A duplexer, a multiplexer, a method of manufacturing the same, and a communication device

Abstract

The application relates to a diplexer, a multiplexer and a preparation method thereof and a communication device, the diplexer comprising a transmitting filter and a receiving filter which are arranged in a stack, the transmitting filter being arranged opposite to the receiving filter; the transmitting filter or the receiving filter comprising a central resonator and at least one ring resonator which is nested in the central resonator, an electric connection relationship in parallel or in series being formed between the central resonator and the at least one ring resonator. The diplexer provided by the application adopts a filter with a special structure, the filter adopts a nested arrangement mode for multiple resonators, the occupied area is reduced compared with the same number of resonators in the prior art, the integration degree is higher, the volume of the diplexer is smaller, and the diplexer has excellent device performance.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a duplexer, a multiplexer, a method for manufacturing the same, and communication equipment. Background Technology

[0002] The trend towards broadband wireless communication demands that base station RF front-end duplexers and multiplexers have smaller size, higher power capacity, and lower cost while maintaining essentially unchanged performance in terms of loss. However, current technologies often require filters composed of multiple resonant units, resulting in a large area occupied by the filters and correspondingly large duplexers and multiplexers. With the accelerating trend towards miniaturization and high performance in communication equipment, even higher requirements are being placed on the size and performance of filters.

[0003] Therefore, there is an urgent need in this field to develop a duplexer and multiplexer that occupy a smaller area and have higher performance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, one of the objectives of this invention is to provide a duplexer. This duplexer occupies a small area, has high integration density, and possesses a high Q value, resulting in excellent device performance.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The present invention provides a duplexer, the duplexer comprising a transmit filter (Tx) and a receive filter (Rx) stacked together, the transmit filter and the receive filter being arranged facing each other;

[0007] The transmitting filter or receiving filter includes a center resonator and at least one ring resonator nested within the center resonator, wherein the center resonator and the at least one ring resonator are electrically connected in parallel or in series.

[0008] In this invention, the "opposite arrangement" means that the resonator side of the transmitting filter is adjacent to the resonator side of the receiving filter, and the two substrates are distributed on the outermost side.

[0009] In this invention, the number of ring resonators includes, but is not limited to, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, etc.

[0010] The duplexer provided by this invention employs a specially structured filter that nests multiple resonators. Compared to existing technologies with the same number of resonators, this reduces the area occupied, increases integration density, and results in a smaller duplexer size. Furthermore, by using a nested arrangement and ensuring spacing between the central resonator and each ring resonator, this structure reduces transverse wave propagation, improves the Q value, and leads to a duplexer with superior device performance.

[0011] Preferably, both the transmitting filter and the receiving filter independently include a center resonator and at least one ring resonator nested within the center resonator, wherein the center resonator and the at least one ring resonator are electrically connected in parallel or in series.

[0012] Preferably, the number of ring resonators is ≥2, such as 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc.; and / or there is a gap between the center resonator and adjacent ring resonators, or between ring resonators. Preferably, the width of the gap is 18-25μm, such as 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, etc., preferably 20μm.

[0013] Preferably, the shape of the central resonator includes a circle, triangle, rectangle, pentagon, hexagon, or irregular shape;

[0014] And / or, the shape of the ring resonator includes a circular ring, a triangular ring, a quadrilateral ring, a pentagonal ring, a hexagonal ring, or an irregular ring; and / or the edges of the central resonator and its adjacent ring resonators are not parallel to each other; and / or, the edges of any adjacent ring resonators are not parallel to each other.

[0015] In this invention, the triangular ring refers to a ring formed by hollowing out the middle of a triangle, which is the same as the circular ring. The same applies to quadrilateral rings, pentagonal rings, hexagonal rings, and irregularly shaped rings.

[0016] In a preferred embodiment of the present invention, using different shapes for adjacent resonators can reduce the parasitic effects of the resonators, thereby further improving the quality factor.

[0017] Preferably, the transmitting filter and the receiving filter further include their respective substrates, and the center resonator and at least one ring resonator of the transmitting filter or the receiving filter are disposed on the substrate of the filter, and the substrate is provided with an acoustic reflection structure; preferably, the acoustic reflection structure is a cavity.

[0018] Preferably, the central resonator and the at least one ring resonator share a common acoustic reflection structure; or the central resonator and the at least one ring resonator each correspond to an independent acoustic reflection structure. Preferably, the edge shape of the resonator is consistent with the edge shape of the acoustic reflection structure.

[0019] Preferably, the shape of the cavity includes a circle, triangle, rectangle, pentagon, hexagon, or irregular shape.

[0020] Preferably, the center resonator and the at least one ring resonator each include a lower electrode layer (BE layer), a piezoelectric layer (PZ layer), and an upper electrode layer (TE layer) stacked sequentially, and at least one of the center resonator and the ring resonator includes a mass load layer.

[0021] Preferably, the electrical connection between the resonators is formed by interconnecting the upper or lower electrode layers of the central resonator and the at least one ring resonator.

[0022] Preferably, both the center resonator and the ring resonator include stress relief holes that penetrate any one or at least two of the lower electrode layer, the piezoelectric layer, and the upper electrode layer.

[0023] Preferably, the piezoelectric layers of the central resonator and the at least one ring resonator are separated from each other.

[0024] Preferably, a support pillar is provided in the cavity, and the support pillar is placed perpendicular to the lower electrode layer. Providing a support pillar in the cavity of the substrate can effectively prevent the collapse of the lower electrode layer, piezoelectric layer, upper electrode layer, and mass load layer.

[0025] Preferably, the substrate of the transmitting filter and the substrate of the receiving filter are located on opposite sides of the duplexer, and the resonator structures of the transmitting filter and the receiving filter are located between the two substrates. That is, "the transmitting filter and the receiving filter are arranged facing each other".

[0026] Preferably, the mass load layer of the transmitting filter is adjacent to but not connected to the mass load layer of the receiving filter.

[0027] Preferably, the transmitting filter and the receiving filter are connected by a sealing ring, which is disposed around the periphery of the transmitting filter and the receiving filter.

[0028] Preferably, the sealing ring is connected to the electrode structure or substrate of the transmitting filter and the receiving filter.

[0029] According to common knowledge in the field, a resonator is a unit composed of an upper electrode, a piezoelectric layer, and a lower electrode. When there is a voltage drop between the two electrodes, resonance will occur along the vertical direction. A filter is at least two resonators connected in series and in parallel to enable signal passage in a certain frequency band and prevent signal passage in frequency bands other than that band.

[0030] The circuit connection of different resonators in the filter is conventional technical knowledge in this field, and those skilled in the art can make specific selections according to actual needs. This invention does not impose specific limitations on this.

[0031] A duplexer is a device consisting of two filters: a receiving filter to receive signals and a transmitting filter to transmit signals. To ensure that the transmitting and receiving frequency bands are different, there needs to be clear isolation between the receiving and transmitting filters to ensure the normal operation of the two frequency bands, and to achieve simultaneous reception and transmission of signals.

[0032] A second objective of the present invention is to provide a multiplexer, which includes the duplexer described in the first objective.

[0033] A third objective of this invention is to provide a multiplexer comprising at least two transmit filters and at least two receive filters, wherein the transmit filters and receive filters are stacked and the transmit filters are arranged facing each other.

[0034] At least one transmitting filter or receiving filter includes a center resonator and at least one ring resonator nested within the center resonator, wherein the center resonator and the at least one ring resonator are electrically connected in parallel or in series.

[0035] This invention does not limit the specific number of transmit and receive filters in a multiplexer. The number of transmit and receive filters can be independently, including but not limited to two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, etc. For example, when the number of transmit and receive filters is two, it is called a quadruple multiplexer.

[0036] Preferably, the multiplexer includes a first substrate and a second substrate;

[0037] The multiplexer includes a first transmit filter, a second transmit filter, a first receive filter, and a second receive filter;

[0038] The first transmitting filter and the first receiving filter are arranged facing each other, and the second transmitting filter and the second receiving filter are arranged facing each other;

[0039] The first transmitting filter and the second transmitting filter share a first substrate, and the first receiving filter and the second receiving filter share a second substrate.

[0040] In a preferred embodiment of the present invention, the multiplexer is a quadruple multiplexer, with two transmitting filters disposed on the same substrate and two receiving filters disposed on the same substrate, i.e., the transmitting filters are distributed on the same side and the receiving filters are distributed on the same side.

[0041] Preferably, the multiplexer includes a first substrate and a second substrate;

[0042] The multiplexer includes a first transmit filter, a second transmit filter, a first receive filter, and a second receive filter;

[0043] The first transmitting filter and the first receiving filter are arranged facing each other, and the second transmitting filter and the second receiving filter are arranged facing each other;

[0044] The first transmitting filter and the second receiving filter share a first substrate, and the second transmitting filter and the first receiving filter share a second substrate.

[0045] In a preferred embodiment of the present invention, the multiplexer is a quadruple multiplexer, with its two transmitting filters distributed on opposite sides and its two receiving filters distributed on opposite sides.

[0046] The fourth objective of this invention is to provide a method for manufacturing the duplexer described in the first objective, the multiplexer described in the second objective, or the multiplexer described in the third objective, wherein the manufacturing method includes the following steps:

[0047] (1) A cavity is etched on the substrate, and a thin film is deposited in the cavity to form a substrate;

[0048] (2) A lower electrode layer, a pressure electrode layer and an upper electrode layer are sequentially deposited on the substrate;

[0049] (3) A mass-loaded layer is prepared on the upper electrode layer;

[0050] (4) A cavity release hole is prepared through the lower electrode layer, the piezo electrode layer, the upper electrode layer and the mass load layer, and the deposited thin film in the cavity is released through the cavity release hole to form a cavity on the substrate;

[0051] (5) Deposit a sealing ring on the substrate or the lower electrode to obtain a transmitting filter or a receiving filter;

[0052] (6) Bond the sealing rings in the transmitting filter and the receiving filter to obtain the duplexer or multiplexer.

[0053] In step (2) above, by designing the mask plate used in the deposition process, multiple nested filters of the present invention can be fabricated at one time.

[0054] Preferably, the preparation method further includes step (4') after step (4): etching stress relief holes through any one or at least two of the lower electrode layer, piezoelectric layer and upper electrode layer;

[0055] Preferably, step (1) specifically includes: coating a substrate with adhesive, exposing and developing it, baking it, dry etching it and wet etching it to form a cavity, then depositing a thin film in the cavity and chemically mechanically polishing it to obtain a substrate.

[0056] Preferably, the substrate material includes any one or at least a combination of two of Si, GaAs, SiC, or GaN.

[0057] Preferably, the material of the thin film includes any one or at least a combination of two of PSG oxide, metal nitride, or metal oxide.

[0058] Preferably, step (2) further includes: coating the deposited lower electrode layer with a resist, exposing and developing it, baking it, dry etching it and wet etching it to obtain a lower electrode layer of the target size;

[0059] And / or, step (2) further includes: depositing a barrier layer before depositing the lower electrode layer.

[0060] Preferably, the barrier layer is made of AlN. By pre-depositing the barrier layer, the crystal orientation of the lower electrode layer can be improved.

[0061] Preferably, in step (2), the deposition method includes physical vapor deposition, chemical vapor deposition, or epitaxial deposition.

[0062] Preferably, step (3) specifically includes: applying adhesive, exposing, developing, etching, thinning, removing adhesive and cleaning on the upper electrode layer to obtain a mass load layer;

[0063] Alternatively, step (3) may specifically include: applying adhesive, exposing, and developing the upper electrode layer, then depositing a mass load layer material, and then removing the adhesive and cleaning to obtain the mass load layer.

[0064] Preferably, the method for depositing the mass-loaded layer material in step (3) includes physical vapor deposition, chemical vapor deposition, or epitaxial deposition.

[0065] Preferably, the materials of the lower electrode layer, the upper electrode layer, and the mass load layer each independently include metallic materials and / or non-metallic materials.

[0066] The metallic material includes any one or at least two combinations of elemental Mo, elemental Al, elemental W, Mo alloys, Al alloys, or W alloys.

[0067] Preferably, the non-metallic material comprises doped polycrystalline silicon.

[0068] Preferably, the material of the piezoelectric layer includes any one or at least a combination of two of AlN, ZnO, or lead zirconate titanate (PZT).

[0069] Preferably, step (4) specifically includes: applying resist, exposing, developing, dry etching, and removing resist on the mass load layer to obtain a cavity release hole that penetrates the lower electrode layer, the pressure electrode layer, the upper electrode layer, and the mass load layer; releasing the deposited film in the cavity by wet etching to form a cavity on the substrate.

[0070] Preferably, step (5) specifically includes: depositing a sealing ring material on the substrate or the lower electrode layer, followed by coating, exposure, development, etching, thinning, removing the adhesive and cleaning to obtain the sealing ring;

[0071] Alternatively, step (5) may specifically include: applying adhesive, exposing, developing, depositing sealing ring material, removing adhesive and cleaning on the substrate or the lower electrode layer to obtain the sealing ring.

[0072] Preferably, in step (5), the deposition method includes physical vapor deposition, chemical vapor deposition, or epitaxial deposition.

[0073] Preferably, the sealing ring material includes any one or at least a combination of two of TiW, Au, or Cu.

[0074] Preferably, step (6) further includes thinning after the bonding.

[0075] For example, bonding methods include, for instance, Au-Au or Cu-Cu intermetallic bonding, bonding between metal compounds, and bonding between nonmetals.

[0076] The fifth objective of this invention is to provide a communication device comprising the duplexer described in the first objective, the multiplexer described in the second objective, or the multiplexer described in the third objective.

[0077] Compared with the prior art, the present invention has the following beneficial effects:

[0078] This invention introduces a filter with multiple nested resonators into a duplexer or multiplexer. Compared to the same number of resonators in existing technologies, this reduces the area occupied, increases integration density, and results in a smaller duplexer or multiplexer size. Furthermore, by employing a nested structure and ensuring spacing between the central resonator and each ring resonator, this structure reduces transverse wave propagation, which helps improve the Q value, resulting in a duplexer or multiplexer with superior device performance. Attached Figure Description

[0079] Figure 1 This is a top view of the filter in Embodiment 1 of the present invention;

[0080] Figure 2a The filter edge in Embodiment 1 of the present invention Figure 1 Cross-sectional view of dashed line A;

[0081] Figure 2b The filter edge in Embodiment 1 of the present invention Figure 1 Cross-sectional view of dashed line A';

[0082] Figure 3 This is a cross-sectional view of the duplexer provided in Embodiment 1 of the present invention;

[0083] Figure 4 This is a top view of the filter in Embodiment 3 of the present invention;

[0084] Figure 5 The filter edge in Embodiment 4 of the present invention Figure 1 Cross-sectional view of dashed line A;

[0085] Figure 6 This is a cross-sectional view of the duplexer provided in Embodiment 4 of the present invention;

[0086] Figure 7 This is a cross-sectional view of the four-tool provided in Embodiment 5 of the present invention;

[0087] Figure 8 This is a cross-sectional view of the four-tool provided in Embodiment 6 of the present invention;

[0088] Figure 9 The filter edge in Embodiment 7 of the present invention Figure 1 Cross-sectional view of dashed line A;

[0089] Figure 10 The filter edge provided in Embodiment 8 of the present invention Figure 1 Cross-sectional view of dashed line A';

[0090] Figure 11 The filter edge provided in Embodiment 9 of the present invention Figure 1 Cross-sectional view of dashed line A';

[0091] Figure 12The filter edge provided in Embodiment 10 of the present invention Figure 1 Cross-sectional view of dashed line A';

[0092] Figure 13 This is a top view of the filter in Scale 1.

[0093] Wherein, 1-center resonator, 2-first ring resonator, 3-second ring resonator, 4-third ring resonator, 5-fourth ring resonator, 6-spacer, 100-substrate, 200-lower electrode layer, 300-piezoelectric layer, 400-upper electrode layer, 500-mass load layer, 600-cavity, 700-sealing ring, 800-stress relief hole, 900-support post, 101-first substrate, 102-second substrate. Detailed Implementation

[0094] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0095] Example 1

[0096] This embodiment provides a duplexer, the cross-sectional structure of which is as follows: Figure 3 As shown, the duplexer includes a transmit filter and a receive filter stacked together, and the top views of the transmit filter and the receive filter are as shown. Figure 1 As shown, the device includes a central resonator 1 and four ring resonators nested within it: a first ring resonator 2, a second ring resonator 3, a third ring resonator 4, and a fourth ring resonator 5. There are gaps 6 between the central resonator and adjacent ring resonators, and between any two adjacent ring resonators. The width of each gap is 20 μm. The central resonator 1 is pentagonal, and all four ring resonators are also pentagonal rings.

[0097] The transmit filter and receive filter along Figure 1 The cross-sectional structure of dashed line A is as follows Figure 2a As shown, it includes a substrate 100 and a cavity 600 disposed on the substrate 100. The central resonator and the ring resonator are both disposed on the substrate 100, and the central resonator and the ring resonator each include a lower electrode layer 200, a piezoelectric layer 300, an upper electrode layer 400 and a mass load layer 500 sequentially stacked along a direction away from the substrate 100. The electrical connection between the resonators is formed by the interconnection of the upper electrode layer or the lower electrode layer of the central resonator and the ring resonator.

[0098] The transmit filter and receive filter along Figure 1 The cross-sectional structure of dashed line A' is as follows Figure 2bAs shown, the piezoelectric layers 300 of the five resonators are interconnected, and each of the five resonators independently has a cavity 600 with a shape consistent with the edge of the resonator. It should be noted that... Figure 2b The cross-sectional view shown mainly illustrates the connection between the piezoelectric layer, the upper electrode layer, and the lower electrode layer, as well as the structure of the cavity on the substrate. Some detailed structures are not shown in the figure. The same applies to other cross-sectional views along the dashed line A' in the following text.

[0099] The transmitting filter and the receiving filter are arranged facing each other and connected by a sealing ring 700;

[0100] The sealing ring is connected to the lower electrode of the transmitting filter and the receiving filter.

[0101] The method for preparing the duplexer provided in this embodiment is as follows:

[0102] (1) A hexagonal cavity is formed by coating, exposure and development, baking, dry etching and wet etching on the substrate, followed by deposition of a thin film in the cavity and chemical mechanical polishing to obtain the substrate.

[0103] (2) A lower electrode layer, a pressure electrode layer and an upper electrode layer are sequentially deposited on the substrate;

[0104] (3) Applying adhesive, exposing, developing, etching, thinning, removing adhesive and cleaning are performed on the upper electrode layer to obtain a mass load layer;

[0105] (4) Applying adhesive, exposing, developing, dry etching, and removing adhesive on the mass load layer to obtain a cavity release hole that penetrates the lower electrode layer, the pressure electrode layer, the upper electrode layer, and the mass load layer. The deposited film in the cavity is released by wet etching to form a cavity on the substrate.

[0106] (5) Deposit sealing ring material on the lower electrode layer, and then perform coating, exposure, development, etching, thinning, removal of adhesive and cleaning to obtain the sealing ring;

[0107] The transmitting filter and the receiving filter are prepared according to the steps (1)-(5) above;

[0108] (6) Bond the sealing rings in the transmitting filter and the receiving filter together and thin them to obtain the duplexer.

[0109] Example 2

[0110] This embodiment provides a duplexer, which differs from Embodiment 1 only in that the transmitting filter and receiving filter do not include the third ring resonator 4 and the fourth ring resonator 5, while the rest are the same as Embodiment 1.

[0111] Example 3

[0112] This embodiment provides a duplexer, which differs from Embodiment 1 only in that the top view structure of the transmitting filter and the receiving filter is as follows. Figure 4 As shown, it includes a central resonator 1, a first ring resonator 2, and a second ring resonator 3. The central resonator 1 is quadrilateral in shape, the first ring resonator 2 is pentagonal in shape, and the second ring resonator 3 is hexagonal in shape. The rest are the same as in Embodiment 1.

[0113] Example 4

[0114] This embodiment provides a duplexer, the cross-sectional structure of which is as follows: Figure 6 As shown, the duplexer includes a transmit filter and a receive filter stacked together, and the top views of the transmit filter and the receive filter are as shown. Figure 1 As shown, the device includes a central resonator 1 and four ring resonators nested within it: a first ring resonator 2, a second ring resonator 3, a third ring resonator 4, and a fourth ring resonator 5. There are gaps 6 between the central resonator and adjacent ring resonators, and between any two adjacent ring resonators. The width of each gap is 20 μm. The central resonator 1 is pentagonal, and all four ring resonators are also pentagonal rings.

[0115] The transmit filter and receive filter along Figure 1 The cross-sectional structure of dashed line A is as follows: Figure 5 As shown, it includes a substrate 100 and a cavity 600 disposed on the substrate 100. The central resonator and the ring resonator are both disposed on the substrate 100, and the central resonator and the ring resonator each include a lower electrode layer 200, a piezoelectric layer 300, an upper electrode layer 400 and a mass load layer 500 sequentially stacked along a direction away from the substrate 100, and stress relief holes 800 penetrating the piezoelectric layer 300 and the upper electrode layer 400; the electrical connection between the resonators is formed by the interconnection of the upper electrode layer or the lower electrode layer of the central resonator and the ring resonator.

[0116] Figure 5 Only a cross-sectional view of one resonator is shown in the diagram; the other resonators have the same structure. It should be noted that in the filter provided in this embodiment, the piezoelectric layers 300 of the five resonators are separated from each other, and each of the five resonators independently has a cavity with a shape consistent with the edge of the resonator.

[0117] The transmitting filter and the receiving filter are arranged facing each other and connected by a sealing ring 700;

[0118] The sealing ring is connected to the lower electrode of the transmitting filter and the receiving filter.

[0119] The method for preparing the duplexer provided in this embodiment differs from that in Embodiment 1 only in that step (4) is performed after step (4): stress relief holes are etched through the upper electrode layer and the piezoelectric layer. The rest is the same as in Embodiment 1.

[0120] Example 5

[0121] This embodiment provides a four-tool, the cross-sectional structure of which is as follows: Figure 7 As shown, the multiplexer includes a first substrate 101 and a second substrate 102;

[0122] The quadruple converter includes a first transmit (Tx1) filter, a second transmit (Tx2) filter, a first receive (Rx1) filter, and a second receive (Rx2) filter. The top views of the aforementioned filters are shown below. Figure 1 As shown, the device includes a central resonator 1 and four ring resonators nested within it: a first ring resonator 2, a second ring resonator 3, a third ring resonator 4, and a fourth ring resonator 5. There are gaps 6 between the central resonator and adjacent ring resonators, and between any two adjacent ring resonators. The width of each gap is 20 μm. The central resonator 1 is pentagonal, and all four ring resonators are also pentagonal rings.

[0123] Both the central resonator and the ring resonator are disposed on a substrate, and a cavity is provided on the substrate; wherein, both the central resonator and the ring resonator include a lower electrode layer, a piezoelectric layer, an upper electrode layer and a mass load layer stacked sequentially along the direction away from the substrate;

[0124] The first transmitting filter and the first receiving filter are stacked, and the second transmitting filter and the second receiving filter are stacked; the transmitting filter and the receiving filter are positioned facing each other.

[0125] The first transmitting filter and the second transmitting filter share the first substrate 101, and the first receiving filter and the second receiving filter share the second substrate 102.

[0126] The transmitting filter and the receiving filter are connected by a sealing ring 700, which is disposed on the periphery of the transmitting filter and the receiving filter.

[0127] The two transmit filters and two receive filters mentioned above are along... Figure 1 The cross-sectional structure of dashed line A is the same as that of the transmitting filter and receiving filter in Example 1, as shown below. Figure 2aAs shown, it includes a substrate 100 and a cavity 600 disposed on the substrate 100. The central resonator and the ring resonator are both disposed on the substrate 100, and the central resonator and the ring resonator each include a lower electrode layer 200, a piezoelectric layer 300, an upper electrode layer 400 and a mass load layer 500 sequentially stacked along a direction away from the substrate 100. The electrical connection between the resonators is formed by the interconnection of the upper electrode layer or the lower electrode layer of the central resonator and the ring resonator.

[0128] The two transmit filters and two receive filters mentioned above are along... Figure 1 The cross-sectional structure of the dashed line A' is the same as that of the transmitting filter and receiving filter in Example 1, as shown below. Figure 2b As shown, the piezoelectric layers 300 of the five resonators are interconnected, and each of the five resonators has an independent cavity 600 that conforms to the shape of the resonator edge.

[0129] The preparation method of the four-tool provided in this embodiment is as follows:

[0130] (1) A hexagonal cavity is formed by coating, exposure and development, baking, dry etching and wet etching on the substrate, followed by deposition of a thin film in the cavity and chemical mechanical polishing to obtain the substrate.

[0131] (2) A lower electrode layer, a pressure electrode layer and an upper electrode layer are sequentially deposited on the substrate;

[0132] (3) Applying adhesive, exposing, developing, etching, thinning, removing adhesive and cleaning are performed on the upper electrode layer to obtain a mass load layer;

[0133] (4) Applying adhesive, exposing, developing, dry etching, and removing adhesive on the mass load layer to obtain a cavity release hole that penetrates the lower electrode layer, the pressure electrode layer, the upper electrode layer, and the mass load layer. The deposited film in the cavity is released by wet etching to form a cavity on the substrate.

[0134] (5) Deposit sealing ring material on the lower electrode layer, and then perform coating, exposure, development, etching, thinning, removal of adhesive and cleaning to obtain the sealing ring;

[0135] The first transmitting filter and the second transmitting filter, which share the first substrate, and the first receiving filter and the second receiving filter, which share the second substrate, are prepared according to the steps (1)-(5) above.

[0136] (6) Bond the sealing rings in the above-obtained transmit filter and receive filter (bonding them in the manner that the first transmit filter and the first receive filter face each other, and the second transmit filter and the second receive filter face each other), and thin them to obtain the quadcopter.

[0137] Example 6

[0138] This embodiment provides a four-tool, the cross-sectional structure of which is as follows: Figure 8 As shown, the multiplexer includes a first substrate 101 and a second substrate 102;

[0139] The multiplexer includes a first transmit (Tx1) filter, a second transmit (Tx2) filter, a first receive (Rx1) filter, and a second receive (Rx2) filter. The top views of the aforementioned filters are shown below. Figure 1 As shown, the device includes a central resonator 1 and four ring resonators nested within it: a first ring resonator 2, a second ring resonator 3, a third ring resonator 4, and a fourth ring resonator 5. There are gaps 6 between the central resonator and adjacent ring resonators, and between any two adjacent ring resonators. The width of each gap is 20 μm. The central resonator 1 is pentagonal, and all four ring resonators are also pentagonal rings.

[0140] Both the central resonator and the ring resonator are disposed on a substrate, and a cavity is provided on the substrate; wherein, both the central resonator and the ring resonator include a lower electrode layer, a piezoelectric layer, an upper electrode layer and a mass load layer stacked sequentially along the direction away from the substrate;

[0141] The first transmitting filter and the first receiving filter are stacked, and the second transmitting filter and the second receiving filter are stacked; the transmitting filter and the receiving filter are positioned facing each other.

[0142] The first transmitting filter and the second receiving filter share the first substrate 101, and the second transmitting filter and the first receiving filter share the second substrate 102.

[0143] The transmitting filter and the receiving filter are connected by a sealing ring 700, which is disposed on the periphery of the transmitting filter and the receiving filter.

[0144] The two transmit filters and two receive filters mentioned above are along... Figure 1 The cross-sectional structure of dashed line A is the same as that of the transmitting filter and receiving filter in Example 1, as shown below. Figure 2a As shown, it includes a substrate 100 and a cavity 600 disposed on the substrate 100. The central resonator and the ring resonator are both disposed on the substrate 100, and the central resonator and the ring resonator each include a lower electrode layer 200, a piezoelectric layer 300, an upper electrode layer 400 and a mass load layer 500 sequentially stacked along a direction away from the substrate 100. The electrical connection between the resonators is formed by the interconnection of the upper electrode layer or the lower electrode layer of the central resonator and the ring resonator.

[0145] The two transmit filters and two receive filters mentioned above are along... Figure 1 The cross-sectional structure of the dashed line A' is the same as that of the transmitting filter and receiving filter in Example 1, as shown below. Figure 2b As shown, the piezoelectric layers 300 of the five resonators are interconnected, and each of the five resonators has an independent cavity 600 that conforms to the shape of the resonator edge.

[0146] The preparation method of the four-tool provided in this embodiment is as follows:

[0147] (1) A hexagonal cavity is formed by coating, exposure and development, baking, dry etching and wet etching on the substrate, followed by deposition of a thin film in the cavity and chemical mechanical polishing to obtain the substrate.

[0148] (2) A lower electrode layer, a pressure electrode layer and an upper electrode layer are sequentially deposited on the substrate;

[0149] (3) Applying adhesive, exposing, developing, etching, thinning, removing adhesive and cleaning are performed on the upper electrode layer to obtain a mass load layer;

[0150] (4) Applying adhesive, exposing, developing, dry etching, and removing adhesive on the mass load layer to obtain a cavity release hole that penetrates the lower electrode layer, the pressure electrode layer, the upper electrode layer, and the mass load layer. The deposited film in the cavity is released by wet etching to form a cavity on the substrate.

[0151] (5) Deposit sealing ring material on the lower electrode layer, and then perform coating, exposure, development, etching, thinning, removal of adhesive and cleaning to obtain the sealing ring;

[0152] The first transmitting filter and the second receiving filter, which share the first substrate, and the second transmitting filter and the first receiving filter, which share the second substrate, are prepared according to the steps (1)-(5) above.

[0153] (6) Bond the sealing rings in the above-obtained transmit filter and receive filter (bonding them in the manner that the first transmit filter and the first receive filter face each other, and the second transmit filter and the second receive filter face each other), and thin them to obtain the quadcopter.

[0154] Example 7

[0155] This embodiment provides a duplexer, which differs from Embodiment 1 only in that the transmit filter and receive filter are... Figure 1 The cross-sectional structure of dashed line A is as follows Figure 9 As shown, a support column 900 is provided in the cavity of the substrate, and the rest is the same as in Example 1.

[0156] Example 8

[0157] This embodiment provides a duplexer, which differs from Embodiment 1 only in that the transmit filter and receive filter (top view as shown) are... Figure 1 In the diagram, the piezoelectric layers 300 of the five resonators are separated from each other, and the transmitting filter and receiving filter are along... Figure 1 The cross-sectional structure of dashed line A' is as follows Figure 10 As shown.

[0158] Example 9

[0159] This embodiment provides a duplexer, which differs from Embodiment 1 only in the transmit filter and receive filter (top view as shown). Figure 1 In the diagram shown, five resonators share a cavity 600, and the transmit filter and receive filter are along... Figure 1 The cross-sectional structure of dashed line A' is as follows Figure 11 As shown.

[0160] Example 10

[0161] This embodiment provides a duplexer, which differs from Embodiment 1 only in the transmit filter and receive filter (top view as shown). Figure 1 In the diagram, the piezoelectric layers 300 of the five resonators are separated from each other, and a support post 900 is provided below the lower electrode 200. The transmitting filter and the receiving filter are along... Figure 1 The cross-sectional structure of dashed line A' is as follows Figure 12 As shown.

[0162] Comparative Example 1

[0163] This comparative example provides a duplexer, which differs from Embodiment 1 only in that the top view of the filter is as follows. Figure 13 As shown, it includes five independently set pentagonal resonators, and the rest are the same as in Example 1.

[0164] The duplexers and multiplexers provided in the above embodiments, which use nested resonators to form filters, have a smaller footprint and higher integration compared to the filters in Comparative Example 1, which use independent resonators. Both duplexers and multiplexers have a smaller overall size. Furthermore, the spacing between the different resonators reduces the transmission of transverse waves, which is beneficial for improving the performance of the duplexers and multiplexers.

[0165] The applicant declares that the detailed method of the present invention is illustrated by the above embodiments, but the present invention is not limited to the above detailed method, that is, it does not mean that the present invention must rely on the above detailed method to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A duplexer, characterized in that, The duplexer includes a transmit filter and a receive filter stacked together, with the transmit filter and the receive filter facing each other. The transmitting filter or receiving filter includes a center resonator and at least one ring resonator nested within the center resonator. The center resonator and the at least one ring resonator are electrically connected in parallel or in series through the interconnection of the upper electrode layer or the lower electrode layer. The central resonator is spaced apart from the adjacent ring resonator and between two adjacent ring resonators. This structure can reduce the transmission of transverse waves. The upper electrode layer of the central resonator does not necessarily have to be connected to the upper electrode layer of all ring resonators; The number of ring resonators is ≥2; The transmitting filter and the receiving filter also include their respective substrates. The center resonator and at least one ring resonator of the transmitting filter or the receiving filter are disposed on the substrate of the filter, and the substrate is provided with an acoustic reflection structure. The edges of the central resonator and the adjacent ring resonator are not parallel to each other. The edges of any adjacent ring resonators are not parallel to each other.

2. The duplexer according to claim 1, characterized in that, The width of the interval is 18-25 μm.

3. The duplexer according to claim 1, characterized in that, The acoustic reflection structure is a cavity.

4. The duplexer according to claim 1, characterized in that, Both the central resonator and the at least one ring resonator include a lower electrode layer, a piezoelectric layer, and an upper electrode layer stacked sequentially, and at least one of the central resonator and the ring resonator includes a mass load layer.

5. The duplexer according to claim 1, characterized in that, The substrate of the transmitting filter and the substrate of the receiving filter are respectively located on both sides of the duplexer, and the resonator structure of the transmitting filter and the receiving filter is located between the two substrates.

6. The duplexer according to claim 1, characterized in that, The transmitting filter and the receiving filter are connected by a sealing ring, which is disposed on the periphery of the transmitting filter and the receiving filter.

7. The duplexer according to claim 6, characterized in that, The sealing ring is connected to the electrode structure or substrate of the transmitting filter and the receiving filter.

8. A multiplexer, characterized in that, The multiplexer includes the duplexer according to any one of claims 1-7.

9. A multiplexer, characterized in that, The multiplexer includes at least two transmit filters and at least two receive filters, wherein the transmit filters and receive filters are stacked and the transmit filters are arranged facing each other; At least one transmitting filter or receiving filter includes a center resonator and at least one ring resonator nested within the center resonator, wherein the center resonator and the at least one ring resonator are electrically connected in parallel or in series through the interconnection of an upper electrode layer or a lower electrode layer. The central resonator is spaced apart from the adjacent ring resonator and between two adjacent ring resonators. This structure can reduce the transmission of transverse waves. The upper electrode layer of the central resonator does not necessarily have to be connected to the upper electrode layer of all ring resonators; The number of ring resonators is ≥2; The transmitting filter and the receiving filter also include their respective substrates. The center resonator and at least one ring resonator of the transmitting filter or the receiving filter are disposed on the substrate of the filter, and the substrate is provided with an acoustic reflection structure. The edges of the central resonator and the adjacent ring resonator are not parallel to each other. The edges of any adjacent ring resonators are not parallel to each other.

10. The multiplexer according to claim 9, characterized in that, The multiplexer includes a first substrate and a second substrate; The multiplexer includes a first transmit filter, a second transmit filter, a first receive filter, and a second receive filter; The first transmitting filter and the first receiving filter are arranged facing each other, and the second transmitting filter and the second receiving filter are arranged facing each other; The first transmitting filter and the second transmitting filter share a first substrate, and the first receiving filter and the second receiving filter share a second substrate.

11. The multiplexer according to claim 10, characterized in that, The multiplexer includes a first substrate and a second substrate; The multiplexer includes a first transmit filter, a second transmit filter, a first receive filter, and a second receive filter; The first transmitting filter and the first receiving filter are arranged facing each other, and the second transmitting filter and the second receiving filter are arranged facing each other; The first transmitting filter and the second receiving filter share a first substrate, and the second transmitting filter and the first receiving filter share a second substrate.

12. A method for preparing a duplexer according to any one of claims 1-7 or a multiplexer according to any one of claims 8-11, characterized in that, The preparation method includes the following steps: (1) A cavity is etched on the substrate, and a thin film is deposited in the cavity to form a substrate; (2) A lower electrode layer, a piezoelectric electrode layer, and an upper electrode layer are sequentially deposited on the substrate; (3) A mass-loaded layer is prepared on the upper electrode layer; (4) A cavity release hole is prepared through the lower electrode layer, the piezoelectric electrode layer, the upper electrode layer and the mass load layer, and the deposited thin film in the cavity is released through the cavity release hole to form a cavity on the substrate; (5) A sealing ring is deposited on the substrate or the lower electrode layer to obtain a transmitting filter or a receiving filter; (6) Bond the sealing rings in the transmitting filter and the receiving filter to obtain the duplexer or multiplexer.

13. The preparation method according to claim 12, characterized in that, The preparation method further includes step (4') after step (4): etching stress relief holes through any one or at least two of the lower electrode layer, piezoelectric layer and upper electrode layer.

14. A communication device, characterized in that, The communication device includes a duplexer as described in any one of claims 1-7, or a multiplexer as described in any one of claims 8-11.

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