CN214756273U

CN214756273U - Wide-passband filter based on film bulk acoustic resonator

Info

Publication number: CN214756273U
Application number: CN202120566813.2U
Authority: CN
Inventors: 姜伟; 高安明
Original assignee: Zhejiang Xintang Zhixin Technology Co ltd
Current assignee: Zhejiang Xingyao Semiconductor Co.,Ltd.
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2021-11-16
Anticipated expiration: 2031-03-19

Abstract

The utility model provides a wide passband filter based on film bulk acoustic resonator, including film bulk acoustic resonator module and with film bulk acoustic resonator module series connection and/or parallelly connected resonant network, film bulk acoustic resonator module includes one or more film bulk acoustic resonators, resonant network includes the series connection/or the parallel circuit of electric capacity and inductance. The utility model provides a conventional filter bandwidth based on bulk acoustic wave syntonizer hardly widened problem. A plurality of transmission zeros are generated through a resonant network formed by lumped elements, so that wide passband frequency response and good out-of-band rejection effect are obtained. The utility model discloses adopt the syntonizer among the topology network, solved the poor problem of conventional lumped element filter passband to stop band transition steepness. The characteristic of the resonator can well help the filter to improve the steepness of the side band, so that an excellent band-pass filtering effect is obtained.

Description

Wide-passband filter based on film bulk acoustic resonator

Technical Field

The utility model relates to a wave filter field specifically relates to a wide passband filter based on film bulk acoustic resonator.

Background

With the rapid development of 5G communication, the market demand for miniaturized, high-performance, high-operating-frequency filters is higher and higher. There is a filter based on bulk acoustic wave resonators (chinese patent application No. CN 201710320471.4) in the prior art, which proposes a bulk acoustic wave resonator and connects multiple resonators in a specific manner to obtain the desired filter response.

The defects of the prior art are as follows: the bandwidth of the conventional filter based on the bulk acoustic wave resonator is difficult to widen, and the filter provided by the patent can realize wide-passband filter response by connecting specific lumped elements around the resonator; the steepness of the sideband of the conventional filter based on the lumped element is difficult to improve, but the filter provided by the patent can well improve the steepness of the passband edge by reasonably adopting the resonators; the conventional filter based on the bulk acoustic wave resonator usually needs to process the resonator and the lumped element separately, and the IPD technology adopted by the filter in the process of processing the lumped element can be compatible with the standard photoetching process used for processing the resonator, so that the processing process is greatly simplified, and the cost is reduced; the conventional filter needs to independently package the resonators and then connect the required lumped elements, and the patent proposes that the lumped elements are directly packaged with the resonators after being processed by utilizing an IPD technology, so that the space required by the whole filter is greatly saved, and the miniaturization of an integrated system is facilitated; there are some filters in the market today that use resonators and IPD lumped elements to combine, but in order to obtain better performance, often have higher requirements for the parameter value and Q value of the capacitance and inductance, which greatly increases the process difficulty and cost, and the capacitance and inductance values required by the filter proposed by this patent are all in the common use range, which greatly increases the feasibility and practicability of the filter.

SUMMERY OF THE UTILITY MODEL

To the defect among the prior art, the utility model aims at providing a wide passband filter based on film bulk acoustic resonator.

According to the utility model provides a pair of wide passband filter based on film bulk acoustic resonator, including film bulk acoustic resonator module and with film bulk acoustic resonator module series connection and/or parallelly connected resonant network, film bulk acoustic resonator module includes one or more film bulk acoustic resonators, resonant network includes the series connection/or the parallel circuit of electric capacity and inductance.

Preferably, the resonant network comprises a plurality of first resonant networks connected in series with the film bulk acoustic resonator, and the first resonant networks comprise capacitors and inductors connected in parallel.

Preferably, the resonant network comprises a second resonant network connected in parallel to one side of the resonator, the second resonant network comprising two parallel circuits, one of which comprises a capacitor and an inductor connected in series, the other of which comprises an inductor; one end of the second resonant network is grounded.

Preferably, the resonator further comprises a third resonant network connected in parallel to the other side of the resonator, the third resonant network comprises a capacitor and an inductor which are connected in series, and one end of the third resonant network is grounded.

Preferably, the film bulk acoustic resonator module comprises two film bulk acoustic resonators connected in series.

Preferably, fourth resonant networks are arranged on two sides of the film bulk acoustic resonator module, and each fourth resonant network comprises a capacitor and an inductor which are connected in series.

Preferably, the thin film bulk acoustic resonator module further comprises a fifth resonant network arranged on two sides of the thin film bulk acoustic resonator module, the fifth resonant network comprises two thin film bulk acoustic resonators and an inductor which are connected in series, and one end of the fifth resonant network is grounded.

According to the utility model provides a pair of wide passband filter based on film bulk acoustic resonator, including middle network structure and the topological network of setting in middle network structure both sides, middle network structure includes the series connection/or the parallel circuit of electric capacity and inductance, the topological network includes one or more film bulk acoustic resonators.

Preferably, the intermediate network structure comprises a sixth resonant network connected in series, the sixth resonant network comprising an inductance and a capacitance connected in series; the resonant circuit further comprises a seventh resonant network, one end of the seventh resonant network is grounded, the other end of the seventh resonant network is connected into the sixth resonant network, and the seventh resonant network comprises an inductor and a capacitor which are connected in parallel.

Preferably, one end of the intermediate network structure is connected to an eighth resonant network, the other end of the intermediate network structure is connected to a ninth resonant network, and the eighth resonant network comprises a film bulk acoustic resonator and an inductor which are connected in series; the ninth resonant network comprises a first circuit and a second circuit, wherein the first circuit comprises an inductor, and the second circuit comprises two film bulk acoustic wave resonators and an inductor which are connected in series.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the utility model provides a conventional filter bandwidth based on bulk acoustic wave syntonizer hardly widened problem. A plurality of transmission zeros are generated through a resonant network formed by lumped elements, so that wide passband frequency response and good out-of-band rejection effect are obtained.

2. The utility model discloses adopt the syntonizer among the topology network, solved the poor problem of conventional lumped element filter passband to stop band transition steepness. The characteristic of the resonator can well help the filter to improve the steepness of the side band, so that an excellent band-pass filtering effect is obtained.

3. The utility model discloses an adopt can process required lumped element with the compatible integrated passive ware (IPD) piece technique of standard lithography process, solved the problem that conventional wave filter need independently process acoustic resonator and lumped element to effectual reduction technology complexity and cost.

4. The utility model discloses an adopt and encapsulate lumped element and acoustic wave syntonizer method together, solved the problem that conventional wave filter need independently encapsulate lumped element and acoustic wave syntonizer to reduce whole wave filter occupation space widely, also improved the poor stability's of system problem simultaneously.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a topological structure diagram of a first embodiment of the wide-passband filter based on the film bulk acoustic resonator of the present invention.

Fig. 2 is a schematic diagram of the frequency response of the topology.

Fig. 3 is a topological structure diagram of a second embodiment of the wide passband filter based on the film bulk acoustic resonator of the present invention.

Fig. 4 is a schematic diagram of the frequency response of the topology.

Fig. 5 is a topological structure diagram of a third embodiment of the wide passband filter based on the film bulk acoustic resonator of the present invention.

Fig. 6 is a schematic diagram of the frequency response of the topology.

Fig. 7 is a schematic diagram of a package structure of a wide-passband filter based on a film bulk acoustic resonator.

The figures show that:

1-film bulk acoustic wave resonator

2-metal electrode

3-integrated capacitor

4-integrated inductor

Detailed Description

The present invention will be described in detail with reference to the following embodiments. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that various changes and modifications can be made by one skilled in the art without departing from the spirit of the invention. These all belong to the protection scope of the present invention.

As shown in fig. 1 to 7, the present invention provides a wide pass band filter based on bulk acoustic wave resonators, which is composed of a series of lumped elements and a plurality of individual acoustic wave resonators, and has three topologies, each of which has superior filtering performance.

Fig. 1 shows a topology of a wide-passband filter based on bulk acoustic wave resonators according to the present patent, which is composed of a bulk acoustic wave resonator 1 and a series of lumped capacitors and inductors. The capacitors and inductors form five resonant networks, and each network can generate a transmission zero point. The parallel networks formed by L1 and C1, L2 and C2, and L3 and C3 are sequentially connected in series at two sides of the resonator; the network formed by connecting L4 in series with C4 and then connecting L5 in parallel is connected in parallel in the main branch, and the other end is grounded; similarly, the network formed by the series connection of C5 and L6 is connected in parallel on the right side of the resonator, and the other end is connected to ground. The corresponding transmission zero frequency can be moved by reasonably adjusting the values of each capacitor and each inductor in the circuit, so that five transmission zeros can be closed around a passband, and a wide passband filtering response with better out-of-band rejection is formed. It is worth mentioning that the lumped element parameter values required for the filter are within a range that is easily realized in practical processing. In addition, the filter characteristics of the resonators themselves may further help to optimize the out-of-band rejection effect of the passband. Finally, by properly designing the lumped elements and the resonator, a high frequency filter having a wide pass band, high steepness, and a good out-of-band rejection as shown in fig. 2 can be obtained.

Fig. 3 shows another topology of the wide-passband filter based on bulk acoustic wave resonators proposed by this patent. The filter is composed of a series of acoustic wave resonators and a collection element, and the whole filter is symmetrically distributed. The middle acoustic wave resonator array is distributed in a pi shape, and a band-pass filter response with a certain bandwidth can be generated. The network of C6 and L7 serves primarily as impedance matching at the input and output ports on either side of the resonator array. In addition, the inductor L8 connected in series with the resonator and grounded mainly serves to widen the bandwidth. By reasonably adjusting the parameter values of the capacitance and the inductance, the filter with wide pass band, good impedance matching and steep side band as shown in fig. 4 can be obtained.

Fig. 5 shows a third topology of the wide-passband filter based on bulk acoustic wave resonators proposed in this patent. Similarly, the filter consists of bulk acoustic wave resonators and lumped elements connected by a specific topology. The filter topology middle part is composed of a network structure which can realize wide-passband filtering and is composed of L10 and C7, C9 and L14, L11 and C8, and C10 and L15. The left side of the network structure is connected with a topological network consisting of two acoustic wave resonators and two inductors (L9, L13) in series, and the right side of the network structure is connected with a topological network consisting of an acoustic wave resonator and an inductor L12 in series. The two topological networks on the two sides have band-stop filtering responses, and the working frequencies of the stop bands are respectively distributed on the two sides of the whole filter pass band, so that the filter is helped to realize sharp attenuation at the edge of the pass band, and good steepness is obtained. The overall filter response of the filter is shown in fig. 6, and the performance such as the bandwidth of the passband and the steepness of the sideband can be optimized by reasonably adjusting the value of the lumped elements in the filter.

The lumped element required by the proposed filter can be realized by Integrating Passive Devices (IPD) technology. The IPD technology can be compatible with a standard photoetching process of resonator processing, and through a reasonable design process flow, the lumped element can be processed while the acoustic resonator is processed, so that the processing cost is saved. As shown in fig. 7, the resonator is connected to the topology network formed by packaging the integrated capacitor 3 and the integrated inductor 4 through the metal electrode 2, and a filter package device is obtained. The filter packaging device obtained by the integrated passive device technology can be perfectly integrated in a specific integrated circuit, so that the occupied space and the processing cost of the filter are greatly reduced, and the stability of the filter is effectively improved.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

The foregoing description of the specific embodiments of the invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by those skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.

Claims

1. The wide-passband filter based on the film bulk acoustic resonator is characterized by comprising a film bulk acoustic resonator module and a resonant network connected in series and/or in parallel with the film bulk acoustic resonator module, wherein the film bulk acoustic resonator module comprises one or more film bulk acoustic resonators, and the resonant network comprises a series and/or parallel circuit of a capacitor and an inductor.

2. The film bulk acoustic resonator-based wide passband filter according to claim 1, wherein the resonant network comprises a plurality of first resonant networks connected in series with the film bulk acoustic resonator, the first resonant networks comprising a capacitor and an inductor connected in parallel.

3. The film bulk acoustic resonator-based wide passband filter according to claim 2, wherein the resonant network comprises a second resonant network connected in parallel to one side of the resonator, the second resonant network comprising two parallel circuits, one of the circuits comprising a capacitor and an inductor connected in series and the other circuit comprising an inductor; one end of the second resonant network is grounded.

4. The film bulk acoustic resonator-based wide passband filter according to claim 3, further comprising a third resonant network connected in parallel to the other side of the resonator, the third resonant network comprising a capacitor and an inductor connected in series, one end of the third resonant network being connected to ground.

5. The film bulk acoustic resonator-based wide passband filter according to claim 1, wherein the film bulk acoustic resonator module comprises two film bulk acoustic resonators connected in series.

6. The film bulk acoustic resonator-based wide passband filter according to claim 5, wherein the film bulk acoustic resonator module is provided with a fourth resonant network on both sides, and the fourth resonant network comprises a capacitor and an inductor connected in series.

7. The film bulk acoustic resonator-based wide passband filter according to claim 6, further comprising a fifth resonant network disposed on both sides of the film bulk acoustic resonator module, wherein the fifth resonant network comprises two film bulk acoustic resonators and an inductor connected in series, and one end of the fifth resonant network is grounded.

8. The wide-passband filter based on the film bulk acoustic resonator is characterized by comprising an intermediate network structure and topological networks arranged on two sides of the intermediate network structure, wherein the intermediate network structure comprises series and/or parallel circuits of capacitors and inductors, and the topological networks comprise one or more film bulk acoustic resonators.

9. The film bulk acoustic resonator-based wide passband filter according to claim 8, wherein the intermediate network structure comprises a sixth resonant network connected in series, the sixth resonant network comprising an inductor and a capacitor connected in series; the resonant circuit further comprises a seventh resonant network, one end of the seventh resonant network is grounded, the other end of the seventh resonant network is connected into the sixth resonant network, and the seventh resonant network comprises an inductor and a capacitor which are connected in parallel.

10. The film bulk acoustic resonator-based wide passband filter according to claim 9, wherein one end of the intermediate network structure is connected to an eighth resonant network, and the other end of the intermediate network structure is connected to a ninth resonant network, the eighth resonant network comprising a film bulk acoustic resonator and an inductor connected in series; the ninth resonant network comprises a first circuit and a second circuit, wherein the first circuit comprises an inductor, and the second circuit comprises two film bulk acoustic wave resonators and an inductor which are connected in series.