Filter, radio frequency front-end circuit, radio frequency transceiving device and electronic equipment

Abstract

The invention discloses a filter, a radio frequency front-end circuit, a radio frequency transceiving device and electronic equipment. The filter comprises a first feeder line, a first multimode resonator and a second feeder line; the first feeder line is provided with an input end; the first multi-mode resonator is located on one side of the first feeder line, the first multi-mode resonator and the first feeder line are arranged at an interval and are coupled, and the first multi-mode resonator has a first resonant mode supporting a first frequency band, a second resonant mode supporting a second frequency band and a third resonant mode supporting a third frequency band; the second feeder line is located on the side, away from the first feeder line, of the first multi-mode resonator, the second feeder line and the first multi-mode resonator are arranged in a spaced mode and coupled, and the second feeder line is provided with an output end. The filter can achieve band pass of the first frequency band, the second frequency band and the third frequency band, and is low in cost and small in size.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a filter, a radio frequency front-end circuit, a radio frequency transceiver, and an electronic device. Background Art

[0002] A filter is a frequency-selective device that allows specific frequency bands within a signal to pass through. Filters are an essential component of electronic devices such as mobile phones and in-vehicle terminals. The filters used in related technologies are single-band filters. To pass multiple frequency bands, multiple filters must be combined, which is costly and typically large. Summary of the Invention

[0003] In a first aspect, an embodiment of the present application provides a filter, comprising:

[0004] a first feeder having an input end;

[0005] a first multimode resonator, the first multimode resonator being located on one side of the first feeder, the first multimode resonator being spaced apart from and coupled to the first feeder, the first multimode resonator having a first resonance mode supporting a first frequency band, a second resonance mode supporting a second frequency band, and a third resonance mode supporting a third frequency band; and

[0006] A second feeder is located on a side of the first multi-mode resonator away from the first feeder, the second feeder is spaced apart from and coupled to the first multi-mode resonator, and the second feeder has an output end.

[0007] In a second aspect, an embodiment of the present application provides a radio frequency front-end circuit, which includes the filter as described in the first aspect.

[0008] In a third aspect, an embodiment of the present application provides a radio frequency transceiver device, the radio frequency transceiver device comprising:

[0009] radiators; and

[0010] The RF front-end circuit as described in the second aspect.

[0011] In a fourth aspect, an embodiment of the present application provides an electronic device, which includes the radio frequency transceiver as described in the third aspect.

[0012] In summary, the filter provided in the embodiments of the present application has a first multimode resonator having a first resonant mode supporting a first frequency band, a second resonant mode supporting a second frequency band, and a third resonant mode supporting a third frequency band. Therefore, the filter can utilize a single first multimode resonator to pass signals in the first, second, and third frequency bands. In other words, the filter of the present application is an integrated three-band filter, offering low cost and compact size. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 A schematic diagram of the structure of a filter provided in one embodiment of the present application;

[0015] Figure 2 for Figure 1 Schematic diagram of the first multi-mode resonator shown in ;

[0016] Figure 3 for Figure 2 A schematic diagram of a first resonant unit in a first multi-mode resonator shown in ;

[0017] Figure 4 for Figure 3 Schematic diagram of size details of the first resonant unit;

[0018] Figure 5 for Figure 3 A schematic diagram illustrating structural details of the first resonant unit;

[0019] Figure 6 for Figure 1 A schematic diagram of a first coupling gap between a first multimode resonator and a first feed line in the filter shown;

[0020] Figure 7 A schematic structural diagram of a filter provided in another embodiment of the present application;

[0021] Figure 8 for Figure 7 Schematic diagram of a second multimode resonator shown in ;

[0022] Figure 9 for Figure 8 A schematic diagram of a second resonant unit in a second multi-mode resonator shown in ;

[0023] Figure 10for Figure 9 Schematic diagram of size details of the first resonant unit;

[0024] Figure 11 for Figure 9 A schematic diagram illustrating structural details of the first resonant unit;

[0025] Figure 12 for Figure 7 Schematic diagram of the dimensions of each coupling gap in the filter shown;

[0026] Figure 13 A schematic diagram of a first multi-mode resonator according to an embodiment of the present application;

[0027] Figure 14 (a) in Figure 13 Schematic diagram of the equivalent structure of the first multi-mode resonator in terms of odd-mode resonant modes and;

[0028] Figure 14 (b) in Figure 13 Schematic diagram of the equivalent structure of the first multi-mode resonator in terms of the even-mode resonance mode and;

[0029] Figure 15 A schematic diagram of a resonance mode generated by a first multi-mode resonator in a filter provided in one embodiment of the present application;

[0030] Figure 16 A relationship diagram between the first coupling gap, the second coupling gap, and the coupling coefficient in a filter according to an embodiment of the present application;

[0031] Figure 17 This is a schematic diagram of HSS simulation of a filter provided in one embodiment of the present application;

[0032] Figure 18 A schematic diagram of a radio frequency front-end circuit provided in one embodiment of the present application;

[0033] Figure 19 A schematic diagram of a radio frequency transceiver device provided in one embodiment of the present application;

[0034] Figure 20 A schematic diagram of an electronic device provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. In addition, the reference to "embodiment" or "implementation method" in the present application means that the specific features, structures or characteristics described in conjunction with the embodiment or implementation method may be included in at least one embodiment of the present application. The appearance of the phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is understood explicitly and implicitly by those skilled in the art that the embodiments described in the present application can be combined with other embodiments. It should be noted that, for ease of explanation, in the embodiments of the present application, the same figure numerals represent the same parts, and for the sake of brevity, detailed descriptions of the same parts are omitted in different embodiments.

[0036] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0037] See also Figure 1 , Figure 1 This is a schematic structural diagram of a filter provided in one embodiment of the present application. The filter 10 includes a first feeder 300, a first multimode resonator 100, and a second feeder 500. The first feeder 300 has an input end 300a. The first multimode resonator 100 is located on one side of the first feeder 300, and the first multimode resonator 100 is spaced apart and coupled to the first feeder 300. The first multimode resonator 100 has a first resonant mode supporting a first frequency band, a second resonant mode supporting a second frequency band, and a third resonant mode supporting a third frequency band. The second feeder 500 is located on a side of the first multimode resonator 100 away from the first feeder 300, and the second feeder 500 is spaced apart and coupled to the first multimode resonator 100, and the second feeder 500 has an output end 500a.

[0038] The first feeder 300 has an input terminal 300a, and the input terminal 300a is used to receive a signal to be filtered. For the convenience of description, the signal to be filtered is also referred to as a first signal.

[0039] The first multimode resonator 100 is also referred to as a resonant unit or a resonator unit. The first multimode resonator 100 is spaced apart from and coupled to the first feeder 300. The first multimode resonator 100 is configured to couple with the first feeder 300 to receive the signal to be filtered. That is, the first multimode resonator 100 is configured to couple with the first feeder 300 to receive the first signal.

[0040] The first multi-mode resonator 100 has a first resonant mode supporting a first frequency band, a second resonant mode supporting a second frequency band, and a third resonant mode supporting a third frequency band. In other words, the first multi-mode resonator 100 has a first resonant mode, a second resonant mode, and a third resonant mode, and is used to pass signals in the first frequency band, the second frequency band, and the third frequency band.

[0041] In one embodiment, the first multi-mode resonator 100 is configured to pass signals of a first frequency band, a second frequency band, and a third frequency band, and filter out signals of other frequency bands except the signals of the first frequency band, the second frequency band, and the third frequency band, to obtain a second signal.

[0042] It should be noted that the filter 10 can pass signals in the first frequency band, the second frequency band, and the third frequency band, but it should not be understood that all of the signals in the first frequency band, the second frequency band, and the third frequency band must be present in the first signal. The first signal may include at least one of the signals in the first frequency band, the second frequency band, and the third frequency band.

[0043] Specifically, if the first signal includes at least one of a signal in a first frequency band, a signal in a second frequency band, and a signal in a third frequency band, the first multimode resonator 100 is configured to pass the at least one signal and filter out signals in other frequency bands to obtain the second signal. It should be noted that the signals in other frequency bands refer to signals in the first signal that are in frequency bands other than the first, second, and third frequency bands.

[0044] For example, in one embodiment, when the first signal includes signals in a first frequency band, a second frequency band, a third frequency band, and signals in other frequency bands, the first multimode resonator 100 is configured to pass the signals in the first frequency band, the second frequency band, and the third frequency band, and filter out the signals in the other frequency bands to obtain a second signal. In other words, in this embodiment, the second signal includes signals in the first frequency band, the second frequency band, and the third frequency band.

[0045] In another embodiment, if the first signal includes two of a signal in a first frequency band, a signal in a second frequency band, and a signal in a third frequency band, the first multimode resonator 100 is configured to pass the two signals while filtering out signals in other frequency bands to obtain a second signal. In other words, in this embodiment, the second signal includes the two signals.

[0046] In another embodiment, if the first signal includes one of a signal in a first frequency band, a signal in a second frequency band, and a signal in a third frequency band, the first multimode resonator 100 is configured to pass the one signal and filter out signals in the other frequency bands to obtain the second signal. In other words, the second signal includes the one signal.

[0047] The second feeder 500 is located on a side of the first multimode resonator 100 away from the first feeder 300 . The second feeder 500 is spaced apart from and coupled to the first multimode resonator 100 , and outputs the second signal through the output end 500 a .

[0048] In summary, the filter 10 provided in the embodiments of the present application has a first multimode resonator 100 that has a first resonant mode supporting a first frequency band, a second resonant mode supporting a second frequency band, and a third resonant mode supporting a third frequency band. Therefore, the filter 10 can utilize a single first multimode resonator 100 to pass signals in the first, second, and third frequency bands. In other words, the filter 10 of the present application is an integrated three-band filter 10, which is low-cost and compact.

[0049] Next, the specific structure of the first multi-mode resonator 100 is described in detail. Figure 2 and Figure 3 , Figure 2 for Figure 1 Schematic diagram of the first multi-mode resonator shown in ; Figure 3 for Figure 2Schematic diagram of the first resonant unit in the first multimode resonator shown in . The first multimode resonator 100 includes two symmetrically arranged first resonant units 110. The first resonant unit 110 includes a first branch 111, a second branch 112, a third branch 113 and a first connecting portion 114. One end of the second branch 112 is connected to one end of the first branch 111. One end of the third branch 113 is connected to the other end of the second branch 112. The first branch 111, the second branch 112 and the third branch 113 cooperate to form a first enclosed space 110a. The other end of the third branch 113 is opposite to the other end of the first branch 111 and is spaced apart to form a first opening 110b, and the first opening 110b is connected to the first enclosed space 110a. The first connecting portion 114 is connected to the second branch 112, and the first connecting portions 114 of the two first resonant units 110 are connected.

[0050] In this embodiment, the two first resonant units 110 are symmetrical along the dotted line L0. The two first resonant units 110 are arranged along a first direction D1. In this embodiment, the first direction D1 is the length direction of the first multimode resonator 100. The first multimode resonator 100 includes two symmetrically arranged first resonant units 110. Therefore, the first multimode resonator 100 is also referred to as a symmetrical transmission network.

[0051] In this embodiment, the first connecting portion 114 is connected to the second branch 112, the first connecting portions 114 of the two first resonant units 110 in the first multi-mode resonator 100 are connected, and the first connecting portion 114 of one of the two first resonant units 110 and the first connecting portion 114 of the other of the two first resonant units 110 are also arranged along the first direction D1.

[0052] The first multimode resonator 100 provided in the embodiment of the present application includes two symmetrically arranged first resonance units 110, and the first resonance unit 110 includes a first branch 111, a second branch 112, a third branch 113 and a first connecting portion 114, which can realize a first resonance mode supporting the first frequency band, a second resonance mode supporting the second frequency band and a third resonance mode supporting the third frequency band. In addition, the filter 10 provided in the embodiment of the present application can reduce the complexity of the design, and the structure is simple and easy. The filter 10 provided in the embodiment of the present application has a first resonance mode supporting the first frequency band, a second resonance mode supporting the second frequency band and a third resonance mode supporting the third frequency band. Therefore, the filter 10 can use a first multimode resonator 100 to realize the signal passing through the first frequency band, the signal passing through the second frequency band and the signal passing through the third frequency band. That is, the filter 10 of the present application is an integrated three-band filter 10, which is low in cost and small in size.

[0053] Please also refer to Figure 3 and Figure 4 , Figure 4 for Figure 3 Schematic diagram illustrating the size details of the first resonant unit in FIG. The width of the first branch 111 is W1, the width of the second branch 112 is W2, the width of the third branch 113 is W3, and the width of the first connecting portion 114 is W4. The first multimode resonator 100 satisfies at least one of the following conditions: W1 < W2 and W3 < W2; W4 = W2.

[0054] In this embodiment, the first branch 111 has the same width at all locations. The second branch 112 has the same width at all locations. The third branch 113 has the same width at all locations. The first connecting portion 114 has the same width at all locations.

[0055] The first multi-mode resonator 100 satisfies at least one of the following conditions: W1<W2 and W3<W2; W 4＝ W2 specifically includes: the first multimode resonator 100 may satisfy W1<W2 and W3<W2, but does not satisfy W4=W2; or, the first multimode resonator 100 satisfies W4=W2, but does not satisfy W1<W2 and W3<W2; or, the first multimode resonator 100 satisfies W1<W2 and W3<W2, and also satisfies W4=W2.

[0056] In one embodiment, the width of the first branch 111 can be equal to the width of the third branch 113, that is, W1 = W3. When the width of the first branch 111 is equal to the width of the third branch 113, the design of the first resonant unit 110 can be simplified. It is understood that in other embodiments, the width of the first branch 111 can also be different from the width of the third branch 113.

[0057] The first multimode resonator 100 in the filter 10 provided in the embodiment of the present application satisfies at least one of the following conditions: W1 < W2 and W3 < W2; W4 = W2. On the one hand, the design complexity of the first multimode resonator 100 can be reduced, and the structure is simple and easy to implement. On the other hand, the filter 10 provided in the embodiment of the present application can have a first resonant mode that supports the first frequency band, a second resonant mode that supports the second frequency band, and a third resonant mode that supports the third frequency band. Therefore, the filter 10 can use a first multimode resonator 100 to pass signals in the first frequency band, the second frequency band, and the third frequency band. That is, the filter 10 of the present application is an integrated three-band filter 10, which is low in cost and small in size.

[0058] Please also refer to Figure 3and Figure 5 , Figure 5 for Figure 3 Schematic diagram of the structural details of the first resonant unit in the figure. The first branch 111 includes a first sub-branch 1111, a second sub-branch 1112 and a third sub-branch 1113 that are bent and connected in sequence. The third sub-branch 1113 is opposite to the first sub-branch 1111 and is spaced apart. The second branch 112 includes a fourth sub-branch 1121 and a fifth sub-branch 1122 that are bent and connected. One end of the fourth sub-branch 1121 is connected to an end of the third sub-branch 1113 that is away from the second sub-branch 1112. One end of the third branch 113 is connected to an end of the fifth sub-branch 1122 that is away from the fourth sub-branch 1121, and the other end of the third branch 113 is spaced apart from an end of the first sub-branch 1111 that is away from the second sub-branch 1112 to form the first opening 110b.

[0059] In the first branch 111, the first sub-branch 1111 extends along a first direction D1, the second sub-branch 1112 extends along a second direction D2, and the third sub-branch 1113 extends along the first direction D1. The third sub-branch 1113 is closer to the first feeder 300 than the first sub-branch 1111. In this embodiment, the first direction D1 is perpendicular to the second direction D2.

[0060] In the second branch 112, the fourth sub-branch 1121 extends along the first direction D1. The fifth sub-branch 1122 extends along the second direction D2. Since the width of the second branch 112 is greater than the width of the first branch 111 (i.e., W1 < W2), the width of the fourth sub-branch 1121 is greater than the width of the third sub-branch 1113. The side of the fourth sub-branch 1121 close to the first feeder 300 is flush or approximately flush with the side of the third sub-branch 1113 close to the first feeder 300. In this way, the design and preparation of the first resonant unit 110 can be facilitated, simplifying the design difficulty of the first resonant unit 110.

[0061] In one embodiment, the first connecting portion 114 is connected to the middle portion of the fifth sub-branch 1122. This simplifies the design of the first resonant unit 110.

[0062] Compared to the fourth sub-branch 1121 of the second branch 112 , the third branch 113 is away from the first feeder 300 .

[0063] In the filter 10 provided in this embodiment, the first branch 111, the second branch 112 and the third branch 113 in the first multimode resonator 100 are structurally designed so that the first multimode resonator 100 of the filter 10 has a first resonance mode that supports the first frequency band, a second resonance mode that supports the second frequency band and a third resonance mode that supports the third frequency band. Therefore, the filter 10 can use a first multimode resonator 100 to pass the signal of the first frequency band, the signal of the second frequency band and the signal of the third frequency band. That is, the filter 10 of the present application is an integrated three-band filter 10 with low cost and small size. In addition, the structures of the first branch 111, the second branch 112 and the third branch 113 are simple, which can be conducive to simplifying the design and facilitating preparation.

[0064] Please see further Figure 3 and Figure 5 The two first resonant units 110 are arranged along the first direction D1. The second sub-branch 1112 extends along the second direction D2, and the third sub-branch 1113 and the fourth sub-branch 1121 both extend along the first direction D1. The sum of the length of the third sub-branch 1113 along the first direction D1 and the length of the fourth sub-branch 1121 along the first direction D1 is greater than the length of the second sub-branch 1112 along the second direction D2.

[0065] In this embodiment, the two first resonant units 110 are arranged along the first direction D1, and the sum of the length of the third sub-branch 1113 along the first direction D1 and the length of the fourth sub-branch 1121 along the first direction D1 is greater than the length of the second sub-branch 1112 along the second direction D2. Therefore, the portion of the first multimode resonator 100 directly facing the first feeder 300 can be made longer. The first multimode resonator 100 can couple more energy of the first signal input by the first feeder 300, so that the energy of the second signal output by the first multimode resonator 100 is larger, and the performance is better.

[0066] In one embodiment, the first resonant mode is an odd-mode resonant mode, and the first resonant mode has a first resonant frequency point f that supports the first frequency band. 11 The second resonance mode is an even-mode resonance mode, and the second resonance mode has a second resonance frequency point f that supports the second frequency band. 12 The third resonance mode is an odd-mode resonance mode, and the third resonance mode has a third resonance frequency point f that supports the third frequency band. 13 , where f 11 <f 12 <f 13 .

[0067] In one embodiment, the first frequency band is a transmit sub-band (RX) of the B1 frequency band or a transmit sub-band (RX) of the N1 frequency band; the second frequency band is a transceiver frequency band (TRX) of the B41 frequency band or a transceiver frequency band (TRX) of the N41 frequency band; and the third frequency band is a transceiver frequency band (TRX) of the N77 frequency band. However, this should not be construed as limiting the embodiments of the present application. It is understood that in other embodiments, the first frequency band, the second frequency band, and the third frequency band may also be other operating frequency bands.

[0068] In one embodiment, the first frequency band is a transmit sub-band (RX) of the B1 frequency band or a transmit sub-band (RX) of the N1 frequency band, and the center operating frequency of the first frequency band is 2.10 GHz. The second frequency band is a transceiver frequency band (TRX) of the B41 frequency band or a transceiver frequency band (TRX) of the N41 frequency band, and the center operating frequency of the second frequency band is 2.55 GHz. The third frequency band is a transceiver frequency band (TRX) of the N77 frequency band, and the center operating frequency of the third frequency band is 4.20 GHz.

[0069] In the filter 10 in this embodiment, the first resonant mode is an odd-mode resonant mode, the second resonant mode is an even-mode resonant mode, and the third resonant mode is an odd-mode resonant mode. Therefore, the filter 10 can realize the signal of the first frequency band corresponding to the first resonant mode, the signal of the second frequency band corresponding to the second resonant mode, and the signal of the third frequency band corresponding to the third resonant mode.

[0070] Therefore, the filter 10 can pass signals in the first frequency band, the second frequency band, and the third frequency band using a first multimode resonator 100. That is, the filter 10 of the present application is an integrated three-band filter 10 with low cost and small size.

[0071] Please also refer to Figure 1 and Figure 6 , Figure 6 for Figure 1 A schematic diagram of a first coupling gap between a first multimode resonator and a first feeder in a filter is shown. A first coupling gap 100a is provided between the first multimode resonator 100 and the first feeder 300, and a width g1 of the first coupling gap 100a satisfies: g1≤1.5mm.

[0072] The width g1 of the first coupling gap 100a may be, but is not limited to, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0073] The size of the first coupling gap 100a between the first multimode resonator 100 and the first feeder 300 determines, to a certain extent, the bandwidths of the first, second, and third frequency bands. The first coupling gap 100a between the first multimode resonator 100 and the first feeder 300 has a width g1 that satisfies the requirement g1 ≤ 1.5 mm. This allows the filter 10 to have relatively large bandwidths in the first, second, and third frequency bands, resulting in better performance.

[0074] See also Figure 7 , Figure 7 This is a schematic structural diagram of a filter provided in another embodiment of the present application. In this embodiment, the filter 10 includes a first feeder 300, a first multimode resonator 100, and a second feeder 500. The first feeder 300, the first multimode resonator 100, and the second feeder 500 are described above and will not be repeated here. In addition, in this embodiment, the filter 10 also includes a second multimode resonator 200. The filter 10 also includes a second multimode resonator 200, which can be incorporated into the filter 10 provided in any of the previous embodiments. The second multimode resonator 200 is located on the side of the first multimode resonator 100 facing away from the first feeder 300. The second multimode resonator 200 is spaced apart from the first multimode resonator 100 by a second coupling gap 100b, and the second multimode resonator 200 is spaced apart and coupled to the second feeder 500. The second multimode resonator 200 has a first mode that supports the first frequency band, a second mode that supports the second frequency band, and a third mode that supports the third frequency band.

[0075] The second multimode resonator 200 is also referred to as a resonant unit or resonator unit. The second multimode resonator 200 is located on a side of the first multimode resonator 100 facing away from the first feeder 300. The second multimode resonator 200 is spaced apart and coupled to the first multimode resonator 100. The first multimode resonator 100 is coupled to the first feeder 300 to receive the signal to be filtered. That is, the first multimode resonator 100 is coupled to the first feeder 300 to receive the first signal. The second multimode resonator 200 cooperates with the first multimode resonator 100 to pass signals in the first frequency band, the second frequency band, and the third frequency band.

[0076] The second multimode resonator 200 has a first mode that supports a first frequency band, a second mode that supports a second frequency band, and a third mode that supports a third frequency band. In other words, the second multimode resonator 200 has a first mode, a second mode, and a third mode, and the second multimode resonator 200 is used to pass signals in the first frequency band, the second frequency band, and the third frequency band. The first mode is also a resonant mode, the second mode is also a resonant mode, and the third mode is also a resonant mode. In order to distinguish the three resonant modes in the second multimode resonator 200 from the resonant modes in the first multimode resonator 100, the three resonant modes in the second resonator are named the first mode, the second mode, and the third mode, respectively.

[0077] Compared to the filter 10 including the first multimode resonator 100 but not including the second multimode resonator 200, the filter 10 in this embodiment includes the first multimode resonator 100 and the second multimode resonator 200. The first multimode resonator 100 and the second multimode resonator 200 cooperate so that the first frequency band passed by the filter 10 has a relatively large bandwidth, the second frequency band passed by the filter 10 has a relatively large bandwidth, and the third frequency band passed by the filter 10 has a relatively large bandwidth.

[0078] In one embodiment, the first multimode resonator 100 cooperates with the second multimode resonator 200 to pass signals in a first frequency band, a second frequency band, and a third frequency band, and filter out signals in frequency bands other than the first frequency band, the second frequency band, and the third frequency band, to obtain a second signal.

[0079] In summary, the filter 10 provided in the embodiment of the present application has a first multimode resonator 100 that supports a first resonant mode for a first frequency band, a second resonant mode for a second frequency band, and a third resonant mode for a third frequency band; and the second multimode resonator 200 of the filter 10 has a first mode that supports the first frequency band, a second mode that supports the second frequency band, and a third mode that supports the third frequency band. Therefore, the first multimode resonator 100 and the second multimode resonator 200 in the filter 10 cooperate to pass signals in the first frequency band, the second frequency band, and the third frequency band. Furthermore, the first frequency band, the second frequency band, and the third frequency band can each have a relatively large bandwidth.

[0080] In one embodiment, the first multimode resonator 100 is symmetrical to the second multimode resonator 200. When the first multimode resonator 100 is symmetrical to the second multimode resonator 200, the design complexity of the filter 10 can be reduced, and the structure is simple and easy to implement.

[0081] Next, the specific structure of the first multi-mode resonator 100 is described in detail. Figure 8 and Figure 9 , Figure 8 for Figure 7 Schematic diagram of a second multimode resonator shown in ; Figure 9 for Figure 8 Schematic diagram of the second resonant unit in the second multimode resonator shown in . The second multimode resonator 200 includes a symmetrically arranged second resonant unit 210. The second resonant unit 210 includes a first portion 211, a second portion 212, a third portion 213 and a second connecting portion 214. One end of the second portion 212 is connected to one end of the first portion 211. One end of the third portion 213 is connected to the other end of the second portion 212. The first portion 211, the second portion 212 and the third portion 213 cooperate to form a second enclosed space 210a. The other end of the third portion 213 is opposite to the other end of the first portion 211 and is spaced apart to form a second opening 210b. The second opening 210b is connected to the second enclosed space 210a. The second connecting portion 214 is connected to the second portion 212, and the second connecting portions 214 of the two second resonant units 210 are connected.

[0082] In this embodiment, the first multimode resonator 100 and the second multimode resonator 200 are arranged along the second direction D2. The two second resonant units 210 are arranged along the first direction D1. The second multimode resonator 200 includes two symmetrically arranged second resonant units 210. Therefore, the second multimode resonator 200 is also referred to as a symmetrical transmission network. In the schematic diagram of this embodiment, the second multimode resonator 200 includes two second resonant units 210 symmetrically arranged along the dashed line L1 as an example.

[0083] In this embodiment, the second connecting portion 214 is connected to the second portion 212, and the second connecting portions 214 of the two second resonant units 210 in the second multi-mode resonator 200 are connected. The second connecting portion 214 of one of the two second resonant units 210 and the second connecting portion 214 of the other of the two second resonant units 210 are also arranged along the first direction D1.

[0084] The second multimode resonator 200 provided in the embodiment of the present application includes two symmetrically arranged second resonance units 210, and the second resonance unit 210 includes a first part 211, a second part 212, a third part 213 and a second connecting part 214, which can realize the first mode supporting the first frequency band, the second mode supporting the second frequency band and the third mode supporting the third frequency band. In addition, the filter 10 provided in the embodiment of the present application can reduce the complexity of the design and has a simple and easy structure. The filter 10 provided in the embodiment of the present application has a first mode supporting the first frequency band, a second mode supporting the second frequency band and a third mode supporting the third frequency band. Therefore, the filter 10 can use the first multimode resonator 100 and the second multimode resonator 200 to cooperate to realize the signal passing through the first frequency band, the signal passing through the second frequency band and the signal passing through the third frequency band. That is, the filter 10 of the present application is an integrated three-band filter 10, which has a low cost and a relatively large bandwidth.

[0085] Please also refer to Figure 9 and Figure 10 , Figure 10 for Figure 9 Schematic diagram illustrating the size details of the first resonant unit in FIG. The width of the first portion 211 is W'1, the width of the second portion 212 is W'2, the width of the third portion 213 is W'3, and the width of the second connecting portion 214 is W'4. The second multimode resonator 200 satisfies at least one of the following conditions: W'1 < W'2 and W'3 < W'2; W'4 = W'2.

[0086] In this embodiment, the first portion 211 has the same width at all locations. The second portion 212 has the same width at all locations. The third portion 213 has the same width at all locations. The second connecting portion 214 has the same width at all locations.

[0087] The second multimode resonator 200 satisfies at least one of the following: W'1<W'2 and W'3<W'2; W'4=W'2, specifically including: the second multimode resonator 200 may satisfy W'1<W'2 and W'3<W'2, but does not satisfy W'4=W'2; or, the second multimode resonator 200 satisfies W'4=W'2, but does not satisfy W'1<W'2 and W'3<W'2; or, the second multimode resonator 200 satisfies both W'1<W'2 and W'3<W'2, and also satisfies W'4=W'2.

[0088] In one embodiment, the width of the first portion 211 can be equal to the width of the third portion 213, that is, W'1 = W'3. When the width of the first portion 211 is equal to the width of the third portion 213, the design of the second resonant unit 210 can be simplified. It is understood that in other embodiments, the width of the first portion 211 can also be different from the width of the third portion 213.

[0089] The second multimode resonator 200 in the filter 10 provided in the embodiment of the present application satisfies at least one of the following conditions: W'1<W'2 and W'3<W'2; W'4=W'2. On the one hand, the design complexity of the second multimode resonator 200 can be reduced, and the structure is simple and easy. On the other hand, the filter 10 provided in the embodiment of the present application can have a first mode supporting the first frequency band, a second mode supporting the second frequency band, and a third mode supporting the third frequency band. Therefore, the filter 10 can utilize the first multimode resonator 100 and the second multimode resonator 200 to cooperate to pass the signal of the first frequency band, the signal of the second frequency band, and the signal of the third frequency band. That is, the filter 10 of the present application is an integrated three-band filter 10 with low cost and relatively large bandwidth.

[0090] Please also refer to Figure 7 、 Figure 9 and Figure 11 , Figure 11 for Figure 9 Schematic diagram of the structural details of the first resonant unit in FIG. The first portion 211 includes a first sub-portion 2111, a second sub-portion 2112, and a third sub-portion 2113 that are bent and connected in sequence. The third sub-portion 2113 is opposite to the first sub-portion 2111 and spaced apart. The second portion 212 includes a fourth sub-portion 2121 and a fifth sub-portion 2122 that are bent and connected. One end of the fourth sub-portion 2121 is connected to an end of the third sub-portion 2113 that is away from the second sub-portion 2112. One end of the third portion 213 is connected to an end of the fifth sub-portion 2122 that is away from the fourth sub-portion 2121, and the other end of the third portion 213 is spaced apart from an end of the first sub-portion 2111 that is away from the second sub-portion 2112 to form the second opening 210b.

[0091] In the first portion 211, the first sub-portion 2111 extends along the first direction D1, the second sub-portion 2112 extends along the second direction D2, and the third sub-portion 2113 extends along the first direction D1. The third sub-portion 2113 is closer to the second feeder 500 than the first sub-portion 2111. In this embodiment, the first direction D1 is perpendicular to the second direction D2.

[0092] In the second portion 212, the fourth sub-portion 2121 extends along the first direction D1. The fifth sub-portion 2122 extends along the second direction D2. Because the width of the second portion 212 is greater than the width of the first portion 211 (i.e., W1 < W2), the width of the fourth sub-portion 2121 is greater than the width of the third sub-portion 2113. The side of the fourth sub-portion 2121 near the second feeder 500 is flush or approximately flush with the side of the third sub-portion 2113 near the second feeder 500. This facilitates the design and preparation of the second resonant unit 210, simplifying the design of the second resonant unit 210.

[0093] In one embodiment, the second connecting portion 214 is connected to the middle portion of the fifth sub-portion 2122. In this way, the design difficulty of the second resonant unit 210 can be simplified.

[0094] The third portion 213 is farther away from the second feeder 500 than the fourth sub-portion 2121 of the second portion 212 .

[0095] In the filter 10 provided in this embodiment, the first portion 211, the second portion 212, and the third portion 213 in the second multimode resonator 200 are structurally designed so that the second multimode resonator 200 of the filter 10 has a first mode that supports the first frequency band, a second mode that supports the second frequency band, and a third mode that supports the third frequency band. Therefore, the first multimode resonator 100 and the second multimode resonator 200 can cooperate to pass the signal of the first frequency band, the signal of the second frequency band, and the signal of the third frequency band. That is, the filter 10 of the present application is an integrated three-band filter 10, which has a low cost and a relatively large bandwidth. That is, the filter 10 of the present application is an integrated three-band filter 10, which has a low cost and a small size. In addition, the structures of the first portion 211, the second portion 212, and the third portion 213 are simple, which can be conducive to simplifying the design and facilitating preparation.

[0096] Please see further Figure 8 、 Figure 9 and Figure 11 The two second resonant units 210 are arranged along the first direction D1. The second sub-portion 2112 extends along the second direction D2. The third sub-portion 2113 and the fourth sub-portion 2121 both extend along the first direction D1. The sum of the length of the third sub-portion 2113 along the first direction D1 and the length of the fourth sub-portion 2121 along the first direction D1 is greater than the length of the second sub-portion 2112 along the second direction D2.

[0097] In this embodiment, the two second resonant units 210 are arranged along the first direction D1, and the sum of the length of the third sub-portion 2113 along the first direction D1 and the length of the fourth sub-portion 2121 along the first direction D1 is greater than the length of the second sub-portion 2112 along the second direction D2. Therefore, the portion directly opposite the second multi-mode resonator 200 and the second feeder 500 can be made longer, and the second feeder 500 can couple more energy from the second multi-mode resonator 200. As a result, the energy of the second signal outputted from the output end 500a of the second feeder 500 is greater, thereby achieving better performance.

[0098] Furthermore, in one embodiment, the first mode is an odd-mode resonance mode, and the first mode supports a resonance frequency point f in the first frequency band. 21 The second mode is an even-mode resonance mode, and the second mode supports a resonance frequency point of the second frequency band as the second frequency point f 22 The third mode is an odd-mode resonance mode, and the resonance frequency point of the third frequency band supported by the third mode is the third frequency point f 23 , where f 21 <f 22 <f 23 .

[0099] In one embodiment, the first frequency band is a transmit sub-band (RX) of the B1 frequency band or a transmit sub-band (RX) of the N1 frequency band; the second frequency band is a transceiver frequency band (TRX) of the B41 frequency band or a transceiver frequency band (TRX) of the N41 frequency band; and the third frequency band is a transceiver frequency band (TRX) of the N77 frequency band. However, this should not be construed as limiting the embodiments of the present application. It is understood that in other embodiments, the first frequency band, the second frequency band, and the third frequency band may also be other operating frequency bands.

[0100] In one embodiment, the first frequency band is a transmit sub-band (RX) of the B1 frequency band or a transmit sub-band (RX) of the N1 frequency band, and the center operating frequency of the first frequency band is 2.10 GHz. The second frequency band is a transceiver frequency band (TRX) of the B41 frequency band or a transceiver frequency band (TRX) of the N41 frequency band, and the center operating frequency of the second frequency band is 2.55 GHz. The third frequency band is a transceiver frequency band (TRX) of the N77 frequency band, and the center operating frequency of the third frequency band is 4.20 GHz.

[0101] In the filter 10 in this embodiment, the first mode is an odd-mode resonance mode, the second mode is an even-mode resonance mode, and the third mode is an odd-mode resonance mode. Therefore, the filter 10 can realize the signal of the first frequency band corresponding to the first mode, the signal of the second frequency band corresponding to the second mode, and the signal of the third frequency band corresponding to the third mode.

[0102] Therefore, the filter 10 can utilize the first multimode resonator 100 and the second multimode resonator 200 to pass signals in the first frequency band, the second frequency band, and the third frequency band, and the bandwidths in the first frequency band, the second frequency band, and the third frequency band are relatively large.

[0103] In one embodiment, the first resonant mode has a first resonant frequency point f supporting a first frequency band. 11 , where f 11 <f 21 The second resonant mode has a second resonant frequency point f that supports a second frequency band. 12 , where f 12 <f 22 The third resonance mode has a third resonance frequency point f supporting a third frequency band. 13 , where f 13 <f 23 .

[0104] The first frequency band includes at least the first resonant frequency point and the first frequency point. Therefore, in this embodiment, f 11 <f 21 The first frequency band can have a larger bandwidth. Accordingly, the second frequency band includes at least the second resonant frequency point and the second frequency point. Therefore, in this embodiment, f 12 <f 22 The second frequency band can have a larger bandwidth. Accordingly, the third frequency band includes at least the second resonant frequency point and the second frequency point. Therefore, in this embodiment, f 13 <f 23 The third frequency band can have a larger bandwidth.

[0105] See also Figure 12 , Figure 12 for Figure 7 The filter 10 satisfies at least one of the following conditions: a width g2 of the second coupling gap 100b satisfies g2 ≤ 1.5 mm; a third coupling gap 200a is provided between the second multimode resonator 200 and the second feed line 500, and a width g3 of the third coupling gap 200a satisfies g3 ≤ 1.5 mm.

[0106] The width g2 of the second coupling gap 100b may be, but is not limited to, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0107] The width g3 of the third coupling gap 200a may be, but is not limited to, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0108] The size of the second coupling gap 100b between the second multimode resonator 200 and the first multimode resonator 100, as well as the size of the third coupling gap 200a between the second multimode resonator 200 and the second feeder, also determine, to a certain extent, the bandwidths of the first, second, and third frequency bands. The width g2 of the second coupling gap 100b satisfies the requirement g2 ≤ 1.5 mm. A third coupling gap 200a exists between the second multimode resonator 200 and the second feeder 500, and the width g3 of the third coupling gap 200a satisfies the requirement g3 ≤ 1.5 mm. This results in relatively large bandwidths in the first, second, and third frequency bands of the filter 10, resulting in better performance.

[0109] Furthermore, in this embodiment, a first coupling gap 100 a is defined between the first multi-mode resonator 100 and the first feed line 300 , and a width g1 of the first coupling gap 100 a satisfies: g1 ≤ 1.5 mm.

[0110] The width g1 of the first coupling gap 100a may be, but is not limited to, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0111] The size of the first coupling gap 100a between the first multimode resonator 100 and the first feeder 300 determines, to a certain extent, the bandwidths of the first, second, and third frequency bands. The first coupling gap 100a between the first multimode resonator 100 and the first feeder 300 has a width g1 that satisfies the requirement g1 ≤ 1.5 mm. This allows the filter 10 to have relatively large bandwidths in the first, second, and third frequency bands, resulting in better performance.

[0112] Next, the design concept of the filter 10 provided in the embodiment of the present application is described in detail. When describing the design concept of the filter 10 provided in the embodiment of the present application, the filter 10 including the first feeder 300, the first multimode resonator 100, the second multimode resonator 200, and the second feeder 500 is used as an example for introduction. It is understood that this should not be construed as limiting the filter 10 provided in the embodiment of the present application.

[0113] The filter 10 can also be referred to as a microstrip filter 10. As can be seen from the structures of the first multimode resonator 100 and the second multimode resonator 200 described above, the first multimode resonator 100 is shaped like an "H," and the second multimode resonator 200 is shaped like an "H." Therefore, the filter 10 can also be considered to be composed of two multimode resonator components similar to an "H." The prototype of the multimode resonator is a two-order Chebyshev low-pass prototype. The first multimode resonator 100 includes symmetrically arranged first resonant units 110, thus forming a symmetrical transmission network. The second multimode resonator 200 includes symmetrically arranged second resonant units 210, thus forming a symmetrical transmission network. In other words, an "H"-shaped multimode resonator is a symmetrical transmission network. In this embodiment, the first multimode resonator 100 and the second multimode resonator 200 are designed to be symmetrical about a centerline. The operating frequency bands of the three resonant modes of the filter 10 are designed based on microstrip line theory and even and odd mode analysis theory. Specifically, the central operating frequency of the first frequency band is designed to be 2.10 GHz, the central operating frequency of the second frequency band is designed to be 2.55 GHz, and the central operating frequency of the third frequency band is designed to be 4.20 GHz. It should be noted that the relative fractional bandwidth of the first frequency band is Δ 1st =8.75%, the relative fractional bandwidth of the second frequency band is Δ 2nd =3.97%, the relative fractional bandwidth Δ of the third frequency band 3rd =2.19%.

[0114] In this embodiment, the first multi-mode resonator 100 and the second multi-mode resonator 200 are designed symmetrically. Next, the design concept of the first multi-mode resonator 100 is introduced as an example.

[0115] Please also refer to Figure 13 and Figure 14 (a) and (b) in Figure 13 A schematic diagram of a first multi-mode resonator according to an embodiment of the present application; Figure 14 (a) in Figure 13 Schematic diagram of the equivalent structure of the first multi-mode resonator in terms of odd-mode resonant modes and; Figure 14 (b) in Figure 13 Schematic diagram of the equivalent structure of the first multimode resonator for the even mode resonance mode. Since the first multimode resonator 100 includes two symmetrical first resonance units 110, that is, the first multimode resonator 100 is a symmetrical transmission network. Therefore, the odd-even mode theory analysis method is used for the first multimode resonator 100. For the odd mode resonance mode, it is equivalent to Figure 14 The differential circuit shown in (a) in FIG; For even-mode resonance, the equivalent is Figure 14 The differential mode circuit shown in (b) is Figure 14 For (a) in the figure, the first grounding portion is grounded. For the odd-mode resonant mode, the Figure 14 The structure shown in (a) in the figure; for the even-mode resonance mode, the Figure 14 The structure in (b).

[0116] The first resonant unit 110 of the first multimode resonator 100 includes a first branch 111, a second branch 112, a third branch 113, and a first connecting portion 114. Therefore, the first resonant unit 110 can be considered to include four branches, and the impedances of the first branch 111, the second branch 112, the third branch 113, and the first connecting portion 114 are not consistent. The electrical length constant of the first branch 111 is θ1, corresponding to an actual physical length of L1; the impedance is Y1, corresponding to an actual width of W1. Correspondingly, the electrical length constant of the second branch 112 is θ2, corresponding to an actual physical length of L2; the impedance is Y2, corresponding to an actual width of W2. The electrical length constant of the third branch 113 is θ3, corresponding to an actual physical length of L3; the impedance is Y3, corresponding to an actual width of W3. The electrical length constant of the fourth branch is θ4, corresponding to an actual physical length of L4; the impedance is Y4, corresponding to an actual width of W4. In this embodiment, in order to reduce the number of variables in the first multi-mode resonator 100 and facilitate design, Y4=Y2, W 4＝ W2.

[0117] For the odd-mode resonance mode, the formula of the odd-mode resonance mode is shown in formula (1).

[0118]

[0119] Among them, Y in1 is the impedance of the odd-mode resonant mode, and j represents the imaginary part.

[0120] For Y A See formula (2), Y A This is a formula specific to the odd-mode resonance mode, indicating a short-circuit type.

[0121]

[0122] In order to reduce the number of variables in the first multimode resonator 100 and facilitate the design of the first multimode resonator 100 , θ3=θ4 is set, and θ3=θ4 is combined with formula (1) and formula (2) to obtain formula (3).

[0123]

[0124] According to the resonance condition IM(Y in1 )=0 to obtain formula (4).

[0125] Y2tanh 2 θ3+Y2tanθ2tanθ3+Y3tanθ1tanθ3-Y2tanθ1(tan 2 θ3-1)=0 (4).

[0126] Among them, IM(Y in1 ) represents normalization, IM(Y in1 )=0 is the resonance condition of the odd-mode resonance mode, that is, the imaginary part in formula (3) is equal to zero, and formula (4) is obtained.

[0127] For the even-mode resonance mode, the formula of the even-mode resonance mode is shown in formula (5).

[0128]

[0129] Among them, Y in2 is the impedance of the even-mode resonant mode, and j represents the imaginary part.

[0130] For Y B Please refer to formula (6), Y B This is a formula specific to the even-mode resonance mode, indicating an open-circuit type.

[0131] Y B =jY3tanθ3 (6).

[0132] Combining formula (5) and formula (6) yields formula (7).

[0133]

[0134] Similarly, for formula (7), formula (8) is obtained from the resonance condition of the even mode. That is, the imaginary part of the numerator of formula (7) is equal to zero, which results in formula (8).

[0135] Y2Y3tanθ3+Y2 2 tanθ2+Y1Y2tanθ1+Y1Y2tanθ1tanθ2=0 (8).

[0136] In order to reduce the number of variables and facilitate the design of the filter 10, the concept of impedance ratio is introduced. Definition: K1 = Y1 / Y2, K2 = Y3 / Y1.

[0137] Then, substituting K1=Y1 / Y2, K2=Y3 / Y1 into the equation (4) of the odd-mode resonance mode, we obtain the resonance condition equation (9) of the odd-mode resonance mode. The resonance condition of the odd-mode resonance mode can also be referred to as the odd-mode resonance condition.

[0138] K1tan 2 θ3+K1tanθ2tanθ3+K2tanθ1tanθ3-K1tanθ1(tan 2 θ3-1)=0 (9).

[0139] Accordingly, substituting K1=Y1 / Y2 and K2=Y3 / Y1 into the even-mode resonance mode formula (8), we obtain the resonance condition formula (10) of the even-mode resonance mode. The resonance condition of the even-mode resonance mode can also be referred to as the even-mode resonance condition.

[0140] K2tanθ3+K1tanθ2+K1tan θ1+K1tanθ1tanθ2=0 (10).

[0141] In order to reduce the number of variables and facilitate the design of the filter 10, the concept of electrical length ratio is introduced, as shown in formula (11), where formula (11) includes (11)-a, (11)-b, and (11)-c.

[0142] M1=θ1 / (θ1+θ2+θ3)(11)-a;

[0143] M2=θ2 / (θ1+θ2+θ3)(11)-b;

[0144] M3=θ3 / (θ1+θ2+θ3)(11)-c;

[0145] Substituting formula (11) into the odd-mode resonance condition formula (9), it can be seen that the odd-mode resonance condition can be adjusted by two pairs of impedance ratios K1 and K2 and three pairs of electrical length ratios M1, M2, and M3. Correspondingly, substituting formula (11) into the even-mode resonance condition formula (10), it can be seen that the even-mode resonance condition can be adjusted by two pairs of impedance ratios K1 and K2 and three pairs of electrical length ratios M1, M2, and M3. Thus, it can be seen that the filter 10 provided in the embodiment of the present application can reduce design complexity and has a simple and easy structure.

[0146] By adjusting the two pairs of impedance ratios K1 and K2 and the three pairs of electrical length ratios M1, M2, and M3, the size of the first frequency band, the size of the second frequency band, and the size of the third frequency band supported by the filter 10 can be adjusted, thereby achieving the adjustment of the first frequency band, the second frequency band, and the third frequency band supported by the filter 10. It can be seen that the filter 10 provided in the embodiment of the present application is a frequency-adjustable three-band filter 10.

[0147] The formulas for odd-mode resonance conditions and even-mode resonance conditions are used to obtain a function, and the first multimode resonator 100 of the filter 10 of the present application can generate an odd-mode resonance mode (abbreviated as odd mode) and two even-mode resonance modes (abbreviated as even mode). Figure 15 , Figure 15 This is a schematic diagram of a resonant mode generated by a first multimode resonator in a filter provided in one embodiment of the present application. In this schematic diagram, the horizontal axis represents frequency in GHz, and the vertical axis represents |S21| in dB. The first resonant mode is an odd-mode resonant mode, and the first resonant mode has a first resonant frequency point f that supports the first frequency band. 11 The second resonance mode is an even-mode resonance mode, and the second resonance mode has a second resonance frequency point f that supports the second frequency band. 12 The third resonance mode is an odd-mode resonance mode, and the third resonance mode has a third resonance frequency point f that supports the third frequency band. 13 , where f 11 <f 12 <f 13 .

[0148] As can be seen from the above description, the shape of the first multi-mode resonator 100 is similar to an "H" and has three resonance modes (also called three resonance modes): a first resonance mode, a second resonance mode, and a third resonance mode. Further optimization design results in a Chebyshev-type three-bandpass filter 10 with a second-order resonance mode. Please refer to further Figure 1 or Figure 7The filter 10 provided in the embodiment of the present application further includes a first feeder 300, which may be, but is not limited to, a microstrip coupling feeder. Therefore, microstrip coupling feeding is adopted between the first multimode resonator 100 and the first feeder 300. Introducing the coupling coefficient and the external Q value can affect the center frequency of each frequency band of the first frequency band, the second frequency band, and the third frequency band of the filter 10 and the bandwidth of each resonant mode. Specifically, the external Q value Q e Please refer to formula (12) for the calculation method of the external coupling coefficient M ij Please refer to formula (13) for the formula.

[0149]

[0150] In formula (12), Δf ±90° Indicates the bandwidth over which the phase changes from -90° to +90° at resonance. H and f L Respectively represent the high and low frequencies of the two coupling modes supported by the second multimode resonator 200 and the first multimode resonator 100 in the same frequency band. For example, for a first frequency band, the first mode of the second multimode resonator 200 and the first resonant mode of the first multimode resonator 100 support the first frequency band, then f H represents the maximum frequency of the first frequency band supported by the first mode of the second multimode resonance 200, f L represents the minimum frequency of the first frequency band supported by the first resonance mode of the first multimode resonator 100. Accordingly, for the second frequency band, the second mode of the second multimode resonator 200 and the second resonance mode of the first multimode resonator 100 support the second frequency band, then f H represents the maximum frequency of the second frequency band supported by the second mode of the second multimode resonator 200, f L represents the minimum frequency of the second frequency band supported by the second resonance mode of the first multimode resonator 100. For the third band, the third mode of the second multimode resonator 200 and the third resonance mode of the first multimode resonator 100 support the third frequency band, then f H represents the maximum frequency of the third frequency band supported by the third mode of the second multi-mode resonator 200, f Lrepresents the minimum frequency of the third frequency band supported by the third resonant mode of the first multimode resonator 100. The width g1 of the first coupling gap 100a and the width g2 of the second coupling gap 100b can directly affect the coupling coefficient value after simulation. The first coupling gap 100a is also referred to as the gap length for coupling and feeding between the first feed line 300 and the first multimode resonator 100, and the second coupling gap 100b is also referred to as the gap length between the first multimode resonator 100 and the second multimode resonator 200.

[0151] In one embodiment, the first multimode resonator 100 and the second multimode resonator 200 are symmetrically arranged, and the first feed line 300 and the second feed line 500 are symmetrically arranged. Based on the above theory, appropriate dimensions are selected, and the width g1 of the first coupling gap 100a is designed to satisfy g1 ≤ 1.5 mm; the width g2 of the second coupling gap 100b is designed to satisfy g2 ≤ 1.5 mm. In one embodiment, g1 = 0.4 mm and g2 = 0.3 mm. Furthermore, the coupling coefficients for the three passbands are obtained as M1 = 0.0078, M2 = 0.0324, and M3 = 0.056; and the external Q values ​​are Q1 = 82.1, Q2 = 63.19, and Q2 = 96.27.

[0152] See also Figure 16 , Figure 16 This is a relationship diagram between the first coupling gap, the second coupling gap and the coupling coefficient in a filter according to an embodiment of the present application. Figure 16 (a) is a schematic diagram showing the relationship between the width g1 of the first coupling gap 100a in the filter 10 and the coupling coefficient. Figure 16 (b) is a schematic diagram showing the relationship between the width g2 of the second coupling gap 100b in the filter 10 and the coupling coefficient. Figure 16 (a) and Figure 16 In (b), the horizontal axis is the frequency in GHz, and the vertical axis is the coupling coefficient. Figure 16 (a) and Figure 16 In (b) of FIG. 1 , the second frequency band is marked as BandI. Figure 16 (a) and Figure 16 In (b) of FIG. 1 , the third frequency band is marked as Band II. Figure 16 (a) and Figure 16 The one in (b) is marked as Band III.

[0153] Depend on Figure 16As can be seen from (a) in FIG, the coupling coefficient of the first frequency band (Band I in the figure) is greatly affected by the width g1 of the first coupling gap 100a. The larger g1 is, the smaller the coupling coefficient of the first frequency band is, and the bandwidth of the first frequency band is affected. The larger g1 is, the larger the bandwidth of the first frequency band is. Accordingly, Figure 16 As can be seen from (a) in the figure, the coupling coefficient of the second frequency band (Band II in the figure) is greatly affected by the width g1 of the first coupling gap 100a. The larger g1 is, the smaller the coupling coefficient of the second frequency band is, and the bandwidth of the second frequency band is affected. The larger g1 is, the larger the bandwidth of the second frequency band is. Figure 16 As can be seen from (a) in FIG. 1 , the coupling coefficient in the third frequency band (Band III in the figure) is substantially unaffected by the width g1 of the first coupling gap 100 a .

[0154] Depend on Figure 16 As can be seen from (b) in FIG, the coupling coefficient of the first frequency band (Band I in the figure) is basically not affected by the width g2 of the second coupling gap 100b. Figure 16 As can be seen from (b) in the figure, the coupling coefficient of the second frequency band (Band II in the figure) is greatly affected by the width g2 of the second coupling gap 100b. The larger g2 is, the smaller the coupling coefficient of the second frequency band is, and the bandwidth of the second frequency band is affected. The larger g2 is, the larger the bandwidth of the second frequency band is. Figure 16 As can be seen from (b) in FIG, the coupling coefficient of the third frequency band (Band III in the figure) is greatly affected by the width g2 of the second coupling gap 100b. The larger g2 is, the smaller the coupling coefficient of the third frequency band is, and the bandwidth of the third frequency band is affected. The larger g2 is, the larger the bandwidth of the third frequency band is.

[0155] Furthermore, the filter 10 is simulated using High Frequency Structure Simulator (HFSS) software to obtain actual filtering characteristics S11 and S21. Figure 17 , Figure 17This is a schematic diagram of the HSS simulation of the filter provided in one embodiment of the present application. In this simulation diagram, the horizontal axis is frequency, in GHz, and the vertical axis is magnitude, in dB. Among them, S21 represents the insertion loss parameter of the filter 10, and S11 is the return loss parameter of the filter 10. It can be seen that the filter 10 provided in the embodiment of the present application has three passbands: the first frequency band, the second frequency band, and the third frequency band. The first frequency band is the transmit sub-band (RX) of the B1 frequency band or the transmit sub-band (RX) of the N1 frequency band, and the center operating frequency of the first frequency band is 2.10 GHz. The second frequency band is the transceiver frequency band (TRX) of the B41 frequency band or the transceiver frequency band (TRX) of the N41 frequency band, and the center operating frequency of the second frequency band is 2.55 GHz. The third frequency band is the transceiver frequency band (TRX) of the N77 frequency band, and the center operating frequency of the third frequency band is 4.20 GHz.

[0156] Furthermore, as can be seen from the simulation diagram, there are sufficient transmission zeros TZ1 to TZ6 outside the frequency points of the operating bandwidths of the three passbands, namely, the first frequency band, the second frequency band, and the third frequency band. Specifically, the transmission zeros are TZ1, TZ2, TZ3, TZ4, TZ5, and TZ6.

[0157] The filter 10 provided in the embodiment of the present application has transmission zero points TZ1~TZ6 outside the first frequency band, the second frequency band and the third frequency band. Therefore, the in-band selectivity of the three working frequency bands of the first frequency band, the second frequency band and the third frequency band and the out-band suppression selectivity of the non-working frequency band can be improved, the filtering rectangular coefficient can be increased, and the filtering effect can be improved.

[0158] In summary, a novel microstrip filter 10 is provided in one embodiment of the present application. The filter 10 provided in the embodiment of the present application can pass signals in the first frequency band, the second frequency band and the third frequency band, and is a passband filter 10 of three frequency bands (also called a three-band bandpass filter 10). Compared with the single-band passband filter 10, the three-band bandpass filter 10 provided in the embodiment of the present application is more practical, has lower cost and is smaller in size. Second, the filter 10 provided in the embodiment of the present application can use the impedance ratio and the electrical length ratio to design the frequency point of the first frequency band, the frequency point of the second frequency band and the frequency point of the third frequency band, and the bandpass has design flexibility. Third, the filter 10 provided in the embodiment of the present application adopts a coupling feeding method between the first multimode resonator 100 and the first feed line 300, and the first coupling gap 100a, the second coupling gap 100b and the third coupling gap 200a and the external Q value can be adjusted to adjust the bandwidth of the first frequency band, the second frequency band and the third frequency band.

[0159] See also Figure 18 , Figure 18 This is a schematic diagram of a radio frequency front-end circuit provided in one embodiment of the present application. In this embodiment, the radio frequency front-end circuit 3 includes a filter 10. Please refer to the previous description of the filter 10 and will not be repeated here.

[0160] See also Figure 19 , Figure 19 This is a schematic diagram of a radio frequency transceiver device provided in one embodiment of the present application. In this embodiment, the radio frequency transceiver device 2 includes a radiator 5 and a radio frequency front-end circuit 3. The radio frequency front-end circuit 3 is described above and will not be repeated here.

[0161] The radiator 5 can be a laser direct structuring (LDS) radiator 5, or a flexible printed circuit (FPC) radiator 5, or a print direct structuring (PDS) radiator 5, or a metal branch radiator 5. When the RF transceiver 2 is applied to an electronic device 1, the radiator 5 can be a mechanical design antenna (MDA) radiator 5 designed with metal inserts of the electronic device 1 itself. For example, the radiator 5 can be formed by the middle frame 6 of the plastic and metal of the electronic device 1 (see Figure 20 ) designed antenna radiator 5. In addition, the radiator 5 can also be a metal frame radiator 5 designed with a metal middle frame 6.

[0162] In one embodiment, the filter 10 is located in the signal receiving path of the RF transceiver 2. Specifically, in one embodiment, the RF front-end circuit 3 of the RF transceiver 2 further includes a baseband chip 20 and a low-noise amplifier (LNA) 30. The input end 300a of the filter 10 is electrically connected to the radiator 5, and the output end 500a of the filter 10 is electrically connected to the baseband chip 20. The radiator 5 is configured to receive an electromagnetic wave signal and convert the electromagnetic wave signal into an RF signal to obtain a first signal. The input end 300a of the filter 10 receives the first signal, passes the signals of the first frequency band, the second frequency band, and the third frequency band in the first signal, and filters out the signals of other frequency bands to obtain a second signal, which is output via the output end 500a. The baseband chip 20 receives the second signal and amplifies the power of the second signal. In one embodiment, the RF front-end circuit 3 further includes a baseband chip 20. The baseband chip 20 is electrically connected to the baseband chip 20 to receive the power-amplified second signal.

[0163] In another embodiment, the filter 10 is located in the signal transmission path of the RF transceiver 2. Specifically, in one embodiment, the RF front-end circuit 3 of the RF transceiver 2 further includes a baseband chip 20 and a power amplifier 50 (PA). The baseband chip 20 is configured to output a first signal. The input end 300a of the filter 10 is electrically connected to the baseband chip 20. The input end 300a of the filter 10 receives the first signal, passes signals in the first frequency band, the second frequency band, and the third frequency band within the first signal, and filters out signals in other frequency bands to obtain a second signal, which is output via the output end 500a. The power amplifier 50 is electrically connected to the output end 500a of the filter 10. The power amplifier 50 is configured to amplify the power of the second signal. The filter 10 is electrically connected to the radiator 5 to transmit the amplified second signal to the radiator 5. For ease of description, the filter in the signal reception path of the RF transceiver 2 is labeled 10a; the filter 10 in the signal transmission path of the RF transceiver 2 is labeled 10b.

[0164] It can be understood that the RF front-end circuit 3 provided in the embodiment of the present application is only an introduction to an application scenario of the filter 10, and should not be understood as a limitation on the filter 10 provided in the embodiment of the present application, nor should it be understood that when the filter 10 is applied to the RF front-end circuit 3, the RF front-end circuit 3 must include the baseband chip 20, the baseband chip 20 and the power amplifier 50. The embodiment of the present application does not limit whether the RF front-end circuit 3 includes the baseband chip 20, the baseband chip 20 and the power amplifier 50, as long as the RF front-end circuit 3 includes the filter 10. Further, in the schematic diagram of the present embodiment, the signal receiving path of the RF transceiver 2 includes the filter 10, and the signal transmitting path of the RF transceiver 2 also includes the filter 10 for illustration. It can be understood that in other embodiments, one of the signal receiving path and the signal transmitting path of the RF transceiver 2 includes the filter 10.

[0165] See also Figure 20 , Figure 20 This is a schematic diagram of an electronic device provided in one embodiment of the present application. The electronic device 1 includes a radio frequency transceiver 2. The radio frequency transceiver 2 is described above and will not be described again here.

[0166] The present embodiment provides an electronic device 1, which may be a mobile phone, tablet computer, desktop computer, laptop computer, e-reader, handheld computer, electronic display, notebook computer, ultra-mobile personal computer (UMPC), netbook, cellular phone, personal digital assistant (PDA), augmented reality (AR) / virtual reality (VR) device, media player, smart wearable device, vehicle-mounted terminal, or other device having a radio frequency transceiver 2. In this embodiment, the electronic device 1 is illustrated and described as a mobile phone, which should not be construed as limiting the embodiment of the present application.

[0167] In one embodiment, the electronic device 1 further includes a middle frame 6, a display screen 7 and a back cover 8. The display screen 7 is arranged on one side of the middle frame 6. The display screen 7 is a component in the electronic device 1 that realizes the display function. The display screen 7 can be, but is not limited to, a screen with a touch function, or a screen without a touch function, and this application does not limit this. The back cover 8 is arranged on the other side of the middle frame 6. In other words, the back cover 8 and the display screen 7 are respectively arranged on two opposite sides of the middle frame 6. When the electronic device 1 also includes a battery, the back cover 8 is also called a battery cover. The material of the back cover 8 can be metal or non-metal, and is not limited in this embodiment. It can be understood that the introduction of the embodiment of the present application is an introduction to an application environment of the radio frequency transceiver 2, and should not be understood as a limitation on the electronic device 1 provided in the embodiment of the present application.

[0168] The above is part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A filter, characterized in that: The filter comprises: a first feeder having an input end; a first multimode resonator, the first multimode resonator being located on one side of the first feeder, the first multimode resonator being spaced apart from and coupled to the first feeder, the first multimode resonator having a first resonance mode supporting a first frequency band, a second resonance mode supporting a second frequency band, and a third resonance mode supporting a third frequency band; and A second feeder is located on a side of the first multi-mode resonator away from the first feeder, the second feeder is spaced apart from and coupled to the first multi-mode resonator, and the second feeder has an output end.

2. The filter according to claim 1, wherein The first multi-mode resonator includes two symmetrically arranged first resonance units, and the first resonance units include: First branch; a second branch, one end of the second branch connected to one end of the first branch; a third branch, one end of the third branch being connected to the other end of the second branch, the first branch, the second branch, and the third branch cooperating to form a first enclosed space, the other end of the third branch being opposite to the other end of the first branch and spaced apart to form a first opening, the first opening being connected to the first enclosed space; and The first connecting portion is connected to the second branch, and the first connecting portions of the two first resonant units are connected.

3. The filter according to claim 2, wherein The width of the first branch is W1, the width of the second branch is W2, the width of the third branch is W3, and the width of the first connecting portion is W4. The first multi-mode resonator satisfies at least one of the following conditions: W1<W2 and W3<W2; IN 4＝ W2。 4. The filter according to claim 3, wherein The first branch comprises a first sub-branch, a second sub-branch and a third sub-branch which are bent and connected in sequence, and the third sub-branch is opposite to the first sub-branch and spaced apart; The second branch comprises a fourth sub-branch and a fifth sub-branch connected in a bent manner, one end of the fourth sub-branch being connected to an end of the third sub-branch away from the second sub-branch; One end of the third branch is connected to an end of the fifth sub-branch away from the fourth sub-branch, and the other end of the third branch is spaced apart from an end of the first sub-branch away from the second sub-branch to form the first opening.

5. The filter according to claim 4, wherein The two first resonance units are arranged along a first direction; The second sub-branch extends along the second direction, and the third sub-branch and the fourth sub-branch both extend along the first direction, wherein the sum of the length of the third sub-branch along the first direction and the length of the fourth sub-branch along the first direction is greater than the length of the second sub-branch along the second direction.

6. The filter according to claim 1, wherein The first resonance mode is an odd-mode resonance mode, and the first resonance mode has a first resonance frequency point f that supports the first frequency band. 11 ; The second resonance mode is an even mode resonance mode, and the second resonance mode has a second resonance frequency point f that supports the second frequency band. 12 ; The third resonance mode is an odd-mode resonance mode, and the third resonance mode has a third resonance frequency point f that supports the third frequency band. 13 , where f 11 <f 12 <f 13 .

7. The filter according to claim 1, wherein A first coupling gap is defined between the first multi-mode resonator and the first feed line, and a width g1 of the first coupling gap satisfies: g1≤1.5 mm.

8. The filter according to any one of claims 1 to 7, wherein: The filter further comprises: a second multimode resonator, the second multimode resonator being located on a side of the first multimode resonator facing away from the first feeder, the second multimode resonator being spaced apart from the first multimode resonator by a second coupling gap, and the second multimode resonator being spaced apart from and coupled to the second feeder; The second multi-mode resonator has a first mode supporting the first frequency band, a second mode supporting the second frequency band, and a third mode supporting the third frequency band.

9. The filter according to claim 8, wherein The second multi-mode resonator includes a symmetrically arranged second resonance unit, and the second resonance unit includes: Part 1; a second portion, one end of the second portion being connected to one end of the first portion; a third portion, one end of the third portion being connected to the other end of the second portion, the first portion, the second portion and the third portion cooperating to form a second enclosed space, the other end of the third portion being opposite to and spaced from the other end of the first portion to form a second opening, the second opening being connected to the second enclosed space; and The second connecting portion is connected to the second portion, and the second connecting portions of the two second resonant units are connected.

10. The filter according to claim 9, wherein The width of the first portion is W'1, the width of the second portion is W'2, the width of the third portion is W'3, and the width of the second connecting portion is W'4, wherein the second multi-mode resonator satisfies at least one of the following conditions: W'1<W'2 and W'3<W'2; W'4=W'2.

11. The filter according to claim 10, wherein The first portion includes a first sub-portion, a second sub-portion, and a third sub-portion that are bent and connected in sequence, and the third sub-portion is opposite to the first sub-portion and spaced apart; The second portion includes a fourth sub-portion and a fifth sub-portion connected to each other by bending, and one end of the fourth sub-portion is connected to an end of the third sub-portion away from the second sub-portion; One end of the third portion is connected to an end of the fifth sub-portion away from the fourth sub-portion, and the other end of the third portion is spaced apart from an end of the first sub-portion away from the second sub-portion to form the second opening.

12. The filter according to claim 11, wherein The two second resonance units are arranged along the first direction; The second subsection extends along the second direction, and the third subsection and the fourth subsection both extend along the first direction, wherein the sum of the length of the third subsection along the first direction and the length of the fourth subsection along the first direction is greater than the length of the second subsection along the second direction.

13. The filter according to claim 8, wherein The first mode is an odd-mode resonance mode, and the first mode supports a resonance frequency point f in the first frequency band. 21 ; The second mode is an even-mode resonance mode, and the second mode supports a resonance frequency point of the second frequency band as the second frequency point f 22 ; The third mode is an odd-mode resonance mode, and the resonance frequency point supported by the third mode in the third frequency band is the third frequency point f 23 , where f 21 <f 22 <f 23 .

14. The filter according to claim 13, wherein The first resonance mode has a first resonance frequency point f supporting a first frequency band. 11 , where f 11 <f 21 ; The second resonance mode has a second resonance frequency point f supporting a second frequency band. 12 , where f 12 <f 22 ; The third resonance mode has a third resonance frequency point f supporting a third frequency band. 13 , where f 13 <f 23 .

15. The filter according to claim 8, wherein The filter satisfies at least one of the following: The width g2 of the second coupling gap satisfies: g2≤1.5mm; A third coupling gap is defined between the second multi-mode resonator and the second feed line, and a width g3 of the third coupling gap satisfies: g3≤1.5 mm.

16. A radio frequency front-end circuit, characterized in that: The radio frequency front-end circuit includes the filter according to any one of claims 1-15.

17. A radio frequency transceiver, characterized in that: The radio frequency transceiver device includes: radiators; and The radio frequency front-end circuit according to claim 16.

18. An electronic device, characterized in that: The electronic device includes the radio frequency transceiver according to claim 17.

Images