Reconfigurable acoustic resonator and preparation method thereof

Abstract

The invention discloses a reconfigurable acoustic resonator and a preparation method thereof. The acoustic resonator comprises a supporting substrate; the piezoelectric film is positioned on the supporting substrate and is provided with a groove; a heating metal layer is arranged in the groove; the second insulating dielectric layer is positioned on the heating metal layer; the first bus bar, the second bus bar, the interdigital electrode and the phase change switch are located on the piezoelectric film; wherein the first bus bar and the second bus bar are oppositely arranged on the edge surface of the piezoelectric film; the interdigital electrode is arranged between the first bus bar and the second bus bar and comprises a fixed electrode and a tuning electrode; the two ends of the phase change switch are connected with the tuning electrode. The interdigital electrode on the piezoelectric film is connected with the bus bar through the phase change switch, and the state of the phase change switch can be controlled through the control unit, so that the potential of the tuning electrode is controllable, the electrical condition on the piezoelectric film is changed, and the frequency band movement of the acoustic resonator is realized.

Description

Technical Field

[0001] The invention relates to the field of electronic devices, and in particular to a reconfigurable acoustic resonator and a preparation method thereof. Background Art

[0002] With the development of communication technology, more and more new frequency bands are being opened up. If you want to use one device to achieve filtering functions on multiple frequency bands, you need to use a switch filter group composed of a large number of discrete filters and switches, which will make communication equipment bulky and expensive. In this context, the market demand for tunable RF acoustic filters is increasing, and one of the most promising ways to achieve it is to develop high-performance reconfigurable acoustic resonators. The characteristics of piezoelectric transducers are jointly determined by the geometry, material properties, and electrical boundary conditions of the interdigitated electrodes. After the traditional acoustic resonator is manufactured, the material and shape are determined, and the frequency band cannot be moved. Summary of the invention

[0003] The present invention provides a reconfigurable acoustic resonator, which can control the state of a phase change switch through a control unit to achieve controllable potential of a tuning electrode, thereby changing the electrical conditions on a piezoelectric film, thereby achieving frequency band movement of the acoustic resonator.

[0004] In one aspect, the present invention provides a reconfigurable acoustic resonator, comprising:

[0005] a supporting substrate;

[0006] A piezoelectric film with a groove located on the support substrate; a heat-generating metal layer is arranged in the groove;

[0007] a second insulating medium layer located on the heat-generating metal layer;

[0008] A first bus bar, a second bus bar, interdigital electrodes and a phase change switch located on the piezoelectric film;

[0009] Among them, the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the interdigitated electrodes are arranged between the first bus bar and the second bus bar, and the interdigitated electrodes include a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode.

[0010] Optionally, one end of the tuning electrode is fixedly connected to the first bus bar, and the phase change switch is arranged close to the first bus bar, and further includes:

[0011] A metal block is located at an end of the tuning electrode and at both ends of the fixed electrode.

[0012] Optionally, the fixed electrode is a strip-shaped structure, and the fixed electrode includes a first fixed electrode and a second fixed electrode, the first fixed electrode is fixedly connected to the first bus bar, and the second fixed electrode is fixedly connected to the second bus bar;

[0013] The interdigital electrodes are multiple groups, and each group of the interdigital electrodes includes the first fixed electrode, the second fixed electrode and the tuning electrode which are sequentially arranged at intervals;

[0014] The distance between the free end of the first fixed electrode and the second bus bar is equal to the distance between the free end of the second fixed electrode and the first bus bar.

[0015] Optionally, each group of the interdigital electrodes includes m tuning electrodes with phase change switches, k first fixed electrodes and n second fixed electrodes; wherein n=m+k,

[0016] Optionally, also include:

[0017] a first insulating dielectric layer located on the supporting substrate;

[0018] The piezoelectric film with the groove is located on the first insulating medium layer.

[0019] Optionally, the support substrate includes two types: one containing an air cavity and one not containing an air cavity. For the type containing an air cavity, a preset air cavity exists in the support substrate, the support substrate is composed of a support component and the air cavity, and the tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, and the metal block structure are all located in the area directly above the support substrate;

[0020] The piezoelectric film is located on the supporting component; the air cavity is located between the piezoelectric film and the supporting component; and the groove is arranged on a side of the piezoelectric film away from the supporting substrate.

[0021] Optionally, the sum of the thicknesses of the heat-generating metal layer and the second insulating dielectric layer is equal to the depth of the groove; and the surface of the second insulating dielectric layer away from the heat-generating metal layer is flush with the surface of the piezoelectric film away from the first insulating dielectric layer.

[0022] Optionally, the groove is arranged close to the first bus bar and is parallel to the first bus bar, and the groove passes through the area where the interdigitated electrodes are located; the phase change switch is located on the surface of the second insulating medium layer; and the metal block close to the side of the first bus bar is located on the surface of the second insulating medium layer.

[0023] Optionally, also include:

[0024] a first dummy electrode fixedly connected to the first bus bar; the first dummy electrode and the second fixed electrode are located on the same straight line, and there is a gap between the first dummy electrode and the second fixed electrode;

[0025] A second dummy electrode fixedly connected to the second bus bar; the second dummy electrode and the first fixed electrode or the tuning electrode are located on the same straight line, and there is a gap between the second dummy electrode and the first fixed electrode or the tuning electrode.

[0026] Optionally, also include:

[0027] a reflector located on the piezoelectric film, wherein the reflector is not in contact with the groove; the reflector is an open reflector or a short reflector; the open reflector comprises a plurality of third fixed electrodes arranged in parallel with each other; the plurality of third fixed electrodes have the same size and are distributed at equal intervals, and the ends of the plurality of third fixed electrodes are located on the same straight line; each of the third fixed electrodes is arranged in parallel with the interdigital electrodes;

[0028] The short-circuit reflector includes two third bus bars parallel to each other and a plurality of third fixed electrodes located between the two third bus bars; each of the third fixed electrodes is perpendicular to the two third bus bars; the two third bus bars are perpendicular to the interdigitated electrodes; and both ends of each third fixed electrode are fixedly connected to the two third bus bars.

[0029] Optionally, the support substrate may be a high-speed support substrate, and the material of the support substrate includes silicon carbide, diamond, sapphire, silicon or quartz;

[0030] The material of the piezoelectric film includes lithium niobate and lithium tantalate;

[0031] The materials of the phase change switch include vanadium oxide and sulfur compound.

[0032] Optionally, the material of the first insulating dielectric layer and the second insulating dielectric layer includes silicon dioxide, silicon nitride or aluminum oxide;

[0033] The material of the heating metal layer includes chromium, tungsten, nickel-chromium-silicon, titanium-titanium nitride-tungsten material.

[0034] Optionally, the materials of the tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, and the metal block include a combination of one or more of aluminum, tungsten, chromium, titanium, copper, silver, and gold.

[0035] Optionally, the target elastic waves excited by the piezoelectric film include longitudinal leakage surface acoustic waves, Lamb waves, horizontal shear waves and Rayleigh modes.

[0036] Optionally, the ratio of the thickness of the piezoelectric film to the wavelength of the acoustic resonator is in the range of 0.05 to 0.85.

[0037] Optionally, the piezoelectric film has a thickness ranging from 150 nm to 1.5 μm.

[0038] Optionally, the first fixed electrode has the same potential as the tuning electrode when the phase change switch is turned on; and the second fixed electrode has a different potential than the tuning electrode when the phase change switch is turned on.

[0039] Optionally, a ratio of the resistivity of the material in the phase change switch before the phase change occurs to the resistivity of the material in the phase change switch after the phase change occurs is greater than 100.

[0040] In another aspect, the present invention provides a method for preparing a reconfigurable acoustic resonator, the method comprising:

[0041] providing a supporting substrate;

[0042] forming a piezoelectric film having a groove on the supporting substrate;

[0043] forming a heat-generating metal layer in the groove of the piezoelectric film;

[0044] forming a second insulating dielectric layer on the heat-generating metal layer;

[0045] forming a first bus bar, a second bus bar, interdigital electrodes and a phase change switch on the piezoelectric film;

[0046] Among them, the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the interdigitated electrodes are arranged between the first bus bar and the second bus bar, and the interdigitated electrodes include a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode.

[0047] The present invention has the following beneficial effects:

[0048] The present invention provides a reconfigurable acoustic resonator, comprising a supporting substrate; a piezoelectric film with a groove located on the supporting substrate; a heating metal layer is arranged in the groove; a second insulating medium layer is located on the heating metal layer; a first bus bar, a second bus bar, a forked electrode and a phase change switch are located on the piezoelectric film; wherein the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the forked electrode is arranged between the first bus bar and the second bus bar, and the forked electrode includes a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode. The forked electrode on the piezoelectric film of the present invention is connected to the bus bar through the phase change switch, and the state of the phase change switch can be controlled by the control unit to realize the controllable potential of the tuning electrode, so that the electrical conditions on the piezoelectric film change, and the equivalent capacitance value between the electrodes will change, thereby realizing the frequency band shift of the acoustic resonator and the reconstruction of the acoustic resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 is a schematic structural diagram of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0051] Figure 2 The embodiment of the present invention provides Figure 1 The corresponding cross-section along the dotted line;

[0052] Figure 3 1 is a top view example 1 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0053] Figure 4 1 is a top view example 2 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0054] Figure 5 This embodiment of the present invention provides a Figure 3 Performance diagram of the structure;

[0055] Figure 6 This embodiment of the present invention provides a Figure 4 Performance diagram of the structure;

[0056] Figure 7 1 is a top view example 3 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0057] Figure 8 1 is a top view example 4 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0058] Fig. 9 This embodiment of the present invention provides a Figure 8 Performance diagram corresponding to the structure;

[0059] Fig.10 is a top view example 5 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0060] Fig.11 is a top view example 6 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0061] Fig.12 The embodiment of the present invention provides Fig.11 Performance diagram corresponding to the structure;

[0062] Fig.13 1 is a top view example 7 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0063] Fig.14 1 is an example eight of a top view of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0064] Fig.15 This embodiment of the present invention provides a Fig.13 Performance diagram corresponding to the structure;

[0065] Fig.16 is a top view example nine of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0066] Fig.17 is a schematic structural diagram of a reflection grating provided by an embodiment of the present invention;

[0067] Fig.18 is a top view example 10 of a reconfigurable acoustic resonator provided by an embodiment of the present invention;

[0068] Fig.19 This embodiment of the present invention provides a Figure 1 A cross-sectional view of the structure along the central axis of the tuning electrode;

[0069] Fig. 20 is a cross-sectional view of a reconfigurable acoustic resonator along the central axis of a tuning electrode provided by an embodiment of the present invention;

[0070] Fig.21 This embodiment of the present invention provides a Fig. 20 Performance diagram corresponding to the structure.

[0071] Fig. 22is a schematic diagram of an operating temperature curve of a volatile phase change switch provided by an embodiment of the present invention;

[0072] Fig.23 It is a schematic diagram of an operating temperature curve of a non-volatile phase change switch provided by an embodiment of the present invention.

[0073] The reference numerals in the figures correspond to the following:

[0074] Support substrate 1, first insulating dielectric layer 2, piezoelectric film 3, heat-generating metal layer 4, second insulating dielectric layer 5, tuning electrode 6, first fixed electrode 7, second fixed electrode 8, first bus bar 9, second bus bar 10, phase change switch 11, metal block 12, air cavity 13, first dummy electrode 14, second dummy electrode 15, third fixed electrode 16, third bus bar 17. DETAILED DESCRIPTION

[0075] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0076] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0077] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0078] In this embodiment, the heat-generating metal layer, phase change switch and other control elements can change the electromechanical response characteristics of the acoustic resonator, complete the frequency band shift, and show great application potential. This embodiment uses appropriate tuning principles and a small-sized control structure to complete device integration, which is the key to achieving high-performance reconfigurable acoustic resonators and filters.

[0079] This embodiment provides a reconfigurable acoustic resonator, comprising:

[0080] a supporting substrate;

[0081] A piezoelectric film with a groove located on the support substrate; a heat-generating metal layer is arranged in the groove;

[0082] A first bus bar, a second bus bar, interdigital electrodes and a phase change switch located on the piezoelectric film;

[0083] Among them, the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the interdigitated electrodes are arranged between the first bus bar and the second bus bar, and the interdigitated electrodes include a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode.

[0084] Exemplarily, the thickness and size of the first bus bar and the second bus bar are the same; the phase change switch is arranged on the side of the tuning electrode close to the first bus bar, the phase change switch and the tuning electrode are located on the same straight line, and the phase change switch divides the tuning electrode into two parts.

[0085] Optionally, the fixed electrode and the tuning electrode have the same size, for example, the lengths of the two are the same; the phase change switch is located on the surface of the tuning electrode, and exemplarily, the phase change switch is sleeved on the surface of the tuning electrode; the size of the fixed electrode is the same as the size of the tuning electrode; exemplarily, the length of the fixed electrode is the same as the length of the tuning electrode, and the width of the fixed electrode is the same as the width of the tuning electrode; optionally, the width of the phase change switch is greater than the width of the tuning electrode.

[0086] Exemplarily, one end of the tuning electrode is fixedly connected to the first bus bar, the other end of the tuning electrode maintains a preset distance from the second bus bar, and the phase change switch is arranged close to the first bus bar, further comprising:

[0087] A metal block, the metal block is located at the end of the tuning electrode and at both ends of the fixed electrode. The bottom area of ​​the metal block is the same as the bottom area of ​​the phase change switch;

[0088] The two metal blocks include a first metal block and a second metal block, the first metal block is located at an end of the tuning electrode away from the first bus bar, and the second metal block is located at the end and the fixed end of the fixed electrode. Exemplarily, two metal blocks are arranged on each fixed electrode.

[0089] Exemplarily, the fixed electrode is a strip-shaped structure, and the fixed electrode includes a first fixed electrode and a second fixed electrode, the first fixed electrode is fixedly connected to the first bus bar, and the second fixed electrode is fixedly connected to the second bus bar;

[0090] The interdigital electrodes may be in a plurality of groups, and each group of the interdigital electrodes includes the first fixed electrode, the second fixed electrode and the tuning electrode which are sequentially arranged at intervals;

[0091] The distance between the free end of the first fixed electrode and the second bus bar is equal to the distance between the free end of the second fixed electrode and the first bus bar.

[0092] Exemplarily, each group of interdigitated electrodes includes the first fixed electrode, the second fixed electrode, the tuning electrode and the second fixed electrode arranged in sequence; and the multiple electrodes are arranged in parallel and at equal intervals. Any two adjacent electrodes are fixed on different bus bars, and the electrode here can be any one of the first fixed electrode, the second fixed electrode, the tuning electrode and the second fixed electrode.

[0093] For example, if two adjacent first electrodes and second electrodes are fixed on the first bus bar, the second electrode is fixed on the second bus bar; conversely, if the first electrode is fixed on the second bus bar, the second electrode is fixed on the first bus bar. The first electrode can be any one of the first fixed electrode, the second fixed electrode, the tuning electrode, and the second fixed electrode, and the second electrode can be any one of the first fixed electrode, the second fixed electrode, the tuning electrode, and the second fixed electrode.

[0094] Exemplarily, each group of the interdigital electrodes includes m tuning electrodes with phase change switches, k first fixed electrodes and n second fixed electrodes; wherein n=m+k,

[0095] Exemplary also include:

[0096] a first insulating dielectric layer located on the supporting substrate;

[0097] The piezoelectric film with the groove is located on the first insulating medium layer.

[0098] Exemplarily, the support substrate includes two types: one containing an air cavity and one not containing an air cavity. For the type containing an air cavity, a preset air cavity exists in the support substrate. The support substrate is composed of a support component and the air cavity. The tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, and the metal block structure are all located in the area directly above the support substrate.

[0099] The piezoelectric film is located on the supporting component; the air cavity is located between the piezoelectric film and the supporting component; and the groove is arranged on a side of the piezoelectric film away from the supporting substrate.

[0100] Exemplary also include:

[0101] A second insulating dielectric layer is located on the heating metal layer; wherein the sum of the thicknesses of the heating metal layer and the second insulating dielectric layer is equal to the depth of the groove; and the surface of the second insulating dielectric layer away from the heating metal layer is flush with the surface of the piezoelectric film away from the first insulating dielectric layer.

[0102] Exemplarily, the groove is arranged close to the first bus bar, and the groove is parallel to the first bus bar, and the groove runs through the area where the interdigitated electrodes are located; the length of the groove can be equal to or different from the length of the first bus bar; the phase change switch is located on the surface of the second insulating medium layer; the metal block close to the side of the first bus bar is located on the surface of the second insulating medium layer.

[0103] The phase change switch and the metal block close to one side of the first bus bar are located on the same straight line.

[0104] Exemplary also include:

[0105] a first dummy electrode fixedly connected to the first bus bar; the first dummy electrode and the second fixed electrode are located on the same straight line, and there is a gap between the first dummy electrode and the second fixed electrode;

[0106] A second dummy electrode fixedly connected to the second bus bar; the second dummy electrode and the first fixed electrode or the tuning electrode are located on the same straight line, and there is a gap between the second dummy electrode and the first fixed electrode or the tuning electrode.

[0107] Exemplary also include:

[0108] a reflector located on the piezoelectric film, wherein the reflector is not in contact with the groove; the reflector is an open reflector or a short reflector; the open reflector comprises a plurality of third fixed electrodes arranged in parallel with each other; the plurality of third fixed electrodes have the same size and are distributed at equal intervals, and the ends of the plurality of third fixed electrodes are located on the same straight line; each of the third fixed electrodes is arranged in parallel with the interdigital electrodes;

[0109] The short-circuit reflector includes two third bus bars parallel to each other and a plurality of third fixed electrodes located between the two third bus bars; each of the third fixed electrodes is perpendicular to the two third bus bars; the two third bus bars are perpendicular to the interdigitated electrodes; and both ends of each third fixed electrode are fixedly connected to the two third bus bars.

[0110] Exemplarily, there may be two groups of reflection gratings, and the two groups of reflection gratings are respectively located on both sides of the interdigital electrodes.

[0111] Exemplarily, the support substrate may be a high-speed support substrate, the material of the support substrate includes silicon carbide, diamond, sapphire, silicon or quartz; the material of the piezoelectric film includes lithium niobate and lithium tantalate; the material of the phase change switch includes vanadium oxide and sulfide compounds. The vanadium oxide includes but is not limited to vanadium dioxide (VO2) and vanadium pentoxide (V2O5). The sulfide compounds include but are not limited to germanium telluride (GeTe), germanium antimony telluride (Ge-Sb-Te), and antimony telluride (Sb-Te).

[0112] Exemplarily, the materials of the first insulating dielectric layer and the second insulating dielectric layer include silicon dioxide, silicon nitride or aluminum oxide;

[0113] The material of the heating metal layer includes chromium, tungsten, nickel-chromium-silicon, titanium-titanium nitride-tungsten material.

[0114] Exemplarily, the materials of the tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, and the metal block include a combination of one or more of aluminum, tungsten, chromium, titanium, copper, silver, and gold.

[0115] Exemplarily, the target elastic waves excited by the piezoelectric film include longitudinal leakage surface acoustic waves, Lamb waves, horizontal shear waves and Rayleigh modes.

[0116] Exemplarily, the ratio of the thickness of the piezoelectric film to the wavelength of the acoustic resonator is in the range of 0.05 to 0.85.

[0117] Exemplarily, the piezoelectric film has a thickness ranging from 150 nm to 1.5 μm.

[0118] Exemplarily, the first fixed electrode has the same potential as the tuning electrode when the phase change switch is turned on; and the second fixed electrode has a different potential than the tuning electrode when the phase change switch is turned on.

[0119] Exemplarily, a ratio of the resistivity of the material in the phase change switch before the phase change occurs to the resistivity of the material in the phase change switch after the phase change occurs is greater than 100.

[0120] Exemplarily, the supporting substrate includes two types: one containing an air cavity and one not containing an air cavity. For the type containing an air cavity, there is a preset air cavity in the supporting substrate, and the tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, and the metal block structure are all located in the area directly above the air cavity.

[0121] The effective effects of the present invention are as follows:

[0122] The present invention provides a reconfigurable acoustic resonator, comprising a supporting substrate; a piezoelectric film with a groove located on the supporting substrate; a heating metal layer is arranged in the groove; a first bus bar, a second bus bar, a forked electrode and a phase change switch located on the piezoelectric film; wherein the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the forked electrode is arranged between the first bus bar and the second bus bar, and the forked electrode includes a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode. The forked electrode on the piezoelectric film of the present invention is connected to the bus bar through the phase change switch, and the state of the phase change switch can be controlled by the control unit to realize the controllable potential of the tuning electrode, so that the electrical conditions on the piezoelectric film change, and the equivalent capacitance value between the electrodes will change, thereby realizing the frequency band shift of the acoustic resonator and the reconstruction of the acoustic resonator.

[0123] This embodiment proposes a reconfigurable acoustic resonator. By applying a DC voltage, the heat generated by the heat-generating metal layer guides the phase change switch to undergo a phase change, so that the electrical conditions of the interdigitated electrodes located on the upper surface of the piezoelectric film with grooves change, so that the electrical conditions on the surface of the reconfigurable acoustic resonator are reset, and the reconstruction of the acoustic resonator is completed; by setting appropriate m and n, the arrangement pattern of the tuning electrode, the first fixed electrode and the second fixed electrode on the reconfigurable acoustic resonator is changed, and the resonance characteristics of the reconfigurable acoustic resonator can be customized and optimized; by setting a phase change switch or a metal block at both ends of the interdigitated electrode, the two can jointly play a role in sound field modulation, and effectively suppress the stray mode of the reconfigurable acoustic resonator without increasing the size of the reconfigurable acoustic resonator, thereby increasing the practicality of the reconfigurable acoustic resonator; by making the piezoelectric film suspended through an etching process, the stray mode of the resonator can be suppressed and the loss can be reduced.

[0124] On the other hand, this embodiment further discloses a method for preparing a reconfigurable acoustic resonator, the method comprising:

[0125] providing a supporting substrate;

[0126] forming a piezoelectric film having a groove on the supporting substrate;

[0127] forming a heat-generating metal layer in the groove of the piezoelectric film;

[0128] forming a second insulating dielectric layer on the heat-generating metal layer;

[0129] forming a first bus bar, a second bus bar, interdigital electrodes and a phase change switch on the piezoelectric film;

[0130] Among them, the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the interdigitated electrodes are arranged between the first bus bar and the second bus bar, and the interdigitated electrodes include a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode.

[0131] In an exemplary embodiment, the support substrate may include but is not limited to a high acoustic velocity support substrate, and the piezoelectric film may be prepared on the support substrate by an ion implantation and stripping process, a bonding and grinding process, or a thin film growth process.

[0132] Optionally, the method further includes: forming metal blocks at the end of the tuning electrode and at both ends of the fixed electrode, respectively, and the bottom area of ​​the metal blocks is the same as the bottom area of ​​the phase change switch.

[0133] Optionally, the fixed electrode includes a first fixed electrode and a second fixed electrode, and the first fixed electrode can be set on one side of the first bus bar, and the second fixed electrode can be set on one side of the second bus bar; wherein the interdigitated electrodes are multiple groups, and each group of the interdigitated electrodes includes the first fixed electrode, the second fixed electrode and the tuning electrode arranged in sequence; the distance between the free end of the first fixed electrode and the second bus bar is equal to the distance between the free end of the second fixed electrode and the first bus bar.

[0134] Optionally, the method further includes:

[0135] A first insulating dielectric layer is formed on the supporting substrate; and then the piezoelectric film with the grooves is formed on the first insulating dielectric layer.

[0136] Optionally, the support substrate includes two types: one containing an air cavity and one not containing an air cavity. For the type containing an air cavity, a preset air cavity exists in the support substrate, the support substrate is composed of a support component and the air cavity, and the tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, and the metal block structure are all located in the area directly above the support substrate;

[0137] The piezoelectric film is located on the supporting component; the air cavity is located between the piezoelectric film and the supporting component; and the groove is arranged on a side of the piezoelectric film away from the supporting substrate.

[0138] Exemplarily, the sum of the thicknesses of the heat-generating metal layer and the second insulating dielectric layer is equal to the depth of the groove; and the surface of the second insulating dielectric layer away from the heat-generating metal layer is flush with the surface of the piezoelectric film away from the first insulating dielectric layer.

[0139] Exemplarily, the groove is arranged close to the first bus bar and is parallel to the first bus bar, and the groove passes through the area where the interdigitated electrodes are located; the phase change switch is located on the surface of the second insulating medium layer; and the metal block close to the side of the first bus bar is located on the surface of the second insulating medium layer.

[0140] Exemplarily, the method further includes:

[0141] forming a first dummy electrode on the first bus bar; the first dummy electrode and the second fixed electrode are located on the same straight line, and there is a gap between the first dummy electrode and the second fixed electrode;

[0142] A second dummy electrode is formed on the second bus bar; the second dummy electrode and the first fixed electrode or the tuning electrode are located on the same straight line, and there is a gap between the second dummy electrode and the first fixed electrode or the tuning electrode.

[0143] Exemplarily, the method further includes:

[0144] A reflection grating is formed on the piezoelectric film, and the reflection grating is not in contact with the groove; the reflection grating is an open reflection grating or a short reflection grating; optionally, an open reflection grating can be formed on the piezoelectric film; the open reflection grating includes a plurality of third fixed electrodes arranged in parallel with each other; the plurality of third fixed electrodes have the same size and are distributed at equal intervals, and the ends of the plurality of third fixed electrodes are located on the same straight line; each of the third fixed electrodes is arranged in parallel with the interdigital electrodes;

[0145] Alternatively, a short-circuit reflective grid is formed on the piezoelectric film; the short-circuit reflective grid includes two third bus bars parallel to each other and a plurality of third fixed electrodes located between the two third bus bars; each of the third fixed electrodes is perpendicular to the two third bus bars; the two third bus bars are perpendicular to the interdigitated electrodes; and both ends of each third fixed electrode are fixedly connected to the two third bus bars respectively.

[0146] In order to facilitate understanding of the technical solution of the present application and illustrate the beneficial effects of the present application, specific embodiments will be described below.

[0147] Example 1

[0148] like Figure 1 , Figure 2 as well as Fig.19 As shown, Figure 1 is a schematic structural diagram of a reconfigurable acoustic resonator provided by an embodiment of the present invention; Figure 2 The embodiment of the present invention provides Figure 1 The corresponding cross-section along the dotted line;

[0149] Fig.19 This embodiment of the present invention provides a Figure 1 A cross-sectional view of the structure along the central axis of the tuning electrode; An embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0150] Support substrate 1;

[0151] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0152] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0153] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0154] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0155] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0156] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0157] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line, and the phase change switch 11 divides the tuning electrode 6 into two parts.

[0158] The fixed electrode has the same size as the tuning electrode 6, and the same length as the tuning electrode 6; the phase change switch 11 is located on the surface of the tuning electrode 6, or the phase change switch 11 is sleeved on the surface of the tuning electrode 6; the fixed electrode has the same size as the tuning electrode 6; the width of the phase change switch 11 is greater than the width of the tuning electrode 6;

[0159] In some embodiments, in order to ensure good contact between the tuning electrode 6 and the phase change switch 11 , the tuning electrode 6 may be arranged to cover the surface of the phase change switch 11 , but the tuning electrode 6 is still divided into two ends by the phase change switch 11 .

[0160] One end of the tuning electrode 6 is fixedly connected to the first bus bar 9, the phase change switch 11 is arranged close to the first bus bar 9, and the acoustic resonator further includes:

[0161] A metal block 12 is located at the end of the tuning electrode 6 and at both ends of the fixed electrode.

[0162] The other end of the tuning electrode 6 maintains a preset distance from the second bus bar 10; the bottom area of ​​the metal block 12 is the same as the bottom area of ​​the phase change switch 11; the two metal blocks 12 include a first metal block and a second metal block, the first metal block is located at the end of the tuning electrode 6 away from the first bus bar 9, and the second metal block is located at the end and fixed end of the fixed electrode. Two metal blocks 12 are arranged on each fixed electrode, the fixed electrode is a strip structure, the fixed electrode includes a first fixed electrode 7 and a second fixed electrode 8, the first fixed electrode 7 is fixedly connected to the first bus bar 9, and the second fixed electrode 8 is fixedly connected to the second bus bar 10; the number of interdigital electrodes can be multiple groups, and the specific number can be set according to actual conditions, which is not limited here. Exemplarily, the interdigital electrodes can be set to two groups, each group of the interdigital electrodes includes the first fixed electrode 7, the second fixed electrode 8 and the tuning electrode 6 arranged in sequence; the distance between the free end of the first fixed electrode 7 and the second bus bar 10 is equal to the distance between the free end of the second fixed electrode 8 and the first bus bar 9.

[0163] Exemplarily, each group of interdigitated electrodes may include the first fixed electrode 7, the second fixed electrode 8, the tuning electrode 6 and the second fixed electrode 8 arranged in sequence, and the multiple electrodes are arranged in parallel and at equal intervals. Any two adjacent electrodes are fixed on different bus bars.

[0164] Exemplarily, each group of interdigital electrodes may include a tuning electrode 6 with a phase change switch 11 , a first fixed electrode 7 and two second fixed electrodes 8 .

[0165] Example 2

[0166] like Figure 3 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0167] Support substrate 1;

[0168] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0169] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0170] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0171] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0172] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0173] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0174] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0175] One end of the tuning electrode 6 is fixedly connected to the first bus bar 9, the phase change switch 11 is arranged close to the first bus bar 9, and the acoustic resonator further includes:

[0176] A metal block 12 is located at the end of the tuning electrode 6 and at both ends of the fixed electrode.

[0177] The other end of the tuning electrode 6 maintains a preset distance from the second bus bar 10; the bottom area of ​​the metal block 12 is the same as the bottom area of ​​the phase change switch 11; Figure 3 There is a periodic arrangement pattern in the middle interdigital electrode area, and the acoustic resonator may include j periods of interdigital electrodes. The value of j can be set according to actual conditions and is not specifically limited here. The number of tuning electrodes 6 and the number of first fixed electrodes 7 in a single period are 1 and 1 respectively.

[0178] Example 3

[0179] like Figure 4 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0180] Support substrate 1;

[0181] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0182] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0183] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0184] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0185] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0186] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0187] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line, and the phase change switch 11 divides the tuning electrode 6 into two parts. The acoustic resonator may include j periods of interdigitated electrodes, and the value of j can be set according to actual conditions and is not specifically limited here; Figure 3 compared to, Figure 4 The metal block 12 is missing from the interdigital electrodes.

[0188] Example 4

[0189] like Figure 5-6 As shown, Figure 5 The embodiment of the present invention provides Figure 3 Performance diagram of the structure; Figure 5 The middle support substrate 1 is 4H-SiC, the piezoelectric film is X-cut lithium niobate, and the interdigital electrodes are aluminum; wherein the conventional resonator is a non-reconfigurable resonator in the prior art; Figure 6 The embodiment of the present invention provides Figure 4 Performance diagram of the structure;

[0190] Figure 6 The supporting substrate 1 is 4H-SiC, the piezoelectric film is X-cut lithium niobate, and the interdigital electrodes are aluminum. Figure 6 It can be seen from the figure that there are spurious modes within the frequency band of the main mode. Figure 5 As shown in FIG. 1 , the spurious modes within the frequency band of the main mode are significantly suppressed, which is due to the acoustic field modulation effect of the metal block 12 and the phase change switch 11 .

[0191] Example 5

[0192] like Figure 7 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0193] Support substrate 1;

[0194] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0195] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0196] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0197] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0198] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0199] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0200] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line, and the phase change switch 11 divides the tuning electrode 6 into two parts.

[0201] The acoustic resonator may include j periods of interdigital electrodes, and the value of j may be set according to actual conditions and is not specifically limited here; each group of interdigital electrodes includes a tuning electrode 6 , two first fixed electrodes 7 and three second fixed electrodes 8 .

[0202] Example 6

[0203] like Figure 8 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0204] Support substrate 1;

[0205] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0206] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0207] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0208] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0209] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0210] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0211] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0212] Among them, the acoustic resonator may include j periods of interdigitated electrodes, the value of j can be set according to actual conditions and is not specifically limited here; each group of interdigitated electrodes includes a tuning electrode 6, two first fixed electrodes 7 and three second fixed electrodes 8; and a metal block 12 is set on each electrode. Figure 8 In a single cycle, the number of tuning electrodes 6 and the number of first fixed electrodes 7 are 1 and 2 respectively. Figure 7 compared to, Figure 8 A metal block 12 is added to each electrode.

[0213] like Fig. 9 As shown, Fig. 9 The embodiment of the present invention provides Figure 8 Performance diagram corresponding to the structure;

[0214] Fig. 9The supporting substrate 1 is 4H-SiC, the piezoelectric film is X-cut lithium niobate, and the interdigital electrodes are aluminum.

[0215] Will Fig. 9 and Figure 5 By comparison, it can be seen that a decrease in the ratio of the number of tuning electrodes 6 to the number of first fixed electrodes 7 will reduce the tuning range of the reconfigurable acoustic resonator.

[0216] Example 7

[0217] like Fig.10 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0218] Support substrate 1;

[0219] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0220] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0221] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0222] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0223] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0224] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0225] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, the phase change switch 11 and the tuning electrode 6 are located on the same straight line, and the phase change switch 11 divides the tuning electrode 6 into two parts. The acoustic resonator can include j periods of interdigitated electrodes, and the value of j can be set according to actual conditions and is not specifically limited here; the number of tuning electrodes 6 and the number of first fixed electrodes 7 in a single period are 2 and 1 respectively.

[0226] Example 8

[0227] like Fig.11 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0228] Support substrate 1;

[0229] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0230] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0231] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0232] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0233] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0234] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0235] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0236] Among them, the acoustic resonator may include j periods of interdigitated electrodes, the value of j can be set according to actual conditions and is not specifically limited here; each group of interdigitated electrodes includes a tuning electrode 6, two first fixed electrodes 7 and three second fixed electrodes 8; and a metal block 12 is set on each electrode. Fig.11 In a single cycle, the number of tuning electrodes 6 and the number of first fixed electrodes 7 are 2 and 1 respectively. Fig.10 compared to, Fig.11 A metal block 12 is added to each electrode.

[0237] Fig.12 The embodiment of the present invention provides Fig.11 Performance diagram corresponding to the structure; Fig.12 The supporting substrate 1 is 4H-SiC, the piezoelectric film is X-cut lithium niobate, and the interdigital electrodes are aluminum.

[0238] Will Fig.12 and Figure 5 , Figure 8 By comparison, it can be seen that an increase in the ratio of the number of tuning electrodes 6 to the number of first fixed electrodes 7 will increase the tuning range of the reconfigurable acoustic resonator.

[0239] Example 9

[0240] like Fig.13 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0241] Support substrate 1;

[0242] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0243] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0244] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0245] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0246] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0247] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0248] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0249] The acoustic resonator may include j periods of interdigital electrodes, and the value of j may be set according to actual conditions and is not specifically limited here; each group of interdigital electrodes includes two tuning electrodes 6 , two first fixed electrodes 7 and four second fixed electrodes 8 .

[0250] Example 10

[0251] like Fig.14 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0252] Support substrate 1;

[0253] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0254] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0255] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0256] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0257] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0258] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0259] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0260] Among them, the acoustic resonator may include j periods of interdigitated electrodes, the value of j can be set according to actual conditions and is not specifically limited here; each group of interdigitated electrodes includes two tuning electrodes 6, two first fixed electrodes 7 and four second fixed electrodes 8; and a metal block 12 is set on each electrode. Fig.14 The number of tuning electrodes 6 and the number of first fixed electrodes 7 in a single cycle are 2 and 2 respectively. Fig.13 In comparison, a metal block 12 is added.

[0261] Fig.15 The embodiment of the present invention provides Fig.14 Performance diagram corresponding to the structure; Fig.15 The supporting substrate 1 is 4H-SiC, the piezoelectric film is X-cut lithium niobate, and the interdigital electrodes are aluminum.

[0262] Will Fig.15 and Figure 5 By comparison, it can be seen that the number of tuning electrodes 6 and the number of first fixed electrodes 7 change, but the ratio between the two remains unchanged, and the tuning range of the reconfigurable acoustic resonator does not change significantly.

[0263] Embodiment 11

[0264] like Fig.16 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0265] Support substrate 1;

[0266] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0267] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0268] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0269] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0270] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0271] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0272] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0273] The acoustic resonator may include j periods of interdigital electrodes, and the value of j may be set according to actual conditions and is not specifically limited here; each group of interdigital electrodes includes a tuning electrode 6 , a first fixed electrode 7 and two second fixed electrodes 8 .

[0274] It also includes: a first dummy electrode 14 fixedly connected to the first bus bar 9; the first dummy electrode 14 and the second fixed electrode 8 are located on the same straight line, and there is a gap between the first dummy electrode 14 and the second fixed electrode 8;

[0275] And a second dummy electrode 15 fixedly connected to the second bus bar 10; the second dummy electrode 15 and the first fixed electrode 7 or the tuning electrode 6 are located on the same straight line, and there is a gap between the second dummy electrode 15 and the first fixed electrode 7 or the tuning electrode 6.

[0276] and Figure 4 compared to, Fig.16 A dummy electrode is added to the interdigital electrode; wherein the ratio of the length of the dummy electrode to the distance between the central axes of two adjacent interdigital electrodes is greater than 3; this is beneficial to reducing the in-plane leakage of the sound wave to the front and rear sides.

[0277] Example 12

[0278] like Fig.18 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0279] Support substrate 1;

[0280] A first insulating dielectric layer 2 located on the supporting substrate 1;

[0281] a piezoelectric film 3 with grooves located on the first insulating dielectric layer 2;

[0282] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0283] A second insulating dielectric layer 5 is located on the heating metal layer 4; wherein the sum of the thicknesses of the heating metal layer 4 and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer 4 is flush with the surface of the piezoelectric film 3 away from the first insulating dielectric layer 2.

[0284] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film 3;

[0285] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film 3; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0286] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0287] There are multiple groups of interdigital electrodes, and each group of interdigital electrodes includes a tuning electrode 6 , a first fixed electrode 7 and two second fixed electrodes 8 .

[0288] It also includes: a reflection grating located on the piezoelectric film 3, wherein the reflection grating is in two groups, and the two groups of the reflection grating are respectively located on both sides of the interdigital electrodes.

[0289] The reflector is an open-circuit reflector or a short-circuit reflector; Fig.17 As shown, Fig.17 Figure a in the middle is an open-circuit reflective grating. Fig.17 Figure b is a short-circuit reflector, and the open-circuit reflector includes a plurality of third fixed electrodes 16 arranged in parallel with each other; the plurality of third fixed electrodes 16 have the same size and are distributed at equal intervals, and the ends of the plurality of third fixed electrodes 16 are located on the same straight line; each of the third fixed electrodes 16 is arranged in parallel with the interdigital electrodes;

[0290] The short-circuit reflector includes two third bus bars 17 parallel to each other and a plurality of third fixed electrodes 16 located between the two third bus bars 17; each of the third fixed electrodes 16 is perpendicular to the two third bus bars 17; the two third bus bars 17 are perpendicular to the interdigitated electrodes; and both ends of each third fixed electrode 16 are fixedly connected to the two third bus bars 17 respectively.

[0291] The acoustic resonator may include j periods of interdigitated electrodes, and the value of j may be set according to actual conditions and is not specifically limited here; Fig.16 compared to, Fig.18 Short-circuit reflection gratings are added on both sides of the interdigital electrodes on the piezoelectric film 3, which is beneficial to reduce the in-plane leakage of sound waves to the left and right sides.

[0292] Example 13

[0293] like Fig. 20 As shown, an embodiment of the present invention provides a reconfigurable acoustic resonator, comprising:

[0294] Support substrate 1; the support substrate 1 is composed of a support component and an air cavity 13;

[0295] The support component is provided with a piezoelectric film 3 having a groove; the air cavity 13 is located between the piezoelectric film 3 and the support component, and the groove is provided on a side of the piezoelectric film 3 away from the support substrate 1;

[0296] The heat generating metal layer 4 is located in the groove; the groove is arranged close to the first bus bar 9, and the groove is parallel to the first bus bar 9, and the length of the groove is equal to the length of the first bus bar 9; the phase change switch 11 is located on the surface of the second insulating medium layer 5; the metal block 12 close to the first bus bar 9 is located on the surface of the second insulating medium layer 5. The phase change switch 11 and the metal block 12 close to the first bus bar 9 are located on the same straight line.

[0297] A second insulating dielectric layer 5 is located on the heating metal layer; wherein the sum of the thicknesses of the heating metal layer and the second insulating dielectric layer 5 is equal to the depth of the groove; and the surface of the second insulating dielectric layer 5 away from the heating metal layer is flush with the surface of the piezoelectric film away from the supporting substrate 1.

[0298] A first bus bar 9, a second bus bar 10, interdigital electrodes and a phase change switch 11 located on the piezoelectric film;

[0299] Among them, the first bus bar 9 and the second bus bar 10 are relatively arranged on the edge surface of the piezoelectric film; the interdigitated electrodes are arranged between the first bus bar 9 and the second bus bar 10, and the interdigitated electrodes include a fixed electrode and a tuning electrode 6; both ends of the phase change switch 11 are connected to the tuning electrode 6.

[0300] The thickness and size of the first bus bar 9 and the second bus bar 10 are the same; the phase change switch 11 is arranged on the side of the tuning electrode 6 close to the first bus bar 9, and the phase change switch 11 and the tuning electrode 6 are located on the same straight line. The phase change switch 11 divides the tuning electrode 6 into two parts.

[0301] There are multiple groups of interdigital electrodes, and each group of interdigital electrodes includes a tuning electrode 6, a first fixed electrode 7, and a second fixed electrode 8. Fig.19 compared to, Fig. 20 The first insulating medium layer 2 is not included, and a part of the piezoelectric film 3 is suspended.

[0302] Fig.21 The embodiment of the present invention provides Fig. 20 The performance diagram corresponding to the structure. Fig.21 and Figure 5 By comparison, it can be seen that Fig. 20 The suspended structure is beneficial for the reconfigurable resonator to weaken spurious modes and reduce losses.

[0303] Embodiment 14

[0304] like Figure 22-23 As shown, Fig. 22 is a schematic diagram of an operating temperature curve of a volatile phase change switch provided by an embodiment of the present invention; Fig. 22 The material of the volatile phase change switch is vanadium oxide, such as Fig. 22 As shown, ① before, the material is in the insulator phase, and the phase change switch is closed; ① after ② before, the temperature exceeds the transition temperature, and the phase change switch undergoes an insulator phase-metal phase transition, and the phase change switch is turned on; ② after, the temperature is lower than the transition temperature, and the phase change switch returns to the insulator phase, and the phase change switch is closed.

[0305] Fig.23 is a schematic diagram of an operating temperature curve of a non-volatile phase change switch provided by an embodiment of the present invention; Fig.23 The material of the non-volatile phase change switch in is germanium telluride, etc. Fig.23 As shown in , after ① and before ②, the phase change switch temperature exceeds the melting temperature of the material, the material lattice structure is destroyed, and the phase change switch will be in a high-resistance state; after ② and before ③, the temperature is lower than the melting temperature, but the phase change switch is still in a high-resistance state, and the phase change switch is closed at this time; after ③ and before ④, the phase change switch temperature exceeds the crystallization temperature of the material, the phase change switch lattice structure gradually restores order and returns to a low-resistance state; after ④, the material temperature is lower than the crystallization temperature, but is still in a low-resistance state, and the phase change switch is turned on.

[0306] The materials of phase change switches include but are not limited to vanadium oxides and sulfur compounds. Among them, vanadium oxides include but are not limited to vanadium dioxide (VO2) and vanadium pentoxide (V2O5). Among them, sulfur compounds include but are not limited to germanium telluride (GeTe), germanium antimony telluride (Ge-Sb-Te), and antimony telluride (Sb-Te). VO2 is volatile, and its phase change temperature is about 68°C. To maintain the crystalline state, its temperature must be maintained above the phase change temperature. Compared with sulfur-based phase change switches, it has a faster transition speed, but higher DC power consumption and a smaller resistivity variation range than GeTe; GeTe and Ge-Sb-Te are non-volatile, among which GeTe has a melting point temperature of up to 720°C, and amorphous GeTe shows high resistivity to the outside, and the amorphous state does not require additional temperature to maintain, so it can achieve low power consumption and non-volatility. In addition, given that the transition temperature of some phase change switches is as high as several hundred degrees Celsius, the selection of phase change switch materials must also consider the temperature resistance of other structures of the reconfigurable acoustic resonator, such as the supporting substrate, the piezoelectric film with grooves, and the tuning electrode.

[0307] This embodiment proposes a reconfigurable acoustic resonator. By applying a DC voltage, the heat generated by the heat-generating metal layer guides the phase change switch to undergo a phase change, so that the electrical conditions of the interdigitated electrodes located on the upper surface of the piezoelectric film with grooves change, so that the electrical conditions on the surface of the reconfigurable acoustic resonator are reset, and the reconstruction of the acoustic resonator is completed; by setting appropriate m and n, the arrangement pattern of the tuning electrode, the first fixed electrode and the second fixed electrode on the reconfigurable acoustic resonator is changed, and the resonance characteristics of the reconfigurable acoustic resonator can be customized and optimized; by setting a phase change switch or a metal block at both ends of the interdigitated electrode, the two can jointly play a role in sound field modulation, and effectively suppress the stray mode of the reconfigurable acoustic resonator without increasing the size of the reconfigurable acoustic resonator, thereby increasing the practicality of the reconfigurable acoustic resonator; by making the piezoelectric film suspended through an etching process, the stray mode of the resonator can be suppressed and the loss can be reduced.

[0308] The above disclosures are only several preferred embodiments of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A reconfigurable acoustic resonator, characterized in that: include: a supporting substrate; a piezoelectric film with a groove located on the supporting substrate; A heat-generating metal layer is provided in the groove; a second insulating medium layer located on the heat-generating metal layer; A first bus bar, a second bus bar, interdigital electrodes and a phase change switch located on the piezoelectric film; Among them, the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the interdigitated electrodes are arranged between the first bus bar and the second bus bar, and the interdigitated electrodes include a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode.

2. The acoustic resonator according to claim 1, characterized in that One end of the tuning electrode is fixedly connected to the first bus bar, and the phase change switch is arranged close to the first bus bar, and further comprises: A metal block is located at an end of the tuning electrode and at both ends of the fixed electrode.

3. The acoustic resonator according to claim 1, characterized in that The fixed electrode is a strip-shaped structure, and includes a first fixed electrode and a second fixed electrode, the first fixed electrode is fixedly connected to the first bus bar, and the second fixed electrode is fixedly connected to the second bus bar; The interdigital electrodes are multiple groups, and each group of the interdigital electrodes includes the first fixed electrode, the second fixed electrode and the tuning electrode which are sequentially arranged at intervals; The distance between the free end of the first fixed electrode and the second bus bar is equal to the distance between the free end of the second fixed electrode and the first bus bar.

4. The acoustic resonator according to claim 3, characterized in that Each group of the interdigital electrodes includes m tuning electrodes with phase change switches, k first fixed electrodes and n second fixed electrodes; wherein n=m+k, 5. The acoustic resonator according to claim 1, characterized in that Also includes: a first insulating dielectric layer located on the supporting substrate; The piezoelectric film with the groove is located on the first insulating medium layer.

6. The acoustic resonator according to claim 1, characterized in that The support substrate includes two types: one containing an air cavity and one not containing an air cavity. For the type containing an air cavity, a preset air cavity exists in the support substrate. The support substrate is composed of a support component and the air cavity. The tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, and the metal block structure are all located in the area directly above the support substrate. The piezoelectric film is located on the supporting component; the air cavity is located between the piezoelectric film and the supporting component; and the groove is arranged on a side of the piezoelectric film away from the supporting substrate.

7. The acoustic resonator according to claim 5 or 6, characterized in that: The sum of the thicknesses of the heating metal layer and the second insulating medium layer is equal to the depth of the groove; the surface of the second insulating medium layer away from the heating metal layer is flush with the surface of the piezoelectric film away from the first insulating medium layer.

8. The acoustic resonator according to claim 7, characterized in that The groove is arranged close to the first bus bar and is parallel to the first bus bar, and the groove runs through the area where the interdigitated electrodes are located; the phase change switch is located on the surface of the second insulating medium layer; the metal block close to the side of the first bus bar is located on the surface of the second insulating medium layer.

9. The acoustic resonator according to claim 3, characterized in that Also includes: a first dummy electrode fixedly connected to the first bus bar; the first dummy electrode and the second fixed electrode are located on the same straight line, and there is a gap between the first dummy electrode and the second fixed electrode; A second dummy electrode fixedly connected to the second bus bar; the second dummy electrode and the first fixed electrode or the tuning electrode are located on the same straight line, and there is a gap between the second dummy electrode and the first fixed electrode or the tuning electrode.

10. The acoustic resonator according to claim 8, characterized in that Also includes: a reflector located on the piezoelectric film, the reflector not contacting the groove; the reflector is an open reflector or a short reflector; the open reflector comprises a plurality of third fixed electrodes arranged in parallel with each other; the plurality of third fixed electrodes have the same size and are distributed at equal intervals, and the ends of the plurality of third fixed electrodes are located on the same straight line; each of the third fixed electrodes is arranged in parallel with the interdigital electrodes; The short-circuit reflector includes two third bus bars parallel to each other and a plurality of third fixed electrodes located between the two third bus bars; each of the third fixed electrodes is perpendicular to the two third bus bars; the two third bus bars are perpendicular to the interdigitated electrodes; and both ends of each third fixed electrode are fixedly connected to the two third bus bars.

11. The acoustic resonator according to claim 1, characterized in that The support substrate may be a high-speed support substrate, and the material of the support substrate includes silicon carbide, diamond, sapphire, silicon or quartz; The material of the piezoelectric film includes lithium niobate and lithium tantalate; The materials of the phase change switch include vanadium oxide and sulfur compound.

12. The acoustic resonator according to claim 7, characterized in that The materials of the first insulating dielectric layer and the second insulating dielectric layer include silicon dioxide, silicon nitride or aluminum oxide; The material of the heating metal layer includes chromium, tungsten, nickel-chromium-silicon, titanium-titanium nitride-tungsten material.

13. The acoustic resonator according to claim 7, characterized in that The materials of the tuning electrode, the first fixed electrode, the second fixed electrode, the first bus bar, the second bus bar, the metal block, the third fixed electrode, and the third bus bar include a combination of one or more of aluminum, tungsten, chromium, titanium, copper, silver, and gold.

14. The acoustic resonator according to claim 1, characterized in that The target elastic waves excited by the piezoelectric film include longitudinal leakage surface acoustic waves, Lamb waves, horizontal shear waves and Rayleigh modes.

15. The acoustic resonator according to claim 1, characterized in that The first fixed electrode has the same potential as the tuning electrode when the phase change switch is turned on; the second fixed electrode has a different potential than the tuning electrode when the phase change switch is turned on.

16. The acoustic resonator according to claim 1, characterized in that The ratio of the resistivity of the material in the phase change switch before the phase change occurs to the resistivity of the material in the phase change switch after the phase change occurs is greater than 100.

17. A method for preparing a reconfigurable acoustic resonator, characterized in that: The method comprises: providing a supporting substrate; forming a piezoelectric film having a groove on the supporting substrate; forming a heat-generating metal layer in the groove of the piezoelectric film; forming a second insulating dielectric layer on the heat-generating metal layer; forming a first bus bar, a second bus bar, interdigital electrodes and a phase change switch on the piezoelectric film; Among them, the first bus bar and the second bus bar are relatively arranged on the edge surface of the piezoelectric film; the interdigitated electrodes are arranged between the first bus bar and the second bus bar, and the interdigitated electrodes include a fixed electrode and a tuning electrode; both ends of the phase change switch are connected to the tuning electrode.

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