CN115955211A

CN115955211A - Bulk acoustic wave filter, duplexer and electronic equipment

Info

Publication number: CN115955211A
Application number: CN202111173180.XA
Authority: CN
Inventors: 徐利军; 庞慰
Original assignee: ROFS Microsystem Tianjin Co Ltd
Current assignee: ROFS Microsystem Tianjin Co Ltd
Priority date: 2021-10-08
Filing date: 2021-10-08
Publication date: 2023-04-11

Abstract

The present invention relates to a duplexer, comprising: an antenna; the first filter comprises at least two first grounding pads and at least two first grounding ends, and each first grounding pad is connected with the corresponding first grounding end through the corresponding first inductor; and a second filter disposed adjacent to the first filter, the second filter including at least two second ground pads and at least two second grounds, each second ground pad being connected to a corresponding second ground via a corresponding second inductor, wherein: the side of the first filter and the side of the second filter, which are adjacent to each other, are the inner side of each filter, and the side opposite to the inner side is the outer side of each filter; the first grounding pad closest to the antenna in the first grounding pad is arranged at the inner side of the first filter, and/or the second grounding pad closest to the antenna in the second grounding pad is arranged at the inner side of the second filter. The present invention also relates to a bulk acoustic wave filter, and an electronic device having the duplexer or the bulk acoustic wave filter.

Description

Bulk acoustic wave filter, duplexer and electronic equipment

Technical Field

Embodiments of the present invention relate to the field of semiconductors, and in particular, to a bulk acoustic wave filter, a duplexer, and an electronic device.

Background

The wireless communication technology is rapidly developed towards the directions of multiple frequency bands and multiple modes, a filter, a duplexer and a multiplexer which are key components at the front end of radio frequency are widely concerned, particularly, the filter, the duplexer and the multiplexer are widely applied to the personal mobile communication field which develops the fastest, and the filter and the duplexer which are widely applied to the personal mobile communication field at present are mostly manufactured by a surface acoustic wave resonator or a bulk acoustic wave resonator. Compared with a surface acoustic wave resonator, the bulk acoustic wave resonator has better performance, has the characteristics of high Q value, wide frequency coverage range, good heat dissipation performance and the like, and is more suitable for the development requirement of future 5G communication. Since the resonance of the bulk acoustic wave resonator is generated by mechanical waves, rather than electromagnetic waves, which are the source of resonance, the wavelength of the mechanical waves is much shorter than that of the electromagnetic waves. Therefore, the bulk acoustic wave resonator and the filter formed by the bulk acoustic wave resonator are greatly reduced in size compared with the conventional electromagnetic filter.

The isolation of the duplexer composed of the bulk acoustic wave filter is an important index, and directly influences the performance of a communication system and the user experience. At present, improving isolation of a duplexer is a hot point of research in the field of bulk acoustic wave, and the isolation is usually improved by increasing the number of stages of a filter or introducing a phase cancellation loop, but both methods have limitations and disadvantages, for example, increasing the number of stages can improve the isolation, but can further deteriorate insertion loss of the duplexer, and introducing a phase cancellation loop can also improve the isolation, but can cause the size of the duplexer to be larger, and increase the cost.

The requirement of improving the isolation degree of the duplexer is met on the premise of not increasing the size of the duplexer and not deteriorating the insertion loss of the duplexer in the existing application.

Disclosure of Invention

The present invention has been made to solve at least one of the above-mentioned problems.

According to an aspect of an embodiment of the present invention, there is provided a duplexer including:

an antenna;

the first filter comprises at least two first grounding pads and at least two first grounding ends, and each first grounding pad is connected with the corresponding first grounding end through the corresponding first inductor; and

a second filter disposed adjacent to the first filter, the second filter including at least two second ground pads and at least two second grounds, each second ground pad being connected to a corresponding second ground via a corresponding second inductor,

wherein:

the side of the first filter and the side of the second filter, which are adjacent to each other, are the inner side of each filter, and the side opposite to the inner side is the outer side of each filter;

the first grounding pad closest to the antenna in the first grounding pad is arranged at the inner side of the first filter, and/or the second grounding pad closest to the antenna in the second grounding pad is arranged at the inner side of the second filter.

According to another aspect of the embodiments of the present invention, there is provided a bulk acoustic wave filter including at least two ground pads and at least two grounds, each ground pad being connected to a corresponding ground via a corresponding inductor,

wherein:

the layout of the filter is rectangular, the antenna is arranged on the short side of the rectangle and connected with the filter, and the grounding pad which is closest to the antenna in the grounding pads is arranged on the long side of the rectangle.

Embodiments of the present invention also relate to an electronic device including the bulk acoustic wave filter or the duplexer described above.

Drawings

These and other features and advantages of the various embodiments of the disclosed invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate like parts throughout, and in which:

fig. 1 is a topological structure diagram of a duplexer in accordance with an exemplary embodiment of the present invention;

fig. 2-4 are diagrams illustrating isolation between inductances without mutual inductance of the duplexer shown in fig. 1;

FIGS. 5-7 are schematic diagrams of layout layouts of duplexers according to various exemplary embodiments of the present invention;

fig. 8 is a topology structure diagram of a duplexer in accordance with still another exemplary embodiment of the present invention;

fig. 9 is a schematic diagram of a layout based on the duplexer in fig. 8 according to an exemplary embodiment of the present invention.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be construed as limiting the invention. Some, but not all embodiments of the invention are described. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

In the invention, how to improve the isolation of the duplexer is the problem to be solved by the patent on the premise of not increasing the size of the duplexer and not deteriorating the insertion loss of the duplexer, and the isolation is improved by the reasonable layout of the grounding PAD (namely the grounding PAD).

The layout of the duplexer ground PAD has a very large impact on its performance, especially on the isolation strip, since the different layouts of the ground PADs directly affect the inductive set and coupling of each of its connections.

Based on this, the inventor firstly studies the influence of the inductance of the ground PAD connection of the duplexer on the isolation, as shown in fig. 1, a schematic diagram of the duplexer is shown, which includes a transmitting filter TX and a receiving filter RX, the transmitting filter TX is connected to the common port 1 at one end, and is connected to the transmitting port 2 at the other end, the receiving filter RX is connected to the common port 1 at the other end, and the common port 1 is connected to the external antenna. An inductor can be connected in parallel at the common port 1, so that the matching of the antenna end is improved.

As shown in fig. 1, the transmit filter TX and the receive filter RX share an antenna.

In one embodiment of the invention, the transmit filter TX is a ladder-structured filter comprising at least one series resonator and at least 2 parallel resonators, each parallel arm comprising a parallel resonator. As shown in fig. 2, the resonators of the parallel branches are grounded after being connected with an inductor through a ground PAD, and in fig. 1, the TX filter has only two ground PADs, i.e., a ground PAD T1 and a ground PAD T2, where the ground PAD T1 is a ground PAD connected to the parallel branch closest to the antenna end, the ground PAD T2 is a ground PAD connected to the parallel branch farthest from the antenna end, the ground PAD T1 is grounded after being connected with the inductor L1 in series, and the ground PAD T2 is grounded after being connected with the inductor L2 in series. It should be noted that, in fig. 1, the transmission filter only shows 2 grounded PADs, which is for convenience of description, and the invention is not limited to only 2 grounded PADs. It should be noted that, when the parallel branches of the TX filter are larger than 2, there may be some two parallel branches whose resonators have one end combined together and then connected to some ground PAD.

The receiving filter RX is a filter with a ladder structure, and includes at least one series resonator and at least 3 parallel resonators, each parallel branch includes a parallel resonator, the resonators of the parallel branches are grounded after being connected with an inductor through a grounded PAD, in fig. 1, the RX filter has 3 grounded PADs, i.e., T4, T5 and T6, where the grounded PAD T4 is a grounded PAD connected to the parallel branch closest to the antenna end, the grounded PAD T6 is a grounded PAD connected to the parallel branch farthest from the antenna end, and the grounded PAD T5 is a grounded PAD connected to the middle parallel branch of the filter, the grounded PAD T4 is grounded after being connected with the inductor L4 in series, the grounded PAD T5 is grounded after being connected with the inductor L5 in series, and the grounded PAD T6 is grounded after being connected with the inductor L6 in series. It should be noted that, when the number of parallel branches of the RX filter is greater than 3, one end of the resonator of each of two parallel branches may be merged together and then connected to a ground PAD. It should be noted that, in fig. 1, the receiving filter only shows 3 grounded PADs, which is for convenience of description, and the invention is not limited to only 3 grounded PADs. It should be noted that, when the parallel branches of the receiving filter are larger than 3, there may be two parallel branches whose resonators have one end combined together and then connected to a ground PAD.

In this patent, taking Band7 as an example (the pass Band frequency range of the transmission filter is 2.5GHz-2.57GHz, and the pass Band frequency range of the reception filter is 2.62GHz-2.69 GHz), the influence of mutual inductance of the inductance L2 of the connection ground PAD T2 of the TX filter, the inductance L6 of the connection ground PAD T6 of the RX filter, the inductance L5 of the connection ground PAD T5, and the inductance L4 of the connection ground PAD T4 on the isolation is first studied, wherein the mutual inductance is defined as 12pH, and the result is shown in fig. 2. In fig. 2, a thick solid line is the isolation of the duplexer without mutual inductance between all inductors, a thin solid line is the isolation of the duplexer when mutual inductance exists between the inductor L2 and the inductor L4, a thin dotted line is the isolation of the duplexer when mutual inductance exists between the inductor L2 and the inductor L5, and a thick dotted line is the isolation of the duplexer when mutual inductance exists between the inductor L2 and the inductor L6, as can be seen from fig. 2, the isolation of the duplexer when mutual inductance exists between the inductor L2 and the inductor L6, as can be seen from the topology in fig. 1, the inductor L2 is the inductor connected to the grounding PAD farthest from the antenna end in the TX filter, and the inductor L6 is the inductor connected to the grounding PAD farthest from the antenna end in the RX filter, so that it is concluded that the mutual inductance between the inductor connected to the grounding PAD farthest from the antenna end in the TX filter and the inductor connected to the grounding PAD in the RX filter has the greatest influence on the isolation of the duplexer, so that the distance between the two inductors is as far as possible to the grounding PAD in the layout of the duplexer.

The inventors of the present invention also investigated the effect of mutual inductance of the inductance L1 of the TX filter connected to the ground PAD T1 and the inductance L6 of the RX filter connected to the ground PAD T6, the inductance L5 of the TX filter connected to the ground PAD T5, and the inductance L4 of the RX filter connected to the ground PAD T4 on the isolation, wherein the mutual inductance is defined as 12pH, and the results are shown in fig. 3. In fig. 3, the thick solid line represents the duplexer isolation when the inductor L1 and the inductor L4 are mutually inductive, the thin broken line represents the duplexer isolation when the inductor L1 and the inductor L5 are mutually inductive, and the thick broken line represents the duplexer isolation when the inductor L1 and the inductor L6 are mutually inductive, and it can be seen from fig. 3 that the duplexer isolation when the inductor L1 and the inductor L4 are mutually inductive is preferable. As can be seen from the topology in fig. 1, the inductor L1 is the inductor connected to the ground PAD closest to the antenna end in the TX filter, and the inductor L4 is the inductor connected to the ground PAD closest to the antenna end in the RX filter, so that: the mutual inductance between the inductor connected to the grounding PAD closest to the antenna end in the TX filter and the inductor connected to the grounding PAD closest to the antenna end in the RX filter has the smallest influence on the isolation of the duplexer, so that the two inductors can be very close to each other when the duplexer is laid out, that is, the grounding PADs connected with the two inductors are required to be placed as close as possible.

The inventor of the present invention also studies the influence of mutual inductance between the inductor L4 connected to the ground PAD closest to the antenna end of the RX filter and the inductor L6 connected to the ground PAD farthest from the antenna on the isolation, as shown in fig. 4, the thick solid line is the duplexer isolation when there is no mutual inductance between the inductor L4 and the inductor L6, and the thin solid line is the duplexer isolation when there is mutual inductance between the inductor L4 and the inductor L6, as can be seen from fig. 4, when there is mutual inductance between the inductor L4 and the inductor L6, the isolation deteriorates, so that the distance between the two inductors can be increased during layout arrangement, that is, the distance between the two inductors is required to be increased as far as possible.

In one embodiment of the present invention, the number of ground pads of the RX filter and/or the TX filter is not less than 2, and at least one ground pad is disposed away from the inner side of the corresponding filter.

The above technical solution of this patent is further illustrated by the following specific examples.

Based on the above analysis, the present patent proposes an embodiment of layout of a duplexer capable of improving isolation, as shown in fig. 5, 100 is a package substrate, and a plurality of inductors are fabricated on the package substrate, which is not shown for convenience. The dashed line AB is a line perpendicular to the long side of the substrate and passing through the midpoint thereof, called the center line, and the TX filter wafer and the RX filter wafer are fixed on the substrate by being placed upside down or in the forward direction and are respectively located on both sides of the center line AB, and the distance D therebetween is greater than 100um in one embodiment. As shown in fig. 5, the TX filter wafer and the RX filter wafer are both rectangular with the long sides parallel to the center line, and if the TX filter wafer is located on one side of the center line AB, the RX filter wafer is located on the other side, and vice versa.

Meanwhile, the side of the TX filter wafer and the side of the RX filter wafer close to the central line AB are defined as inner side, and the side far away from the central line AB are defined as outer side. As can be understood, in the present invention, the side where the reception filter and the transmission filter are adjacent to each other is the inside of each filter, and the side opposite to the inside is the outside of each filter.

As shown in fig. 5, the TX filter wafer is located on the upper side of the central line AB, and 101 is a metal sealing ring of the TX filter wafer, which can improve the sealing performance of the wafer and prevent external interference and moisture from entering. The TX filter comprises 4 series resonators S21, S22, S23, S24,3 parallel resonators P21, P22, P23, and two grounding PADs T1 and T2, wherein the grounding PAD T1 is connected with the upper electrode or the lower electrode of the parallel resonator P21 and then connected with an inductor on a substrate, and is the grounding PAD closest to the antenna end. The grounding PAD T2 is connected to the upper electrode or the lower electrode of the parallel resonators P22 and P23, and then connected to the inductor on the substrate, the grounding PAD T2 is also connected to the seal ring 101 and connected to the ground of the substrate through VIA, it should be noted that the grounding PAD T2 is not necessarily connected as such, and the grounding PAD T1 may also be connected to the seal ring 101 and connected to the ground of the substrate through VIA.

There is also an input PAD, in, (input port) and an output PAD, out, (output port) on the wafer, with the input in being located at the bottom left corner of the TX filter wafer and the output out being located at the top right corner of the TX filter wafer.

Further particular emphasis is given to: in one embodiment, the ground PADT1 closest to the antenna end is to be placed inside close to the input in, i.e., along the lower edge of the TX wafer, while the ground PAD T2 farthest from the antenna end is to be placed outside close to the output out, i.e., along the upper edge of the TX wafer.

The RX filter wafer is located on the lower side of the central line AB, and 102 is a metal sealing ring of the RX filter wafer, so that the sealing performance of the wafer can be improved, and external interference and moisture can be prevented from entering. The RX filter comprises 4 series resonators S11, S12, S13, S14,3 shunt resonators P11, P12, P13, and 3 grounding PADs including a grounding PAD T4, a grounding PAD T5 and a grounding PAD T6, wherein the grounding PAD T4 is connected with the upper electrode or the lower electrode of the shunt resonator P11 and then connected with an inductor on the substrate, and the grounding PAD T4 is the grounding PAD closest to the antenna end. The ground PAD T5 is connected to the upper or lower electrode of the parallel resonator P12 and then to the inductor on the substrate. The grounding PAD T6 is connected with the upper electrode or the lower electrode of the parallel resonator P13 and then connected with the inductor on the substrate, and the grounding PAD T6 is the grounding PAD which is farthest away from the antenna end. Ground PAD T6 may also be coupled to seal ring 102 and to the substrate ground VIA, it being noted that ground PAD T6 need not be so coupled, and ground PAD T4 or ground PAD T5 may also be coupled to seal ring 102 and to the substrate ground VIA.

In the RX filter, there are also an input PAD (input port) and an output PAD (output port) on the wafer, where the input in is located at the top left corner of the RX filter wafer and the output out is located at the bottom right corner of the RX filter wafer.

Further particular emphasis is given to: in an alternative embodiment, the ground PAD, i.e. T4, in the RX filter closest to the antenna end is to be placed close to the inner side of the input in, i.e. along the upper edge of the RX wafer as shown in fig. 5, while the ground PAD, i.e. T6, furthest away from the antenna end is to be placed close to the outer side of the output out, i.e. along the lower edge of the RX wafer as shown in fig. 5.

Alternatively, another ground PAD T5 is also placed on the outside, as shown in fig. 5.

The ground PADs of the TX filter and the RX filter are placed such that the mutual inductance between the inductance to which the ground PAD T1 of the TX filter closest to the antenna is connected and the inductance to which the ground PAD T4 of the RX filter closest to the antenna is connected has the smallest influence on the duplexer isolation, so that the two ground PADs can be placed next to each other, i.e., both inside near the input in, while the mutual inductance between the inductance to which the ground PAD T2 of the TX filter farthest from the antenna is connected and the inductance to which the ground PAD T6 of the RX filter farthest from the antenna is connected has the largest influence on the duplexer isolation, so that the distance between the two ground PADs is as large as possible, both outside near the output out.

In one embodiment, the other ground PAD T5 of the RX filter is placed on the outside as shown in fig. 5, but the ground PAD T5 may be placed on the outside as well as shown in fig. 6.

Fig. 7 is an alternative embodiment, in which fig. 7 the layout of the TX filter with less ground PAD remains the same, while the ground PAD T6 of the RX filter furthest from the antenna end is also placed on the inner side, while the other ground PAD T5 is placed on the outer side. Since the ground PAD T4 and the ground PAD T6 are both disposed on the inner side, the mutual inductance between the inductances of the two ground PAD connections will also have a large influence on the isolation according to the previous research results, so that the two are not disposed on the same side in one embodiment of the present invention. In other embodiments, the distance S is as far as possible if the same side must be placed, for example, the distance S is greater than half the length of the corresponding wafer of the RX filter.

In summary, in one embodiment of the invention, the following principle is followed when arranging the grounded PADs of the TX filter and the RX filter:

1. the ground PAD of the transmission filter closest to the antenna end and the ground PAD of the reception filter closest to the antenna end are both disposed inside.

2. The ground PAD of the transmitting filter farthest from the antenna end and the ground PAD of the receiving filter farthest from the antenna end are not placed on the inner side at the same time.

3. The rest of the grounded PAD of the transmitting filter and the rest of the grounded PAD of the receiving filter are not placed at the inner side at the same time.

4. The grounding PAD of the transmitting filter or the receiving filter, which is closest to the antenna end, and the grounding PAD of the transmitting filter or the receiving filter, which is farthest from the antenna end, are not placed on the same side as much as possible, and if the grounding PAD and the grounding PAD are necessarily placed on the same side, the distance is larger than half of the length direction of the layout of the filter.

5. And a transmission filter or a reception filter, when the number of the ground PADs is 3 or more, all the ground PADs are not placed on the same side.

The case where the TX filter has only 2 grounded PADs and the RX filter has 3 grounded PADs is discussed above, and the more general case where both the TX and RX filters have 3 grounded PADs is discussed below.

As shown in fig. 8, the TX filter has 3 grounded PADs, i.e., T1, T2, and T3, where T1 is the grounded PAD connected to the parallel resonator in the parallel branch of the TX filter closest to the antenna end, and T3 is the grounded PAD connected to the parallel resonator in the parallel branch of the TX filter farthest from the antenna end.

Fig. 9 shows this duplexer layout. The ground PAD T1 closest to the antenna of the TX filter wafer is located inside near the input in, while the ground PAD T2 and the ground PAD T3 are both located outside, and likewise the ground PAD T4 closest to the antenna of the RX filter wafer is located inside near the input in, while the ground PAD T5 and the ground PAD T6 are both located outside, although as can be appreciated this layout is not unique and other layouts are possible, in one embodiment of the invention, following the following principle:

The above specific example is described taking as an example that the ground pads of the two filters closest to the antenna are both disposed inside the two filters. However, as can be appreciated, the corresponding technical effect can also be obtained by disposing the ground pad closest to the antenna of one of the two filters of the duplexer inside the filter.

Based on the above, the present invention provides a duplexer, including:

an antenna;

wherein:

Optionally, at least one of the first ground pads far from the antenna is disposed outside the first filter; and/or at least one of the second ground pads, which is far away from the antenna, is disposed outside the second filter.

Optionally, at least one of the first ground pads other than the first ground pad closest to the antenna among the first ground pads is disposed away from an inner side of the first filter; and/or at least one of the second ground pads other than the second ground pad closest to the antenna is disposed away from an inner side of the second filter.

In the present invention, the arrangement inside the filter means that the ground pad is closer to the inner side of the filter than to the outer side of the filter, and in the case where the layout of the filter is rectangular, the arrangement inside the filter means that the distance between the ground pad and the inner side is less than half the width of the layout of the corresponding filter, and further less than one quarter of the width.

In the present invention, the arrangement outside the filter means that the ground pad is closer to the outer side of the filter than to the inner side of the filter, and in the case where the layout of the filter is rectangular, the arrangement outside the filter means that the distance between the ground pad and the outer side is less than half the width of the layout of the corresponding filter, and further less than one quarter of the width.

In the present invention, the inner side away from the filter indicates that the ground pad is closer to the outer side of the filter than the inner side of the filter, and in the case where the layout of the filter is rectangular, the inner side away from the filter indicates that the distance from the inner side of the filter is greater than half the width of the layout of the corresponding filter, and further greater than three quarters of the width.

In the present invention, the outer side distant from the filter means that the ground pad is closer to the inner side of the filter than the outer side of the filter, and in the case where the layout of the filter is rectangular, the outer side distant from the filter means that the distance from the outer side of the filter is more than half the width of the layout of the corresponding filter, and further more than three quarters the width.

In the present invention, when the layout of the filter is rectangular and the antenna is connected to the short side of the layout, the ground pad closest to the antenna means the one closest to the antenna in the direction of the long side, and the ground pad farthest from the antenna means the one farthest from the antenna in the direction of the long side.

In the present invention, although the duplexer is taken as an example to illustrate the arrangement of the ground pads in the filter with respect to the antenna, the arrangement of the ground pads of the present invention can also be applied to a single filter, and based on the above, the present invention also provides a bulk acoustic wave filter, including at least two ground pads and at least two ground terminals, each ground pad being connected to a corresponding ground terminal via a corresponding inductor, wherein: the layout of the filter is rectangular, the antenna is arranged on the short side of the rectangle and connected with the filter, and the grounding pad which is closest to the antenna in the grounding pads is arranged on the long side of the rectangle.

As can be appreciated by those skilled in the art, the bulk acoustic wave resonator according to the present invention may be used to form a filter or an electronic device.

The electronic device includes, but is not limited to, intermediate products such as a radio frequency front end and a filtering and amplifying module, and terminal products such as a mobile phone, WIFI and an unmanned aerial vehicle.

Based on the above, the invention provides the following technical scheme:

1. a duplexer, comprising:

an antenna;

wherein:

2. The duplexer of claim 1, wherein:

at least one first grounding pad far away from the antenna in the first grounding pads is arranged on the outer side of the first filter; and/or at least one of the second ground pads, which is far away from the antenna, is disposed outside the second filter.

3. The duplexer of claim 1, wherein:

at least one of the first ground pads other than the first ground pad closest to the antenna among the first ground pads is disposed away from an inner side of the first filter; and/or

At least one of the second ground pads other than the second ground pad closest to the antenna among the second ground pads is disposed away from an inner side of the second filter.

4. The duplexer of claim 3, wherein:

a first ground pad of the first ground pads, which is farthest from the antenna, is disposed away from an inner side of the first filter; and/or

The second ground pad that is farthest from the antenna among the second ground pads is disposed away from the inner side of the second filter.

5. The duplexer of claim 4, wherein:

the first grounding pad which is farthest away from the antenna in the first grounding pads is arranged on the outer side of the first filter; and/or a second ground pad of the second ground pads, which is farthest from the antenna, is disposed outside the second filter.

6. The duplexer of claim 1, wherein:

a first ground pad, which is farthest from the antenna, of the first ground pads is disposed at an outer side of the first filter, and a first ground pad, which is closest to the antenna, of the first ground pads is disposed at an inner side of the first filter; and/or

A second ground pad, which is farthest from the antenna among the second ground pads, is disposed at an outer side of the second filter, and a second ground pad, which is closest to the antenna among the second ground pads, is disposed at an inner side of the second filter.

7. The duplexer of claim 1, wherein:

a first grounding pad farthest from the antenna and a first grounding pad closest to the antenna in the first grounding pads are arranged on the inner side of the first filter, the layout of the first filter is rectangular, the long edge of the rectangle adjacent to the first filter and the second filter corresponds to the inner side of the first filter, and the distance between the first grounding pad farthest from the antenna and the first grounding pad closest to the antenna in the first grounding pads is greater than half of the length of the long edge in the length direction of the layout of the first filter; and/or

The second ground pad that keeps away from the antenna most in the second ground pad and the second ground pad that is closest to the antenna set up the inboard of second filter, just, the territory of second filter is the rectangle, and the long limit in this rectangle that second filter and first filter are adjacent corresponds to the inboard of second filter, the distance between the second ground pad that keeps away from the antenna most in the second ground pad and the second ground pad that is closest to the antenna is greater than half of the length of the long limit on the territory length direction of second filter.

8. The duplexer of claim 1, wherein:

the number of the first grounding bonding pads is not less than 2, and at least one first grounding bonding pad is far away from the inner side of the first filter; and/or

The number of the second ground pads is not less than 2, and at least one second ground pad is disposed away from the inner side of the second filter.

9. The duplexer of claim 1, wherein:

the layouts of the first filter and the second filter are rectangles, long sides of the rectangles, adjacent to each other, of the first filter and the second filter correspond to the inner sides of the filters, and long sides of the rectangles, opposite to the inner sides, of the first filter and the second filter correspond to the outer sides of the filters.

10. The duplexer of claim 9, wherein:

the distance between the adjacent long sides of the first filter and the second filter is more than 100 mu m; and/or

The distance between the grounding pad arranged on the inner side of the filter and the inner long edge of the layout corresponding to the filter is less than one fourth of the width of the rectangle; and/or

And the distance between the grounding pad arranged on the outer side of the filter and the long side of the outer side of the layout corresponding to the filter is less than one fourth of the width of the rectangle.

11. The duplexer of claim 1, wherein:

the layout of the first filter and the layout of the second filter are both rectangles, and the antenna is connected with the corresponding filter at the short side of each rectangle.

12. The duplexer of any one of claims 1-11, wherein:

the first filter is a transmit filter and the second filter is a receive filter.

13. The duplexer of claim 12 wherein:

the transmission filter is a filter of a ladder structure and includes at least one first series resonator and at least two first parallel resonators, each of which is grounded via a corresponding first ground pad;

the receiving filter is a filter of a ladder structure and includes at least one second series resonator and at least three second shunt resonators, each of which is grounded via a corresponding second ground pad.

14. The duplexer of claim 13, wherein:

the transmission filter comprises a first conductive sealing ring, and a first grounding pad of the transmission filter, which is farthest from the antenna and/or is closest to the antenna, is connected with the first conductive sealing ring; and/or

The receiving filter comprises a second conductive seal ring, and the second ground pad of the receiving filter, which is farthest from the antenna, and/or the second ground pad of the receiving filter, which is closest to the antenna, are/is connected with the second conductive seal ring.

15. The duplexer of claim 13, wherein:

the transmission filter is provided with a first input port and a first output port, and a first ground pad closest to the antenna is arranged on the inner side of the transmission filter adjacent to the first input port; and/or a first ground pad furthest from the antenna is disposed outside the transmit filter adjacent the first output port; and/or

The receiving filter is provided with a second input port and a second output port, and a second ground pad closest to the antenna is disposed inside the receiving filter adjacent to the second input port; and/or a second ground pad furthest from the antenna is disposed outside the receive filter adjacent the second output port.

16. A bulk acoustic wave filter includes at least two ground pads and at least two grounds, each ground pad being connected to a corresponding ground via a corresponding inductor,

wherein:

17. The filter of claim 16, wherein:

the filter is provided with an input port and an output port, and a grounding pad closest to the antenna is arranged on the long side of the rectangle adjacent to the input port.

18. The filter of claim 17, wherein:

the ground pad furthest from the antenna is disposed adjacent to the output port on the other long side of the rectangle.

19. An electronic device comprising a duplexer according to any one of claims 1-15 or a bulk acoustic wave filter according to any one of claims 16-18.

Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. A duplexer, comprising:

an antenna;

wherein:

2. The duplexer of claim 1 wherein:

3. The duplexer of claim 1 wherein:

4. The duplexer of claim 3 wherein:

5. The duplexer of claim 4 wherein:

6. The duplexer of claim 1 wherein:

A second ground pad, which is farthest from the antenna, of the second ground pads is disposed at an outer side of the second filter, and a second ground pad, which is closest to the antenna, of the second ground pads is disposed at an inner side of the second filter.

7. The duplexer of claim 1 wherein:

8. The duplexer of claim 1 wherein:

9. The duplexer of claim 1, wherein:

10. The duplexer of claim 9 wherein:

11. The duplexer of claim 1, wherein:

12. The duplexer of any one of claims 1-11, wherein:

13. The duplexer of claim 12 wherein:

the receiving filter is a filter of a ladder structure and includes at least one second series resonator and at least three second parallel resonators, each of which is grounded via a corresponding second ground pad.

14. The duplexer of claim 13, wherein:

the transmission filter comprises a first conductive sealing ring, and a first grounding pad of the transmission filter, which is farthest from the antenna, and/or a first grounding pad of the transmission filter, which is closest to the antenna, are/is connected with the first conductive sealing ring; and/or

The receiving filter comprises a second conductive seal ring, and the second ground pad of the receiving filter, which is farthest from the antenna and/or the second ground pad of the receiving filter, which is closest to the antenna, is connected with the second conductive seal ring.

15. The duplexer of claim 13 wherein:

wherein:

17. The filter of claim 16, wherein:

18. The filter of claim 17, wherein:

19. An electronic device comprising the duplexer of any one of claims 1-15 or the bulk acoustic wave filter of any one of claims 16-18.