Filter, multiplexer, radio frequency front-end module and electronic equipment

Abstract

The invention relates to a filter, a multiplexer, a radio frequency front-end module and electronic equipment. The filter comprises a substrate, an input terminal and an output terminal, wherein the input terminal and the output terminal are arranged on the substrate; the first series resonance arm and the second series resonance arm are connected in series between the input terminal and the output terminal; each parallel resonance arm is connected between the series resonance arm and the grounding terminal and comprises a first parallel resonance arm, the first parallel resonance arm is connected to the output end of the first series resonance arm, the first parallel resonance arm and the first series resonance arm are arranged in the first direction, and the second parallel resonance arm and the second series resonance arm are arranged in the second direction; the first parallel resonance arm comprises a first resonator and a second resonator which are arranged in parallel, and the first resonator, the second resonator and the second series resonance arm are sequentially arranged in the second direction. According to the filter, the two resonators are arranged in parallel to form the first parallel resonance arm, and the second series resonance arm and the first parallel resonance arm are arranged in the same direction, so that the insertion loss and the size are reduced.

Description

Technical Field

[0001] This application relates to the field of radio frequency, and more particularly to a filter, a multiplexer, a radio frequency front-end module, and an electronic device. Background Technology

[0002] In the field of radio frequency (RF), filters typically achieve signal filtering by interconnecting multiple series resonant arms and multiple parallel resonant arms. To ensure the reliability of the filter, it is usually necessary to balance reducing insertion loss and miniaturization. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this application is to provide a solution that reduces insertion loss and facilitates miniaturization, specifically including the following technical solution: In a first aspect, embodiments of this application provide a filter, including a substrate and a component disposed on the substrate: Input terminals and output terminals; Multiple series resonant arms, including at least a first series resonant arm and a second series resonant arm connected in series between the input terminal and the output terminal; Multiple parallel resonant arms, each parallel resonant arm is connected between the output terminal of a series resonant arm and a ground terminal, and the multiple parallel resonant arms include at least a first parallel resonant arm, which is connected to the output terminal of a first series resonant arm; The first parallel resonant arm and the first series resonant arm are arranged along the first direction. The first parallel resonant arm includes a first resonator and a second resonator arranged in parallel. The first resonator, the second resonator and the second series resonant arm are arranged sequentially along the second direction, and the first direction intersects with the second direction.

[0004] The filter provided in this application achieves its filtering function by connecting multiple series resonant arms in series between the input and output terminals, and connecting a parallel resonant arm in parallel between the output terminal of one series resonant arm and the ground terminal, thereby utilizing the mutual cooperation of the series and parallel resonant arms.

[0005] The filter provided in this application further utilizes a first parallel resonator and a second resonator connected in parallel to form a first parallel resonant arm. This leverages the high quality factor (Q value) inherent in the parallel connection of the first and second resonators. Based on the Q value requirements of the first parallel resonant arm during filter design, the size of the first parallel resonant arm along the second direction is reduced, facilitating the alignment of the second series resonant arm with the first parallel resonant arm. This allows for adjustment of the insertion loss of the filter through the first series resonant arm, thereby reducing the insertion loss and facilitating miniaturization of the filter.

[0006] In one embodiment, the number of electrode fingers of the first resonator is the same as the number of electrode fingers of the second resonator; and / or the finger spacing of the electrode fingers of the first resonator is the same as the finger spacing of the electrode fingers of the second resonator; and / or the aperture of the first resonator is the same as the aperture of the second resonator.

[0007] In one embodiment, the first parallel resonant arm further includes a common reflective grid located between the first resonator and the second resonator along a second direction.

[0008] In one embodiment, the number of fingers of the common reflector is greater than or equal to 12 and less than or equal to 18.

[0009] In one embodiment, the number of electrode fingers of the first resonator is greater than or equal to 70 and less than or equal to 90; and / or the number of electrode fingers of the second resonator is greater than or equal to 70 and less than or equal to 90.

[0010] In one embodiment, the number of electrode fingers of the second series resonant arm is greater than or equal to 70 and less than or equal to 80.

[0011] In one embodiment, the number of electrode fingers of the first series resonant arm is greater than the number of electrode fingers of the second series resonant arm.

[0012] In one embodiment, the aperture of the first parallel resonant arm is greater than or equal to the aperture of the first series resonant arm.

[0013] In one embodiment, the aperture of the second series resonant arm is less than or equal to the aperture of the first parallel resonant arm, and the aperture of the second series resonant arm is greater than the aperture of the first series resonant arm.

[0014] In one embodiment, the input end of the first series resonant arm is connected to the input terminal through a first wire, the output end of the first series resonant arm is close to the first parallel resonant arm along the first direction, the output end of the first series resonant arm is close to the input end of the second series resonant arm, the projection of the output end of the first series resonant arm along the second direction overlaps at most the input end of the second series resonant arm, and the input end of the second series resonant arm is connected to the output end of the first series resonant arm through a second wire.

[0015] In one embodiment, along the second direction, the input terminals are arranged on one side of the first series resonant arm, and the distance between the input terminals and the first series resonant arm is greater than the distance between the input terminals and the second series resonant arm.

[0016] In one embodiment, the plurality of series resonant arms further includes a third series resonant arm connected in series between the second series resonant arm and the output terminal. Along the first direction, the third series resonant arm is arranged on the side of the second series resonant arm away from the first series resonant arm. The input end of the third series resonant arm faces the output end of the second series resonant arm and is connected to the output end of the second series resonant arm through a third wire. The output end of the third series resonant arm is connected to the output terminal through a fourth wire.

[0017] In one embodiment, the width dimensions of the third conductor and the fourth conductor are greater than the width dimensions of the first conductor and the second conductor, respectively.

[0018] In one embodiment, the length of the third series resonant arm along the second direction is greater than the length of the second series resonant arm, and the width of the third conductor is greater than the width of the fourth conductor.

[0019] In one embodiment, along a first direction, the output terminals are arranged on the side of the third series resonant arm away from the first series resonant arm.

[0020] Secondly, embodiments of this application provide a filter, including a substrate and a component disposed on the substrate: Input terminals, output terminals, grounding terminals, and the first support pad; Multiple series resonant arms, including at least a first series resonant arm and a second series resonant arm connected in series between the input terminal and the output terminal; Multiple parallel resonant arms, each parallel resonant arm is connected between the output terminal of a series resonant arm and the ground terminal, and the multiple parallel resonant arms include at least a first parallel resonant arm, which is connected to the output terminal of a first series resonant arm; The input terminal, ground terminal, output terminal, and first support pad are arranged sequentially around the periphery of multiple series resonant arms and multiple parallel resonant arms. In the first direction, the first parallel resonant arm is arranged between the input terminal and the ground terminal, and the second series resonant arm is arranged between the first support pad and the output terminal. In the second direction, the first series resonant arm is arranged between the input terminal and the first support pad.

[0021] The filter provided in this application achieves its filtering function by connecting multiple series resonant arms in series between the input and output terminals, and connecting a parallel resonant arm in parallel between the output terminal of one series resonant arm and the ground terminal, thereby utilizing the mutual cooperation of the series and parallel resonant arms.

[0022] The filter provided in this application also ensures reliable support of the filter by sequentially arranging input terminals, ground terminals, output terminals, and a first support pad around the periphery of each series resonant arm and each parallel resonant arm.

[0023] The first parallel resonant arm is located between the input terminal and the ground terminal, the second series resonant arm is located between the first support pad and the output terminal, and the first series resonant arm is located between the input terminal and the first support pad. This arrangement of the series and parallel resonant arms, utilizing the space between the input terminal, the ground terminal, the output terminal and the first support pad, facilitates the miniaturization of the filter in this application, while ensuring the reliable support of the filter.

[0024] In one embodiment, the second series resonant arm and the first parallel resonant arm are arranged along a second direction, and the aperture of the first parallel resonant arm is larger than the aperture of the second series resonant arm.

[0025] In one embodiment, the plurality of series resonant arms includes a third series resonant arm connected in series between the second series resonant arm and the output terminal, and the plurality of parallel resonant arms includes a second parallel resonant arm connected between the output terminal of the second series resonant arm and the ground terminal. The third series resonant arm and the second parallel resonant arm are arranged along a second direction. Along a first direction, the second parallel resonant arm is arranged between the first parallel resonant arm and the ground terminal, and the third series resonant arm is arranged between the second series resonant arm and the output terminal.

[0026] In one embodiment, the aperture of the second parallel resonant arm is larger than the aperture of the third series resonant arm.

[0027] In one embodiment, the filter further includes a second support pad disposed on the substrate and arranged between the third series resonant arm and the second parallel resonant arm along the second direction.

[0028] In one embodiment, the plurality of parallel resonant arms further includes a third parallel resonant arm, which is connected between the output end of the third series resonant arm and the ground terminal. Along the second direction, the third parallel resonant arm is arranged between the ground terminal and the output terminal.

[0029] Thirdly, embodiments of this application provide a multiplexer, including an antenna, and a transmit filter and a receive filter respectively communicatively connected to the antenna. The receive filter includes a filter, and the input terminal of the filter is used for communicatively connecting to the antenna; or, the transmit filter includes a filter, and the output terminal of the filter is used for communicatively connecting to the antenna.

[0030] Fourthly, embodiments of this application provide a radio frequency front-end module, including a multiplexer.

[0031] Fifthly, embodiments of this application provide an electronic device, including a radio frequency front-end module.

[0032] It is understandable that the multiplexers, RF front-end modules and electronic devices provided in the third, fourth and fifth aspects of this application can also achieve miniaturization and reduction of insertion loss because they adopt the filters provided in the first and second aspects of this application. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application; Figure 2 This is a schematic diagram of the topology of a radio frequency front-end module provided in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of the radio frequency front-end module provided in one embodiment of this application; Figure 4 This is a schematic diagram of the structure of a multiplexer provided in one embodiment of this application; Figure 5 This is a schematic diagram of the filter structure provided in one embodiment of this application; Figure 6 This is a schematic diagram of the filter structure at the grounding terminal in one embodiment of this application; Figure 7 This is a schematic diagram of the filter topology provided in one embodiment of this application; Figure 8 This is a partial structural diagram of the filter provided in one embodiment of this application; Figure 9 This is a schematic diagram of another partial structure of the filter provided in one embodiment of this application; Figure 10 This is a schematic diagram of another partial structure of the filter provided in one embodiment of this application; Figure 11 The comparison shows the insertion loss curves of the filters at different frequencies. Figure 12 The image shows the insertion loss curves of the filter in the embodiment based on different frequencies. Figure 13 This is a schematic diagram of another partial structure of the filter provided in one embodiment of this application; Figure 14 This is another partial structural diagram of the filter provided in one embodiment of this application; Figure 15 This is a schematic diagram of the partial external structure of a filter provided in one embodiment of this application; Figure 16 This is a schematic diagram of another structure of the filter provided in one embodiment of this application; Figure 17 This is a schematic diagram of another partial external structure of the filter provided in one embodiment of this application; Figure 18 This is a schematic diagram of another partial external structure of the filter provided in one embodiment of this application; Figure 19 This is a partial external structural diagram of the filter provided in one embodiment of this application; Figure 20 This is another schematic diagram of the structure of the filter provided in one embodiment of this application; Figure 21 This is another structural schematic diagram of the filter provided in one embodiment of this application at the grounding terminal. Detailed Implementation

[0034] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0035] The following descriptions of the embodiments are based on the accompanying illustrations and are used to illustrate specific embodiments in which this application can be implemented. The component designations used herein, such as "first," "second," etc., are merely for distinguishing the described objects and have no sequential or technical meaning. Unless otherwise specified, the terms "connection" and "linkage" used in this application include both direct and indirect connections (linkages). Directional terms used in this application, such as "up," "down," "front," "back," "left," "right," "inner," "outer," "side," etc., are merely for reference to the accompanying illustrations. Therefore, the use of directional terms is for better and clearer explanation and understanding of this application, and does not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this application.

[0036] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising," "may include," "include," or "may include" used in this application indicate the presence of the corresponding disclosed function, operation, element, etc., and do not limit one or more other functions, operations, elements, etc. Moreover, the terms "comprising" or "include" indicate the presence of the corresponding features, numbers, steps, operations, elements, components, or combinations thereof disclosed in the specification, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, and are intended to cover non-exclusive inclusion.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0038] Please see Figure 1 The diagram shown is a structural schematic of an electronic device 400 provided in one embodiment of this application.

[0039] like Figure 1 As shown, the electronic device 400 of this application includes a circuit board 401 and a radio frequency front-end module 300, with the radio frequency front-end module 300 mounted on the circuit board 401. The circuit board 401 and the radio frequency front-end module 300 are electrically connected.

[0040] In one embodiment, circuit board 401 is a printed circuit board to control the operation of radio frequency front-end module 300. The electronic device 400 of this application receives and / or transmits signals through the radio frequency front-end module 300. Exemplarily, the electronic device 400 includes at least one of a computer, mobile phone, tablet computer, smartwatch, and navigator, etc., and this application does not specifically limit it.

[0041] Please see Figure 2 The diagram shows a topology of the radio frequency front-end module 300 provided in one embodiment of this application.

[0042] like Figure 2As shown, the RF front-end module 300 includes at least a signal terminal 301 and a filter 100. In some cases, the RF front-end module 300 may also include at least one of a switch 302 and an amplifier 303. The signal terminal 301 is used to receive and transmit signals to an external source. Exemplarily, the signal terminal 301 can be used to connect an antenna to receive or transmit signals. The amplifier 303 includes a low-noise amplifier and / or a power amplifier.

[0043] Switch 302 is communicatively connected between signal terminal 301 and filter 100 to control signal transmission between them. Filter 100 outputs a signal with a preset frequency from the signal transmitted to it. Amplifier 303 is electrically connected to filter 100 to amplify the signal processed by filter 100 and output it to subsequent structures, or to transmit the amplified signal to filter 100 for filtering. It is understood that in the RF front-end module 300, there can be one or more filters 100, and multiple filters 100 can constitute a multiplexer 200. This application does not impose any particular limitation on this.

[0044] Please see Figure 3 The diagram shown is a structural schematic of the radio frequency front-end module 300 provided in one embodiment of this application.

[0045] like Figure 3 As shown, the RF front-end module 300 also includes a base plate 304, on which the filter 100 is disposed. In one embodiment, the signal terminal 301, the switch 302, and the amplifier 303 are respectively disposed on the base plate 304. In this embodiment, a metal structure is disposed on the base plate 304, which is used to realize the connection between at least two of the filter 100, the signal terminal 301, the switch 302, and the amplifier 303.

[0046] In one embodiment, such as Figure 3 As shown, the base plate 304 has a plurality of metal bumps 305 protruding from it. The filter 100 includes terminals and pads. Specifically, in Figure 5 and Figure 6 In the illustration, the filter 100 includes input terminals 20, output terminals 30, ground terminals 40, and a first support pad 51 arranged at intervals. Along the thickness direction of the base plate 304, the input terminals 20, output terminals 30, ground terminals 40, and the first support pad 51 are each connected to a metal bump 305. That is, the filter 100 is supported on the base plate 304 via the input terminals 20, output terminals 30, ground terminals 40, and the first support pad 51.

[0047] In one embodiment, the filter 100 further includes a second support pad 52 for connection to a metal bump 305. That is, the second support pad 52 is used to support the filter 100 on the base plate 304 in conjunction with the input terminal 20, the output terminal 30, the ground terminal 40 and the first support pad 51.

[0048] Please see Figure 4 The diagram shown is a structural schematic of the multiplexer 200 provided in one embodiment of this application.

[0049] like Figure 4 As shown, the multiplexer 200 of this application can be a duplexer, a tripplexer, a quadplexer, etc. The multiplexer 200 includes an antenna terminal 201, a transmit filter 202a, and a receive filter 202b. Both the transmit filter 202a and the receive filter 202b include opposing first ports 203 and second ports 204, and the first ports 203 of both the transmit filter 202a and the receive filter 202b are connected to the antenna terminal 201 for communication with the signal terminal 301 on the substrate.

[0050] For the transmitting filter 202a, the first port 203 is used for outputting the signal, and the second port 204 is used for receiving the signal. For the receiving filter 202b, the first port 203 is used for receiving the signal, and the second port 204 is used for outputting the signal.

[0051] In one embodiment, the transmitting filter 202a can be the filter 100 in the present application embodiment. Correspondingly, the first port 203 of the transmitting filter 202a is the output terminal 30 of the filter 100 in the present application, and the second port 204 of the transmitting filter 202a is the input terminal 20 of the filter 100 in the present application.

[0052] In another embodiment, the receiving filter 202b can be the filter 100 in the present application embodiment. Correspondingly, the first port 203 of the receiving filter 202b is the input terminal 20 of the filter 100 in the present application, and the second port 204 of the receiving filter 202b is the output terminal 30 of the filter 100 in the present application.

[0053] Please see Figures 5-7 ,in Figure 5 This is a schematic diagram of the structure of the filter 100 provided in one embodiment of this application. Figure 6 This is a schematic diagram of the filter 100 provided in one embodiment of this application at the grounding terminal 40. Figure 7 This is a schematic diagram of the topology of the filter 100 provided in one embodiment of this application.

[0054] like Figures 5-7As shown, the filter 100 of this application includes a substrate 10, an input terminal 20, an output terminal 30, and a plurality of series resonant arms 60. The input terminal 20, the output terminal 30, and the plurality of series resonant arms 60 are all disposed on the substrate 10. The plurality of series resonant arms 60 are connected in series between the input terminal 20 and the output terminal 30.

[0055] The filter 100 of this application also includes a ground terminal 40 and a plurality of parallel resonant arms 70, each parallel resonant arm 70 being connected between the output terminal of a series resonant arm 60 and the ground terminal 40. The input terminal 20 is used to receive signals, and the output terminal 30 is used to transmit signals. Figure 6 In the series branch shown, each series resonant arm 60 includes an input terminal and an output terminal. The input terminal of each series resonant arm 60 is closer to the input terminal 20 in the series branch than the output terminal of the series resonant arm 60.

[0056] exist Figure 5 In the illustration, the number of series resonant arms 60 is the same as the number of parallel resonant arms 70. The multiple series resonant arms 60 and the multiple parallel resonant arms 70 cooperate to filter the signal input to the input terminal 20, allowing the signal to pass through the passband range formed by the cooperation of each series resonant arm 60 and each parallel resonant arm 70, thereby realizing the filtering and frequency selection function of the filter 100 of this application.

[0057] In this embodiment, the plurality of series resonant arms 60 include at least a first series resonant arm 61 and a second series resonant arm 62, and the plurality of parallel resonant arms 70 include at least a first parallel resonant arm 71. The first series resonant arm 61 and the second series resonant arm 62 are connected in series between the input terminal 20 and the output terminal 30, and the first parallel resonant arm 71 is connected between the output terminal of the first series resonant arm 61 and the ground terminal 40. Specifically, the input terminal of the first series resonant arm 61 is directly connected to the input terminal 20.

[0058] Each series resonant arm 60 and each parallel resonant arm 70 includes at least one interdigital transducer 80. For example, as shown... Figure 8 As shown, the interdigital transducer 80 includes a first busbar 81 and a second busbar 82, which are arranged in parallel and at intervals. The interdigital transducer 80 also includes a plurality of electrode fingers 83, which are arranged in parallel and at intervals between the first busbar 81 and the second busbar 82. The first busbar 81 and the second busbar 82 are used to transmit electrical signals. Some of the electrode fingers 83 are connected to the first busbar 81, and another portion of the electrode fingers 83 are connected to the second busbar 82.

[0059] For ease of description, the electrode finger 83 connected to the first busbar 81 is defined as the first electrode finger 83a, and the electrode finger 83 connected to the second busbar 82 is defined as the second electrode finger 83b.

[0060] Specifically, the first electrode finger 83a and the second electrode finger 83b are alternately arranged along the second direction 002. Both the first electrode finger 83a and the second electrode finger 83b extend along the first direction 001. This ensures that the dimensions of each series resonant arm 60 and parallel resonant arm 70 in the first direction 001 are smaller than their dimensions in the second direction 002, thereby minimizing the arrangement area when arranging the devices. Specifically, as... Figure 8 As shown, along the second direction 002, there is a second electrode finger 83b between any two adjacent first electrode fingers 83a, and there is a first electrode finger 83a between any two adjacent second electrode fingers 83b.

[0061] The first busbar 81 and the second busbar 82 both extend along a second direction 002. The second direction 002 intersects the first direction 001. For example, the second direction 002 and the first direction 001 can be perpendicular to each other, such that each electrode finger 83 has a 90° angle with its connected first busbar 81 or second busbar 82. For example, the second direction 002 and the first direction 001 can also not be perpendicular, such that each electrode finger 83 has an angle greater than 90° with its connected first busbar 81 or second busbar 82.

[0062] In some embodiments, when an external excitation signal is applied to the interdigital transducer 80, the interdigital transducer 80 converts the electrical signal into a surface acoustic wave (SAW). The SAW propagates along the surface of the substrate 10 and is reflected by a reflective grating (not shown in the figure), and is then converted back into an electrical signal by the interdigital transducer 80 for output. In other embodiments, after the interdigital transducer 80 converts the electrical signal into a SAW, the SAW propagates along the surface of the substrate 10 and can be converted back into an electrical signal by other interdigital transducers.

[0063] In the propagation of surface acoustic waves (SAWs), the primary propagation direction is the second direction 002. However, in practice, due to edge effects and acoustic diffraction, the propagation direction of the SAWs formed on the surface of the substrate 10 may also be other directions. In one embodiment, SAWs propagating in other directions are absorbed by a sound-absorbing material (not shown in the figure).

[0064] It is worth mentioning that, Figure 8The illustration shown is an exemplary description of the first series resonant arm 61. In reality, the number and connection method of the interdigital transducers 80 within the first series resonant arm 61 can be other than those shown. The above description is merely an exemplary description based on the interdigital transducer 80. The connection method between the electrode fingers and busbars of each interdigital transducer in other series resonant arms 60 and parallel resonant arms 70 besides the first series resonant arm 61 can be the same as the connection method of the electrode fingers and busbars in the interdigital transducer 80 of this application. This application does not impose any particular limitations in this regard.

[0065] It is worth noting that although the connection method between the electrode fingers and the busbar in any interdigital transducer corresponding to each resonant arm can be the same as the connection method between the electrode fingers and the busbar in the interdigital transducer 80 of this application, the number of interdigital transducers corresponding to each resonant arm, the connection method between the interdigital transducers, and the number and spacing of the electrode fingers in the interdigital transducer can be set separately as needed. This application does not impose any special restrictions on this.

[0066] Please refer to the above. Figure 9 and Figure 10 ,in Figure 9 This is a schematic diagram of another partial structure of the filter 100 provided in one embodiment of this application. Figure 10 This is another partial structural schematic diagram of the filter 100 provided in one embodiment of this application.

[0067] like Figure 9 and Figure 10 As shown, the first parallel resonant arm 71 and the first series resonant arm 61 are arranged along the first direction 001. The first parallel resonant arm 71 includes a first resonator 711 and a second resonator 712 arranged in parallel. The first resonator 711, the second resonator 712 and the second series resonant arm 62 are arranged sequentially along the second direction 002.

[0068] In the design of the filter 100 of this application, the design requirements of each parallel resonant arm 70 take into account the out-of-band rejection effect and insertion loss of the filter 100. The design requirements of each parallel resonant arm 70 are related to its equivalent capacitance and equivalent resistance. For the first parallel resonant arm 71, the first resonator 711 and the second resonator 712 are connected in parallel, such that the equivalent capacitance of the first parallel resonant arm 71 is equal to the sum of the equivalent capacitances of the first resonator 711 and the second resonator 712, while the equivalent resistance of the first parallel resonant arm 71 is less than the sum of the equivalent resistances of the first resonator 711 and the second resonator 712.

[0069] Specifically, the first parallel resonant arm 71 is configured as a first resonator 711 and a second resonator 712. The first resonator 711 has a first capacitor C1 and a first resistor R1, and the second resonator 712 has a second capacitor C2 and a second resistor R2. Numerically, before disassembly, the capacitance C0 of the first parallel resonant arm 71 is C1 + C2, and its resistance is R0. After disassembly and parallel connection of the first resonator 711 and the second resonator 712, the capacitance of the first parallel resonant arm 71 formed by the cooperation of the first resonator 711 and the second resonator 712 is C3 = C1 + C2, and its resistance is R3 = (R1 + C2) / ( ... R2) / (R1+R2). That is, by setting the first parallel resonant arm 71 in the above manner, compared with the first parallel resonant arm in the prior art, the capacitance remains the same while the resistance is reduced. Correspondingly, the Q value of the resonator is increased, and the insertion loss of the filter is reduced.

[0070] That is, the first parallel resonant arm 71 is composed of a first resonator 711 and a second resonator 712 connected in parallel. Under the premise of keeping the equivalent capacitance of the first parallel resonant arm 71 unchanged, the equivalent resistance of the first parallel resonant arm 71 can be reduced, thereby improving the quality factor (Q value) of the first parallel resonant arm 71, which facilitates the reduction of the insertion loss of the filter 100 of this application.

[0071] The design requirements of the first parallel resonant arm 71 in the actual design process of the filter 100 of this application are constant, and the Q value of the first parallel resonant arm 71 is constant. Correspondingly, the Q value of the first parallel resonant arm 71 can be improved by decomposing it into two resonators. After the Q value is improved, the number of resonators required to achieve the same out-of-band suppression is reduced. At this time, the number of electrode fingers of the first parallel resonant arm 71 is reduced, and the space occupied by the first parallel resonant arm 71 along the second direction 002 is reduced, thereby reducing the overall size of the device while ensuring the insertion loss and Q value of the device.

[0072] In this embodiment, along the second direction 002, the first parallel resonant arm 71 and the second series resonant arm 62 are arranged sequentially to fully utilize the space reduced by the parallel connection of the first resonator 711 and the second resonator 712 within the first parallel resonant arm 71. That is, the filter 100 of this application forms the first parallel resonant arm 71 by setting the first resonator 711 and the second resonator 712 in parallel, utilizing the high Q value of the first resonator 711 and the second resonator 712 when connected in parallel, thereby reducing the size of the first parallel resonant arm 71 along the second direction 002 and facilitating the co-arrangement of the second series resonant arm 62 with the first parallel resonant arm 71. In this embodiment, along the second direction 002, the first resonator 711, the second resonator 712, and the second series resonant arm 62 can be arranged in the same column to maximize the utilization of the arrangement space in each area, achieving a reduction in device size while also reducing insertion loss.

[0073] Compared to the prior art where the first and second series resonant arms are arranged in the same column along the second direction, the filter 100 of this application adjusts the dimensional influence of the second series resonant arm 62 on the first series resonant arm 61 along the second direction 002, and removes the limitation on the number of first series resonant arms. In the design process of the filter 100 of this application, under the same layout area or a smaller layout area, the insertion loss of the filter 100 of this application can be further improved by increasing the electrode index of the first series resonant arm 61, thereby reducing the overall insertion loss of the filter 100 of this application.

[0074] On the other hand, compared to the existing technology that adjusts the insertion loss of the filter by adjusting the number of electrode fingers of the first series resonant arm, the first series resonant arm 61 and the second series resonant arm 62 of the filter 100 of this application are spaced apart along the first direction 001. Optionally, the first series resonant arm 61 and the second series resonant arm 62 are respectively arranged in different columns along the first direction 001. When adjusting the number of electrode fingers of the first series resonant arm 61, the size of the first series resonant arm 61 along the second direction 002 will increase. The arrangement scheme of the filter 100 of this application can avoid the impact of increasing the number of electrode fingers of the first series resonant arm 61 on the overall size of the filter 100 while adjusting the insertion loss by adjusting the number of electrode fingers of the first series resonant arm 61, which facilitates the miniaturization of the filter 100 of this application.

[0075] It is worth mentioning that, in Figure 8 and Figure 9In the illustration, the arrangement direction of the first series resonant arm 61 and the first parallel resonant arm 71 is the same as the arrangement direction of the first busbar 81 and the second busbar 82 of the interdigital transducer 80, and both are in the first direction 001. The arrangement direction of the first resonator 711, the second resonator 712, and the second series resonant arm 62 is the same as the arrangement direction of each electrode finger 83 in the interdigital transducer 80, and both are in the second direction 002. Wherein, as... Figure 9 As shown, the first direction 001 is the length direction of the substrate 10, and the second direction 002 is the width direction of the substrate 10. It can be understood that the above arrangement can make full use of the surface space of the substrate 10, improve the surface utilization rate of the substrate 10, and facilitate the miniaturization of the filter 100 of this application.

[0076] In other embodiments, the arrangement direction of the first series resonant arm 61 and the first parallel resonant arm 71 may differ from the arrangement direction of the first busbar 81 and the second busbar 82 of the interdigital transducer 80. The arrangement direction of the first resonator 711, the second resonator 712, and the second series resonant arm 62 may also differ from the arrangement direction of the individual electrode fingers 83 in the interdigital transducer 80. This application does not impose any particular limitation on this.

[0077] In the embodiments of this application, insertion loss can reflect the overall performance and stability of the system. Figure 11 This is a comparison of the insertion loss curves of the filter at different frequencies. Figure 12 This is a graph showing the insertion loss curves of the filter 100 of this application at different frequencies. Figure 11 and Figure 12 The horizontal axis represents frequency in GHz, and the vertical axis represents insertion loss in dB.

[0078] For both the embodiments and comparative examples, the resonator includes a substrate, and an input terminal, an output terminal, a ground terminal, three parallel resonant arms and three series resonant arms disposed on the substrate. The three series resonant arms are connected in series between the input terminal and the output terminal, and each parallel resonant arm is connected to the ground terminal and the output terminal of a series resonant arm.

[0079] In this application, there is one embodiment and one comparative example. In the comparative example, the filter includes a first series resonant arm, a second series resonant arm, and a first parallel resonant arm. The first series resonant arm is connected to the input terminal, the first parallel resonant arm is connected to the output terminal of the first series resonant arm, and the second series resonant arm is connected to the first series resonant arm. The first series resonant arm and the first parallel resonant arm are arranged along a first direction, and the first series resonant arm and the second series resonant arm are arranged along a second direction.

[0080] In this embodiment, the first series resonant arm 61 and the first parallel resonant arm 71 of the filter 100 corresponding to this embodiment are arranged along a first direction 001, and the first parallel resonant arm 71 and the second series resonant arm 62 are arranged along a second direction 002. The first parallel resonant arm 71 is composed of a first resonator 711 and a second resonator 712 connected in parallel, and the first resonator 711, the second resonator 712, and the second series resonant arm 62 are arranged sequentially along the second direction.

[0081] The Q-value requirement for the design of the first parallel resonant arm in the comparative example is the same as the Q-value requirement for the design of the first parallel resonant arm 71 in the embodiment. Except for the parameters of the first and second series resonant arms, all other parameters are identical between the comparative example and the embodiment.

[0082] Figure 11 and Figure 12 The figures show the insertion loss curves of the filters corresponding to the comparative and embodiment examples, respectively. This application can determine the insertion loss of the comparative and embodiment examples by observing the magnitude of the insertion loss within the passband range. The passband range of the comparative and embodiment examples is 758MHz-803MHz.

[0083] like Figure 11 As can be seen, in the comparative example, the passband sideband frequency points are selected as controls. Point m13, with a frequency of 758MHz, has an insertion loss of 1.558dB. Point m14, with a frequency of 803MHz, has an insertion loss of 1.409dB. For example... Figure 12 It can be seen that, in the embodiment, point m2 with a frequency of 758MHz has an insertion loss of 1.453dB, and point m3 with a frequency of 803MHz has an insertion loss of 1.344dB. (Comparison) Figure 11 and Figure 12 It can be seen that, within the passband range, the peak value of the insertion loss in the comparative example is greater than the peak value of the insertion loss in the embodiment.

[0084] That is, the sideband insertion loss and top insertion loss of the passband of the filter 100 in this embodiment are both better than those of the comparative example. This is because the filter 100 of this application forms a first parallel resonant arm 71 by setting a first resonator 711 and a second resonator 712 in parallel, and arranging the second series resonant arm 62 and the first parallel resonant arm 71 along the second direction 002, so that the first series resonant arm 61 has a larger space along the second direction 002, thus removing the limitation on the number of first series resonant arms. This allows the filter 100 of this application to adjust the insertion loss by adjusting the electrode index of the first series resonant arm 61, thereby reducing the insertion loss of the filter 100 of this application and improving the filtering performance of the filter 100 of this application.

[0085] In one embodiment, the number of electrode fingers of the first resonator 711 is the same as the number of electrode fingers of the second resonator 712. Specifically, for the first resonator 711 and the second resonator 712, the number of electrode fingers can affect the equivalent capacitance of the resonator. The fact that the number of electrode fingers of the first resonator 711 is the same as the number of electrode fingers of the second resonator 712 ensures that the equivalent capacitance of the first resonator 711 is the same as that of the second resonator 712, thereby making the impedance characteristics of the first resonator 711 and the second resonator 712 consistent. This guarantees the electromechanical coupling coefficient of the first parallel resonant arm 71 and ensures the filtering reliability of the filter 100 of this application.

[0086] In one embodiment, the finger spacing of the electrode fingers of the first resonator 711 is the same as the finger spacing of the electrode fingers of the second resonator 712. Specifically, in Figure 9 and Figure 10 In the illustration, the finger spacing of the electrodes of the first resonator 711 is a first finger spacing D1, and the finger spacing of the electrodes of the second resonator 712 is a second finger spacing D2. The first finger spacing D1 and the second finger spacing D2 can also affect the equivalent capacitance of the resonator.

[0087] The first finger spacing D1 and the second finger spacing D2 are equal, so that the equivalent capacitance of the first resonator 711 is the same as that of the second resonator 712. This makes the impedance characteristics of the first resonator 711 and the second resonator 712 consistent, which can ensure the electromechanical coupling coefficient of the first parallel resonant arm 71 and ensure the filtering reliability of the filter 100 of this application.

[0088] In one embodiment, the aperture of the first resonator 711 is the same as the aperture of the second resonator 712. Specifically, in Figure 9 and Figure 10 In the illustration, the aperture of the first resonator 711 is the first aperture W1, and the aperture of the second resonator 712 is the second aperture W2. The first aperture W1 and the second aperture W2 can affect the equivalent capacitance of the resonator.

[0089] The first aperture W1 is equal to the second aperture W2, so that the equivalent capacitance of the first resonator 711 is the same as that of the second resonator 712. This makes the impedance characteristics of the first resonator 711 and the second resonator 712 consistent, which can ensure the electromechanical coupling coefficient of the first parallel resonant arm 71 and ensure the filtering reliability of the filter 100 of this application.

[0090] In one embodiment, the first parallel resonant arm 71 further includes a common reflective grating 713, which is located between the first resonator 711 and the second resonator 712 along the second direction 002. Figure 10As shown, a common reflective grating 713 is provided between the first resonator 711 and the second resonator 712. The first resonator 711 and the second resonator 712 share this common reflective grating 713 to reflect the surface acoustic waves generated when the first resonator 711 and the second resonator 712 are working. This reduces the area of ​​the reflective grating between the first resonator 711 and the second resonator 712 while ensuring the filtering performance of the first resonator 711 and the second resonator 712. This reduces the size of the first parallel resonant arm 71 along the second direction 002, facilitating the arrangement of the second series resonant arm 62.

[0091] It is worth noting that when the first parallel resonant arm 71 of the filter 100 of this application includes a common reflective grating 713, the number of electrode fingers, the finger spacing, and the aperture of the first resonator 711 and the second resonator 712 are all equal. That is, when the first parallel resonant arm 71 uses a common reflective grating 713, it is necessary to ensure that the parameters of the first resonator 711 and the second resonator 712 are the same. This ensures that the common reflective grating 713 can reliably reflect the surface acoustic waves when the first resonator 711 and the second resonator 712 are working, thereby ensuring the filtering performance of the first parallel resonant arm 71.

[0092] In one embodiment, the first parallel resonant arm 71 further includes a first reflective grating 714 and a second reflective grating 715. Along the second direction 002, the first reflective grating 714 is arranged on the side of the first resonator 711 away from the common reflective grating 713, and the second reflective grating 715 is arranged on the side of the second resonator 712 away from the common reflective grating 713. The first reflective grating 714 works with the common reflective grating 713 to reflect the surface acoustic waves generated when the first resonator 711 is operating, and the second reflective grating 715 works with the common reflective grating 713 to reflect the surface acoustic waves generated when the second resonator 712 is operating. This ensures the filtering performance of the first parallel resonant arm 71.

[0093] In one embodiment, along the second direction 002, the number of fingers of the common reflective grating 713 is greater than or equal to 12 and less than or equal to 18. Optionally, in this embodiment, the number of fingers of the common reflective grating 713 is set to 15 or 16. On the one hand, this ensures the reflective performance of the common reflective grating 713 and avoids the filtering performance of the first parallel resonant arm 71 being affected by too few fingers of the common reflective grating 713, thereby ensuring the filtering reliability of the filter 100 of this application. On the other hand, it reduces the size of the common reflective grating 713 along the second direction 002, thereby reducing the space occupied by the first parallel resonant arm 71 along the second direction 002, which facilitates the arrangement of the second series resonant arm 62.

[0094] In one embodiment, the number of electrode fingers of the first resonator 711 is greater than or equal to 70 and less than or equal to 90. This ensures the out-of-band rejection effect of the first resonator 711 and avoids increasing the insertion loss of the first resonator 711 due to an insufficient number of electrode fingers, thereby guaranteeing the Q value of the first resonator 711. Furthermore, it ensures the size of the first resonator 711 and avoids increasing the size of the first resonator 711 along the second direction 002 due to an excessive number of electrode fingers, facilitating the miniaturization of the first resonator 711. This, in turn, facilitates the miniaturization of the filter 100 of this application.

[0095] In one embodiment, the number of electrode fingers of the second resonator 712 is greater than or equal to 70 and less than or equal to 90. This ensures the out-of-band rejection effect of the second resonator 712 and avoids increasing its insertion loss due to an insufficient number of electrode fingers, thereby guaranteeing the Q value of the second resonator 712. Furthermore, it ensures the size of the second resonator 712, avoiding an excessive number of electrode fingers that would increase its size along the second direction 002, thus facilitating miniaturization of the second resonator 712. This, in turn, facilitates the miniaturization of the filter 100 of this application.

[0096] In one embodiment, the number of electrode fingers of the second series resonant arm 62 is greater than or equal to 70 and less than or equal to 80. This limits the insertion loss of the second series resonant arm 62, preventing an increase in insertion loss due to an insufficient number of electrode fingers, thereby ensuring the Q value of the second series resonant arm 62. Furthermore, it ensures the size of the second series resonant arm 62, preventing an increase in the size of the second series resonant arm 62 along the second direction 002 due to an excessive number of electrode fingers, thus facilitating miniaturization of the second series resonant arm 62. This, in turn, facilitates the miniaturization of the filter 100 of this application.

[0097] In one embodiment, the number of electrode fingers of the first series resonant arm 61 is greater than the number of electrode fingers of the second series resonant arm 62.

[0098] Please refer to the above. Figure 13 The diagram shown is another partial structural schematic of the filter 100 provided in one embodiment of this application.

[0099] like Figure 13As shown, the number of electrode fingers of the first series resonant arm 61 is greater than the number of electrode fingers of the second series resonant arm 62. On one hand, the filter 100 of this application can make reasonable use of the space along the second direction 002 where the first series resonant arm 61 is located, so that the first series resonant arm 61 has a relatively large number of electrode fingers, thereby reducing the influence of the first series resonant arm 61 on the insertion loss of the filter 100. This reduces the insertion loss of the filter 100 and improves its filtering performance.

[0100] On the other hand, the second series resonant arm 62, which has a relatively small number of electrode fingers, can also make reasonable use of the space on one side of the first parallel resonant arm 71, so as to control the size of the second series resonant arm 62 along the second direction 002 while ensuring the filtering performance of the second series resonant arm 62, which facilitates the miniaturization of the filter 100 of this application.

[0101] In one embodiment, the aperture of the first parallel resonant arm 71 is greater than or equal to the aperture of the first series resonant arm 61. This is because the series resonant arm 60 is in a high-impedance state in the series branch, while the parallel resonant arm 70 is in a low-impedance state in the parallel branch. The first parallel resonant arm 71 with a larger aperture has a larger equivalent capacitance to match the impedance in the parallel branch. Conversely, the first series resonant arm 61 with a smaller aperture has a smaller equivalent capacitance to match the impedance in the series branch.

[0102] That is, by controlling the aperture size of the first parallel resonant arm 71 and the first series resonant arm 61, the impedances in the parallel and series branches of the filter 100 of this application can be matched, thereby improving the impedance matching performance of the filter 100, ensuring the out-of-band rejection effect of the filter 100, and reducing the insertion loss of the filter 100. This improves the filtering reliability of the filter 100.

[0103] In one embodiment, the aperture of the second series resonant arm 62 is less than or equal to the aperture of the first parallel resonant arm 71, and the aperture of the second series resonant arm 62 is greater than the aperture of the first series resonant arm 61. Wherein, as... Figure 13 As shown, the aperture of the second series resonant arm 62 is smaller than the aperture of the first parallel resonant arm 71, so that the size of the second series resonant arm 62 along the first direction 001 is smaller than the size of the first parallel resonant arm 71 along the first direction 001, thereby avoiding the second series resonant arm 62 being too large along the first direction 001 and affecting the arrangement of other series resonant arms 60.

[0104] On the other hand, since the aperture of the first parallel resonant arm 71 is larger than the aperture of the first series resonant arm 61, the filter 100 of this application arranges the second series resonant arm 62 in the same direction as the first parallel resonant arm 71 along the second direction 002, and makes the aperture of the second series resonant arm 62 larger than the aperture of the first series resonant arm 61. This allows for reasonable utilization of the dimensions of the first parallel resonant arm 71 along the first direction 001 and increases the arrangement space of the second series resonant arm 62, thereby controlling the influence of the second series resonant arm 62 on the insertion loss of the filter 100. This achieves the goal of reducing the insertion loss of the filter 100 and improving its filtering performance.

[0105] In one embodiment, the input end of the first series resonant arm 61 is connected to the input terminal 20 through the first wire 91. Along the first direction 001, the output end of the first series resonant arm 61 is close to the first parallel resonant arm 71. The output end of the first series resonant arm 61 is close to the input end of the second series resonant arm 62. The projection of the output end of the first series resonant arm 61 along the second direction 002 overlaps at most with the input end of the second series resonant arm 62. The input end of the second series resonant arm 62 is connected to the output end of the first series resonant arm 61 through the second wire 92.

[0106] For ease of description, the input terminal of the first series resonant arm 61 is defined as the first input terminal 611, the output terminal of the first series resonant arm 61 is defined as the first output terminal 612, the input terminal of the second series resonant arm 62 is defined as the second input terminal 621, and the output terminal of the second series resonant arm 62 is defined as the second output terminal 622.

[0107] Please refer to the above. Figure 14 and Figure 15 ,in Figure 14 This is another partial structural schematic diagram of the filter 100 provided in one embodiment of this application. Figure 15 This is a partial external structural diagram of a filter 100 provided in one embodiment of this application. To facilitate differentiation between the series resonant arms 60, the parallel resonant arms 70, and the wires, cross-sectional lines are used in the illustrations of this embodiment to distinguish the wires between each series resonant arm 60 and each parallel resonant arm 70.

[0108] like Figure 14 and Figure 15As shown, along the first direction 001, the first input terminal 611, the first output terminal 612, and the first parallel resonant arm 71 are arranged in sequence. The first input terminal 611 is close to the input terminal 20, and the input terminal 20 is connected to the first input terminal 611 through the first wire 91. Along the first direction 001, the first input terminal 611, the second input terminal 621, and the second output terminal 622 are arranged in sequence. The second input terminal 621 is close to the first output terminal 612, and the first output terminal 612 is connected to the second input terminal 621 through the second wire 92.

[0109] That is, the first wire 91 is used to achieve conduction between the first series resonant arm 61 and the input terminal 20, and the second wire 92 is used to achieve conduction between the first series resonant arm 61 and the second series resonant arm 62. Both the first wire 91 and the second wire 92 extend along the second direction 002.

[0110] Specifically, the projection of the first output terminal 612 along the second direction 002 partially overlaps with the second input terminal 621. Figure 15 In the illustrated example, along the second direction 002, the first output terminal 612 and the second input terminal 621 are spaced apart. In other embodiments, the projection of the first output terminal 612 along the second direction 002 onto the second series resonant arm 62 coincides only with the second input terminal 621. In this case, the projection of the second wire 92 along the second direction 002 onto the first series resonant arm 61 overlaps only with the first output terminal 612.

[0111] The equivalent main path is defined as the path from input terminal 20 through each series resonant arm 60 to output terminal 30. Specifically, this equivalent main path is described as follows: from input terminal 20, the signal is transmitted via the first wire 91 to the first input terminal 611, then flows along the first direction 001 to the first output terminal 612, then via the second wire 92 to the second input terminal 621, and finally from the second input terminal 621 along the first direction 001 to the second output terminal 622. For example, the equivalent main path is... Figure 16 The thicker line segment with an arrowhead is shown.

[0112] In the equivalent main path of the filter 100 of this application, the arrangement of the first output terminal 612 and the second input terminal 621 along the first direction 001 ensures that the projections of the equivalent main path between the first series resonant arm 61 and the second series resonant arm 62 in the second direction 002 do not overlap. Compared to the prior art scheme that arranges the first series resonant arm and the second series resonant arm along the second direction, the arrangement of the first output terminal 612 and the second input terminal 621 of the filter 100 of this application increases the spacing between the first input terminal 611 and the second input terminal 621, while avoiding electric field coupling phenomena in their equivalent main path, thereby ensuring the filtering performance of the filter 100 of this application. Furthermore, in the first direction 001, the first series resonant arm 61 and the second series resonant arm 62 are respectively arranged in different columns. In their equivalent main path, the input end of the first series resonant arm 61 and the input end of the second series resonant arm 62 are located in different columns and are isolated by the resonator. In this way, the distance between the two is effectively increased, thereby avoiding the problem of severe capacitive coupling between traces in the series main path and ensuring the performance of the filter 100.

[0113] Furthermore, in this embodiment, the projection of the equivalent main path on the second direction 002 does not overlap, and its inductance and resistance values ​​can be further reduced, thereby ensuring the performance of the filter 100.

[0114] On the other hand, the way the equivalent main path of the filter 100 of this application is set also reduces the required wire length in the series main path of the filter 100. This avoids the problem of having to bend the wires in the series main path multiple times when setting the first series resonant arm 61 and the second series resonant arm 62. Multiple bends would cause the bent wires to couple with each other, thus effectively improving the problem of severe capacitive coupling between the corresponding traces in the series main path due to the short distances of different traces caused by multiple bends. It also effectively reduces the insertion loss caused by the wire resistance. Thus, the insertion loss of the filter 100 of this application is reduced and the coupling problem is reduced, thereby improving the performance of the filter 100 of this application.

[0115] In one embodiment, along the second direction 002, the input terminal 20 is arranged on one side of the first series resonant arm 61, and the distance between the input terminal 20 and the first series resonant arm 61 is greater than the distance between the input terminal 20 and the second series resonant arm 62.

[0116] like Figure 14As shown, the input terminal 20 and the first series resonant arm 61 are arranged along the second direction 002. Along the second direction 002, the input terminal 20 is closer to the first series resonant arm 61 than the second series resonant arm 62. This reduces the length of the first conductor 91, decreases the resistance of the series branch of the filter 100, and reduces the insertion loss caused by resistance. This reduces the insertion loss of the filter 100 and improves its performance. Simultaneously, since the first conductor 91 is located closer to the input terminal 20, and the second conductor 92 is located closer to the first support pad 51, and the first conductor 91 and the second conductor 92 are in different columns, the distance between the conductors on the main series path is effectively increased, thereby reducing coupling problems and ensuring filter performance.

[0117] On the other hand, along the second direction 002, the input terminal 20 is closer to the first series resonant arm 61 than the second series resonant arm 62, and the distance between the input terminal 20 and the second input terminal 621 is increased, and the relative distance between the first wire 91 and the second wire 92 is increased, so as to avoid the problem of electric field coupling between the input terminal 20 and the second input terminal 621, as well as between different wires, thereby ensuring the filtering performance of the filter 100 of this application.

[0118] In one embodiment, the plurality of series resonant arms 60 further includes a third series resonant arm 63 connected in series between the second series resonant arm 62 and the output terminal 30. Along the first direction 001, the third series resonant arm 63 is arranged on the side of the second series resonant arm 62 away from the first series resonant arm 61. The input end of the third series resonant arm 63 faces the output end of the second series resonant arm 62 and is connected to the output end of the second series resonant arm 62 through a third wire 93. The output end of the third series resonant arm 63 is connected to the output terminal 30 through a fourth wire 94.

[0119] For ease of description, the input terminal of the third series resonant arm 63 is defined as the third input terminal 631, and the output terminal of the third series resonant arm 63 is defined as the third output terminal 632.

[0120] Please refer to the above. Figure 17 The diagram shows another partial external structure of the filter 100 provided in one embodiment of this application.

[0121] like Figure 17As shown, along the first direction 001, the second input terminal 621, the second output terminal 622, the third input terminal 631, and the third output terminal 632 are arranged sequentially. The third wire 93 is used to connect the second output terminal 622 and the third input terminal 631, and the fourth wire 94 is used to connect the third output terminal 632 and the output terminal 30. The equivalent main path is further described as follows: the signal is transmitted from the second output terminal 622 to the third input terminal 631 via the third wire 93, then from the third input terminal 631 along the first direction 001 to the third output terminal 632, and finally via the fourth wire 94 to the output terminal 30.

[0122] In this design, the second output terminal 622 and the third input terminal 631 are spaced apart along the first direction 001, and the third conductor 93 extends along the first direction 001 so that the projections of the equivalent main paths between the second series resonant arm 62 and the third series resonant arm 63 along the second direction 002 do not overlap. Compared to the prior art scheme where the first and second series resonant arms are arranged along the second direction, the positional relationship between the first and second series resonant arms 61 and 62 of the filter 100 of this application increases the spacing between the third conductor 93 and the second conductor 92, thereby avoiding electric field coupling between the third conductor 93 and the second conductor 92. This improves the filtering reliability of the filter 100 of this application.

[0123] On the other hand, the configuration of the equivalent main path of the filter 100 in this application also reduces the required wire length in the series main path of the filter 100, thereby reducing the insertion loss caused by wire resistance. This reduces the insertion loss of the filter 100 and improves its performance.

[0124] Based on the above embodiments, it can be seen that in this application embodiment, the filter 100 adjusts the parameters of the first resonator 711 and the second resonator 712 of the first parallel resonant arm 71, and changes the arrangement position of the second series resonant arm 62, combined with the corresponding equivalent main path setting method, so as to improve the insertion loss of the filter 100 and the problem of severe wire coupling between the series resonant arms 60 while ensuring the performance of the first parallel resonant arm 71. This improves the filtering performance of the filter 100.

[0125] In one embodiment, the width of the third conductor 93 and the width of the fourth conductor 94 are greater than the width of the first conductor 91 and the width of the second conductor 92, respectively.

[0126] Please refer to the above. Figure 18 and Figure 19 ,in Figure 18This is another partial external structural diagram of the filter 100 provided in one embodiment of this application. Figure 19 This is another partial external structural diagram of a filter 100 provided in one embodiment of this application.

[0127] like Figure 18 and Figure 19 As shown, the width of the first conductor 91 is S1, the width of the second conductor 92 is S2, the width of the third conductor 93 is S3, and the width of the fourth conductor 94 is S4. The third width S3 and the fourth width S4 are both greater than the first width S1 and the second width S2.

[0128] The insertion loss of the filter 100 in this application is also related to the resistance of the wires in the series path. It is understood that setting larger third widths S3 and fourth widths S4 can reduce the resistance of the third wire 93 and the fourth wire 94, thereby reducing the insertion loss of the filter 100 and improving the filtering reliability of the filter 100.

[0129] In one embodiment, the length of the third series resonant arm 63 along the second direction 002 is greater than the length of the second series resonant arm 62, and the width of the third conductor 93 is greater than the width of the fourth conductor 94. The third width S3 is greater than the fourth width S4. This reduces the resistance of the third conductor 93, further reduces the insertion loss of the filter 100, and improves the filtering reliability of the filter 100.

[0130] In one embodiment, along the first direction 001, the output terminal 30 is arranged on the side of the third series resonant arm 63 away from the first series resonant arm 61. That is, along the first direction 001, the second series resonant arm 62, the third series resonant arm 63, and the output terminal 30 are arranged sequentially, so that in the equivalent main path of the filter 100 of this application, the signal can be directly transmitted to the output terminal 30 along the first direction 001 after being transmitted to the second series resonant arm 62. This reduces the length of the equivalent main path, reduces the wire resistance in the series branch of the filter 100 of this application, further reduces the insertion loss of the filter 100 of this application, and improves the filtering reliability of the filter 100 of this application.

[0131] Specifically, in the filter 100 of this application, the equivalent main path between the input terminal 20 and the output terminal 30 extends sequentially first along the second direction 002 to the first series resonant arm 61, then along the second direction 002 to the second series resonant arm 62, and finally along the first direction 001 to the output terminal 30. This reduces the number of bends in the equivalent main path, reduces the length of the equivalent main path, further reduces the insertion loss of the filter 100 of this application, and improves the filtering reliability of the filter 100 of this application.

[0132] On the other hand, the extension direction of the equivalent main path also ensures that there is no overlap between the projections of the equivalent main path along the first direction 001 and the second direction 002, thereby avoiding the phenomenon of electric field coupling in the series branches. This further improves the filtering reliability of the filter 100 of this application.

[0133] Please refer to the above. Figure 20 and Figure 21 ,in Figure 20 This is another structural schematic diagram of the filter 100 provided in one embodiment of this application. Figure 21 This is another schematic diagram of the filter 100 provided in one embodiment of this application at the grounding terminal 40.

[0134] like Figure 20 and Figure 21 As shown, the filter 100 of this application includes a substrate 10, an input terminal 20, an output terminal 30, a ground terminal 40, a first support pad 51, and a plurality of series resonant arms 60. The input terminal 20, output terminal 30, ground terminal 40, first support pad 51, and plurality of series resonant arms 60 are all disposed on the substrate 10. The plurality of series resonant arms 60 are connected in series between the input terminal 20 and the output terminal 30. Specifically, Figure 21 The diagram mainly corresponds to the arrangement of some parallel resonant arms and their corresponding terminals.

[0135] The filter 100 of this application also includes a plurality of parallel resonant arms 70, each parallel resonant arm 70 being connected between the output terminal of a series resonant arm 60 and the ground terminal 40. The input terminal 20 is used for receiving signals, and the output terminal 30 is used for transmitting signals. Figure 20 and Figure 21 In the figure shown, the number of series resonant arms 60 is the same as the number of parallel resonant arms 70. The multiple series resonant arms 60 and the multiple parallel resonant arms 70 cooperate to filter the signal input to the input terminal 20, allowing signals within the passband range formed by the cooperation of each series resonant arm 60 and each parallel resonant arm 70 to pass through, thereby realizing the filtering and frequency selection function of the filter 100 of this application.

[0136] In this embodiment, the plurality of series resonant arms 60 include at least a first series resonant arm 61 and a second series resonant arm 62, and the plurality of parallel resonant arms 70 include at least a first parallel resonant arm 71. The first series resonant arm 61 and the second series resonant arm 62 are connected in series between the input terminal 20 and the output terminal 30, and the first parallel resonant arm 71 is connected between the output terminal of the first series resonant arm 61 and the ground terminal 40. Specifically, the input terminal of the first series resonant arm 61 is directly connected to the input terminal 20.

[0137] exist Figure 20 and Figure 21 In the illustration, input terminal 20, ground terminal 40, output terminal 30, and first support pad 51 are arranged sequentially around the periphery of multiple series resonant arms 60 and multiple parallel resonant arms 70. Based on Figure 3 It is understood that the input terminal 20, output terminal 30, ground terminal 40 and first support pad 51 are disposed on the periphery of each resonant arm, which can ensure the reliable installation of the filter 100 during the installation process of the filter 100 of this application.

[0138] Along the first direction 001, input terminals 20 and ground terminals 40 are arranged at intervals, and output terminals 30 and first support pads 51 are arranged at intervals. Along the second direction 002, input terminals 20 and first support pads 51 are arranged at intervals, and output terminals 30 and ground terminals 40 are arranged at intervals. A first parallel resonant arm 71 is located between input terminals 20 and ground terminals 40, a second series resonant arm 62 is located between the first support pad 51 and output terminals 30, and the first series resonant arm 61 is located between input terminals 20 and the first support pad 51.

[0139] Compared to the existing technology where the first and second series resonant arms are arranged in the same direction along the second direction, the filter 100 of this application adjusts the influence of the second series resonant arm 62 on the spacing between the input terminal 20 and the first support pad 51 along the second direction 002, avoiding an excessively large span between the input terminal 20 and the first support pad 51 that would affect the support strength. This ensures the reliable support of the filter 100 of this application.

[0140] On the other hand, while ensuring reliable support for the filter 100 using the input terminal 20, output terminal 30, ground terminal 40, and first support pad 51, series resonant arms 60 and parallel resonant arms 70 are arranged in the space between the input terminal 20, ground terminal 40, output terminal 30, and first support pad 51. This improves the space utilization of the substrate 10 and facilitates the miniaturization of the filter 100.

[0141] In one embodiment, the second series resonant arm 62 and the first parallel resonant arm 71 are arranged along a second direction 002, and the aperture of the first parallel resonant arm 71 is larger than the aperture of the second series resonant arm 62. Since the series resonant arm 60 is in a high-impedance state in the series branch, while the parallel resonant arm 70 is in a low-impedance state in the parallel branch, the first parallel resonant arm 71 with a larger aperture is provided, resulting in a larger equivalent capacitance to match the impedance in the parallel branch. The second series resonant arm 62 with a smaller aperture is provided, resulting in a smaller equivalent capacitance to match the impedance in the series branch.

[0142] That is, the aperture sizes of the first parallel resonant arm 71 and the second series resonant arm 62 are configured to match the impedances in the parallel and series branches of the filter 100 of this application, thereby improving the impedance matching performance of the filter 100, ensuring the out-of-band rejection effect of the filter 100, and reducing the insertion loss of the filter 100. This improves the filtering reliability of the filter 100.

[0143] On the other hand, the aperture of the second series resonant arm 62 is smaller than the aperture of the first parallel resonant arm 71, so that the size of the second series resonant arm 62 along the first direction 001 is smaller than the size of the first parallel resonant arm 71 along the first direction 001, thereby avoiding the second series resonant arm 62 being too large along the first direction 001 and affecting the arrangement of other series resonant arms 60.

[0144] In one embodiment, the plurality of series resonant arms 60 includes a third series resonant arm 63 connected in series between the second series resonant arm 62 and the output terminal 30, and the plurality of parallel resonant arms 70 includes a second parallel resonant arm 72 connected between the output terminal of the second series resonant arm 62 and the ground terminal 40. The third series resonant arm 63 and the second parallel resonant arm 72 are arranged along a second direction 002. Along a first direction 001, the second parallel resonant arm 72 is arranged between the first parallel resonant arm 71 and the ground terminal 40, and the third series resonant arm 63 is arranged between the second series resonant arm 62 and the output terminal 30.

[0145] exist Figure 20 and Figure 21 In the illustration, the third series resonant arm 63 and the second parallel resonant arm 72 are used to cooperate with the first series resonant arm 61, the second series resonant arm 62, and the first parallel resonant arm 71 to realize the filtering function of the filter 100 of this application. The first parallel resonant arm 71 and the second parallel resonant arm 72 are arranged between the input terminal 20 and the ground terminal 40, while the third series resonant arm 63 and the second series resonant arm 62 are arranged between the first support pad 51 and the output terminal 30, so that the series resonant arms 60 and the parallel resonant arms 70 in the filter 100 are close to each other. This optimizes the routing between the parallel resonant arms 70 and the series resonant arms 60, avoids coupling between the traces, and facilitates the manufacturing and installation of the filter 100.

[0146] On the other hand, the second parallel resonant arm 72 is located between the input terminal 20 and the ground terminal 40, and the third series resonant arm 63 is located between the first support pad 51 and the output terminal 30. The gap between the input terminal 20 and the ground terminal 40 and the gap between the first support pad 51 and the output terminal 30 can also be used to improve the space utilization of the substrate 10, which is conducive to the miniaturization of the filter 100 of this application.

[0147] In one embodiment, the aperture of the second parallel resonant arm 72 is larger than the aperture of the third series resonant arm 63. This is to match the impedance in the parallel and series branches of the filter 100, thereby improving the impedance matching performance of the filter 100, ensuring the out-of-band rejection effect of the filter 100, and reducing the insertion loss of the filter 100. This improves the filtering reliability of the filter 100.

[0148] On the other hand, the aperture of the third series resonant arm 63 is smaller than the aperture of the second parallel resonant arm 72, so that the size of the third series resonant arm 63 along the first direction 001 is smaller than the size of the second parallel resonant arm 72 along the first direction 001, thereby avoiding the third series resonant arm 63 being too large along the first direction 001 and affecting the arrangement of other series resonant arms 60.

[0149] In one embodiment, the filter 100 further includes a second support pad 52 disposed on the substrate 10. Specifically, the second support pad 52, the third series resonant arm 63, and the second parallel resonant arm 72 may be arranged in the same column, along the second direction 002, with the second support pad 52 arranged between the third series resonant arm 63 and the second parallel resonant arm 72. Figure 20 and Figure 21 In the illustration, the second support pad 52 is used to support the central region of the substrate 10, in order to cooperate with the input terminal 20, output terminal 30, ground terminal 40 and the first support pad 51 to enhance the support strength of the filter 100 of this application.

[0150] On the other hand, based on the design requirements of the filter 100 of this application, the setting of the second support pad 52 can ensure the pad ratio requirement of the filter 100 of this application, thereby reducing the size of the input terminal 20, output terminal 30, ground terminal 40 and first support pad 51 while ensuring the functions of the input terminal 20, output terminal 30, ground terminal 40 and first support pad 51, which facilitates the arrangement of each series resonant arm 60 and each parallel resonant arm 70.

[0151] Specifically, reducing the size of the input terminal 20, output terminal 30, ground terminal 40, and first support pad 51 increases the spacing between the input terminal 20 and the first support pad 51, facilitating the adjustment of the insertion loss of the filter 100 by adjusting the electrode index of the first series resonant arm 61. It also increases the spacing between the input terminal 20 and the ground terminal 40, and between the first support pad 51 and the output terminal 30, allowing the filter 100 to adjust its insertion loss and out-of-band rejection by adjusting the aperture sizes of the corresponding series resonant arm 60 and parallel resonant arm 70. This improves the filtering performance of the filter 100.

[0152] It is worth noting that although the arrangement of the second support pad 52 can improve the spacing between the input terminal 20, the output terminal 30, the ground terminal 40 and the first support pad 51, it is also necessary to ensure that the spacing between the input terminal 20 and the first support pad 51, the spacing between the input terminal 20 and the ground terminal 40, the spacing between the ground terminal 40 and the output terminal 30, and the spacing between the first support pad 51 and the output terminal 30 meet the packaging requirements of the filter 100 of this application.

[0153] In one embodiment, the plurality of parallel resonant arms 70 further includes a third parallel resonant arm 73, which is connected between the output terminal of the third series resonant arm 63 and the ground terminal 40. Along the second direction 002, the third parallel resonant arm 73 is arranged between the ground terminal 40 and the output terminal 30. The third parallel resonant arm 73 is used to cooperate with the first series resonant arm 61, the second series resonant arm 62, the third series resonant arm 63, the first parallel resonant arm 71, and the second parallel resonant arm 72 to realize the filtering function of the filter 100 of this application.

[0154] Along the second direction 002, the third parallel resonant arm 73 is located between the output terminal 30 and the ground terminal 40, so as to utilize the gap between the output terminal 30 and the ground terminal 40 to arrange the third parallel resonant arm 73, thereby improving the space utilization of the substrate 10 and facilitating the miniaturization of the filter 100 of this application.

[0155] It should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0156] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0157] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art will understand that implementing all or part of the processes of the above embodiments, and making equivalent changes according to the claims of this invention, still falls within the scope of this invention.

Claims

1. A filter, characterized in that, Includes a substrate, and a component disposed on the substrate: Input terminals and output terminals; Multiple series resonant arms, including at least a first series resonant arm and a second series resonant arm connected in series between the input terminal and the output terminal; Multiple parallel resonant arms, each of the parallel resonant arms being connected between the output terminal of a series resonant arm and a ground terminal, the multiple parallel resonant arms including at least a first parallel resonant arm, the first parallel resonant arm being connected to the output terminal of the first series resonant arm; The first parallel resonant arm and the first series resonant arm are arranged along a first direction. The first parallel resonant arm includes a first resonator and a second resonator arranged in parallel. The first resonator, the second resonator and the second series resonant arm are arranged sequentially along a second direction. The first direction intersects with the second direction.

2. The filter according to claim 1, characterized in that, The number of electrode fingers of the first resonator is the same as the number of electrode fingers of the second resonator; and / or the finger spacing of the electrode fingers of the first resonator is the same as the finger spacing of the electrode fingers of the second resonator; And / or the aperture of the first resonator is the same as the aperture of the second resonator.

3. The filter according to claim 1, characterized in that, The first parallel resonant arm also includes a common reflective grid, which is located between the first resonator and the second resonator along the second direction.

4. The filter according to claim 3, characterized in that, The number of fingers of the common reflective grating is greater than or equal to 12 and less than or equal to 18.

5. The filter according to any one of claims 1-4, characterized in that, The number of electrode fingers of the first resonator is greater than or equal to 70 and less than or equal to 90; and / or the number of electrode fingers of the second resonator is greater than or equal to 70 and less than or equal to 90.

6. The filter according to any one of claims 1-5, characterized in that, The number of electrode fingers of the second series resonant arm is greater than or equal to 70 and less than or equal to 80.

7. The filter according to any one of claims 1-6, characterized in that, The number of electrode fingers in the first series resonant arm is greater than the number of electrode fingers in the second series resonant arm.

8. The filter according to any one of claims 1-7, characterized in that, The aperture of the first parallel resonant arm is greater than or equal to the aperture of the first series resonant arm.

9. The filter according to any one of claims 1-8, characterized in that, The aperture of the second series resonant arm is less than or equal to the aperture of the first parallel resonant arm, and the aperture of the second series resonant arm is greater than the aperture of the first series resonant arm.

10. The filter according to any one of claims 1-9, characterized in that, The input end of the first series resonant arm is connected to the input terminal through a first wire. Along the first direction, the output end of the first series resonant arm is close to the first parallel resonant arm. The output end of the first series resonant arm is close to the input end of the second series resonant arm. The projection of the output end of the first series resonant arm along the second direction overlaps with the input end of the second series resonant arm. The input end of the second series resonant arm is connected to the output end of the first series resonant arm through a second wire.

11. The filter according to claim 10, characterized in that, Along the second direction, the input terminals are arranged on one side of the first series resonant arm, and the distance between the input terminals and the first series resonant arm is greater than the distance between the input terminals and the second series resonant arm.

12. The filter according to claim 10, characterized in that, The plurality of series resonant arms also includes a third series resonant arm connected in series between the second series resonant arm and the output terminal. Along the first direction, the third series resonant arm is arranged on the side of the second series resonant arm away from the first series resonant arm. The input end of the third series resonant arm faces the output end of the second series resonant arm and is connected to the output end of the second series resonant arm through a third wire. The output end of the third series resonant arm is connected to the output terminal through a fourth wire.

13. The filter according to claim 12, characterized in that, The width of the third conductor and the width of the fourth conductor are respectively greater than the width of the first conductor and the width of the second conductor.

14. The filter according to claim 12, characterized in that, The length of the third series resonant arm along the second direction is greater than the length of the second series resonant arm, and the width of the third conductor is greater than the width of the fourth conductor.

15. The filter according to claim 12, characterized in that, Along the first direction, the output terminals are arranged on the side of the third series resonant arm away from the first series resonant arm.

16. A filter, characterized in that, Includes a substrate, and a component disposed on the substrate: Input terminals, output terminals, grounding terminals, and the first support pad; Multiple series resonant arms, including at least a first series resonant arm and a second series resonant arm connected in series between the input terminal and the output terminal; Multiple parallel resonant arms, each of the parallel resonant arms being connected between the output terminal of one of the series resonant arms and the ground terminal, the multiple parallel resonant arms including at least a first parallel resonant arm, the first parallel resonant arm being connected to the output terminal of the first series resonant arm; The input terminal, the ground terminal, the output terminal, and the first support pad are arranged sequentially around the periphery of the plurality of series resonant arms and the plurality of parallel resonant arms. Along a first direction, the first parallel resonant arm is arranged between the input terminal and the ground terminal, and the second series resonant arm is arranged between the first support pad and the output terminal. Along a second direction, the first series resonant arm is arranged between the input terminal and the first support pad.

17. The filter according to claim 16, characterized in that, The second series resonant arm and the first parallel resonant arm are arranged along the second direction, and the aperture of the first parallel resonant arm is larger than the aperture of the second series resonant arm.

18. The filter according to claim 16, characterized in that, The plurality of series resonant arms includes a third series resonant arm connected in series between the second series resonant arm and the output terminal. The plurality of parallel resonant arms includes a second parallel resonant arm connected between the output terminal of the second series resonant arm and the ground terminal. The third series resonant arm and the second parallel resonant arm are arranged along the second direction. Along the first direction, the second parallel resonant arm is arranged between the first parallel resonant arm and the ground terminal, and the third series resonant arm is arranged between the second series resonant arm and the output terminal.

19. The filter according to claim 18, characterized in that, The aperture of the second parallel resonant arm is larger than the aperture of the third series resonant arm.

20. The filter according to claim 18, characterized in that, The filter further includes a second support pad, which is disposed on the substrate and arranged between the third series resonant arm and the second parallel resonant arm along the second direction.

21. The filter according to claim 18, characterized in that, The plurality of parallel resonant arms also includes a third parallel resonant arm, which is connected between the output end of the third series resonant arm and the ground terminal. Along the second direction, the third parallel resonant arm is arranged between the ground terminal and the output terminal.

22. A multiplexer, characterized in that, The device includes an antenna, and a transmit filter and a receive filter respectively communicatively connected to the antenna, wherein the receive filter includes a filter as described in any one of claims 1-21, and the input terminal of the filter is used for communicatively connecting to the antenna; or, the transmit filter includes a filter as described in any one of claims 1-21, and the output terminal of the filter is used for communicatively connecting to the antenna.

23. A radio frequency front-end module, characterized in that, Includes the multiplexer as described in claim 22.

24. An electronic device, characterized in that, Includes the radio frequency front-end module as described in claim 23.

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