DMS filter, electroacoustic filter and multiplexer

Abstract

An improved DMS filter is provided, having an electrode structure between a first port and a second port. The line connection is implemented by a multi-layer crossover between dielectric materials. An insulating patch (L2) is between the crossing conductor layers (L1, L3). The signal line can be implemented through the multi-conductor layers (L1, L3) to reduce the coil impedance and the upper conductor layer (L3) of the signal line can partially cover the insulating patch (L2). The insulating patch can extend through the acoustic path to achieve temperature compensation.

Description

Technical Field

[0001] This application relates to improved DMS filters and electroacoustic filters and multiplexers including such DMS filters. Background Art

[0002] Mobile communication devices require RF filters to distinguish desired RF signals from unwanted RF signals. Corresponding RF filters can include electroacoustic components such as electroacoustic resonators and DMS filters (DMS = dual-mode SAW; SAW = surface acoustic wave). A DMS filter includes one or more input IDTs and one or more output IDTs (IDT = interdigital transducer). The IDTs are arranged between electroacoustic reflectors. The DMS filter works with surface waves (SAW = surface wave). To this end, the transducer has an electrode structure coupled to a piezoelectric material. Due to the piezoelectric effect, such an electrode structure and the piezoelectric material together convert between electromagnetic RF signals and acoustic RF signals. The input transducer typically receives an electromagnetic RF signal from an external current environment (e.g., from an antenna) and accordingly provides a filtered electromagnetic RF signal on the output transducer, which is typically connected to an output port to an external current environment (e.g., a low-noise amplifier of a mobile communication device).

[0003] Such DMS filters can include other circuit elements, e.g., other filtering elements, on the RF filter or mobile communication device. The operation of such filters depends on, e.g., the electrical losses and acoustic losses of the filtering structure. In addition, the frequency characteristics of the RF filter should not be dominated by temperature-induced frequency drift. In addition, the corresponding RF filter should comply with specifications regarding impedance matching, bandwidth, and selectivity level. In addition, the corresponding RF filter should be producible with low production costs and comply with the current trend towards miniaturization. Summary of the Invention

[0004] To this end, DMS filters are provided according to the independent claims. The dependent claims provide preferred embodiments.

[0005] The DMS filter includes a first and a second port.

[0006] The DMS filter can be an 11-IDT DMS filter. Among the eleven IDTs, six IDTs can serve as the first IDTs and five IDTs can serve as the second IDTs. In addition, the DMS filter can have a first acoustic reflector and a second acoustic reflector. The first IDTs can be electrically connected to the first port. The second set of IDTs can be electrically connected to the second port.

[0007] In addition, the DMS filter may include a piezoelectric material. Additionally, the DMS filter may have an electrode structure disposed above or on the piezoelectric material. The electrode structure may be electrically connected between a first port and a second port.

[0008] The electrode structure may have a multi-layer structure. Then, the multi-layer structure may include a metal material and a dielectric material.

[0009] Six first IDTs and five second IDTs may be part of the electrode structure. Thus, the IDTs may be electrically connected between the first port and the second port. Specifically, the first IDTs and the second IDTs are acoustically coupled. Thus, two acoustic reflectors and eleven IDTs together create the acoustic active elements of the DMS filter.

[0010] The number of IDTs is not specifically limited to eleven. The DMS filter may have more than eleven or less than eleven IDTs. However, the 11-IDT DMS filter seems to provide a good compromise between performance and the space required for the filter structure.

[0011] The 11-IDT DMS filter has an electrical loss different from that of an n-IDT DMS filter by a factor of approximately (1 - (n / 11)*(n / 11)). One term of (n / 11) is due to the number of fingers in the transformation (when all impedances should be maintained). The other term of (n / 11) is due to the length of the corresponding fingers. Thus, as an example, when compared with a 9-IDT DMS filter, the electrical loss is reduced by a factor of 0.33.

[0012] The DMS filter may be electrically connected to an external current environment via the first port and the second port respectively. The DMS filter may be coupled to other filtering elements, such as passive impedance elements or other electroacoustic resonators, to generate a more complex electroacoustic RF filter.

[0013] Specifically, the DMS filter may be electrically connected in series to a ladder-shaped circuit topology to provide an electroacoustic filter with excellent filtering performance and high power durability. Such a filter may be used as a receiving filter for a mobile communication device.

[0014] The electrode structure of the DMS filter may be directly disposed on the piezoelectric material. However, one or more sub-layers may be disposed between the electrode structure and the piezoelectric material.

[0015] By providing an electrode structure as a multi-layer structure and by providing a multi-layer structure with metal and dielectric materials, an improved signal conductor in the structure of a DMS filter can be obtained. To this end, the dielectric material and the metal are arranged relative to each other such that electrical losses such as capacitive losses or ohmic losses are reduced. In addition, by configuring the DMS filter disclosed according to the present invention, the necessary chip area can be minimized, costs can be reduced, and the size can be helped to be miniaturized. Additionally, the parasitic capacitance can be reduced and the possible filtering bandwidth can be increased. Accordingly, the DMS filter may establish a band-pass filter or a band-stop filter.

[0016] The IDT of the DMS filter may include a bus bar and electrode fingers. Each electrode finger is electrically connected to one or two bus bars of the IDT. When adjacent electrode fingers are connected to opposite electrode bus bars, an acoustic excitation center is placed between the two electrode fingers. The electrode fingers extend substantially perpendicular to the propagation direction of the surface wave. In addition, the electrode fingers have an extension orthogonal to the normal direction of the piezoelectric material.

[0017] Such a DMS filter provides reduced electrodes and parasitic losses while the required chip area is reduced. Therefore, such a DMS filter is compatible with the ongoing trend towards minimization and the filter layer structure is compatible with traditional layer deposition and structuring techniques.

[0018] The IDT may be a first IDT and a second IDT, which may be respectively arranged between two acoustic reflectors to confine the acoustic energy to the active region of the resonator, to increase the quality factor Q of the DMS structure and reduce losses. Accordingly, the bandwidth filter has a reduced insertion loss in the passband.

[0019] The DMS filter may include a first inter-IDT connection and a second inter-IDT connection. Each IDT may have a first bus bar and a second bus bar. The first bus bars of the first IDT may be electrically connected to each other via the first inter-IDT connection. The second bus bars of the second IDT may be electrically connected to each other via the second inter-IDT connection.

[0020] Therefore, relative to the first inter-IDT connection and the second inter-IDT connection, the IDTs are electrically connected in parallel and the reverse bus bars are typically grounded.

[0021] Specifically, the first bus bar of the first IDT may be electrically connected to the first port, and the second bus bar of the second IDT may be electrically connected to the second port.

[0022] From the perspective of the RF signal, the DMS filter structure can be entered via the first port as an input port. Via the first IDT connection, the RF signal is divided into several sub-signals, which enter via its first busbar to establish the output of the first IDT, the first IDT. The second busbar of the first IDT can be electrically connected to the ground potential. The energy excitation of the sub-signals within the first IDT is transmitted to the acoustic wave of the second IDT. The first busbar of the second IDT can be electrically connected to the ground potential. All the second busbars of the second DTS establish the output component of the second IDT. In the second IDT, the acoustic energy is converted into electromagnetic energy provided to the second IDT connection. The second IDT resources can be electrically connected or coupled to the second port which can be used as the output port of the DMS filter.

[0023] The first and second IDT connections can include a lower metal strip and an upper metal strip.

[0024] The lower metal strip and the upper metal strip can be strips of a multi-layer structure of different layers arranged as an electrode structure. The provision of the electrode structure as a multi-layer structure allows for the selection of different levels of materials, for example, for the layer including the lower metal strip and the layer including the upper metal strip according to different requirements. The material layers closer to the piezoelectric material can be selected according to their acoustic (i.e., electromechanical) properties. The material layers further away from the piezoelectric material can be selected according to their electrical properties.

[0025] Therefore, the lower metal strip can include a metal or a layered structure that provides good delamination resistance and / or electroacoustic migration ability and has a layer height optimized for electroacoustic coupling and reflectivity. Typically, the resulting layer height is low and implies a higher resistance. The metal or material layer system of the upper metal strip can be selected to provide a low resistivity and a higher layer height.

[0026] Therefore, the lower metal strip can include a metal or a layered structure that provides good resistance to delamination and / or electroacoustic migration, along with a layer height optimized for electroacoustic coupling and reflectivity. Typically, the height of the resulting layer is low and implies a high resistance. The metal or material layer system of the upper metal strip can be selected to provide a low impedance and a high layer height.

[0027] Therefore, the lower metal strip can comprise or consist of copper, aluminum, titanium, chromium, silver, gold, and other suitable materials.

[0028] The upper metal strip can include or consist of silver, gold, aluminum, copper, titanium, and other suitable materials.

[0029] The DMS filter can also include a third IDT connection and a fourth IDT connection. Each of the third IDT connection and the fourth IDT connection can include an internal metal strip.

[0030] The term "inner" is related to the central excitation region and the transverse (y) direction perpendicular to the propagation direction of the surface wave.

[0031] Specifically, with respect to the occupied area of the element, the inner metal strip can be arranged between the lower metal strip and / or the upper metal strip with respect to the transverse direction.

[0032] In contrast, the terms "lower" and "upper" refer to their respective vertical positions (z).

[0033] When the connections between the first and second IDTs, especially the upper metal strip, respectively reduce the impedance at the first port and at the second port, the connections between the third IDTs and the connections between the fourth IDTs can help reduce the impedance of the electrode structure when it comes to the ground connection.

[0034] The connection between the third IDTs can be electrically connected to the ground connection of the second IDT and the connection between the fourth IDTs is electrically connected to the ground connection of the first IDT to reduce the ground impedance.

[0035] Correspondingly, the lower metal strip, the upper metal strip and the inner metal strip can be strip patches extending in the longitudinal direction and arranged in the transverse direction between the central excitation region and the corresponding first port or second port. The length of the metal strip can be substantially equal to the length of the effective region between the acoustic reflectors.

[0036] The inner metal strip can be longer than the lower metal strip and the upper metal strip. The connections between the second IDTs and their corresponding metal strips can be shorter than the connections between the first IDTs.

[0037] Correspondingly, the connection between the third IDTs can be electrically connected to the first bus of the second conductor and the connection between the fourth IDTs can be electrically connected to the first bus of the second conductor, so as to obtain an impedance with a reduced potential to the ground.

[0038] The DMS filter can further include insulating patches. The filter can include an insulating patch between the connection between the third IDTs and the first connection C1 and another insulating patch between the connection between the fourth IDTs and the second connection C2.

[0039] At least a part of the material of the insulating patch can be in the vertical position between the connection between the third IDTs and the first connection in the multi-layer structure. The connection between the fourth IDTs can be in the same vertical position as the connection between the third IDTs, and the connection between the second IDTs can be in the same vertical position as the connection between the first IDTs.

[0040] The elements of the inner IDT connection can have a thickness of 0.08 μm ≤ t ≤ 0.5 μm, such as 0.15 μm, in the vertical direction for the lower strip, and a thickness of 0.7 μm ≤ t ≤ 3 μm, such as 2.5 μm, for the upper strip and the inner strip.

[0041] The insulating patch can have a - in the vertical direction - thickness for 0.5 μm ≤ t ≤ 1.5 μm, for example, 0.87 μm.

[0042] The insulating patch is connected to the internal IDT together to establish a conductor crossover. According to the present invention, the position and size of the corresponding strips allow a significant reduction of the parasitic capacitance, while the total conductor length of the structure is kept short within the DMS filter so that the ohmic losses are also kept at a minimum.

[0043] The insulating patch preferably consists of an electrode structure of a dielectric material multi-layer structure. The dielectric material can be selected according to its dielectric properties (such as its dielectric constant, dielectric loss). However, due to the dual nature of the electro-acoustic filter being electrically active and acoustically active, the mechanical properties of the dielectric material can also be used to increase the waveguide of the filter structure.

[0044] The insulating patch can also be used to enhance other characteristics of the DMS filter. If applied close to or on top of the electrode fingers, the material of the insulating patch can be used to reduce the temperature-induced drift of the characteristic frequency. The characteristic frequency can be the center frequency of the passband or the frequency of the left or right passband edge.

[0045] For this purpose, the dielectric material, such as the insulating patch, can be a material that cancels the temperature-induced frequency shift or a carrier frequency substrate or a piezoelectric material.

[0046] In addition to the insulating patch, another TCF (temperature coefficient of frequency) compensation layer can be arranged above and / or below the electrode structure or below the piezoelectric material.

[0047] Furthermore, it is possible that each second IDT is arranged between two first IDTs in a linear arrangement.

[0048] The linear arrangement relates to the IDTs, as well as the acoustic reflectors, for example, the IDTs are arranged together along a straight line. The lateral compensation of the IDT with respect to other IDTs can be substantially 0.

[0049] The extension of the linear arrangement is substantially parallel to the direction of acoustic wave propagation in the x direction.

[0050] It is also possible that the electrode fingers are placed along a straight line determined by an inclination angle defined with respect to the direction of acoustic propagation.

[0051] In addition, it is possible that the coverage area of the IDT is symmetric with respect to a symmetry line perpendicular to the direction of SAW propagation.

[0052] Specifically, the symmetry line is substantially parallel to the extension of the electrode fingers. In the case of an 11-IDT DMS filter, the symmetry line is within the center of the second IDT.

[0053] The symmetry mentioned above is valid when the structure of the DMS filter is projected onto the surface of the piezoelectric material that forms the footprint. When the structure is involved along the vertical direction, the symmetry line can have a symmetry plane as the equivalent in three dimensions.

[0054] The corresponding symmetry plane is then perpendicular to the propagation direction of the SAW.

[0055] In addition, when vertical construction is involved, the multilayer structure can include lower metal strips connecting the first and second IDTs in the first layer. In addition, the multilayer structure can include upper metal strips connecting the first and second IDTs in the third layer. In addition, the multilayer structure can include insulating patches in the second layer, arranged between the first and third layers.

[0056] In addition, to reduce the ohmic losses in the third layer, the third layer can have a greater thickness than the first layer. As a result, the conductor obtains a larger cross-section, leading to reduced ohmic losses.

[0057] Additionally, the connections between the third IDTs and the connections between the fourth IDTs can be connected to the ground potential, so that the electrical connection of each IDT is improved.

[0058] The first IDT can be the input IDT and the second IDT can be the output IDT.

[0059] Therefore, the first IDT can be electrically connected to the first port, which can be the input port, and the second IDT can be electrically connected to the second port, which can be the output port.

[0060] The DMS filter can further include a TC (temperature compensation) structure. The TC structure can be a multilayer TC structure. The multilayer TC structure can include a TC material (TC = temperature compensation), which is located below the piezoelectric material, between the piezoelectric material and the electrode structure, between the elements of the electrode structure and / or above the electrode structure. Specifically, the multilayer TC structure can include a TC material layer above the electrode structure and insulating patches within the electrode structure. Advantageously, the TC material and a dielectric material can be used to construct the insulating patches for forming line crossings.

[0061] In addition, the DMS filter can be a TF-SAW DMS filter (TF = thin film).

[0062] In the TF-SAW DMS filter, the piezoelectric material is provided as a piezoelectric thin film. The piezoelectric thin film can be a single crystal material. However, the piezoelectric material can be provided as a polycrystalline material.

[0063] Piezoelectric thin film materials can be provided using thin film layer deposition techniques such as CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), MBE (Molecular Beam Epitaxy), and sputtering, etc. In addition, techniques such as "smart-cut" technology or grinding can be used to obtain thin films of polycrystalline materials.

[0064] The piezoelectric material can be aluminum nitride or scandium-doped aluminum nitride, lithium tantalate, lithium niobate, or quartz. When single crystal piezoelectric materials are required, lithium tantalate and lithium niobate are preferably used.

[0065] The upper metal strip (UMS) of the first inter-digital transducer connection (IIC1) and / or the second inter-digital transducer connection (IIC2) can cover the insulating patch (IP) with a covering width o1.

[0066] The internal metal strip (IMS) of the third inter-digital transducer connection (IIC3) and / or the fourth inter-digital transducer connection (IIC4) is located on top of the insulating patch (IP) with a full width.

[0067] The upper metal strip (UMS) of the first inter-digital transducer connection (IIC1) can completely cover the lower metal strip (LMS) of IIC1, and / or the upper metal strip (LMS) of the second inter-digital transducer connection (IIC2) can completely cover the lower metal strip (LMS) of IIC2.

[0068] The insulating patch (IP) may not cover the lower metal strip (LMS).

[0069] The electrode structure may not include the lower metal strip (LMS).

[0070] The insulating patch (IP) can cover the first connection (C1) of the first inter-digital transducer (IDT1) and the second connection (C2) of the second inter-digital transducer (IDT2).

[0071] The insulating patch (IP) does not overlap with the second bus bar (B1) or the first bus bar (B2).

[0072] In addition, the DMS filter is part of an electroacoustic filter, such as an electroacoustic RF filter (e.g., for mobile communication devices).

[0073] In addition, the corresponding electroacoustic filter can be part of a multiplexer (e.g., a duplexer, a triplexer, a quadruplexer, or a higher-order multiplexer).

[0074] Specifically, the electroacoustic filter may be a receiving filter for a mobile communication device.

[0075] As a receiving filter of a mobile communication device, for example, in a front-end circuit, an electroacoustic filter can be electrically connected between common ports (e.g., ports connected to an antenna), and a low-noise amplifier.

[0076] The width of the upper metal layer connecting the first and / or second IDTs can be between 10 μm and 25 μm (e.g., 14 μm).

[0077] The width of the connection between the third IDTs and / or the connection between the fourth IDTs can be between 8 μm and 20 μm (e.g., 10 μm). The lateral distances between the internal metal strips of the connection between the first IDTs and the connection between the third IDTs and between the internal metal strips of the connection between the second IDTs and the connection between the fourth IDTs can be between 3 μm and 10 μm, e.g., 5 μm. The lateral distance between the internal metal strip and the bus bar of the IDT can be between 6 μm and 15 μm, e.g., 11 μm.

[0078] The length of the IDT along the longitudinal direction and the width of the IDT along the lateral direction (especially the aperture of the IDT) and the number of IDTs of each DMS filter can be selected such that the specifications regarding impedance matching with other circuit elements can be complied with.

[0079] Preferably, the finger length of the IDT is reduced such that the sum of the electrical and acoustic losses is minimized.

[0080] Compared with a DMS filter having nine IDTs, an 11-IDT filter provides an improved trade-off between area consumption and performance. In addition, the IDT can have a growing metallization ratio η≥0.5, the thickness of the metal growing in the vertical direction >150 nm, respectively, and a growing finger cross-section to increase conductivity.

[0081] The ground / ground connection order at the distal electrode fingers of the IDT reduces capacitive coupling, which increases the broadband selection level of the filter.

[0082] The insulating patch can comprise or consist of an oxide of silicon, e.g., silicon dioxide, or an organic material such as BCB (BCB = benzocyclobutene).

[0083] The filter can also include connection pads for electrically connecting the electrode structure to an external circuit environment. The connection pads for connecting the structure to the ground potential can include two pads, which are arranged on opposite sides of the track, e.g., for a dual ground connection. However, only a single connection pad can be used for connection to the ground and a corresponding conductor loop from one side of the track to the corresponding other side of the track. This loop can electrically connect the internal metal strips of the DMS filter structure.

[0084] In terms of the central aspect of the preferred embodiment, the details of the working principle and the bias embodiment are shown in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Specific embodiments of the inventive concept will now be described by way of example, with reference to the accompanying drawings, in which:

[0086] Figure 1 An 11-IDT DMS filter is shown, with the main elements shown in the form of a top view of a first metal layer;

[0087] Figure 2 A cross-sectional view through the IDT is shown;

[0088] Figure 3 The orientation of the IDT within the track relative to the transverse direction y is shown;

[0089] Figure 4 The use of a dielectric material to produce conductive path crossings is shown;

[0090] Figure 5 The element positions of the connections between the first and second IDTs and between the third and fourth IDTs are shown.

[0091] Figure 6 The possibility of providing material for the TC layer for the crossover lines above the track is shown;

[0092] Figure 7 A cross-sectional view showing the position of the TC layer material is shown;

[0093] Figure 8 An enlarged view of the multilayer construction electrode structure in cross-section is shown;

[0094] Figure 9a 、 Figure 9b A top view of an enlarged cross-section showing the distance along the transverse direction; and

[0095] Figure 10 The use of the DMS filter in a duplexer is shown. DETAILED DESCRIPTION

[0096] Figure 1 A top view above the central element of the DMS filter DMSF is shown. The DMS filter DMSF has eleven IDTs. Six IDTs are the first IDTs, IDT1, and five IDTs are the second IDTs, IDT2. All the IDTs and reflectors establish a linear configuration defining the track. Each second IDT, IDT2, is arranged between the first IDTs, IDT1. The distal first IDT, IDT1, is configured between the acoustic reflector and the second IDTs, IDT2.

[0097] Each IDT in the first IDT is electrically connected to the first port P1. Each IDT in the second IDT is electrically connected to the second port P2. Each port of the reference potential can be the ground potential. The first IDT is connected to the first port along with their bus bar B1 and the first ground C1 (compared to Figure 3 ). The second IDT is connected to the second port along with their second bus bar B2 and the second connection C2. The second connection of the first IDT can also be electrically connected to the ground potential and the first connection C1 of the second DT can also be electrically connected to the ground potential. The two-dimensional footprint of the IDT and / or the conductor segments supplying the IDT with RF signals can have symmetry along with the symmetry line SL, extending along the direction in which the electrode fingers extend and penetrating the central second IDT.

[0098] When it comes to a three-dimensional structure, the symmetry line SL corresponds to a mirror plane, perpendicular to the acoustic wave propagation direction x. The transverse direction is represented by y.

[0099] Figure 1 The possible metal structures in the DMS structure are shown, which are established in the first layer L1 of the multi-layer structure of the electrode structure (compared to Figure 5 and Figure 8 ).

[0100] Figure 2 A cross-section of the multi-layer structure illustrating the electrode structure is shown. Specifically, Figure 2 the cross-section AA is shown corresponding to Figure 5 the position AA shown. The electrode structure ES is disposed on the piezoelectric material PM. The piezoelectric material PM is disposed on the carrier substrate CS. The electrode structure ES along with the multi-layer structure MLC includes the first IDT interconnection IIC1 and the second IDT interconnection IIC2. The first IDT interconnection IIC1 can have a lower metal strip LMS and an upper metal strip UMS. The second IDT interconnection can have a lower metal strip LMS and an upper metal strip UMS. The LMS can be from the metal layer L1 generated by the first lithography and the UMS can be from the metal layer L3 generated by the third lithography.

[0101] The LMS can be omitted to further reduce the size of the MLC if the UMS exhibits a sufficiently high conductivity.

[0102] In addition, the electrode structure ES has a third inter-IDT connection IIC3 and a fourth inter-IDT connection IIC4. The first and second inter-IDT connections IIC1, IIC2 can be provided to conduct RF signals from the first port to the DMS and from the DMS to the second port. The third inter-IDT connection IIC3 and the fourth inter-IDT connection IIC4 can be provided to enable connection to the ground potential. To electrically disperse the ground from the input and output ports, the dielectric material DM is provided in the form of an insulating patch IP between the internal metal strip of the low metal conductor C1 and the third inter-IDT connection in the second insulating layer L2.

[0103] To minimize area consumption and thus minimize the construction size, while minimizing the risk of lithographic manufacturing failure of the multi-layer structure MLC connection with the inherent offset tolerance between layers. The UMS portion of IIC1 covers the insulating patch of the dielectric material DM.

[0104] Figure 3 The directions of the IDTs are shown, (e.g., the positions of the first bus bar B1 and the first connection C1 and the second bus bar B2 and the second connection C2) are related to the positions of the first port and the second port. The first connection C1 of IDT1 in the first IDT is electrically connected to the first port P1 and the first bus bar B1 of the first IDT. The second connection C2 of IDT2 in the second IDT is electrically connected to the second port P2 and the second bus bar B2 of the second IDT. The second connection C2 of IDT1 in the first IDT and the first connection C1 of IDT2 in the second IDT are electrically connected to the ground potential.

[0105] Figure 4 The position of the insulating patch IP that includes or consists of the dielectric material DM at the position of the cross-conduction, preventing electrical short circuits of the conductors that are electrically grounded or electrically connected between the first and second ports respectively, is shown. The insulating patch can be produced by a second lithography operation for constructing the second dielectric layer L2. Advantageously, for reducing the size, the insulating patch can only cover the connections C1, C2, but not the connection bus bars B1, B2 and the lower metal strips LMS IIC1, IIC2.

[0106] Accordingly, Figure 5 The positions for the third inter-IDT connection IIC3 and for the fourth inter-IDT connection IIC4 are shown. In addition, the positions of the lower metal strip LMS and the upper metal strip UMS for the first and second inter-IDT connections IIC1, IIC2 are also shown.

[0107] IC1 UMS, IIC2 UMS, IIC3 IMS and IIC4 IMS can be produced in the third lithography operation for constructing the third metal layer L3. Typically, L3 includes a thick, highly conductive metal layer to minimize ohmic impedance losses.

[0108] The lateral position (y) of the internal IDT connecting the lower and upper metal strips of the IIC is substantially the same. However, the internal metal strip and the upper metal strip are arranged at the same vertical level and are composed of the material of the same layer L3, which simplifies the production steps.

[0109] Position AA shows Figure 2 the position of the cross-section shown.

[0110] Figure 6 Shows the possibility of arranging the material of the TC layer TCL above the track. The material of the TC layer can include a rectangular main patch RMP and a rectangular smaller patch RSP for each IDT. The rectangular smaller patch RSP additionally serves as Figure 4 the DM and IP in, and enables the conductor to pass through without an additional conductive layer.

[0111] Figure 7 Shows the cross-section of the material system at Figure 6 the position BB shown. The material of the TC layer TCL is arranged above the material of the electrode finger EF.

[0112] Figure 8 Shows the layer structure of the electrode structure including a first layer L1 in which the electrode fingers can be constructed, a second layer L2 including an insulating patch of a conductive electrode and advantageously simultaneously TC operation and, a second layer L2 including a dielectric material of an insulating patch and advantageously simultaneously including a TC function, and a third layer L3 including an upper metal strip and an internal metal strip. The first layer can be directly arranged on the piezoelectric material PM. The piezoelectric material can be arranged on the carrier substrate CS.

[0113] However, additional materials of the TC layer can be arranged between the carrier substrate CS and the piezoelectric material and / or between the piezoelectric materials PM and between the first layer L1 or above the third layer or above the first layer.

[0114] Figure 9a Shows the characteristic distances in the lateral y. D1 represents the lateral external position of the IDT bus bar and between the third IDT interconnections IIC3. D3 represents the longitudinal distance between the upper metal strip and the internal metal strip. W2 shows the width of the internal metal strip. W4 shows the width of the upper metal strip. O1 shows the overlap between the insulating patch and the upper metal strip. The insulating patch IP of the dielectric material DM covers at least part of the upper metal strip UMS.

[0115] Figure 9bShows the characteristic distance in the lateral direction y. D1 shows the lateral external position between the IDTs bus and the connection IIC3 between the third IDT. D3 shows the lateral distance between the upper metal strip and the internal metal strip. W2 shows the width of the internal metal strip. W4 shows the width of the upper metal strip. O1 shows the overlap between the upper metal strip and the insulating patch. The insulating patch IP of the dielectric material DM does not cover the lower metal strip LMS of the first IDT connection IIC1 but overlaps at least partially with the upper metal strip UMS.

[0116] Compared to Figure 9a the shown electrode structure, the insulating patch IP of the dielectric material DM has a reduced extension in the longitudinal direction.

[0117] Figure 10 Shows the basic circuit topology of the duplexer DU. The duplexer DU includes a transmit filter TXF and a receive filter RXF. The transmit filter TXF is typically between the transmit port and the antenna port connected to the antenna AN. The receive filter TXF and the receive filter RXF have signal paths based on a ladder-type similar circuit topology with series resonators SR connected in series between the input port and the output port. In addition, the parallel path includes parallel resonators PR that electrically connect the signal path to the ground potential.

[0118] To match the frequency-dependent receive filter RXF, transmit filter TXF, and / or antenna, an impedance matching circuit IMC can be connected between the transmit filter TXF and the receive filter RXF, for example, at the antenna port.

[0119] In the ladder-type similar current topology of the receive filter RXF, the filter output port DMS filter DMSF is configured to be electrically connected.

[0120] For the receive filter RXF, the ladder-type similar current topology provides good power sustainability and the DMS filter DMSF enhances insulation and selectivity levels while reducing the chip space requirement.

[0121] List of reference symbols

[0122] AN: Antenna

[0123] B1,B2: First, second busbars of the IDT

[0124] C1,C2: First, second connections of the IDT

[0125] CS: Carrier substrate

[0126] d1,d3: Distances

[0127] DM: Dielectric material

[0128] DMSF: DMS Filter

[0129] DU: Multiplexer

[0130] EF: Electrode Finger

[0131] ES: Electrode Structure

[0132] IDT: Interdigital Transducer

[0133] IDT1: First IDT

[0134] IDT2: Second Interdigital Transducer

[0135] IIC1, IIC2: Connection between the First and Second IDTs

[0136] IIC3, IIC4: Connection between the Third and Fourth IDTs

[0137] IMC: Impedance Matching Circuit

[0138] IMP: Internal Metal Strip

[0139] IP: Insulating Patch

[0140] L1, L2, L3: First, Second, Third Layers

[0141] LMS: Lower Metal Strip

[0142] R1: First Acoustic Reflector

[0143] R2: Second Acoustic Reflector

[0144] MLC: Multilayer Structure

[0145] o1, o2: Coverage Width

[0146] P1: First Port

[0147] P2: Second Port

[0148] PM: Piezoelectric Material

[0149] PR: Parallel Resonator

[0150] RMP: Rectangular Main Patch

[0151] RSP: Rectangular Smaller Patch

[0152] RXF: Receive Filter

[0153] SL: Symmetry Line

[0154] SR: Series Resonator

[0155] TCL: Temperature Compensation Layer

[0156] TXF: Transmit Filter

[0157] UMS: Upper Metal Strip

[0158] w2, w4: Strip Width

[0159] x: Propagation Direction of SAW

[0160] y: Lateral Direction

[0161] z: Vertical Direction

Claims

1. A DMS filter, comprising: A first port and a second port, A piezoelectric material, An electrode structure disposed above or on the piezoelectric material and electrically connected between the first port and the second port, Wherein The electrode structure has a multi-layer structure, The multi-layer structure includes a metal material and a dielectric material, and the electrode structure includes: A first acoustic reflector and a second acoustic reflector; A first IDT and a second IDT, wherein the first IDT and the second IDT are disposed between the first acoustic reflector and the second acoustic reflector; and A first inter-IDT connection and a second inter-IDT connection, wherein: Each IDT has a first bus bar and a first connection and a second bus bar and a second connection, The first connection of the first IDT and the first bus bar are electrically connected via the first inter-IDT connection, The second connection of the second IDT and the second bus bar are electrically connected via the second inter-IDT connection, and Wherein the first inter-IDT connection and the second inter-IDT connection include a lower metal strip and an upper metal strip.

2. The DMS filter according to claim 1, wherein the electrode structure includes: A third inter-IDT connection and a fourth inter-IDT connection, Wherein each of the third inter-IDT connection and the fourth inter-IDT connection includes an internal metal strip.

3. The DMS filter according to claim 2, wherein the dielectric material of the electrode structure includes An insulating patch located between the third inter-IDT connection and the first connection of the first IDT; and An insulating patch located between the fourth inter-IDT connection and the second connection of the second IDT.

4. The DMS filter according to claim 1, wherein the multi-layer structure includes: The lower metal strips of the first inter-IDT connection and the second inter-IDT connection in the first layer, The upper metal strips of the first inter-IDT connection and the second inter-IDT connection in the third layer, An insulating patch in the second layer between the first layer and the third layer.

5. The DMS filter according to claim 4, wherein the third layer has a greater thickness than the first layer.

6. The DMS filter according to claim 4, wherein the third layer has a higher conductivity than the first layer.

7. The DMS filter according to claim 2, wherein the third inter-IDT connection and the fourth inter-IDT connection are connected to a ground potential.

8. The DMS filter according to claim 1, wherein the first IDT is an input IDT and the second IDT is an output IDT.

9. The DMS filter according to claim 1, further comprising a TC layer.

10. The DMS filter according to claim 9, wherein the TC layer is additionally used as an insulator for line crossing.

11. The DMS filter according to claim 1 is a TF-SAW DMS filter.

12. The DMS filter according to claim 4, wherein the upper metal strip UMS connecting IIC1 between the first IDTs and / or the upper metal strip UMS connecting IIC2 between the second IDTs covers the insulation patch IP with a coverage width o1.

13. The DMS filter according to claim 3, wherein the internal metal strip IMS connecting IIC3 between the third IDTs and / or the internal metal strip IMS connecting IIC4 between the fourth IDTs is located on top of the insulation patch IP and has a full width w2.

14. The DMS filter according to claim 4, wherein the upper metal strip UMS connecting IIC1 between the first IDTs completely covers the lower metal strip LMS of IIC1, and / or the upper metal strip UMS connecting IIC2 between the second IDTs completely covers the lower metal strip LMS of IIC2.

15. The DMS filter according to claim 14, wherein the insulation patch does not cover the lower metal strip LMS.

16. The DMS filter according to claim 4, wherein the electrode structure does not have the lower metal strip LMS.

17. The DMS filter according to claim 3, wherein the insulation patch covers the first connection C1 of the first IDT and the second connection C2 of the second IDT.

18. The DMS filter according to claim 17, wherein the insulation patch does not cover the first bus bar B1 and / or the second bus bar B2.

19. An electroacoustic filter comprising a DMS filter according to one of the preceding claims.

20. A multiplexer comprising the electroacoustic filter according to claim 19.

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