A high-adjacent-band rejection large bandwidth filter

Abstract

The application provides a large-bandwidth filter with high adjacent band rejection, which forms multiple narrow-band rejection curves in a wide frequency band range that needs to be rejected by designing stepped band-stop filter units with different film thicknesses, and then uses an LC matching network to connect the multiple stepped band-stop filter units in series to form a large-bandwidth and extremely deep rejection curve, and when the matching network is a series inductor, the series inductor works with a series resonator, so that the series resonance point of the series resonator is shifted to the outside of the stop band, thereby reducing the interference on the stop band and reducing the peak in the stop band rejection, and finally connecting a hybrid resonant network to a parallel branch to form an extremely deep zero point at a low frequency point.

Description

Technical Field

[0001] This invention belongs to the field of acoustic wave filtering technology, specifically relating to a wide bandwidth filter with high adjacent band suppression. Background Technology

[0002] With the rapid development of wireless communication technology, from 4G to 5G and 6G, the demand for spectrum is increasing and the spectrum is becoming more and more crowded. This makes communication face the challenge of crosstalk. In addition, communication protocol standards define many widebands, such as N79 and Wi-Fi 6E, which can reach up to 1975MHz, while the transition band is only 150MHz.

[0003] LC filters based on traditional IPD and LTCC technologies are suitable for high-bandwidth applications, such as 5G sub-6 GHz and millimeter-wave bands. However, these passive components are limited by material and manufacturing processes, making it difficult to achieve high Q values. This means a transition band of several hundred megahertz is required, and the suppression is not deep. Cavity filters have high Q values, but their large size makes it difficult to meet the miniaturization requirements of current RF modules. Acoustic filters, on the other hand, have high Q values ​​and good bandwidth. Among them, bulk acoustic filters have already achieved high-frequency filtering performance in products.

[0004] Patent application CN116865714A discloses a filter for the N79 band, comprising: at least one acoustic resonator and an IPD filter circuit; wherein the acoustic resonator and the IPD filter circuit are connected in series sequentially, or the acoustic resonator and the IPD filter circuit are connected in series at intervals; the IPD filter circuit is used to form a passband in the N79 band. This filter for the N79 band achieves its target requirements by integrating the acoustic resonator and the IPD filter circuit. Both are fabricated using semiconductor technology, allowing them to be manufactured on the same wafer. Furthermore, the filter's circuitry and structure can combine large bandwidth and fast roll-off, simultaneously achieving low insertion loss in the N79 band and high suppression of WiFi 6E. However, the architecture shown in this invention only meets a bandwidth of approximately 600 dB, and the high suppression of the 5G band for WiFi 6E mentioned is unlikely to exceed 40 dB.

[0005] Patent application CN119788021B discloses a broadband high-slope filter based on the embedding of a piezoelectric acoustic resonator and an LC passive circuit. It includes a stepped filter unit and an LC resonant network, connected in series, or connected in series with intervals. The stepped filter unit includes a series filter trunk and multiple parallel filter branches. The first end of the series filter trunk serves as the input terminal, and the two ends of each parallel filter branch are connected to ground and the series trunk, respectively. At least one series hybrid resonant unit is disposed on the series filter trunk, which is used to form poles in the passband to expand the passband bandwidth. At least one acoustic resonator or parallel hybrid resonant unit is disposed on each parallel filter branch. This filter can achieve high bandwidth, high out-of-band rejection, and a narrow transition band. However, this invention struggles to achieve wider out-of-band rejection exceeding 50dB in adjacent frequency bands, which cannot meet the increasing demands for anti-interference.

[0006] Although the aforementioned patents can form an extremely narrow transition band and a large bandwidth, the suppression of adjacent bands is still not deep enough. Therefore, there is an urgent need to design a filter circuit that can simultaneously satisfy the requirements of having an ultra-large bandwidth and having extremely deep suppression to avoid interference from adjacent frequency bands. This invention aims to provide a high adjacent band suppression and large bandwidth circuit. Summary of the Invention

[0007] This invention provides a wide-bandwidth filter with high adjacent band suppression. This filter can provide ultra-high suppression and rapid descent in adjacent frequency bands, while achieving a large passband bandwidth and low insertion loss.

[0008] This invention provides a wide-bandwidth filter with high adjacent-band suppression, comprising: a stepped band-stop filter unit module, an LC matching unit, and a hybrid resonant network;

[0009] The stepped band-stop filter unit module includes multiple stepped band-stop filter units connected in series, and matching inductors connected in series between the stepped band-stop filter units. Each stepped band-stop filter unit includes multiple series resonators on the main series circuit and parallel resonators on the parallel branches between the series resonators. The film thickness of the series resonator of the current stepped band-stop filter unit is the same as that of the parallel resonator of the next stepped band-stop filter unit. The film thickness of the series resonators of different stepped band-stop filter units is different, and the film thickness of the parallel resonators is also different.

[0010] The LC matching unit is located at both ends of the stepped band-stop filter unit module or between different stepped band-stop filter units.

[0011] The hybrid resonant network is located on the parallel branch between the stepped band-stop filter unit module and the LC matching unit.

[0012] This invention designs stepped band-stop filter units with different film thicknesses to form multiple narrow-band suppression curves within the wide frequency range requiring suppression. Then, an LC matching network is used to connect multiple stepped band-stop filter units in series to form a large bandwidth and extremely deep suppression curve. At the same time, when the matching network is a series inductor, it works with a series resonator to shift the series resonant point of the series resonator to the left into the stopband with a zero, thereby reducing interference to the stopband and reducing the spikes formed between the individual band-stop filter units. Finally, a hybrid resonant network is connected to a parallel branch to form an extremely deep zero at low frequencies.

[0013] Preferably, the stepped band-stop filter unit is provided with at least one series resonator and at least two parallel resonators to form a Π-type stepped filter unit, and the two ends of the parallel resonators are respectively connected to the ground wire and the series trunk.

[0014] Preferably, the stepped band-stop filter unit is provided with at least two series resonators and at least one parallel resonator to form a T-shaped stepped filter unit, and the two ends of the parallel resonator are respectively connected to the ground wire and the series trunk.

[0015] Preferably, the resonant frequency of the series resonator in the stepped band-stop filter unit is lower than the resonant frequency of the parallel resonator.

[0016] Preferably, the LC matching unit is an inductor Ls disposed in the series trunk or an inductor Lm disposed in the parallel branch;

[0017] The inductor Ls is connected to different stepped band-stop filter units at both ends, or one end is connected to a stepped band-stop filter unit and the other end is connected to the output or input terminal.

[0018] One end of the inductor Lm is connected to the series main circuit, and the other end is grounded.

[0019] The series inductor Ls provided by this invention can play the role of impedance matching between stepped filter units. In addition, when the series inductor Ls is connected in series with the series resonator, the position of the series resonant point fs of the series resonator can be adjusted, and an additional pole is formed in the high-frequency passband.

[0020] The parallel inductor Lm provided by this invention can play the role of impedance matching between stepped filter units. In addition, when the parallel inductor Lm is connected in parallel with the parallel resonator Ap, the position of the parallel resonant point fp of the parallel resonator Ap can be adjusted, and an additional pole is formed at low frequency.

[0021] Preferably, the stepped band-stop filter unit network module includes a stepped band-stop filter unit one and a stepped band-stop filter unit two;

[0022] The stepped band-stop filter unit includes two series resonators As1 arranged in the series trunk and a parallel resonator Ap1 in the parallel trunk between the series resonators As1.

[0023] The stepped band-stop filter unit 2 includes three series resonators As2 arranged on the series trunk line and parallel resonators Ap2 arranged on two parallel trunk lines between the series resonators As2.

[0024] The film thickness of the series resonator As1 is the same as that of the parallel resonator Ap2.

[0025] The film thicknesses of the series resonators As1 and As2 are different.

[0026] The parallel resonators Ap1 and Ap2 have different film thicknesses.

[0027] The parallel resonant point of the series resonator As2 and the series resonant point of the parallel resonator Ap2 provided by the present invention provide deep zeros for filter unit two. The parallel resonant point of the series resonator As1 and the series resonant point of the parallel resonator Ap1 provided by the present invention provide deep zeros for filter unit one. Through the above-mentioned deep zeros, a deeply suppressed stopband is formed in the corresponding frequency range, and the stopbands formed by filter unit one and filter unit two are adjacent to each other.

[0028] Preferably, the LC matching unit is located on a series trunk line or a parallel branch line.

[0029] Preferably, the LC matching unit is a single inductor. This invention uses a single inductor as the LC matching unit to increase the resonator Kt when adjusting the resonator frequency, while simultaneously generating additional zeros and poles.

[0030] When the single inductor provided by this invention is a matching inductor Ls located on the series trunk, it can form more poles with the series resonator As, and at the same time, the series resonant frequency fs of the series resonator As is shifted to the left to the desired frequency band, thereby achieving better suppression.

[0031] The single inductor provided by this invention, when the parallel inductor Lm located on the parallel branch is connected in parallel with the parallel resonator Ap, can form an additional pole at low frequency, and at the same time shift the parallel resonant point fp of the parallel resonator Ap to the desired frequency, thereby achieving better suppression.

[0032] Preferably, the hybrid resonant network is grounded at one end and connected to a series trunk at the other end. The hybrid resonant network includes a series unit consisting of a first capacitor and a first inductor connected in series, and a second capacitor connected in parallel with the series unit. This hybrid resonant network can provide a deep zero at the low frequency of the filter curve.

[0033] More preferably, the first and second capacitors replace the layered acoustic resonator to provide more deep zeros at low frequencies.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] This invention generates multiple bandstops by connecting multiple stepped bandstop filter units in series between adjacent frequency bands. By making the film thickness of the series resonator of the current stepped bandstop filter unit the same as that of the parallel resonator of the next stepped bandstop filter unit, the bandstops are adjacent, and the series resonant points of the parallel resonator and the series resonator are basically coincident. This allows for obtaining a suitable bandstop bandwidth, thereby achieving a suppression width and extremely deep suppression height by superimposing multiple bandstop networks in adjacent frequency bands, while achieving ultra-large bandwidth within the required passband frequency range.

[0036] If the film thickness of the parallel resonator of the subsequent stepped band-stop filter unit is thicker than that of the series resonator of the current stepped band-stop filter unit, the frequency of the series resonant point of the parallel resonator will be lower than that of the series resonant point of the series resonator. As a result, the band-stop bandwidth of the subsequent stepped band-stop filter unit will be narrower, and the series resonant point of the series resonator may not fall within the stopband range, thus affecting the suppression effect.

[0037] If the film thickness of the parallel resonator of the subsequent stepped band-stop filter unit is thinner than the film thickness of the series resonator of the current stepped band-stop filter unit, then the series resonant point of the parallel resonator has a higher frequency than the series resonant point of the series resonator. As a result, the band-stop bandwidth of the subsequent stepped band-stop filter unit becomes wider, and the series resonant point of the series resonator can fall within the stopband. However, this results in insufficient suppression depth of the subsequent stepped band-stop filter unit.

[0038] This invention uses a matching inductor connected in series between stepped band-stop filter units to move the series resonant point of the series resonator, which is also the pole of the filter, to a stopband range with deep suppression. This prevents the generation of spikes between the stopbands formed by the stepped band-stop filter units connected in series. In addition, the inductor can also achieve impedance matching between the stepped band-stop filter units. Attached Figure Description

[0039] Figure 1 The present invention provides a stepped band-stop filter unit composed of acoustic resonators, which is provided as a specific embodiment of the present invention.

[0040] Figure 2 The filter circuit provided in a specific embodiment of the present invention is formed by two stepped band-stop filter units connected in series.

[0041] Figure 3The diagram shows the S21 parameter curve and impedance curve of each resonator formed by two stepped band-stop filter units connected in series in a specific embodiment of the present invention.

[0042] Figure 4 This is a schematic diagram of the LC matching network located in a parallel branch, provided for a specific embodiment of the present invention.

[0043] Figure 5 This is a schematic diagram of an LC matching network located in a series trunk, provided for a specific embodiment of the present invention.

[0044] Figure 6 This is a schematic diagram of a stepped band-stop filter unit connected in series with an LC matching network in the middle, and the input and output terminals connected to the LC matching network, provided in a specific embodiment of the present invention.

[0045] Figure 7 A schematic diagram of a hybrid resonant network provided for a specific embodiment of the present invention.

[0046] Figure 8 This is a schematic diagram of a wide-bandwidth filter architecture with high adjacent band suppression, based on a stepped band-stop filter unit, an LC matching network, and a hybrid resonant network, provided for a specific embodiment of the present invention.

[0047] Figure 9 This is a schematic diagram of another wide-bandwidth filter architecture with high adjacent band suppression, based on a stepped band-stop filter unit, an LC matching network, and a hybrid resonant network, provided as a specific embodiment of the present invention.

[0048] Figure 10 This is a schematic diagram of another wide-bandwidth filter architecture with high adjacent band suppression, based on a stepped band-stop filter unit, an LC matching network, and a hybrid resonant network, provided as a specific embodiment of the present invention.

[0049] Figure 11 A schematic diagram of the S-parameter curves of a large-bandwidth filter architecture with high adjacent-band suppression provided for a specific embodiment of the present invention.

[0050] Figure 12 This is a magnified schematic diagram of the S-parameter curves of a large-bandwidth filter architecture with high adjacent-band suppression provided in a specific embodiment of the present invention.

[0051] Figure 13 A schematic diagram of the S-parameter curves of a high adjacent-bandgap filter architecture with high adjacent-bandgap suppression provided in a specific embodiment of the present invention, without auxiliary lines for the filter unit.

[0052] Figure 14 An electromagnetic simulation model and S-parameter diagram of a high-adjacent-bandgap filter architecture with high adjacent-bandgap suppression are provided for a specific embodiment of the present invention, wherein, Figure 14(a) in the figure is an electromagnetic simulation model of a large-bandwidth filter architecture with high adjacent band suppression provided in a specific embodiment of the present invention. Figure 14 (b) in the diagram is a schematic diagram of S-parameters.

[0053] Figure 15 This is a physical diagram of a test device for a high adjacent-bandwidth filter architecture with high adjacent-band suppression provided in a specific embodiment of the present invention. Figure 15 (a) in the diagram is the actual manufacturing path. Figure 15 (b) in the diagram is a physical diagram of a wide-bandwidth filter architecture with high adjacent band suppression. Detailed Implementation

[0054] The following detailed description is provided with specific implementation examples. These examples are only relevant parts of the invention and are intended to help those skilled in the art understand the principles of the invention; they do not constitute any limitation on the invention. It should be noted that corresponding structural adjustments and changes can be made based on the concept of this invention, and all such modifications and changes fall within the scope of protection of this invention.

[0055] The 5.15-5.85GHz and 5.925-7.125GHz frequency bands are two extremely important bands for WiFi and 6G communication, both possessing extremely large bandwidths, but are prone to interference due to their proximity. To achieve a passband in one band and wide and deep suppression in the other, this invention cleverly connects stepped acoustic bandstop filter units in series via an LC matching network. This achieves the lateral and longitudinal superposition of narrower stopband suppression, resulting in wide and deep stopband suppression. Simultaneously, a hybrid resonant network is connected to form the required extremely deep nulls at low frequencies.

[0056] This invention provides a stepped band-stop filter unit composed of acoustic resonators. Since the design frequency band chosen for this invention is a high-frequency bandpass, the network consists of two or more series resonators As and one or more parallel resonators Ap, forming a T-shaped stepped filter unit. One end of the parallel resonator is connected between two adjacent series resonators, and the other end is, but is not limited to, grounding. This filter unit, through the transmission zeros and poles generated by the acoustic resonators, can achieve a band-stop filter effect with fast transition and deep suppression, while simultaneously exhibiting passband performance at high or low frequencies.

[0057] In one specific embodiment, such as Figure 1 As shown, the T-type stepped filter unit provided in this embodiment includes two series resonators As1 and a parallel resonator Ap1 on the parallel branch between the two series resonators As1.

[0058] like Figure 2As shown, another T-shaped stepped filter unit two provided in this embodiment includes three series resonators As2 and two parallel resonators Ap2. This embodiment designs the film thickness of the resonators in the two T-shaped stepped filter units one and two in a related manner. This filter circuit has a wide bandstop. Specifically, the film thickness of the series resonator As1 in the stepped bandstop filter unit one is the same, while the film thickness of its parallel resonator Ap1 is thinner than As1. The film thickness of the series resonator As2 in the filter unit two is the same, while the film thickness of its parallel resonator Ap2 is the same as the film thickness of the series resonator As1 in the filter unit one.

[0059] like Figure 3 As shown, by Figure 2 The S-parameter curves obtained by connecting two stepped band-stop filter units in series are shown. The frequency range of f2-f3 is band-stopped by filter unit two, and the frequency range of f4-f5 is band-stopped by filter unit one. Although the two are superimposed to obtain a wide stopband, there is a bulge in the middle of the stopband, the suppression is not deep enough, and the performance of the passband frequency band curve is poor.

[0060] The zero point at frequency f2 is provided by the parallel resonant point fp of the series resonator As2;

[0061] The zero point at frequency f3 is provided by the series resonant point fs of the parallel resonator Ap2;

[0062] The zero point at frequency f4 is provided by the parallel resonant point fp of the series resonator As1;

[0063] The zero point at frequency f5 is provided by the series resonant point fs of the parallel resonator Ap1;

[0064] The series resonator As1 and the parallel resonator Ap2 have the same film thickness, meaning they have the same frequency.

[0065] like Figure 4 As shown in the figure, a specific embodiment of the present invention provides a filter circuit in which an LC matching network and a stepped band-stop filter unit are connected in parallel, wherein the LC matching network is an inductor Lm.

[0066] In a specific embodiment of this invention, when the LC matching network is in a parallel branch, one end is connected to the series main circuit, and the other end is connected to the ground wire. Compared with the prior art, when the parallel inductor Lm mentioned in this invention is located in the parallel branch and connected in parallel with the parallel resonator Ap1, it can form an additional pole at low frequencies, and at the same time shift the parallel resonant point fp of the parallel resonator Ap1 to the desired frequency, thereby achieving better suppression.

[0067] like Figure 5 As shown in the figure, a specific embodiment of the present invention provides an LC matching network connected to a stepped band-stop filter unit, wherein the LC matching network is an inductor Ls.

[0068] When the LC matching network in a specific embodiment of the present invention is in the series trunk, the series inductor Ls not only has the function of impedance matching, but also can move the series resonant point fs of the series resonator to the left, so that the pole formed by the series resonant point is located outside the stopband to be suppressed, or moved to the zero position of the filter unit, thereby eliminating the stopband bump generated by the pole, and thus obtaining a wide and deep band-stop performance.

[0069] In a specific embodiment of the present invention, the LC matching network can be located at both ends of the stepped band-stop filter unit, acting as a bridge for the stepped band-stop filter unit.

[0070] In a specific embodiment of the present invention, the LC matching network can be located at the input and output ends, serving as input-output matching.

[0071] like Figure 6 As shown in the figure, a specific embodiment of the present invention provides a filter circuit composed of a stepped band-stop filter unit and an LC matching network. The stepped band-stop filter unit includes filter unit one, filter unit two, etc. The stepped band-stop filter units in this circuit are connected in series with matching inductors at intervals, and the input and output terminals are impedance matched by parallel inductors Lm. The series matching inductor Ls moves the series resonant point of the series resonator, which is also the pole of the filter, to a stopband range with deep suppression, preventing spikes from forming between the stopbands of the series stepped band-stop filter units. Furthermore, this inductor also achieves impedance matching between the individual stepped band-stop filter units.

[0072] like Figure 7 As shown in the figure, a specific embodiment of the present invention provides a hybrid resonant unit, which is composed of two capacitors and one inductor, wherein the capacitor Cp and the inductor Lp are connected in series, and the capacitor C0 is connected in parallel with the series unit formed by Cp and Lp.

[0073] A specific embodiment of the present invention provides a hybrid resonant unit in which the capacitor can be replaced with an acoustic resonator, thereby obtaining a resonant unit with multiple zeros.

[0074] like Figure 8As shown in the figure, a specific embodiment of the present invention provides an ultra-wide bandwidth filter architecture with high adjacent band rejection. The architecture includes a stepped band-stop filter unit, an LC matching unit, and a hybrid resonant network. The stepped band-stop filter unit module includes multiple stepped band-stop filter units connected in series. Matching inductors Ls are connected in series between the stepped band-stop filter units. The stepped band-stop filter unit is a T-shaped stepped filter unit such as filter unit one and filter unit two. The LC matching unit is disposed on the parallel branch at both ends of the stepped band-stop filter unit module. The LC matching unit is a single inductor Lm. The hybrid resonant network is disposed between the LC matching unit and the stepped band-stop filter unit module. One end of the hybrid resonant network is grounded, and the other end is connected to the series trunk. The hybrid resonant network includes a series unit consisting of a first capacitor and a first inductor connected in series, and a second capacitor connected in parallel with the series unit.

[0075] like Figure 9 As shown, a specific embodiment of the present invention also provides an ultra-wideband filter architecture with high adjacent band suppression, which is similar to... Figure 8 Unlike the ultra-wideband filter architecture shown, the LC matching unit is a single inductor Ls set in the series trunk, which is connected in series with the stepped band-stop filter unit.

[0076] like Figure 10 As shown, it is from Figure 9 The circuit shown is derived from a specific circuit topology with three stepped band-stop filter units. In this circuit topology, filter unit one, filter unit two, and filter unit three are connected in sequence through a series matching inductor. The three band-stop frequency bands are superimposed to form a band-stop interval with wide and deep suppression, and a passband with low insertion loss and large bandwidth is formed at high frequencies.

[0077] like Figure 11 and 12 as well as Figure 13 The following is a specific embodiment of the present invention. Figure 10 The filter S-parameter diagram shows that f2-f3 form a stepped band-stop filter unit two, f4-f5 form a stepped band-stop filter unit one, and f6-f7 form a stepped band-stop filter unit three. These three stepped band-stop filter units are connected in series through an LC matching network to achieve a 700MHz bandwidth stopband with 55dB suppression, while simultaneously achieving a passband range of 5.925GHz-7.125GHz. The minimum insertion loss within the band is 1.4dB. By introducing a hybrid resonant network, an extremely deep zero is formed at f1, resulting in suppression of over 55dB at 2.4GHz. This effectively achieves a 6GHz passband for Wi-Fi while significantly minimizing interference from low-frequency Wi-Fi bands.

[0078] To verify the feasibility of the theory behind this invention, electromagnetic simulation studies and actual chip manufacturing were conducted. For example... Figure 14 As shown, Figure 14 (a) in the figure is based on the present invention. Figure 10 Electromagnetic simulation model of a high adjacent-band suppression filter circuit topology. Figure 14 (b) shows a comparison of the S-parameters of the electromagnetic simulation model and the schematic circuit, which are basically identical.

[0079] Figure 15 (a) in the middle shows Figure 10 The actual fabrication of the chip structure is illustrated, showing a chip including independent resonators, capacitors, and inductors; a hybrid filter constructed from multiple chips; and a bonding diagram of different chips. Specifically, the capacitor chip is gold-bonded to the resonator chip, and the resulting chip is then flip-chip bonded to the inductor chip, thereby obtaining the high adjacent-bandgap rejection, wide-bandwidth filter provided in this specific embodiment of the invention. Figure 15 As shown in (b) in the figure, it can be observed in the fixture.

[0080] In a specific embodiment of this invention, a stepped band-stop filter unit composed of acoustic resonators and a hybrid resonator unit are organically cascaded through an LC matching network. This cleverly utilizes the series superposition characteristics of the band-stop filter units. By designing the film thickness of the band-stop filter resonators, multiple band-stop filter unit networks form a wide and deep stopband suppression. Simultaneously, a series inductor is used to shift the series resonant frequency of the series resonators to the desired position, avoiding pole interference. Furthermore, the interaction between the matching network and the band-stop filter units creates low impedance and mutual impedance matching at high frequencies (5.925-7.125 GHz), resulting in a low insertion loss and flat passband. The properly embedded hybrid resonator unit can introduce extremely deep zeros at low frequencies, thus achieving suppression. The filter circuit obtained through these steps can achieve an ultra-wide bandwidth of 1200 MHz at high frequencies, while suppressing adjacent band signals to over 50 dB and possessing an extremely fast transition band. This provides an excellent solution to the challenges brought by the development of WIFI 6 / 7 and 5G / 6G, effectively solving signal interference problems.

Claims

1. A wide-bandwidth filter with high adjacent-band suppression, characterized in that, include: Stepped band-stop filter module, LC matching unit and hybrid resonant network; The stepped band-stop filter unit module includes multiple stepped band-stop filter units connected in series, and LC matching units connected in series between the stepped band-stop filter units. Each stepped band-stop filter unit includes multiple series resonators on the main series path and parallel resonators on the parallel branches between the series resonators. The film thickness of the series resonator of the current stepped band-stop filter unit is the same as that of the parallel resonator of the next stepped band-stop filter unit. The film thickness of the series resonators of different stepped band-stop filter units is different, and the film thickness of the parallel resonators is also different. The stepped band-stop filter unit network module includes stepped band-stop filter unit one and stepped band-stop filter unit two. The stepped band-stop filter unit includes two series resonators As1 arranged in the series trunk and a parallel resonator Ap1 in the parallel trunk between the series resonators As1. The stepped band-stop filter unit 2 includes three series resonators As2 arranged on the series trunk line and parallel resonators Ap2 arranged on two parallel trunk lines between the series resonators As2. The film thickness of the series resonator As1 is the same as that of the parallel resonator Ap2. The film thicknesses of the series resonators As1 and As2 are different. The parallel resonators Ap1 and Ap2 have different film thicknesses; The LC matching unit is an inductor Ls installed in the series trunk or an inductor Lm installed in the parallel branch; The inductor Ls is connected to different stepped band-stop filter units at both ends, or one end is connected to a stepped band-stop filter unit and the other end is connected to the output or input terminal. One end of the inductor Lm is connected to the series main circuit, and the other end is grounded; The LC matching unit is a single inductor; The hybrid resonant network is located between the stepped band-stop filter unit module and the LC matching unit. One end of the hybrid resonant network is grounded, and the other end is connected to the series trunk.

2. The high adjacent-bandwidth suppression, wide-bandwidth filter according to claim 1, characterized in that, The stepped band-stop filter unit is provided with at least one series resonator and at least two parallel resonators to form a Π-type stepped filter unit. The two ends of the parallel resonators are respectively connected to the ground wire and the series trunk.

3. The high adjacent-bandwidth suppression, wide-bandwidth filter according to claim 1, characterized in that, The stepped band-stop filter unit is provided with at least two series resonators and at least one parallel resonator to form a T-shaped stepped filter unit. The two ends of the parallel resonator are respectively connected to the ground wire and the series trunk.

4. The high adjacent-bandwidth suppression, wide-bandwidth filter according to claim 1, characterized in that, In the stepped band-stop filter unit, the resonant frequency of the series resonator is lower than that of the parallel resonator.

5. The high adjacent-bandwidth suppression, wide-bandwidth filter according to claim 1, characterized in that, The hybrid resonant network includes a series unit consisting of a first capacitor and a first inductor connected in series, and a second capacitor connected in parallel with the series unit. This hybrid resonant network can provide a deep zero at the low frequency of the filter curve.

6. The high adjacent-bandwidth suppression, wide-bandwidth filter according to claim 5, characterized in that, Replace the first and second capacitors with acoustic resonators.

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