A filter structure and a radio frequency module

Abstract

The application discloses a filter structure, comprising: a substrate; a first pad, a first signal line, a second signal line and a third signal line located on a first surface of the substrate, the first signal line being electrically connected with the first pad, the first signal line and the second signal line transmitting the same signal, and the first signal line and the third signal line transmitting different signals; at least one filter located on a first side of the substrate, the filter comprising a first filter unit and a second filter unit, the first filter unit being electrically connected with the first signal line, and the second filter unit being electrically connected with the second signal line; wherein the first signal line and the second signal line are arranged along a first direction, in the first direction, the third signal line is at least partially located between the first signal line and the second signal line, the first signal line and the second signal line are electrically connected through a connecting line, in a second direction, the connecting line overlaps the third signal line, and the connecting line is electrically insulated from the third signal line, so as to improve the out-of-band rejection performance of the filter.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a filter structure and a radio frequency module. Background Technology

[0002] In the field of semiconductor manufacturing technology, with the continuous iteration and upgrading of mobile communication technology, the demand for multi-frequency and multi-mode compatibility, high-speed and low-latency communication has placed higher integration, miniaturization and better overall performance requirements on the RF modules of mobile communication terminals. As the core component in the RF module responsible for screening target operating frequency band signals and filtering out unwanted spurious interference signals, the filter's performance directly determines the signal processing capability of the RF front-end and is a key fundamental component for ensuring the signal quality of mobile communication terminals.

[0003] Among the core performance indicators of filters, out-of-band rejection (OUTR) is the key indicator determining their anti-interference capability. This indicator characterizes the filter's ability to attenuate interference signals outside the target operating frequency band and is a core metric for measuring the filter's signal isolation effect. Its performance directly determines the signal anti-interference capability, receiving sensitivity, and transmission and reception stability of mobile communication terminals in complex electromagnetic environments. Therefore, how to effectively improve the out-of-band rejection performance of filters has become a core technical problem that urgently needs to be solved. Summary of the Invention

[0004] In view of the above problems, this application provides a filter structure and an RF module to improve the out-of-band rejection performance of the filter. The specific solution is as follows:

[0005] A filter structure, comprising:

[0006] Base;

[0007] A first pad, a first signal line, a second signal line, and a third signal line are located on a first surface of the substrate, wherein the first signal line is electrically connected to the first pad, the first signal line and the second signal line transmit the same signal, and the first signal line and the third signal line transmit different signals;

[0008] At least one filter located on a first side of the substrate, the filter comprising a first filtering unit and a second filtering unit, the first filtering unit being electrically connected to the first signal line and the second filtering unit being electrically connected to the second signal line;

[0009] The first signal line and the second signal line are arranged along a first direction. In the first direction, the third signal line is at least partially located between the first signal line and the second signal line. The first signal line and the second signal line are electrically connected by a connecting line. In the second direction, the connecting line overlaps with the third signal line and the connecting line is electrically insulated from the third signal line. The first direction is parallel to the first surface of the substrate, and the second direction is perpendicular to the substrate.

[0010] Optionally, the first surface of the substrate includes a first metal layer and a second metal layer arranged along the second direction;

[0011] The first signal line includes a first portion and a second portion stacked together, the first portion being located in the first metal layer and the second portion being located in the second metal layer;

[0012] The second signal line includes a third portion and a fourth portion stacked together, the third portion being located in the first metal layer and the fourth portion being located in the second metal layer.

[0013] Optionally, the third signal line includes a fifth portion, which is located in the first metal layer or in the second metal layer.

[0014] Optionally, the fifth part is located in the first metal layer, the connecting line is located in the second metal layer, and the fifth part and the connecting line are electrically insulated from each other by a first insulating structure.

[0015] Optionally, the fifth portion is located in the second metal layer, the connecting line is located in the first metal layer, and the fifth portion and the connecting line are electrically insulated from each other by a first insulating structure.

[0016] Optionally, the connecting line is located on the first surface of the substrate.

[0017] Optionally, the substrate includes a piezoelectric layer and a groove located within the piezoelectric layer, the groove extending from a first surface of the substrate to a portion of the interior of the piezoelectric layer; the connecting line is located on the surface of the groove.

[0018] Optionally, the fifth portion is located in the first metal layer, and the third signal line further includes a sixth portion located in the second metal layer, wherein the fifth portion and the sixth portion are stacked.

[0019] The substrate includes a piezoelectric layer and a groove located within the piezoelectric layer, the groove extending from a first surface of the substrate to a portion of the interior of the piezoelectric layer; the connecting line is located on the surface of the groove, and the fifth portion and the connecting line are electrically insulated from each other by a second insulating structure.

[0020] Optionally, the first filtering unit and the second filtering unit are located in the first metal layer, and a first insulating layer is provided on the side of the first filtering unit and the second filtering unit away from the substrate, and the first insulating structure is located in the first insulating layer.

[0021] Optionally, one end of the connecting line is electrically connected to a first position of the first signal line, and the other end is electrically connected to a second position of the second signal line;

[0022] In the third direction, the first position of the first signal line has a first width, the second position of the second signal line has a second width, the width of the connecting line is not greater than the first width and not greater than the second width, and the third direction is parallel to the substrate and intersects with the first direction.

[0023] Optionally, the length of the connecting line is the shortest distance between the first signal line and the second signal line.

[0024] Optionally, in the second direction, the number of signal line portions that overlap with the connecting line is no more than 1, and the signals transmitted by the signal line portions that overlap with the connecting line are different from the signals transmitted by the first signal line.

[0025] Optionally, the first pad is a ground pad, and the third signal line is an input signal line or an output signal line of the filter structure.

[0026] A radio frequency module comprising the filter structure described in any one of the preceding claims.

[0027] The filter structure provided in this application includes a substrate, a first pad located on a first surface of the substrate, a first signal line, a second signal line, and a third signal line, as well as a first filter unit and a second filter unit located on a first side of the substrate. The first signal line is electrically connected to the first pad, the first filter unit is electrically connected to the first signal line, and the second filter unit is electrically connected to the second signal line. The first and second signal lines transmit the same signal, while the third signal line transmits a different signal than the first signal line. The first and second signal lines are arranged along a first direction, and in this first direction, the third signal line is at least partially located between the first and second signal lines. This application electrically connects the first and second signal lines by providing a connecting line that overlaps with the third signal line in a second direction, thereby achieving a bridge-like electrical connection between the first and second signal lines, which are physically separated in the first direction by the third signal line. This shortens the interconnection path between the first and second signal lines, reduces the parasitic inductance introduced by the interconnection path, and effectively improves the out-of-band rejection performance of the filter.

[0028] Furthermore, in the filter structure provided in this application, the connecting line and the third signal line are electrically insulated in the second direction by an insulating structure, so that when the connecting line and the third signal line overlap in the second direction, a short circuit will not occur between the connecting line and the third signal line. Moreover, the filter structure provided in this application achieves the connection between the first signal line and the second signal line through the connecting line that overlaps with the third signal line in the second direction, eliminating the need to wrap the connecting line around the third signal line side along the substrate surface. This ensures that the electrical connection between the first signal line and the second signal line does not occupy additional layout space on the first surface of the substrate, thus balancing the compactness of the chip layout, adapting to the design requirements of filter miniaturization and high integration, and improving the freedom of layout design to adapt to different application requirements. Attached Figure Description

[0029] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0030] Figure 1 This is a schematic diagram of a filter structure in the prior art;

[0031] Figure 2 A schematic diagram of a filter structure provided in an embodiment of this application;

[0032] Figure 3 This is a cross-sectional structural diagram of a filter structure provided in an embodiment of this application;

[0033] Figure 4 A cross-sectional structural schematic diagram of a filter structure provided in another embodiment of this application;

[0034] Figure 5 This is a cross-sectional structural diagram of a filter structure provided in another embodiment of this application;

[0035] Figure 6 This is a cross-sectional structural diagram of a filter structure provided in another embodiment of the present application;

[0036] Figure 7 A cross-sectional structural schematic diagram of a filter structure provided in another embodiment of this application;

[0037] Figure 8 This is a cross-sectional structural diagram of a filter structure provided in another embodiment of the present application;

[0038] Figure 9 This is an equivalent circuit diagram of a filter structure provided in yet another embodiment of the present application;

[0039] Figure 10 This is a schematic diagram of the layout of the control group 40417_RX combined Die filter;

[0040] Figure 11 A schematic diagram showing the layout of the filter structure provided in this application embodiment applied to a 40417_RX combined Die filter;

[0041] Figure 12 for Figure 10 The diagram shows the isolation test curves of the structure in the B41 band from 1.8 GHz to 3.0 GHz.

[0042] Figure 13 for Figure 10 The diagram shows the isolation test curves of the structure in the B41 band from 1.5 GHz to 6.0 GHz.

[0043] Figure 14 for Figure 10 The structure shown and Figure 11 The diagram shows a comparison of isolation test curves for the structure shown in the B41 band from 1.8 GHz to 3.0 GHz.

[0044] Figure 15 for Figure 10 The structure shown and Figure 11 The diagram shows a comparison of isolation test curves for the structure shown in the B41 band from 1.5 GHz to 6.0 GHz.

[0045] Figure 16 for Figure 10 The structure shown and Figure 11 The diagram shows a comparison of insertion loss test curves for the structure shown in the B41 passband. Detailed Implementation

[0046] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0047] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the implementation methods provided in the embodiments of this application can be combined with each other without contradiction.

[0048] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] As described in the background section, how to effectively improve the out-of-band rejection performance of filters has become a core technical problem that urgently needs to be solved.

[0050] In the layout design and mass production of filter chips, the miniaturized package size limits the physical area of ​​the chip, resulting in a limited number of pads that can be placed on its surface for external connections. Therefore, multiple signal lines transmitting the same signal in a filter chip need to be connected to the same pad. However, in the actual wiring of the filter chip, the signal lines that need to be connected to the same pad may be distributed in different locations on the chip, and there may even be signal lines transmitting other signals between the target pad and the one being electrically connected. This means that the signal line cannot be electrically connected to the target pad in a straight line on the same plane, but can only be electrically connected to the target pad by winding.

[0051] like Figure 1 As shown, Figure 1 This diagram illustrates a filter structure in the prior art. In this diagram, the first signal line 101 and the second signal line 102 are two signal lines transmitting the same signal and need to be connected to the same pad. The third signal line 103 is a signal line transmitting a different signal than the first signal line 101. The third signal line 103 is located in the same plane as the first signal line 101 and the second signal line 102, and is at least partially located between the first signal line 101 and the second signal line 102, physically isolating the first signal line 101 and the second signal line 102. To address this, designers typically add a winding 104 to the side of the third signal line 103 to electrically connect the first signal line 101 and the second signal line 102, thereby achieving interconnection and conduction of the two signal lines. They are then connected to the same pad to achieve the transmission of the same signal. It should be noted that this diagram is for clear and intuitive illustration of the existing technology. Figure 1 The signal traces are simplified and drawn as straight lines. In practical applications, signal traces can be designed as straight lines, polygonal lines, curves, or any combination thereof, depending on the specific layout of the filter, wiring density, and performance optimization requirements. This routing method directly leads to a longer conduction path in the connection between two signal lines, resulting in the following two problems:

[0052] Firstly, current mass production design guidelines from major global wafer foundries generally require a safe spacing of 25μm to 30μm or more between adjacent conductors. If the spacing between adjacent conductors does not meet this design requirement, it increases the risk of short circuits between them, thereby reducing the mass production yield of semiconductor devices. Furthermore, the scheme of winding wires around other signal lines requires additional planar layout space in the filter chip, which can easily lead to insufficient spacing between the windings and other surrounding signal lines, thus affecting the mass production yield of the filter.

[0053] Secondly, long connecting lines formed by winding around other signal lines can couple with nearby signal lines transmitting different signals. This coupling affects the signal isolation and out-of-band rejection of the filter, thus interfering with the filter's performance. Furthermore, if the two signal lines to be connected are grounded traces, the path length of the connecting line is positively correlated with the filter's ground parasitic inductance. It should be noted that "ground parasitic inductance" refers to the fact that the grounding conductor itself acts like a small inductor, hindering current flow; the longer the conductor, the stronger this hindering effect. Therefore, the increased path length resulting from winding around other signal lines increases the filter's ground parasitic inductance, leading to a decrease in the filter's out-of-band rejection performance.

[0054] In view of this, embodiments of this application provide a filter structure, including:

[0055] Base;

[0056] A first pad, a first signal line, a second signal line, and a third signal line are located on a first surface of the substrate, wherein the first signal line is electrically connected to the first pad, the first signal line and the second signal line transmit the same signal, and the first signal line and the third signal line transmit different signals;

[0057] At least one filter located on a first side of the substrate, the filter comprising a first filtering unit and a second filtering unit, the first filtering unit being electrically connected to the first signal line and the second filtering unit being electrically connected to the second signal line;

[0058] The first signal line and the second signal line are arranged along a first direction. In the first direction, the third signal line is at least partially located between the first signal line and the second signal line. The first signal line and the second signal line are electrically connected by a connecting line. In the second direction, the connecting line overlaps with the third signal line and the connecting line is electrically insulated from the third signal line. The first direction is parallel to the first surface of the substrate, and the second direction is perpendicular to the substrate.

[0059] To facilitate understanding of the filter structure in this embodiment, please refer to the attached diagram. Figure 2 To explain, Figure 2 This is a schematic diagram of a filter structure provided in an embodiment of this application.

[0060] Optionally, in one embodiment of this application, the first surface of the substrate 201 is provided with a first pad 202, a first signal line 203, a second signal line 204, and a third signal line 205. The first pad 202 is used to electrically connect the filter to an external circuit. Optionally, the first pad 202 can be a signal input pad, a signal output pad, or a ground pad. The first pad 202 is electrically connected to the first signal line 203. The first signal line 203 and the second signal line 204 are used to transmit the same signal. In scenarios where the number of metal pads that can be set in the filter chip is limited by the miniaturized package size, the first signal line 203 and the second signal line 204 need to be electrically connected so that they share the same pad. The third signal line 205 is used to transmit a signal different from the first signal line 203. The first surface of the substrate 201 is also provided with a first filtering unit 206 and a second filtering unit 207. The first filtering unit 206 is electrically connected to the first signal line 203, and the second filtering unit 207 is electrically connected to the second signal line 204.

[0061] The first signal line 203 and the second signal line 204 are arranged along a first direction parallel to the first surface of the substrate 201. In this embodiment, the first direction is... Figure 2 The vertical direction is shown. In the first direction, the third signal line 205 is at least partially located between the first signal line 203 and the second signal line 204, forming a physical separation between the first signal line 203 and the second signal line 204 in the same plane. The first signal line 203 and the second signal line 204 are electrically connected by a connecting line 208. The intersection area of ​​the connecting line 208 and the third signal line 205 represents an overlapping area between them in a second direction perpendicular to the first surface of the substrate 201. It should be noted that in this embodiment, the connecting line 208 and the third signal line 205 are located in different conductive layers, and they are electrically insulated from each other by an insulating structure, so that the first signal line 203 and the third signal line 205, as well as the second signal line 204 and the third signal line 205, will not short-circuit. It should also be noted that the relative position of the connecting line 208 and the third signal line 205 in the second direction is not limited in this embodiment. That is, in the second direction, the connecting line 208 can be located above or below the third signal line 205.

[0062] It should be noted that in this embodiment, the third signal line 205 can be electrically connected to the first filter unit 206, the second filter unit 207, or other structures in the filter. This application does not limit this connection, as long as the third signal line 205 transmits different signals than the first signal line 203. It should also be noted that, to clearly and intuitively demonstrate the core bridging wiring structure of this application, Figure 2 Each signal trace is simplified and drawn as a straight line. In practical applications, the signal traces can be designed as straight lines, polygonal lines, curves, or any combination thereof, depending on the specific layout of the filter, wiring density, and performance optimization requirements. The specific shape of the traces does not affect the implementation of the technical solution of this application.

[0063] Therefore, in the filter structure provided in this application embodiment, the first signal line 203 and the second signal line 204 are electrically connected by setting a connecting line 208 that overlaps with the third signal line 205. This bridge-type connecting line does not need to be wound on the side of the third signal line 205, which can shorten the interconnection path length between the first signal line 203 and the second signal line 204, thereby reducing the parasitic inductance introduced by the interconnection path and effectively improving the out-of-band rejection performance of the filter.

[0064] Optionally, in one embodiment of this application, the first surface of the substrate includes a first metal layer and a second metal layer arranged along the second direction;

[0065] The first signal line includes a first portion and a second portion stacked together, the first portion being located in the first metal layer and the second portion being located in the second metal layer;

[0066] The second signal line includes a third portion and a fourth portion stacked together, the third portion being located in the first metal layer and the fourth portion being located in the second metal layer.

[0067] like Figure 3 As shown, Figure 3This is a cross-sectional view of a filter structure provided in an embodiment of this application. The first surface of the substrate 201 is provided with a first metal layer and a second metal layer stacked along a second direction. The second direction is perpendicular to the first surface of the substrate 201. The first metal layer is located on the side closer to the substrate 201, and the second metal layer is located on the side of the first metal layer away from the substrate 201. The first signal line includes a first portion 302 and a second portion 303 stacked together. The first portion 302 is located within the first metal layer, and the second portion 303 is located within the second metal layer. The first portion 302 and the second portion 303 are stacked and electrically connected, together forming the first signal line. The second signal line includes a third portion 304 and a fourth portion 305 stacked together. The third portion 304 is located within the first metal layer, and the fourth portion 305 is located within the second metal layer. The third portion 304 and the fourth portion 305 are stacked and electrically connected, together forming the second signal line.

[0068] It should be noted that in the filter, the core device for realizing the mutual conversion of electrical energy and acoustic energy includes an interdigital transducer, which includes interdigital electrodes. Optionally, in one embodiment of this application, the substrate includes a piezoelectric layer, and the interdigital electrodes include two sets of electrodes that are interleaved. When a voltage is applied to the two sets of interleaved electrodes, a strong electric field is formed between the interleaved electrodes, causing the piezoelectric layer in the substrate to produce a piezoelectric effect and excite sound waves.

[0069] Optionally, in one embodiment of this application, the interdigitated electrodes are located in the first metal layer, so that the first part, the third part and the interdigitated electrodes can be fabricated simultaneously, simplifying the process flow of the filter structure.

[0070] It should be noted that in this embodiment, due to the fabrication requirements of the interdigitated electrodes, the thickness of the first metal layer is several hundred nanometers. However, metal wires with nanometer-thickness have a large sheet resistance, resulting in significant signal loss during signal transmission and degrading the insertion loss performance of the filter. In the filter structure provided in this embodiment, the first signal line includes not only a first portion located in the first metal layer but also a second portion located in the second metal layer. By superimposing the second portion on the first portion, the thickness of the first signal line in the second direction is increased, reducing the impedance of the first signal line and thus reducing its signal transmission loss. Similarly, the second signal line includes not only a third portion located in the first metal layer but also a fourth portion located in the second metal layer. By superimposing the fourth portion on the third portion, the thickness of the second signal line in the second direction is increased, reducing its impedance and thus reducing its signal transmission impedance.

[0071] Optionally, in one embodiment of this application, the thickness of the second metal layer can be at the micrometer level, which is much greater than that of the first metal layer. By designing both the first and second signal lines as structures in which the first and second metal layers are stacked and electrically connected, the signal transmission impedance of the signal lines is reduced, thereby effectively reducing the loss during signal transmission and improving the working performance of the filter.

[0072] Based on any of the above embodiments, in one embodiment of this application, the third signal line includes a fifth portion, which is located in the first metal layer or the second metal layer. When the fifth portion is located in the first metal layer, the third signal line can be directly electrically connected to the filter functional structure disposed in the same layer; when the fifth portion is located in the second metal layer, the third signal line can reduce its impedance by means of the micron-level thickening design of the second metal layer, effectively reducing the loss during signal transmission. It should be noted that regardless of which metal layer the third signal line is located in, it can form an interlayer insulating overlapping structure with the connecting line, retaining the core advantage of short-path interconnection, and the out-of-band rejection performance of the filter will not be affected by the adjustment of the layer position of the third signal line.

[0073] Optionally, in one embodiment of this application, the fifth portion is located in the first metal layer, the connecting line is located in the second metal layer, and the fifth portion and the connecting line are electrically insulated from each other by a first insulating structure. Figure 4 As shown, Figure 4 This is a cross-sectional schematic diagram of the filter structure provided in this embodiment. The fifth portion 401 of the third signal line is located within the first metal layer and is used to transmit signals different from the first and second signal lines. The connecting line 208 is located within the second metal layer, and its two ends are electrically connected to the second portion 303 of the first signal line and the fourth portion 305 of the second signal line, respectively, to achieve short-path interconnection between the first and second signal lines. The first insulating structure 402 is an insulating dielectric layer filled between the fifth portion 401 of the third signal line and the connecting line 208, physically separating the fifth portion 401 from the connecting line 208, blocking the current conduction path between them, and achieving electrical insulation between the fifth portion 401 and the connecting line 208, thus preventing short-circuit faults between the two lines transmitting different signals. In this embodiment, the connecting line does not need to be routed around the side of the third signal line, which can shorten the length of the connecting line, i.e., shorten the interconnection path length between the first and second signal lines, reduce the parasitic inductance introduced by the interconnection path, and effectively improve the out-of-band rejection performance of the filter. Moreover, the connecting lines are located in the second metal layer and can be fabricated simultaneously with the second and fourth parts, thereby effectively improving the out-of-band rejection performance of the filter without increasing the manufacturing process of the filter structure.

[0074] Optionally, in another embodiment of this application, the fifth portion is located in the second metal layer, the connecting line is located in the first metal layer, and the fifth portion and the connecting line are electrically insulated from each other by a first insulating structure. In this embodiment, the two ends of the connecting line are electrically connected to the first portion of the first signal line located in the first metal layer and the third portion of the second signal line located in the first metal layer, respectively, to achieve short-path interconnection between the first signal line and the second signal line, reduce the parasitic inductance introduced by the interconnection path, and effectively improve the out-of-band rejection performance of the filter. The fifth portion of the third signal line and the connecting line have an overlapping area in the second direction. The first insulating structure is an insulating dielectric layer filling the overlapping area. The first insulating structure physically separates the fifth portion and the connecting line, blocking the current conduction path between them, achieving electrical insulation between them, and avoiding short-circuit faults between the two lines transmitting different signals.

[0075] Based on the above embodiments, optionally, in one embodiment of this application, the connecting line is located on the first surface of the substrate. For example... Figure 5 As shown, Figure 5 This is a cross-sectional schematic diagram of the filter structure provided in this embodiment. The fifth portion 401 of the third signal line is located within the second metal layer and is used to transmit signals different from the first and second signal lines. The connecting line 208 is located within the first metal layer, and its two ends are electrically connected to the first portion 302 of the first signal line and the third portion 304 of the second signal line, respectively, to achieve short-path interconnection between the first and second signal lines, reduce parasitic inductance introduced by the interconnection path, and effectively improve the out-of-band rejection performance of the filter. The first insulating structure 402 is an insulating dielectric layer filled between the fifth portion 401 of the third signal line and the connecting line 208, physically separating the fifth portion 401 from the connecting line 208, blocking the current conduction path between them, and achieving electrical insulation between them. In this embodiment, the connecting line is located on the first surface of the substrate and within the first metal layer of the substrate. It can be fabricated simultaneously with the first metal layer, eliminating the need for additional connecting line fabrication. This effectively simplifies the overall fabrication process of the filter chip, reduces the number of process steps, and lowers the chip manufacturing cost.

[0076] Optionally, in another embodiment of this application, the substrate includes a piezoelectric layer and a groove located within the piezoelectric layer, the groove extending from a first surface of the substrate to a portion of the interior of the piezoelectric layer; the connecting line is located on the surface of the groove. Figure 6 As shown, Figure 6This is a cross-sectional schematic diagram of the filter structure provided in this embodiment. The fifth portion 401 of the third signal line is located within the second metal layer and is used to transmit signals different from the first and second signal lines. The groove is located inside the piezoelectric layer of the substrate 201, extending downwards from the first surface of the substrate 201 to a preset depth of the piezoelectric layer, where the preset depth is greater than zero. The connecting line 208 is located on the surface of the groove, and its two ends are electrically connected to the first portion 302 of the first signal line and the third portion 304 of the second signal line, respectively, to achieve interconnection and conduction between the first and second signal lines. In this embodiment, the length of the connecting line is not limited, as long as it can complete the signal connection between the first and second signal lines. In this embodiment, the connecting line is located inside the groove, which effectively saves the planar layout space of the first surface of the substrate and reduces the overall height of the filter. It should be noted that in this embodiment, there is no interdigitated transducer structure in the groove area; that is, in the second direction, there is no overlapping area between the connecting line and the interdigitated transducer, to reduce the impact on the interdigitated transducer when a portion of the piezoelectric layer is removed and the connecting line is inserted.

[0077] Optionally, in one embodiment of this application, the fifth portion is located in the first metal layer, and the third signal line further includes a sixth portion located in the second metal layer. The fifth portion and the sixth portion are stacked and electrically connected to reduce signal transmission loss of the third signal line by using the stacked fifth and sixth portions as the third signal line. In this embodiment, the substrate includes a piezoelectric layer and a groove located within the piezoelectric layer. The groove extends from the first surface of the substrate to a portion of the interior of the piezoelectric layer. The connecting line is located on the surface of the groove, and the fifth portion and the connecting line are electrically insulated from each other by a second insulating structure. Figure 7 As shown, Figure 7 This is a cross-sectional schematic diagram of the filter structure provided in this embodiment; wherein, the fifth portion 401 and the sixth portion 701 of the third signal line are stacked, the groove is located inside the piezoelectric layer of the substrate 201, extending downward from the first surface of the substrate 201 to a preset depth of the piezoelectric layer, the preset depth being greater than zero; the connecting line 208 is located on the surface of the groove, and its two ends are electrically connected to the first portion 302 of the first signal line and the third portion 304 of the second signal line, respectively, to realize the interconnection and conduction of the first signal line and the second signal line; the second insulating structure 702 fills the space between the fifth portion 401 and the connecting line 208, physically separating the two and achieving electrical insulation. It should be noted that in this embodiment, no interdigitated transducer structure is provided in the groove area, that is, in the second direction, there is no overlapping area between the connecting line and the interdigitated transducer, in order to reduce the impact on the interdigitated transducer when a part of the piezoelectric layer is removed and the connecting line is inserted.

[0078] and Figure 6 The difference between the embodiments shown is that, Figure 7The connecting lines are not fabricated simultaneously with the first part of the first signal line and the third part of the second signal line, but are fabricated separately. In this embodiment, the process sequence of the filter structure includes: forming a groove in the piezoelectric layer, forming a connecting line on the surface of the groove, and then forming a first metal layer and a second metal layer on the surface of the substrate.

[0079] Based on any of the above embodiments, in one embodiment of this application, the connecting line 208 is located on the surface of the groove, or the connecting line 208 is located at the bottom of the groove, with its upper surface lower than the first surface of the substrate 201, such as... Figure 8 As shown, the groove can also be filled to be flush with the first surface of the substrate 201, and so on. Figure 7 As shown. This application does not impose any limitations on this; it depends on the specific circumstances.

[0080] Optionally, in one embodiment of this application, when the connecting line 208 is located at the bottom of the groove and its upper surface is lower than the first surface of the substrate 201, the surface of the second insulating structure 702 away from the connecting line 208 is flush with the first surface of the substrate 201, so that the arrangement of the connecting line 208 and the second insulating structure 702 does not increase the height of the filter structure, and makes the surface on which the first metal layer is formed a flat surface, reducing the process difficulty of the first metal layer. However, this application does not limit this, and it depends on the specific situation.

[0081] Optionally, in one embodiment of this application, based on any of the above embodiments, the first filtering unit and the second filtering unit are located in the first metal layer, and a first insulating layer is disposed on the side of the first filtering unit and the second filtering unit away from the substrate. In this embodiment, the first filtering unit and the second filtering unit, as the core functional structures of the filter, are located within the first metal layer; the first insulating layer completely covers the upper surface of the first filtering unit, the second filtering unit, and a portion of the first metal layer, so that when the second metal layer is fabricated, the first insulating layer can be used to provide physical protection for the first filtering unit, the second filtering unit, and other structures, preventing short circuits.

[0082] Optionally, in one embodiment of this application, when the connecting line and the third signal line are insulated by the first insulating structure, the first insulating structure is located in the first insulating layer. That is, when the connecting line and the first part of the first signal line and the third part of the second signal line are fabricated at the same time, the first insulating structure can be formed at the same time when the first insulating layer is fabricated, thereby simplifying the fabrication process of the filter chip, reducing the number of process steps, and reducing the manufacturing cost of the filter.

[0083] In another embodiment of this application, when the connecting line and the third signal line are insulated by the second insulating structure, the second insulating structure is not located in the first insulating layer, that is, the second insulating structure is not formed at the same time as the first insulating layer is made. In this embodiment, the manufacturing process of the filter structure includes: forming a groove in the piezoelectric layer, forming a connecting line on the surface of the groove, forming a second insulating structure in a partial area on the surface of the substrate, then forming a first metal layer, the first part and the third part of the first metal layer are electrically connected to the connecting line, then forming the first insulating layer, and after the first insulating layer is made, forming the second metal layer.

[0084] Optionally, in one embodiment of this application, based on any of the above embodiments, the connecting line does not overlap with any of the interdigitated electrodes in the second direction. As mentioned earlier, the interdigitated electrodes are the core functional components of the surface acoustic wave (SAW) filter. If the connecting line overlaps with the interdigitated electrodes in the second direction, and the connecting line and the interdigitated electrodes are located in the same first metal layer, they will make direct physical contact in the same plane, leading to a short circuit and causing the filter to fail. If the connecting line is located above the interdigitated electrodes and overlaps with them in the second direction, the connecting line will change the dielectric constant distribution and stress distribution of the dielectric layer above the interdigitated electrodes, thereby interfering with the propagation of the acoustic signal and affecting the filter's performance. Therefore, by setting the connecting line to not overlap with any of the interdigitated electrodes in the second direction, this embodiment can minimize the interference of the connecting line's cross-bridge wiring on the filter's core acoustic performance, improving out-of-band suppression while ensuring the filter's acoustic signal transmission performance.

[0085] Based on any of the above embodiments, optionally, in one embodiment of this application, one end of the connecting line is electrically connected to a first position of the first signal line, and the other end is electrically connected to a second position of the second signal line; in a third direction, the first position of the first signal line has a first width, the second position of the second signal line has a second width, the width of the connecting line is not greater than the first width and not greater than the second width, and the third direction is parallel to the substrate and intersects the first direction. In this embodiment, limiting the width of the connecting line to not greater than the first width and not greater than the second width allows the end of the connecting line facing the first signal line to be fully electrically connected to the first signal line, and the end of the connecting line facing the second signal line to be fully electrically connected to the second signal line, thereby avoiding the risk of short circuits inside the filter structure due to exposed areas at both ends of the connecting line.

[0086] Based on the above embodiments, optionally, the width of the connecting line is the smaller value between the first width and the second width, so as to maximize the width of the connecting line, reduce the signal transmission impedance of the connecting line, and reduce signal transmission loss, while avoiding the risk of short circuits inside the filter structure due to exposed areas at both ends of the connecting line. However, this application does not limit this, and it depends on the specific circumstances.

[0087] Optionally, in one embodiment of this application, based on any of the above embodiments, the length of the connecting line is the shortest distance between the first signal line and the second signal line. In this embodiment, regardless of whether the overall routing shape of the first signal line and the second signal line is a straight line, a broken line, a curve, or any other arbitrary shape, the connecting line only connects the two closest connection points between the two signal lines, and the connecting line itself is a straight line segment, i.e., the shortest distance between the two signal lines. Since the parasitic inductance of the connecting line is positively correlated with its length, the shorter the length, the smaller the introduced parasitic inductance. Limiting the length of the connecting line to the shortest distance between the first signal line and the second signal line can reduce the parasitic inductance introduced by the interconnection path between the first signal line and the second signal line to the theoretical minimum value, thereby minimizing the parasitic inductance introduced by the connecting line and improving the out-of-band rejection performance of the filter.

[0088] Based on any of the above embodiments, optionally, in one embodiment of this application, the number of signal line portions overlapping with the connecting line in the second direction is no more than one, and the signals transmitted by the signal line portions overlapping with the connecting line are different from the signals transmitted by the first signal line. Setting the number of signal line portions overlapping with the connecting line to no more than one can minimize signal coupling interference between different signal lines. However, this application does not limit this, and it depends on the specific circumstances.

[0089] Based on any of the above embodiments, optionally, in one embodiment of this application, the first pad is a ground pad, and the third signal line is an input signal line or an output signal line of the filter structure. In this embodiment, the first pad serves as a ground pad, used to provide a ground potential for the filter structure. The first pad is electrically connected to the first signal line and the second signal line. The first signal line and the second signal line together serve as ground signal lines, providing a grounding path for functional structures such as the first filter unit and the second filter unit. The third signal line serves as an input signal line or an output signal line of the filter structure, used to transmit the RF input signal to be filtered, or to transmit the RF output signal processed by the filter. Since the first signal line and the second signal line are ground signal lines, by setting a bridge-type electrical connection between the first signal line and the second signal line, which are physically separated in the first direction by the third signal line, the interconnection conduction path between the first signal line and the second signal line can be shortened, the parasitic inductance introduced by the ground path can be reduced, and the out-of-band rejection capability of the filter can be optimized.

[0090] Based on the above embodiments, in one embodiment of this application, the filter structure further includes a second pad and a third pad. The second pad is electrically connected to the input signal line in the filter structure and is used to provide the filter structure with an input radio frequency signal. The third pad is electrically connected to the output signal line of the filter structure and is used to output the radio frequency signal output by the filter structure.

[0091] Based on any of the above embodiments, optionally, in one embodiment of this application, the first filtering unit in the filter structure can be a parallel resonator, a surface acoustic wave filter, or a series resonator; similarly, the second filtering unit in the filter structure can be a parallel resonator, a surface acoustic wave filter, or a series resonator, as long as the first filtering unit is electrically connected to the first signal line, the second filtering unit is electrically connected to the second signal line, and the first and second signal lines transmit the same signal. It should be noted that in this embodiment, the first filtering unit and the second filtering unit are the core functional components of the filter structure, and their implementation forms can be flexibly selected according to the actual design requirements of the filter. It should also be noted that in this embodiment, the selection of the first filtering unit and the second filtering unit can be independent of each other; that is, they can both use the same type of device or different types of devices to meet different filtering performance requirements, making them applicable to scenarios with different frequency bands and performance requirements.

[0092] It should be noted that in any of the above embodiments, the filter structure may include one first filter unit or at least two first filter units. Similarly, the filter structure may include one second filter unit or at least two second filter units. This application does not limit this, and it depends on the specific circumstances.

[0093] like Figure 9 As shown, in one embodiment of this application, the filter structure includes: a surface acoustic wave (SAW) filter 8051 and a SAW filter 8052 connected in parallel between the input terminal IN and the output terminal OUT; a series resonator 808 between the input terminal IN and the SAW filter; a series resonator 807 between the SAW filter and the output terminal OUT; and a parallel resonator 806 between the output terminal OUT and the ground terminal GND. Optionally, in this embodiment, the first pad is a ground pad, and the first signal line and the second signal line are used to transmit ground signals. In one implementation of this embodiment, the first filtering unit can be either the SAW filter 8051 or the SAW filter 8052, and the second filtering unit can be the parallel resonator 806. In another implementation, the second filtering unit can be either the SAW filter 8051 or the SAW filter 8052, and the first filtering unit can be the parallel resonator 806. In other implementations of this application, the first filtering unit and the second filtering unit can also have other implementations, depending on the specific circumstances.

[0094] The following description uses the B41 band as the pass signal of the filter structure and the third signal line as the input signal line as an example to illustrate the filter structure provided in this application embodiment. Each ground signal line corresponding to the B41 band on the filter chip is connected to the same ground pad, such as the first pad, and the entire circuit is ultimately grounded through this ground pad. It should be noted that the B41 band has high suppression requirements for the 2.4GHz WiFi band. The general standard in this technical field is an suppression value not exceeding -30dB, with some requirements specifying an suppression value not exceeding -35dB or -40dB.

[0095] like Figures 10-11 As shown, Figure 10 and Figure 11 for Figure 9 The diagram shows the layout of the two filter structures corresponding to the equivalent circuit shown. Figure 10 This is a schematic diagram of one layout of the control group 40417_RX die (bare chip) filter structure. Figure 11 This application provides a schematic diagram of the layout of the filter structure including a 40417_RX die (bare chip). Continuing... Figure 10 and Figure 11As shown, the filter structure includes: two dual-mode surface acoustic wave (DMS) filters (8051 and 8052) connected in parallel between the signal input and signal output terminals in the B41 frequency band; a parallel resonator 806 electrically connected between the signal output terminal and the ground terminal; a series resonator 807 connected in series between the surface acoustic wave filter 805 and the parallel resonator 806; and a series resonator 808 connected in series between the signal input terminal and the surface acoustic wave filter 805. The first filtering unit can be either the surface acoustic wave filter 8051 or the surface acoustic wave filter 8052, and the second filtering unit can be the parallel resonator 806. In this embodiment, the first pad 801 is a ground pad; the second pad 802 is an input signal pad, electrically connected to the B41 band input signal line, used to provide the filter structure with the input B41 band radio frequency signal; the third pad 803 is an output signal pad, electrically connected to the B41 band output signal line, used to output the B41 radio frequency signal output by the filter structure; the first signal line 810 and the second signal line 809 transmit the same ground signal, and the third signal line 811 is an output signal line, used to output the B41 band signal output by the filter structure. Figure 10 and Figure 11 The difference is, Figure 10 The first signal line 810 and the second signal line 809 are electrically connected by a winding method, and the connection wire is as follows: Figure 10 The connecting line (dashed line) in the middle is 812. Figure 11 The first and second signal lines are electrically connected using a bridge method, and the connection is as follows: Figure 11 Connector 813 in the middle.

[0096] It should be noted that, continuing as Figure 10 and Figure 11 As shown, the dual-mode surface acoustic wave filter 805 includes multiple grounding locations that need to be grounded. Therefore, the grounding signal line of the first filter unit (i.e., surface acoustic wave filter 805) is wrapped around the first filter unit (i.e., surface acoustic wave filter 805) at multiple locations.

[0097] Optionally, in one embodiment of this application, the filter structure further includes a fourth pad 804, which is connected to pads of other frequency bands (such as the B40 band) in the filter structure. For example, the fourth pad 804 is an input signal pad for the B40 band and is electrically connected to the input signal line of the B40 band to provide the filter structure with an input B40 band radio frequency signal. This application does not limit this, and it depends on the specific circumstances.

[0098] like Figure 12 and Figure 13 As shown, Figure 12 for Figure 10 The diagram shows the isolation test curves of the filter structure in the B41 band from 1.8 GHz to 3.0 GHz. Figure 13 for Figure 10 The diagram shows the isolation test curves of the filter structure in the B41 band from 1.5 GHz to 6.0 GHz. The vertical axis of both graphs represents isolation in dB, and the horizontal axis represents the test frequency in GHz. From Figure 12 It can be seen that, Figure 10 The filter structure shown typically exhibits an isolation value higher than -30dB in the 2.3GHz to 2.5GHz frequency range corresponding to the 2.4GHz WiFi band, failing to meet industry-standard acceptable design criteria. From Figure 13 It can be seen that, Figure 10 The filter structure shown has poor overall isolation performance in the high-frequency range of 2.9 GHz to 6.0 GHz, which cannot meet the requirements of high-performance RF systems.

[0099] This is because Figure 10 The relatively long overall length of the connecting line 812 introduces a significant parasitic grounding inductance, leading to a substantial deterioration in the suppression performance on the left side of the B41 passband. It should be noted that the B41 passband frequency range is 2496MHz to 2690MHz, with the left side referring to the frequency region extending from the 2496MHz low-frequency cutoff point towards even lower frequencies. Furthermore, the long, winding connecting line 812 generates significant parasitic signal coupling with surrounding conductor structures, further exacerbating the decline in out-of-band suppression performance and ultimately resulting in… Figure 10 The filter structure shown cannot meet industry standards and practical application requirements.

[0100] like Figure 14 and Figure 15 As shown, Figure 14 for Figure 10 and Figure 11 The diagram shows a comparison of the isolation test curves of the filter structure in the B41 band from 1.8 GHz to 3.0 GHz. Figure 15 for Figure 10 and Figure 11 The diagram shows a comparison of the isolation test curves of the filter structure in the B41 band from 1.5 GHz to 6.0 GHz. Curve 'a' in both graphs represents... Figure 10 The test results of the filter structure shown are given, with curve b representing... Figure 11 The test results for the filter structure shown are presented. Figure 14 It can be seen that, Figure 11 The filter structure shown has significantly lower isolation in the 2.3GHz to 2.5GHz region corresponding to the 2.4GHz WiFi band than the filter structure shown. Figure 10The filter structure shown achieves an overall performance boost of 5dB~10dB, and can stably reach -30dB and below, meeting the general qualification standards in this technical field. Figure 15 It can be seen that, Figure 11 The filter structure shown exhibits significantly better isolation performance in the high-frequency range of 2.9 GHz to 6.0 GHz than... Figure 10 The filter structure shown can achieve an overall improvement of 5dB~15dB, effectively enhancing the overall suppression performance.

[0101] like Figure 16 As shown, Figure 16 for Figure 11 The filter structure shown is similar to Figure 10 The diagram shows a comparison of insertion loss test curves for the filter structure within the B41 passband. Curve a in the diagram represents... Figure 10 The test results of the filter structure shown are given, with curve b representing... Figure 11 The test results for the filter structure shown are illustrated. The vertical axis represents insertion loss in dB, and the horizontal axis represents the test frequency in GHz. The figure marks the two boundary frequencies of the B41 passband: point m6 corresponds to the 2.496 GHz low-frequency cutoff, and point m7 corresponds to the 2.690 GHz high-frequency cutoff. Figure 16 The data shows that Figure 11 The insertion loss of the filter structure shown in the B41 passband is... Figure 10 The filter structures shown are basically the same, and the insertion loss index does not deteriorate significantly. This indicates that while the out-of-band suppression performance is improved by connecting the first signal line and the second signal line through bridge wiring, the passband transmission performance of the filter is not negatively affected.

[0102] Therefore, the filter structure provided in this application embodiment, which uses a bridge-type connecting line to electrically connect the first signal line and the second signal line, effectively solves the problems of large parasitic inductance and decreased out-of-band rejection performance caused by long-distance winding connecting lines due to the limited number of pads in the 40417_RX die filter. This significantly improves the out-of-band rejection performance of the 2.4GHz WiFi band and high-frequency bands above 2.9GHz, without deteriorating the filter's passband insertion loss. It should be noted that although this application embodiment describes the filter applied to the B41 band as an example, the solution of using a bridge-type connecting line to electrically connect the first signal line and the second signal line provided in this application embodiment is also applicable to the design of other frequency bands within the same chip, and has good mass production application value.

[0103] In addition, this application also provides a radio frequency module, including the filter structure provided in any of the foregoing embodiments.

[0104] In summary, the filter structure and RF module provided in this application utilize an electrically insulated connecting line that overlaps with the third signal line layer to achieve short-path bridging interconnection of the first and second signal lines, which transmit the same signal but are physically separated by the third signal line. This effectively solves the problems of large parasitic interconnection inductance, poor out-of-band rejection performance, and insufficient spacing with surrounding metal structures that affect mass production yield caused by traditional side-wound solutions. At the same time, by using short-path bridging interconnection, the interconnection conduction path between the first and second signal lines is shortened, reducing the parasitic inductance introduced by the interconnection conduction path, thereby effectively improving the out-of-band rejection performance of the filter. It is suitable for the miniaturized and highly integrated design requirements of multi-band integration and can be widely used in various surface acoustic wave filters and RF modules, with high mass production application value.

[0105] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0106] It should be noted that, in the description of this application, the accompanying drawings and embodiments are illustrative rather than restrictive. The same reference numerals throughout the embodiments identify the same structures. It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in an article or device comprising the aforementioned element.

[0107] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A filter structure, characterized in that, include: Base; A first pad, a first signal line, a second signal line, and a third signal line are located on a first surface of the substrate, wherein the first signal line is electrically connected to the first pad, the first signal line and the second signal line transmit the same signal, and the first signal line and the third signal line transmit different signals; At least one filter located on a first side of the substrate, the filter comprising a first filtering unit and a second filtering unit, the first filtering unit being electrically connected to the first signal line and the second filtering unit being electrically connected to the second signal line; The first signal line and the second signal line are arranged along a first direction. In the first direction, the third signal line is at least partially located between the first signal line and the second signal line. The first signal line and the second signal line are electrically connected by a connecting line. In the second direction, the connecting line overlaps with the third signal line and the connecting line is electrically insulated from the third signal line. The first direction is parallel to the first surface of the substrate, and the second direction is perpendicular to the substrate.

2. The filter structure according to claim 1, characterized in that, The first surface of the substrate includes a first metal layer and a second metal layer arranged along the second direction; The first signal line includes a first portion and a second portion stacked together, the first portion being located in the first metal layer and the second portion being located in the second metal layer; The second signal line includes a third portion and a fourth portion stacked together, the third portion being located in the first metal layer and the fourth portion being located in the second metal layer.

3. The filter structure according to claim 2, characterized in that, The third signal line includes a fifth portion, which is located in the first metal layer or in the second metal layer.

4. The filter structure according to claim 3, characterized in that, The fifth part is located in the first metal layer, the connecting line is located in the second metal layer, and the fifth part and the connecting line are electrically insulated from each other by a first insulating structure.

5. The filter structure according to claim 3, characterized in that, The fifth part is located in the second metal layer, the connecting line is located in the first metal layer, and the fifth part and the connecting line are electrically insulated from each other by a first insulation structure.

6. The filter structure according to claim 5, characterized in that, The connecting line is located on the first surface of the substrate.

7. The filter structure according to claim 5, characterized in that, The substrate includes a piezoelectric layer and a groove located within the piezoelectric layer, the groove extending from a first surface of the substrate to a portion of the interior of the piezoelectric layer; the connecting line is located on the surface of the groove.

8. The filter structure according to claim 3, characterized in that, The fifth portion is located in the first metal layer, and the third signal line further includes a sixth portion located in the second metal layer, wherein the fifth portion and the sixth portion are stacked. The substrate includes a piezoelectric layer and a groove located within the piezoelectric layer, the groove extending from a first surface of the substrate to a portion of the interior of the piezoelectric layer; the connecting line is located on the surface of the groove, and the fifth portion and the connecting line are electrically insulated from each other by a second insulating structure.

9. The filter structure according to any one of claims 4-7, characterized in that, The first filtering unit and the second filtering unit are located on the first metal layer, and a first insulating layer is provided on the side of the first filtering unit and the second filtering unit away from the substrate. The first insulating structure is located on the first insulating layer.

10. The filter structure according to any one of claims 1-8, characterized in that, One end of the connecting line is electrically connected to the first position of the first signal line, and the other end is electrically connected to the second position of the second signal line. In the third direction, the first position of the first signal line has a first width, the second position of the second signal line has a second width, the width of the connecting line is not greater than the first width and not greater than the second width, and the third direction is parallel to the substrate and intersects with the first direction.

11. The filter structure according to any one of claims 1-8, characterized in that, The length of the connecting line is the shortest distance between the first signal line and the second signal line.

12. The filter structure according to any one of claims 1-8, characterized in that, In the second direction, the number of signal line portions that overlap with the connecting line is no more than 1, and the signals transmitted by the signal line portions that overlap with the connecting line are different from the signals transmitted by the first signal line.

13. The filter structure according to any one of claims 1-8, characterized in that, The first pad is a ground pad, and the third signal line is an input signal line or an output signal line of the filter structure.

14. A radio frequency module, characterized in that, Includes the filter structure described in any one of claims 1-13.

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