Dual mass resonator with low support loss
By designing a mechanical resonator with two identical mass blocks and setting up an anchor area in the middle of the connecting beam to achieve acoustic energy cancellation, the problem of high support loss of existing mechanical resonators is solved, improving the quality factor and reducing the impact on repetition and hysteresis problems.
Patent Information
- Application Number
- CN202380081861.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-12-02
- Filing Date
- 2023-08-04
- Publication Date
- 2025-06-24
AI Technical Summary
Existing mechanical resonators have high support loss problems, resulting in a reduced quality factor and are susceptible to repetition and hysteresis problems.
A mechanical resonator comprising two identical mass blocks is designed, connected by at least one connecting beam and attached to the middle of the connecting beam in at least one anchor region to achieve acoustic energy cancellation, thereby reducing support loss.
By counteracting acoustic energy, the support loss of the mechanical resonator is significantly reduced, its quality factor is improved, and the impact on repetition and hysteresis problems is reduced.
Smart Images
Figure CN120202616A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a dual-mass resonator with low support loss. Specifically, the dual-mass resonator includes two identical mass blocks adapted to vibrate in phase in a direction perpendicular to the direction of the connecting beam. The resonator can be of various shapes (e.g., rectangular shape). Background Art
[0002] Resonators are very popular and widely used in different applications, but they have relatively high support loss, which reduces their quality factor. When the resonator vibrates, part of the acoustic energy leaks into the substrate and dissipates.
[0003] Considerable efforts have been made to reduce the support loss by making changes to the anchor region, or the resonator body and / or even the substrate. However, there are still some very popular resonators that may not have sufficiently low support loss.
[0004] Therefore, there is a need for techniques for reducing the support loss (or anchor region loss) in mechanical resonators. Summary of the Invention
[0005] In one aspect, a mechanical resonator includes: two identical mass blocks adapted to oscillate in phase in a direction perpendicular to the direction of the connecting beam; at least one connecting beam connecting the two identical mass blocks; and at least one anchor region attached to the middle of at least one connecting beam.
[0006] In one embodiment, the two identical mass blocks are resonator plates, and at least one anchor region is anchored to the substrate.
[0007] At least one anchor region may include two anchor regions attached to the middle of at least one connecting beam in opposite directions.
[0008] Furthermore, at least one connecting beam includes an outer ring at its middle, and at least one anchor region is disposed at the center of the outer ring and connected to the outer ring via two sub-connecting beams.
[0009] The outer ring may be in the shape of a rectangular ring.
[0010] Alternatively, the outer ring may be in the shape of a circular ring.
[0011] In an embodiment using electrostatic transduction, a direct current (DC) bias voltage is applied to the entire mechanical resonator.
[0012] In an embodiment using piezoelectric transduction, an alternating current (AC) voltage signal is applied to one port of the mechanical resonator, and the resulting AC voltage or current signal is measured using the other port of the mechanical resonator.
[0013] For piezoelectric transduction, each of the two resonator plates is made of a piezoelectric material or includes a semiconductor layer covered with a thin layer of piezoelectric material.
[0014] In addition, each of the two resonator plates further includes a patterned metal layer formed as an electrode on top of the thin layer of piezoelectric material.
[0015] The mechanical resonator may also include a first anchor region and a second anchor region, wherein one end of the first anchor region is electrically connected to the patterned metal layer formed on one of the two resonator plates, and the other end of the first anchor region is anchored to ground, and one end of the second anchor region is electrically connected to the patterned metal layer formed on the remaining one of the two resonator plates, and the other end of the second anchor region is anchored to ground.
[0016] In another embodiment, each of the two resonator plates is divided into an upper part and a lower part, wherein a first patterned metal layer is formed on the upper parts of the two resonator plates, and a second patterned metal layer is formed on the lower parts of the two resonator plates.
[0017] The connecting beam may also be divided into an upper part covered with the first patterned metal layer and a lower part covered with the second patterned metal layer.
[0018] In addition, an AC voltage signal may be applied to the first patterned metal layer and the second patterned metal layer.
[0019] In another embodiment, each of the two resonator plates is divided into an outer part and an inner part, wherein a first patterned metal layer is formed on the outer parts of the two resonator plates, and a second patterned metal layer is formed on the inner parts of the two resonator plates.
[0020] In an embodiment, at least one connecting beam may include a first connecting beam and a second connecting beam, wherein the first connecting beam is at least partially covered with the first patterned metal layer, and the second connecting beam is at least partially covered with the second patterned metal layer.
[0021] In addition, the first connecting beam includes a first anchor region, wherein one end of the first anchor region is electrically connected to the first patterned metal layer, and the other end of the first anchor region is anchored to ground.
[0022] Furthermore, the second connecting beam includes a second anchor region, wherein one end of the second anchor region is electrically connected to the second patterned metal layer, and the other end of the second anchor region is anchored to ground.
[0023] From the following detailed description of the exemplary embodiments of the present disclosure disclosed in conjunction with the accompanying drawings, those skilled in the art will be more clear about other solutions, advantages and prominent features of the present disclosure.
[0024] Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: The terms "comprising" and "including" and their derivatives mean including but not limiting; the term "or" is inclusive and means and / or; the phrases "associated with" and "associated therewith" and their derivatives may mean including, being included within, interconnected with, containing, being contained within, connected to or connected with, coupled to or coupled with, capable of communicating with, cooperating with, interlacing, juxtaposing, adjacent to, combined with or combined with, having, having the attribute of, and the like. It should be noted that the functions associated with any particular controller may be centralized or distributed, whether local or remote. Definitions of certain words and phrases are provided in this patent document, and those skilled in the art should understand that in many instances, if not most instances, these definitions apply to the prior and future use of such defined words and phrases. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] To more fully understand the present disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like components:
[0026] Figure 1A Figure 1A FIG. shows an example schematic diagram of a mechanical resonator having two plates adapted to oscillate in a direction perpendicular to the direction of a connecting beam.
[0027] Figure 1B Figure 1B FIG. shows an example image of a vibrating mechanical resonator having two plates adapted to oscillate in a direction perpendicular to the direction of a connecting beam.
[0028] Figure 2 Figure 2 FIG. shows an example schematic diagram of a mechanical resonator having two plates and an anchor region adapted to oscillate in a direction perpendicular to the direction of a connecting beam.
[0029] Figure 3 Figure 3 FIG. shows another example schematic diagram of a mechanical resonator having two plates and an anchor region adapted to oscillate in a direction perpendicular to the direction of a connecting beam.
[0030] Figure 4 Figure 4 FIG. shows an example schematic diagram of a mechanical resonator having two plates and two anchor regions adapted to oscillate in a direction perpendicular to the direction of a connecting beam.
[0031] Figure 5 Figure 5 Another exemplary schematic diagram of a mechanical resonator having two plates and two anchor regions adapted to oscillate in a direction perpendicular to the direction of the connecting beam, according to an embodiment of the present disclosure, is shown.
[0032] Figure 6 Figure 6 Another exemplary schematic diagram of a mechanical resonator having two plates and four anchor regions adapted to oscillate in a direction perpendicular to the direction of the connecting beam, according to an embodiment of the present disclosure, is shown.
[0033] It should be noted that throughout the drawings, like reference numerals are used to describe the same or similar elements, features, and structures. Detailed Description
[0034] The following discussion Figures 1A to 6 and the various embodiments used herein to describe the principles of the present disclosure are for illustration only and should not be construed in any way as limiting the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any appropriately arranged system and method. The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the embodiments of the present disclosure defined by the claims and their equivalents. The following description includes various specific details to assist in understanding, but these specific details should be considered merely as examples. Thus, those of ordinary skill in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. Additionally, descriptions of known functions and structures may be omitted for clarity and conciseness.
[0035] Those skilled in the art should be clear that the following description of the various embodiments of the present disclosure is for illustrative purposes only and not for the purpose of limiting the present disclosure defined by the appended claims and their equivalents.
[0036] Although ordinal numbers such as "first", "second", etc. are used to describe various components, those components are not limited herein. Such terms are only used to distinguish one component from another. For example, without departing from the teachings of the inventive concept, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.
[0037] The terms used herein are merely for describing the various embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms used herein are also intended to include the plural forms. It will be further understood that when used in this specification, the terms "comprising" and / or "having" indicate the presence of the stated features, quantities, steps, operations, components, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, steps, operations, components, elements, or combinations thereof.
[0038] The anchor loss can affect the resonator in various ways. First, the anchor loss can reduce the overall quality factor of the resonator, and it can make the quality factor of the resonator dependent on the substrate boundary conditions and stress. Second, the anchor loss makes the resonator vulnerable to repeatability and hysteresis problems. The present disclosure provides a mechanical resonator designed to reduce the anchor loss during operation.
[0039] Figure 1A An example schematic diagram of a mechanical resonator 10A according to an embodiment of the present disclosure is shown. Figure 1B An example image 10B of a vibrating mechanical resonator having two anchor regions according to an embodiment of the present disclosure is shown.
[0040] The mechanical resonator 10 includes two resonator plates 11, 12, two anchor regions 14, 15, and connection beams 13 that connect the two anchor regions 14, 15 to the resonator plates 11, 12. The connection beams 13 can be connected to the nodes of the resonator plates 11, 12. The two resonator plates 11, 12 vibrate in the direction of arrow 12a perpendicular to the direction of the connection beams 13.
[0041] The resonator plates 11, 12, the anchor regions 14, 15, and the connection beams 13 can be etched into a substrate (e.g., a substrate having silicon, doped silicon, N-type silicon, P-type silicon, silicon oxide, silicon carbide, germanium, etc.).
[0042] The two resonator plates 11, 12 are two identical mass blocks connected by the connection beams 13. The two resonator plates 11, 12 can have various sizes and / or shapes. In one embodiment, the two resonator plates 11, 12 can be rectangular in shape. For example, the two resonator plates 11 and 12 can be of any size between a square of 10 μm × 10 μm and a square of 1 m × 1 m.
[0043] The anchor regions 14, 15 can be etched from substrates 14A and 15A made of various materials (e.g., N-type or P-type silicon, silicon oxide, silicon carbide, germanium, etc.).
[0044] To actuate the two resonator plates, electrostatic or piezoelectric transducers can be used for the mechanical resonator 10. Alternatively, piezoresistive, electromagnetic, or thermal transducers can be used for the mechanical resonator 10. In the case of electrostatic transduction, a DC voltage is applied to the entire resonator including the resonator plates and the connection beams. In the case of piezoelectric transduction, an AC voltage signal is applied to one port of the mechanical resonator 10 (e.g., an electrode on the resonator plate), and the other port of the mechanical resonator 10 (e.g., the anchor region or the beam) is used to measure the resulting AC voltage or current signal.
[0045] As a result of electrostatic or piezoelectric transduction, two resonator plates 11, 12 oscillate in the directions of arrows 11a, 12a perpendicular to the connecting beam 13 in the same phase.
[0046] With the above structure, the respective sound energy amplitudes leaking into the connecting beam 13 from the two resonator plates 11, 12 will be equal but in opposite directions, and thus cancel each other out at the center of the connecting beam.
[0047] Two anchor regions 14, 15 can be attached to the center of the connecting beam 13 in opposite directions. The center of the connecting beam is a good location for anchoring the resonator 10 because the support loss can be minimized due to the cancellation of the respective sound energies leaking from the two resonator plates 11, 12.
[0048] Figure 2 An exemplary schematic diagram of a mechanical resonator 20 with one anchor region according to an embodiment of the present disclosure is shown.
[0049] Similar to Figure 2 the mechanical resonator 20 includes two resonator plates 21, 22, a connecting structure 23, and an anchor region 28. The two resonator plates 21, 22 can be two identical mass blocks connected by beams. For the sake of brevity, the repeated description of the same components will be omitted.
[0050] The connecting structure 23 includes an outer ring 23c at the middle, and the anchor region 25 is disposed at the center of the outer ring 23c via two inner connecting beams 23d and 23e. In this embodiment, the outer ring 23c is in the shape of a circular ring.
[0051] The anchor region 25 is disposed at the center of the connecting beam 23, where the respective sound energies leaking from the two resonator plates 21, 22 cancel each other out, and thus the support loss can be minimized. In addition, the anchor region 25 can be etched from a substrate made of various materials (e.g., N- or P-type silicon, silicon oxide, silicon carbide, and germanium).
[0052] Using electrostatic or piezoelectric transduction, two resonator plates 21, 22 oscillate in the directions of arrows 21a, 22a perpendicular to the connecting beam 23 in the same phase.
[0053] Figure 3 Another exemplary schematic diagram of a mechanical resonator 30 with one anchor region according to an embodiment of the present disclosure is shown.
[0054] Similar to Figure 2 the mechanical resonator 30 includes two resonator plates 31, 32, a connecting structure 33, and an anchor region 38. For the sake of brevity, the repeated description of the same components will be omitted.
[0055] The connection structure 33 includes an outer ring 33c located in the middle, and the anchor regions 35 are disposed at the center of the outer ring 33c via two inner connection beams 33d and 33e. In this embodiment, the outer ring 33c is in the shape of a rectangular ring. In addition, the resonant plates 31 and 32 can also have various shapes, such as rectangular, circular, polygonal, etc. The inner connection beams 33d and 33e can be connected to the nodes of the resonant plates 31 and 32.
[0056] Using electrostatic or piezoelectric transduction, the two resonant plates 31 and 32 oscillate in the directions of the arrows 31a and 32a perpendicular to the direction of the connection beam 33 in the same phase.
[0057] Figure 4 An exemplary schematic diagram of a mechanical resonator 40 having two anchor regions and patterned electrodes according to an embodiment of the present disclosure is shown.
[0058] Similar to Figure 2 the mechanical resonator 40 includes two resonant plates 41 and 42, and connection beams 43 that connect the two anchor regions 45 and 46 to the resonant plates 41 and 42. For the sake of brevity, the repeated description of the same components will be omitted.
[0059] Each of the two resonant plates 41 and 42 includes a semiconductor layer covered with a thin layer of piezoelectric material. Patterned metal layers 41b and 42b are formed as electrodes on top of the thin layers 41a and 42a of the piezoelectric material.
[0060] One end of the anchor region 45 is electrically connected to the patterned metal layer 41b, and the other end of the anchor region 45 is anchored to the ground; and one end of the anchor region 46 is electrically connected to the patterned metal layer 42b, and the other end of the anchor region 46 is anchored to the ground.
[0061] Similarly, when an AC voltage signal is applied to the electrodes to generate piezoelectric transduction, the two resonant plates 41 and 42 oscillate in the same phase in a direction perpendicular to the direction of the connection beam 43.
[0062] Figure 5 Another exemplary schematic diagram of a mechanical resonator 50 having two anchor regions and patterned electrodes according to an embodiment of the present disclosure is shown.
[0063] Similar to Figure 4 the mechanical resonator 50 includes two resonant plates 51 and 52 and connection beams 55 that connect the two anchor regions 56 and 57 to the resonant plates 51 and 52. For the sake of brevity, the repeated description of the same components will be omitted.
[0064] In this embodiment, both of the two resonator plates 51 and 52 are divided into an upper part and a lower part. A patterned metal layer 53 is formed on the upper parts of the resonator plates 51 and 52, and a patterned metal layer 54 is formed on the lower parts of the resonator plates 51 and 52. The connecting beam 55 can also be divided into an upper part and a lower part covered by the patterned metal layers 53 and 54.
[0065] When an AC voltage signal is applied to the patterned metal layers 53 and 54, the two resonator plates 51 and 52 oscillate in the same phase in a direction perpendicular to the direction of the connecting beam 55.
[0066] Figure 6 Another exemplary schematic diagram of a mechanical resonator 60 having two anchor regions and patterned electrodes according to an embodiment of the present disclosure is shown.
[0067] Similar to Figure 2 the mechanical resonator 60 includes two resonator plates 61 and 62 and connecting beams 65 and 68. Two anchor regions 66 and 67 are provided at the center of the connecting beam 65 in opposite directions; and two anchor regions 69 and 70 are provided at the center of the connecting beam 68 in opposite directions. For the sake of brevity, the repeated description of the same components will be omitted.
[0068] In this embodiment, both of the two resonator plates 61 and 62 are divided into an inner part and an outer part. A patterned metal layer 63 is formed on the outer parts of the resonator plates 61 and 62 and is connected to the anchor region 66 anchored to the ground. A patterned metal layer 64 is formed on the inner parts of the resonator plates 61 and 62 and is connected to the anchor region 70 anchored to the ground.
[0069] When an AC voltage signal is applied to the patterned metal layers 63 and 64 to generate piezoelectric transduction, the two resonator plates 61 and 62 oscillate in the same phase in a direction perpendicular to the direction of the connecting beams 65 and 68.
[0070] The above mechanical resonator can be a rectangular mass resonator made of a single semiconductor material (e.g., single crystal silicon) vibrating in its bulk acoustic width / length expansion mode. These resonators can operate in the first expansion mode or any higher mode. Such resonators made of silicon are called bulk acoustic wave resonators (SiBAR).
[0071] Another example of the above resonator can consist of a semiconductor layer covered with a thin layer of a piezoelectric material and a patterned metal layer formed on top to form an electrode. These resonators can have a mode shape similar to that of the SiBAR. Such resonators made of silicon can be called thin film piezoelectric on silicon (TPoS) resonators.
[0072] Another example of such a resonator can be a contour mode resonator made of a piezoelectric material. Additionally, there is a patterned metal layer on the top side (and even the bottom side) that can be used as an electrode. The mode shape can be similar to that of the other resonators described above.
[0073] Although the present disclosure has been described using example embodiments, various changes and modifications will be apparent to those skilled in the art. The present disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.
Claims
1. A mechanical resonator, comprising: Two identical mass blocks adapted to oscillate in the same phase in a direction perpendicular to the direction of at least one connecting beam; Said at least one connecting beam connecting said two identical mass blocks; And At least one anchor region attached to the middle of said at least one connecting beam.
2. The mechanical resonator according to claim 1, wherein Said two identical mass blocks are resonant plates, and Said at least one anchor region is anchored to a substrate.
3. The mechanical resonator according to claim 1, wherein Said at least one anchor region includes two anchor regions which are attached to the middle of said at least one connecting beam in opposite directions.
4. The mechanical resonator according to claim 1, wherein Said at least one connecting beam includes an outer ring at its middle, and Said at least one anchor region is disposed at the center of said outer ring and is connected to said outer ring via two sub-connecting beams.
5. The mechanical resonator according to claim 4, wherein Said outer ring is in the shape of a rectangular ring.
6. The mechanical resonator according to claim 4, wherein Said outer ring is in the shape of a circular ring.
7. The mechanical resonator according to claim 1, wherein When using electrostatic transduction, a DC bias voltage is applied to the entire mechanical resonator.
8. The mechanical resonator according to claim 1, wherein When using piezoelectric transduction, each of the two resonant plates includes a semiconductor layer covered by a thin layer of piezoelectric material.
9. The mechanical resonator according to claim 8, wherein Each of said two resonant plates further includes a patterned metal layer formed as an electrode on top of said thin layer of piezoelectric material.
10. The mechanical resonator according to claim 9, wherein An AC voltage signal is applied to the patterned metal layer of each of said two resonant plates.
11. The mechanical resonator according to claim 9, comprising: A first anchor region; And A second anchor region, wherein One end of said first anchor region is electrically connected to the patterned metal layer formed on one of said two resonant plates, and the other end of said first anchor region is anchored to ground; and One end of said second anchor region is electrically connected to the patterned metal layer formed on the remaining one of said two resonant plates, and the other end of said second anchor region is anchored to ground.
12. The mechanical resonator according to claim 10, wherein Each of said two resonant plates is divided into an upper part and a lower part, wherein A first patterned metal layer is formed on the upper parts of said two resonant plates, and A second patterned metal layer is formed on the lower parts of said two resonant plates.
13. The mechanical resonator according to claim 12, wherein Said connecting beam is divided into an upper part covered by said first patterned metal layer and a lower part covered by said second patterned metal layer.
14. The mechanical resonator according to claim 12, wherein Said AC voltage signal is applied to said first patterned metal layer and said second patterned metal layer.
15. The mechanical resonator according to claim 1, wherein, each of the two resonator plates is divided into an outer part and an inner part, wherein, a first patterned metal layer is formed on the outer parts of the two resonator plates, and a second patterned metal layer is formed on the inner parts of the two resonator plates.
16. The mechanical resonator according to claim 15, wherein, the at least one connecting beam includes a first connecting beam and a second connecting beam, wherein, the first connecting beam is at least partially covered by the first patterned metal layer, and the second connecting beam is at least partially covered by the second patterned metal layer.
17. The mechanical resonator according to claim 16, wherein, the first connecting beam includes a first anchor region, wherein one end of the first anchor region is electrically connected to the first patterned metal layer, and the other end of the first anchor region is anchored to the ground, and the second connecting beam includes a second anchor region, wherein one end of the second anchor region is electrically connected to the second patterned metal layer, and the other end of the second anchor region is anchored to the ground.