High-frequency ultra-wideband band-pass filter and high-frequency ultra-wideband filtering system

Abstract

The utility model belongs to the technical field of filters, and particularly relates to a high-frequency ultra-wideband band-pass filter, which comprises an input matching module, an LC electrical module, an acoustic resonance module and an output matching module. The input matching module receives a signal after being successfully matched with the input end, so that the signal is processed by the LC electrical module and the acoustic resonance module until reaching the output matching module, and then the signal is output; according to the utility model, an IPD semiconductor integrated passive device is adopted in the LC electrical module, and an FBAR film bulk acoustic resonator is adopted in the acoustic resonance module, so that the problems that a single IPD filter is poor in roll-off performance and a single FBAR filter cannot realize ultra-wideband design indexes can be solved, and the LC electrical module is matched with the acoustic resonance module; the roll-off coefficient and out-of-band rejection can be improved, meanwhile, out-of-band signals are better suppressed, and the requirements of ultra wide band, high frequency, high rejection and fast roll-off performance are met.

Description

Technical Field

[0001] The utility model belongs to the technical field of filters, and particularly relates to a high-frequency ultra-wideband band-pass filter and a high-frequency ultra-wideband filtering system. Background Art

[0002] With the continuous evolution of mobile communication technologies such as 5G and 6G, the communication system has higher and higher requirements for the utilization rate of spectrum resources. Filters with large bandwidth and high rectangularity coefficient can effectively reduce out-of-band interference and improve the signal-to-noise ratio in the band, thereby improving communication quality. There are various types of broadband filters, including IPD filters, cavity filters, thin-film bulk acoustic wave filters (FBAR filters), and dielectric filters. Cavity filters have excellent filtering performance, but some types are large in volume and high in cost; dielectric filters have a high Q value, but the parasitics are close and need to be customized. IPD filters achieve their functions by integrating passive devices, but due to the characteristics of these passive devices, their roll-off performance is not good, that is, the attenuation rate of the filter at the edge of the passband is slow, and it is difficult to effectively isolate low-frequency signals. The FBAR filter uses a thin-film bulk acoustic wave resonator as the core component and can provide relatively better filtering performance. However, when achieving the design index of broadband (such as 2 GHz), it faces great challenges, especially in the precise control of bandwidth and resonance frequency.

[0003] Attempting to directly combine IPD filters and FBAR filters, although in theory it can make up for their respective deficiencies, in actual operation, this combination will bring a series of new problems. First, due to the differences in the manufacturing processes and material costs of the two types of filters, directly combining them will significantly increase the overall cost of the system. Second, it is difficult to fully match the parameters of IPD filters and FBAR filters. Even through precise tuning, it is very difficult to maintain a consistent filtering effect throughout the frequency range. This parameter mismatch may cause irregular responses in the passband or stopband of the filter, thereby affecting the performance of the system and making it difficult to meet the designed filtering index.

[0004] Therefore, there is an urgent need to develop a new high-frequency ultra-wideband band-pass filter and a high-frequency ultra-wideband filtering system to solve the technical problems that the single IPD filter has poor roll-off performance and the single FBAR filter cannot achieve the design index.

[0005] It should be noted that the above information disclosed in this background art section is only used to understand the background art of the concept of this application. Therefore, the above description is not considered to constitute information on the prior art. Summary of the Utility Model

[0006] The embodiments of the present disclosure at least provide a high-frequency ultra-wideband band-pass filter and a high-frequency ultra-wideband filtering system.

[0007] In the disclosed example, the FBAR filter and the IPD element are integrated on the same chip in a certain layout. The hybrid design technology route of IPD and FBAR filter combines the advantages of both, achieving miniaturization, high performance, and high selectivity of the filter. This technology route deeply explores aspects such as material selection, process integration, structure design, and performance optimization, aiming to improve the overall performance of the filter.

[0008] In a first aspect, an embodiment of the present disclosure provides a high-frequency ultra-wideband bandpass filter, which includes: an input matching module, an LC electrical module, an acoustic resonance module, and an output matching module; wherein the input matching module, the LC electrical module, and the output matching module are connected in sequence, the acoustic resonance module is connected in parallel with the LC electrical module, and the input matching module is connected to the input terminal, and the output matching module is connected to the output terminal; after the input matching module successfully matches with the input terminal, it receives a signal, so that the signal is processed by the LC electrical module and the acoustic resonance module until the output matching module outputs the signal after successfully matching with the output terminal.

[0009] In an optional implementation manner, the input matching module includes: a first inductor and a first connection capacitor; two ends of the first inductor are respectively connected to the input terminal and the LC electrical module, one end of the first connection capacitor is connected between the first inductor and the input terminal, and the other end of the first connection capacitor is grounded.

[0010] In an optional implementation manner, the LC electrical module includes: at least one high-pass filter circuit; each of the high-pass filter circuits is connected in series in sequence, and the first high-pass filter circuit is connected to the input matching module, and the last high-pass filter circuit is connected to the output matching module.

[0011] In an optional implementation manner, a first high-pass filter circuit and a second high-pass filter circuit are provided, that is, the first high-pass filter circuit is connected in series with the second high-pass filter circuit, the first high-pass filter circuit is connected to the input matching module, and the second high-pass filter circuit is connected to the output matching module.

[0012] In an optional implementation manner, the first high-pass filter circuit includes: a first capacitor, a second capacitor, a third capacitor, and a second inductor; the first capacitor and the third capacitor are connected in series in sequence, one end of the second capacitor is connected between the first capacitor and the third capacitor, and the other end of the second capacitor is connected in series with the second inductor and then grounded; the second high-pass filter circuit includes: a fourth capacitor, a fifth capacitor, a sixth capacitor, and a third inductor; the fourth capacitor and the sixth capacitor are connected in series in sequence, one end of the fifth capacitor is connected between the fourth capacitor and the sixth capacitor, and the other end of the fifth capacitor is connected in series with the third inductor and then grounded.

[0013] In an alternative embodiment, the acoustic resonance module includes: at least one acoustic wave resonance circuit; each of the acoustic wave resonance circuits is connected in parallel with a corresponding high-pass filter circuit.

[0014] In an alternative embodiment, the acoustic wave resonance circuit includes: at least one thin film bulk acoustic resonator; each of the thin film bulk acoustic resonators is arranged in series or in parallel or in a combination of series and parallel.

[0015] In an alternative embodiment, three acoustic wave resonance circuits are provided; the three acoustic wave resonance circuits are respectively connected in parallel between the input matching module and the first high-pass filter circuit, between the first high-pass filter circuit and the second high-pass filter circuit, and between the second high-pass filter circuit and the output matching module, and each of the acoustic wave resonance circuits is grounded.

[0016] In an alternative embodiment, the output matching module includes: a fourth inductor and a second connection capacitor; two ends of the fourth inductor are respectively connected to the output terminal and the LC electrical module, one end of the second connection capacitor is connected between the fourth inductor and the output terminal, and the other end of the second connection capacitor is grounded.

[0017] In a second aspect, an embodiment of the present disclosure further provides a high-frequency ultra-wideband filtering system, which includes: the band-pass filter, a substrate and a plastic package shell as described above; wherein the plastic package shell is mounted on the substrate, and the band-pass filter is encapsulated in the plastic package shell and the substrate.

[0018] The beneficial effect of the present utility model is that by adopting integrated passive devices in the LC electrical module and thin film bulk acoustic resonators in the acoustic resonance module, the present utility model can solve the problems of poor roll-off performance of a single IPD filter and the inability of a single FBAR filter to achieve ultra-wideband design indicators. By matching the LC electrical module with the acoustic resonance module, the roll-off coefficient and out-of-band rejection can be improved, and at the same time, signals outside the band can be better suppressed, meeting the requirements of ultra-wideband, high frequency, high rejection, and fast roll-off performance.

[0019] Other features and advantages of the present utility model will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present utility model. The objectives and other advantages of the present utility model are achieved and obtained by the structures specifically pointed out in the specification, the claims, and the drawings.

[0020] To make the above objectives, features, and advantages of the present utility model more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic block diagram of a high-frequency ultra-wideband bandpass filter provided by an embodiment of the present disclosure;

[0023] Figure 2 It is a circuit diagram of a high-frequency ultra-wideband bandpass filter provided by an embodiment of the present disclosure;

[0024] Figure 3 It is a structural diagram of a high-frequency ultra-wideband bandpass filter provided by an embodiment of the present disclosure;

[0025] Figure 4 It is a component distribution diagram of a high-frequency ultra-wideband bandpass filter provided by an embodiment of the present disclosure;

[0026] Figure 5 It is a simulation diagram of a high-frequency ultra-wideband bandpass filter provided by an embodiment of the present disclosure.

[0027] In the figure:

[0028] 1. Input matching module; 2. LC electrical module; 3. Acoustic resonance module; 4. Output matching module; 5. Substrate; 6. Plastic package housing; 601. First installation cavity; 602. Second installation cavity; 7. Electrical unit; 8. Acoustic unit;

[0029] IN, Input terminal; OUT, Output terminal;

[0030] L1, First inductor; L2, Second inductor; L3, Third inductor; L4, Fourth inductor; CP1, First connection capacitor; CP2, Second connection capacitor; C1, First capacitor; C2, Second capacitor; C3, Third capacitor; C4, Fourth capacitor; C5, Fifth capacitor; C6, Sixth capacitor; F1, First thin film bulk acoustic resonator; F2, Second thin film bulk acoustic resonator; F3, Third thin film bulk acoustic resonator. Specific embodiments

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0032] The terms used herein are only for describing specific exemplary configurations and are not intended to be limiting. As used herein, the singular articles "a", "an", and "the" may also be intended to include the plural forms, unless clearly stated otherwise herein. The terms "comprising", "including", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or their combinations. The method steps, processes, and operations described herein should not be construed as necessarily requiring them to be performed in the particular order discussed or shown, unless specifically identified as an order of performance. Additional or alternative steps may be employed.

[0033] As used herein, phrases such as "in one embodiment", "according to one embodiment", "in some embodiments", etc. generally refer to the fact that the specific feature, structure, or characteristic after the phrase may be included in at least one embodiment of the present disclosure. Thus, a specific feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example", "exemplary", etc. are used "as an example, instance, or illustration. Any embodiment, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other embodiments, aspects, or designs. Instead, the use of the terms "example", "exemplary", etc. is intended to present concepts in a specific manner.

[0034] IPD refers to Integrated passive devices, specifically integrated passive components; FBAR refers to Film Bulk Acoustic Resonator, specifically thin-film bulk acoustic resonators.

[0035] The following will describe in detail some embodiments of the present utility model with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments may be combined with each other.

[0036] As Figures 1 to 5As shown in the figure, an embodiment of the present disclosure provides a band-pass filter for high-frequency ultra-wideband, which includes: an input matching module 1, an LC electrical module 2, an acoustic resonance module 3, and an output matching module 4; wherein the input matching module 1, the LC electrical module 2, and the output matching module 4 are connected in sequence, the acoustic resonance module 3 is connected in parallel with the LC electrical module 2, the input matching module 1 is connected to the input terminal IN, and the output matching module 4 is connected to the output terminal OUT; after the input matching module 1 successfully matches with the input terminal IN, it receives a signal, so that the signal is processed by the LC electrical module 2 and the acoustic resonance module 3 until the output matching module 4 outputs a signal after successfully matching with the output terminal OUT.

[0037] Specifically, by adopting integrated passive devices in the LC electrical module 2 and thin-film bulk acoustic resonators in the acoustic resonance module 3, the problems of poor roll-off performance of a single IPD filter and the inability of a single FBAR filter to achieve ultra-wideband design specifications can be solved. Matching the LC electrical module 2 with the acoustic resonance module 3 can improve the roll-off coefficient and out-of-band rejection, while better suppressing out-of-band signals and meeting the requirements of ultra-wideband, high-frequency, high rejection, and fast roll-off performance.

[0038] In at least one embodiment, please refer to Figure 2 , the input matching module 1 includes: a first inductor L1 and a first connection capacitor CP1; both ends of the first inductor L1 are respectively connected to the input terminal IN and the LC electrical module 2, one end of the first connection capacitor CP1 is connected between the first inductor L1 and the input terminal IN, and the other end of the first connection capacitor CP1 is grounded.

[0039] Specifically, setting the first inductor L1 and the first connection capacitor CP1 at the input terminal IN plays the role of input matching.

[0040] In at least one embodiment, the LC electrical module 2 includes: at least one high-pass filter circuit; each of the high-pass filter circuits is connected in series in sequence, and the first high-pass filter circuit is connected to the input matching module 1, and the last high-pass filter circuit is connected to the output matching module 4.

[0041] Specifically, the high-pass filter circuit adopts integrated passive devices, which have advantages such as a wide bandwidth, high integration, small size, and low cost.

[0042] In at least one embodiment, please refer to Figure 2 , a first high-pass filter circuit and a second high-pass filter circuit are provided, that is, the first high-pass filter circuit is connected in series with the second high-pass filter circuit, the first high-pass filter circuit is connected to the input matching module 1, and the second high-pass filter circuit is connected to the output matching module 4.

[0043] Specifically, on the basis of setting the first high-pass filter circuit and the second high-pass filter circuit, the number of high-pass filter circuits can also be increased to meet the design requirements.

[0044] In at least one embodiment, refer to Figure 2 , the first high-pass filter circuit includes: a first capacitor C1, a second capacitor C2, a third capacitor C3, and a second inductor L2; the first capacitor C1 and the third capacitor C3 are connected in series in sequence, one end of the second capacitor C2 is connected between the first capacitor C1 and the third capacitor C3, and the other end of the second capacitor C2 is connected in series with the second inductor L2 and then grounded; the second high-pass filter circuit includes: a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a third inductor L3; the fourth capacitor C4 and the sixth capacitor C6 are connected in series in sequence, one end of the fifth capacitor C5 is connected between the fourth capacitor C4 and the sixth capacitor C6, and the other end of the fifth capacitor C5 is connected in series with the third inductor L3 and then grounded.

[0045] Specifically, the first capacitor C1, the second capacitor C2, the third capacitor C3, and the second inductor L2 form a T-type high-pass filter unit, and the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, and the third inductor L3 also form a T-type high-pass filter unit, which can achieve the function of improving the roll-off coefficient and out-of-band rejection.

[0046] In at least one embodiment, the acoustic resonance module 3 includes: at least one acoustic wave resonance circuit; each of the acoustic wave resonance circuits is connected in parallel with the corresponding high-pass filter circuit.

[0047] Specifically, multiple acoustic wave resonance circuits can be set to meet the design requirements.

[0048] In at least one embodiment, the acoustic wave resonance circuit includes: at least one thin film bulk acoustic resonator; each of the thin film bulk acoustic resonators is arranged in series or in parallel or in a combination of series and parallel.

[0049] Specifically, multiple thin film bulk acoustic resonators can be set to meet the design requirements.

[0050] In at least one embodiment, refer to Figure 2 , three of the acoustic wave resonance circuits are set; the three acoustic wave resonance circuits are respectively connected in parallel between the input matching module 1 and the first high-pass filter circuit, between the first high-pass filter circuit and the second high-pass filter circuit, and between the second high-pass filter circuit and the output matching module 4, and each of the acoustic wave resonance circuits is grounded.

[0051] Specifically, refer to Figure 2, a first thin film bulk acoustic resonator F1 is arranged in parallel between the input matching module 1 and the first high-pass filter circuit, a second thin film bulk acoustic resonator F2 is arranged in parallel between the first high-pass filter circuit and the second high-pass filter circuit, and a third thin film bulk acoustic resonator F3 is arranged in parallel between the second high-pass filter circuit and the output matching module 4.

[0052] Specifically, each acoustic resonator circuit is connected in parallel between the input matching module 1, the first high-pass filter circuit, the second high-pass filter circuit, and the output matching module 4, so as to improve the roll-off coefficient and out-of-band rejection, and well suppress the signals in the 5G band.

[0053] Specifically, by cooperating the LC electrical module 2 and the acoustic resonator module 3, the advantages of integrated passive devices and thin film bulk acoustic resonators can be combined to meet the requirements of 2GHz ultra-wideband, high frequency, high rejection, and fast roll-off performance.

[0054] In at least one embodiment, the output matching module 4 includes: a fourth inductor L4 and a second connection capacitor CP2; both ends of the fourth inductor L4 are respectively connected to the output terminal OUT and the LC electrical module 2, one end of the second connection capacitor CP2 is connected between the fourth inductor L4 and the output terminal OUT, and the other end of the second connection capacitor CP2 is grounded.

[0055] Specifically, a fourth inductor L4 and a second connection capacitor CP2 are arranged at the output terminal OUT to play the role of output matching.

[0056] Based on the same inventive concept, please refer to Figures 3 to 5 , at least one embodiment further provides a high-frequency ultra-wideband filtering system, which includes: a band-pass filter, a substrate 5, and a plastic package 6 as provided in the above embodiments; wherein the plastic package 6 is mounted on the substrate 5, and the band-pass filter is encapsulated in the plastic package 6 and the substrate 5.

[0057] Specifically, the design dimensions of the band-pass filter, the substrate 5, and the plastic package 6 are 1.4*1.1*0.6mm.

[0058] Specifically, please refer to Figure 3 , wherein a first installation cavity 601 and a second installation cavity 602 are provided between the plastic package 6 and the substrate 5; the LC electrical module 2 in the band-pass filter is located in the first installation cavity 601, and the acoustic resonator module 3 is located in the second installation cavity 602.

[0059] Specifically, please refer to Figures 3 to 4 , the substrate 5 includes some ground inductors and connection inductors in the circuit, and the substrate 5 is a substrate 5 prepared by a multi-layer lamination process, including a ceramic substrate 5 or a PCB substrate 5.

[0060] Specifically, please refer toFigures 3 to 4 , each thin-film bulk acoustic resonator belongs to the acoustic unit 8 and is integrally installed together.

[0061] Specifically, the function of each thin-film bulk acoustic resonator is to reduce the bandwidth of the transition band.

[0062] Specifically, please refer to Figures 3 to 4 , the LC electrical module 2 belongs to the electrical unit 7 and is integrally installed together.

[0063] Specifically, please refer to Figures 3 to 4 , the LC electrical module 2 is fabricated using glass as a substrate, and silicon, gallium arsenide, glass, or sapphire can also be used as the substrate material, and is formed by photolithography, etching, deposition, or sputtering.

[0064] Specifically, the plastic package 6 is a polymer-filled package, aiming to isolate the influence of the external environment on the chip.

[0065] Specifically, the band-pass filter combines electrical and acoustic characteristics to achieve a band-pass filter design with miniaturization, large bandwidth, narrow transition band, and high rectangularity coefficient.

[0066] Specifically, the high-frequency ultra-wideband filtering system is prepared using a mature semiconductor process, with high process precision and suitable for mass production.

[0067] Please refer to Figure 5 , after simulating the band-pass filter, the band-pass filter can achieve a WiFi 5 - 7 GHz ultra-wideband filter, with a bandwidth of 1975 MHz (5150 MHz - 7125 MHz), an insertion loss better than 3.5 dB, a 5G band rejection better than 30 dB, and a rejection in some bands reaching 40 dB.

[0068] In summary, the present utility model can solve the problems of poor roll-off performance of a single IPD filter and the inability of a single FBAR filter to achieve ultra-wideband design specifications by adopting integrated passive devices in the LC electrical module and thin-film bulk acoustic resonators in the acoustic resonance module. By matching the LC electrical module with the acoustic resonance module, the roll-off coefficient and out-of-band rejection can be improved, while better suppressing out-of-band signals, meeting the requirements of ultra-wideband, high-frequency, high rejection, and fast roll-off performance.

[0069] Although this patent document contains many details, it should not be construed as limiting any utility model or the scope of the claims, but rather as a description of the features of specific embodiments of a particular utility model. Certain features described in the context of separate embodiments of this patent document may also be implemented in combination in a single embodiment. Conversely, the various functions described in the context of a single embodiment may also be implemented separately in multiple embodiments, or in any suitable sub-combination. Additionally, although the above features may be described as acting in certain combinations, and even initially claimed as such, in some cases, one or more features from a claim combination may be removed from the combination, and the claim combination may be directed to a sub-combination or a variant of the sub-combination.

[0070] Likewise, although the operations are described in a particular order in the drawings, this should not be construed to mean that such operations must be performed in the particular order shown or in sequence to obtain the desired result, or that all of the illustrated operations must be performed. Additionally, the separation of various system components in the embodiments of this patent document should not be construed as requiring such separation in all embodiments.

[0071] Only some implementations and examples are described, and other implementations, enhancements, and variations may be made based on what is described and illustrated in this patent document.

[0072] Although several embodiments are provided in this disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the disclosure. The current examples are considered illustrative rather than restrictive and are not limited to the details given. For example, various elements or components may be combined or integrated in another system, or certain features may be omitted or not implemented.

[0073] Furthermore, without departing from the scope of the disclosure, the discrete or separate technologies, systems, subsystems, and methods described and illustrated in the various embodiments may be combined or integrated with other systems, modules, technologies, or methods. Other items shown or discussed as being coupled may be directly connected, or may be indirectly coupled or communicate electrically, mechanically, or otherwise through some interface, device, or intermediate component. Those skilled in the art can determine other examples of changes, substitutions, and alterations without departing from the spirit and scope disclosed herein.

Claims

1. A high-frequency ultra-wideband bandpass filter, characterized in that: include: An input matching module, an LC electrical module, an acoustic resonance module and an output matching module; wherein The input matching module, the LC electrical module, and the output matching module are connected in sequence, the acoustic resonance module is connected in parallel with the LC electrical module, and the input matching module is connected to the input end, and the output matching module is connected to the output end; The input matching module receives a signal after successfully matching with the input end, so that the signal is processed by the LC electrical module and the acoustic resonance module, until the output matching module outputs a signal after successfully matching with the output end.

2. The bandpass filter according to claim 1, characterized in that The input matching module includes: a first inductor and a first connection capacitor; Two ends of the first inductor are respectively connected to the input end and the LC electrical module, one end of the first connection capacitor is connected between the first inductor and the input end, and the other end of the first connection capacitor is grounded.

3. The bandpass filter according to claim 1, wherein: The LC electrical module includes: at least one high-pass filter circuit; The high-pass filter circuits are connected in series in sequence, and the first high-pass filter circuit is connected to the input matching module, and the last high-pass filter circuit is connected to the output matching module.

4. The bandpass filter according to claim 3, characterized in that A first high-pass filter circuit and a second high-pass filter circuit are provided, that is, The first high-pass filter circuit is connected in series with the second high-pass filter circuit. The first high-pass filter circuit is connected to an input matching module, and the second high-pass filter circuit is connected to an output matching module.

5. The bandpass filter according to claim 4, characterized in that The first high-pass filter circuit includes: a first capacitor, a second capacitor, a third capacitor and a second inductor; The first capacitor and the third capacitor are connected in series in sequence, one end of the second capacitor is connected between the first capacitor and the third capacitor, and the other end of the second capacitor is connected in series with the second inductor and then grounded; The second high-pass filter circuit includes: a fourth capacitor, a fifth capacitor, a sixth capacitor and a third inductor; The fourth capacitor and the sixth capacitor are connected in series in sequence, one end of the fifth capacitor is connected between the fourth capacitor and the sixth capacitor, and the other end of the fifth capacitor is connected in series with the third inductor and then grounded.

6. The bandpass filter according to claim 4, characterized in that The acoustic resonance module includes: at least one acoustic wave resonance circuit; Each of the acoustic wave resonance circuits is connected in parallel with a corresponding high-pass filter circuit.

7. The bandpass filter according to claim 6, characterized in that The acoustic wave resonance circuit comprises: at least one thin film bulk acoustic wave resonator; The film bulk acoustic wave resonators are arranged in series or in parallel or in a combination of series and parallel.

8. The bandpass filter according to claim 6, wherein: Setting three of the acoustic wave resonance circuits; The three acoustic wave resonance circuits are respectively connected in parallel between the input matching module and the first high-pass filter circuit, between the first high-pass filter circuit and the second high-pass filter circuit, and between the second high-pass filter circuit and the output matching module, and each of the acoustic wave resonance circuits is grounded.

9. The bandpass filter according to claim 1, wherein: The output matching module includes: a fourth inductor and a second connection capacitor; Two ends of the fourth inductor are respectively connected to the output end and the LC electrical module, one end of the second connection capacitor is connected between the fourth inductor and the output end, and the other end of the second connection capacitor is grounded.

10. A high-frequency ultra-wideband filtering system, characterized in that: include: The bandpass filter, substrate and plastic package as described in any one of claims 1 to 9; in The plastic package shell is installed on the substrate, and the band pass filter is packaged in the plastic package shell and the substrate.

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