equipotential connection and the C-axis pointing relationship will be described below with reference to FIG. 10.

As shown in FIG. 10, the sub-resonators Rsub1-Rsub4 have upper electrodes EH1-EH4, lower electrodes EL1-EL4, and piezoelectric layers A1-A4 respectively; the piezoelectric layers of the four sub-resonators have C-axis directions C1-C4, respectively. The electrodes of the sub-resonator are equipotentially connected by conductors (solid lines F1, F2 and F3 and broken lines D1, D2 and D3).

Among them, EH1-F1-EL2-F2-EH3-F3-EH4 forms one set of equipotential connections (here called A), and EL1-D1-EH2-D2-EL3-D3-EL4 forms another set of equipotential connections (called For B). If A occupies the first potential, then B occupies the second potential. When the equipotential connection is established, all the connected electrodes in A all have the first potential, and accordingly, all the connected electrodes in B have the second potential.

When referring to the C-axis pointing relationship between a certain sub-resonator and the piezoelectric layers of other sub-resonators, it is referred to the potential. For example, although the C axes (C1 and C2) of Rsub1 and Rsub2 have the same geometric orientation in the figure, by referring to the potential, it can be seen that C1 is directed from the second potential to the first potential, and C2 is directed from the first potential to the second potential , So C1 and C2 are reversed in the sense of potential. In the same way, C2 and C3 with opposite geometric directions in the figure are in the same direction in the sense of potential. The relationship between C3 and C4 in the sense of potential is easier to judge than the previous two examples (C3 and C4 are opposite in the sense of potential).

With reference to the above description, in the embodiment of the present invention, the split resonator has two pins, and the two pins occupy the first potential and the second potential, respectively. Each sub-resonator has the above-mentioned first potential on one side and the above-mentioned second potential on the other side. That is, each split resonator contains only two sets of equipotential connections. The C axis of the piezoelectric layer of each sub-resonator is directed from the first potential to the second potential, or from the second potential to the first potential. The C-axis of the piezoelectric layer of at least one sub-resonator is opposite to the C-axis of the piezoelectric layer of at least one of the remaining sub-resonators.

11A and 11B are respectively a top view and a cross-sectional view of a split resonator according to an embodiment of the present invention. As shown in FIG. 11A, the resonator SR0 is split into six sub-resonators SR1-SR6. It can be seen that after the split, the total area of the sub-resonators does not change significantly compared to before the split, but the total circumference of the sub-resonators increases significantly from before the split. The dotted line in FIG. 1 is the split perimeter than before the split. The added part. Therefore, the ratio of the total circumference after splitting to the total area of the resonator also increases significantly.

If the resonator in FIG. 1 is cut along the line A1A2, a schematic cross-sectional view in FIG. 11B can be obtained. If the resonator is not split, the heat generated during the operation of the resonator SR0 can only be dissipated into the substrate from the Q1 and Q2 sandwich structures of the resonator. When the SR0 splits, the heat dissipation path increases significantly. At this time, heat is dissipated to the substrate not only through Q1 and Q2, but also through the Q3-Q6 path. Therefore, the above split structure improves the power capacity of the resonator by improving the heat dissipation efficiency of the resonator.

In the embodiment of the present invention, the gap between the electrodes or the piezoelectric layers of the adjacent sub-resonators after splitting is not less than half an acoustic wave wavelength, and the preferred range is not less than two acoustic wave wavelengths.

In the embodiments of the present invention, the materials of the upper electrode and the lower electrode may be selected from the following metals: molybdenum, ruthenium, gold, magnesium, aluminum, tungsten, titanium, chromium, iridium, osmium, platinum, gallium, and germanium.

The piezoelectric layer material may be selected from aluminum nitride, zinc oxide, lead titanium zirconate, lithium niobate, and the above materials doped with a certain proportion of rare earth elements. The piezoelectric material is a thin film with a thickness of less than 10 micrometers, and has a single crystal or polycrystalline structure, and is made by a sputtering (Sputtering) or organic metal vapor deposition (MOCVD) process.

According to an embodiment of the present invention, a traditional single resonator in an electronic device is split into a polygon resonator group composed of several polygonal sub-resonators. The above single resonator may be a polygon and may have curved sides. Polygons and can be curved sides. This structure increases the perimeter area ratio of the resonator, thereby improving the heat dissipation performance of the resonator and the overall power capacity of the electronic device.

The above specific embodiments do not limit the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can occur depending on design requirements and other factors. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

A split resonator, characterized by:

The split resonator is a resonator group composed of multiple sub-resonators connected in parallel, and the shape of the sub-resonators is polygonal;

The split resonator has two pins, and the two pins occupy a first potential and a second potential, respectively.
The split resonator according to claim 1, wherein:

Each of the sub-resonators has the first potential on one side and the second potential on the other side.
The split resonator according to claim 1 or 2, wherein the C axis of the piezoelectric layer of each of the sub-resonators is directed from the first potential to the second potential, or by the first The second potential points to the first potential.
The split resonator according to claim 3, wherein the C-axis direction of the piezoelectric layer of at least one sub-resonator is opposite to the C-axis direction of the piezoelectric layer of at least one of the remaining sub-resonators.
The split resonator according to claim 4, wherein:

More than two of the sub-resonators are spatially symmetric and/or more than three of the sub-resonators are centrally symmetric.
The split resonator according to claim 1, wherein each of the plurality of sub-resonators maintains acoustic isolation.
The split resonator according to claim 6, characterized in that the gap width of the upper electrode or the lower electrode or the piezoelectric layer of two adjacent sub-resonators is not less than half an acoustic wave wavelength, or not less than 2 acoustic wave wavelengths.
The split resonator according to claim 1, wherein the split resonator has two sets of equipotential interconnections, wherein the first set of equipotential interconnections is composed of electrodes of the sub-resonator at the first potential and these electrodes The electrical connection between the second group of equipotential interconnection is composed of the electrodes of the sub-resonator at the second potential and the electrical connections between these electrodes.
The split resonator according to claim 8, wherein the structure of the equipotential interconnection is a serial type and/or a branch type.
The split resonator according to claim 1, wherein the upper electrode and the lower electrode are made of metal, a multi-layer composite material of metal or an alloy.
A split resonator according to claim 1, wherein the metal comprises at least one of the following: molybdenum, ruthenium, gold, magnesium, aluminum, tungsten, titanium, chromium, iridium, osmium, platinum, gallium ,germanium.
The split resonator according to claim 1, wherein the material of the piezoelectric layer comprises: aluminum nitride, zinc oxide, lead zirconate titanate, lithium niobate, and a rare earth element doped with a certain proportion The above materials.