An extractor and a communication device including the same

Abstract

The present disclosure relates to an extractor and a communication device including the same. The extractor includes a band-pass filter connected between a common terminal and a first input / output terminal, and a band-stop filter connected between the common terminal and a second input / output terminal; the band-pass filter has N series branches and M parallel branches, where N and M are natural numbers; the first series branch is closer to the common terminal than the first parallel branch, the first series branch is the series branch closest to the common terminal among the N series branches, and the first parallel branch is the parallel branch closest to the common terminal among the M parallel branches; the impedance of the first series branch is greater than the impedance of the I-th series branch, where 1 < I < N; the parallel branch closest to the first input / output terminal among the M parallel branches has the lowest resonance frequency relative to the other parallel branches, and the resonance frequencies of the other parallel branches are the same or approximately the same.

Description

Technical Field

[0001] The present disclosure relates to a communication device, and more particularly, to a communication device including an extractor. Background Art

[0002] Portable communication devices, such as mobile phones, laptops, or personal digital assistants, need to acquire and transmit signals. Different signals correspond to different communication methods and frequency ranges; for example, communication methods based on the cellular method, the WIFI method, and the GPS method are adopted to acquire and transmit different signals. To meet the requirements of signal acquisition and transmission of portable communication devices, extractors have emerged. With the increasing commercialization of 5G, the demand for extractors is also increasing.

[0003] Please refer to Figure 1 and Figure 2 , Figure 1 which shows a structural block diagram of an extractor in the prior art, Figure 2 and Figure 1 which is a frequency response diagram of a band-stop filter in the extractor shown. The extractor 10 includes a common terminal A, input / output terminals B and C, a band-pass filter 20, and a band-stop filter 30. The band-pass filter 20 is connected between the common terminal A and the input / output terminal B, the band-stop filter 30 is connected between the common terminal A and the input / output terminal C, and the common terminal A is also connected to an antenna component 40. As Figure 2 shown in the prior art extractor, the conventional design of the band-pass filter will introduce abnormal zeros at the passband edge of the band-stop filter, where "freq" is the frequency and "dB(S(3,1))" is the insertion loss. Therefore, the industry expects to develop extractors with high performance. Summary of the Invention

[0004] In view of the above technical problems, the present disclosure has carefully designed the extractor, avoided the technical defects of the extractor in the prior art, and successfully developed a high-performance extractor that eliminates abnormal zeros at the passband edge of the band-stop filter.

[0005] A brief overview of the present disclosure will be given below to provide a basic understanding of some aspects of the present disclosure. It should be understood that this overview is not an exhaustive overview of the present disclosure. It is not intended to identify the key or important parts of the present disclosure, nor is it intended to limit the scope of the present disclosure. Its purpose is only to present some concepts in a simplified form as a prelude to the more detailed description to follow.

[0006] According to one aspect of the present disclosure, an extractor is provided, including: an external terminal, a common terminal, a first input / output terminal, a second input / output terminal, a band-pass filter connected between the common terminal and the first input / output terminal, and a band-stop filter connected between the common terminal and the second input / output terminal; the band-pass filter has N series branches and M parallel branches, where N and M are natural numbers; the first series branch is closer to the common terminal than the first parallel branch, the first series branch is the series branch closest to the common terminal among the N series branches, and the first parallel branch is the parallel branch closest to the common terminal among the M parallel branches; the impedance of the first series branch is greater than the impedance of the I-th series branch, where 1 < I < N; the parallel branch closest to the first input / output terminal among the M parallel branches has the lowest resonance frequency compared to other parallel branches, and the resonance frequencies of other parallel branches are the same or approximately the same.

[0007] Further, the impedance of the first series branch is calculated by an impedance formula; the impedance formula is Z = 1 / jωC_0, where C_0 = (ε_ZZ^S A) / 2d, Z is the input impedance, j is the imaginary unit, ω is the frequency, A is the area of the resonator, 2d is the thickness of the piezoelectric layer, ε_ZZ^S is the dielectric constant, and C_0 is the capacitance value.

[0008] Further, the band-stop filter has P series branches and Q parallel branches, P and Q are natural numbers; the series branch closest to the common terminal among the P series branches of the band-stop filter is closer to the common terminal than the parallel branch closest to the common terminal among the Q parallel branches.

[0009] Further, the number of parallel branches in the band-pass filter is at least greater than or equal to 3.

[0010] Further, each of the N series branches includes at least one series resonator, and the area of the series resonator in the first series branch is 1 / 2 - 2 / 3 of the area of the series resonator in the I-th series branch, where 1 < I < N.

[0011] Further, the area A of the series resonator in the first series branch is 4.5e-9 ≤ A ≤ 6e-9 square meters.

[0012] Further, the parallel branch closest to the first input / output terminal in the band-pass filter has the thickest mass loading layer compared to other parallel branches, and the thicknesses of the mass loading layers of other parallel branches are the same or approximately the same.

[0013] Further, the parallel resonator in the parallel branch closest to the first input / output terminal has a first mass loading layer and a second mass loading layer, and the parallel resonators in other parallel branches have a first mass loading layer.

[0014] Further, the extractor further has a first matching unit, which is connected to the external terminal and the common terminal and is used to match the input impedance of the extractor.

[0015] Further, the first matching unit is connected in series between the external terminal and the common terminal; or the first matching unit is connected in parallel between the common terminal and the ground terminal.

[0016] Further, the band-pass filter further includes a second matching unit, which is connected to the first input / output terminal.

[0017] Further, the first matching unit and the second matching unit form a coupling.

[0018] Further, the band-stop filter further includes a third matching unit, which is connected to the first input / output terminal.

[0019] Further, an inductor and a resonant unit connected in series are provided on the series branch of the band-stop filter closest to the common terminal. According to another aspect of the present disclosure, a communication device is provided, and the communication device includes the extractor of any one of the above.

[0020] The present disclosure improves the performance of the extractor by improving the structure of the band-pass filter in the extractor to eliminate the abnormal zeros at the channel edges of the band-stop filter. Description of the Drawings

[0021] The specific content of the present disclosure will be described below with reference to the drawings, which will help to more easily understand the above and other objects, features and advantages of the present disclosure. The drawings are only for showing the principle of the present disclosure. The dimensions and relative positions of the units do not have to be drawn to scale in the drawings.

[0022] Figure 1 Showing the structural block diagram of the extractor in the prior art;

[0023] Figure 2 For Figure 1 Showing the frequency response diagram of the band-stop filter in the extractor shown;

[0024] Figure 3 Showing the structural block diagram of the extractor in the embodiment of the present disclosure;

[0025] Figure 4 Showing the specific circuit structural diagram of the extractor in the embodiment of the present disclosure;

[0026] Figure 5 For Figure 4 Schematic diagram of the basic physical structure of the resonator included in the extractor shown;

[0027] Figure 6 Circuit structure diagram of the extractor of the comparative example shown;

[0028] Figure 7 Frequency response diagram of the band-stop filter of the embodiment of the present disclosure and the comparative example. Specific embodiments

[0029] In the following, the exemplary disclosure of the present disclosure will be described in conjunction with the accompanying drawings. For clarity and conciseness, not all features for implementing the present disclosure are described in the specification. However, it should be understood that many decisions specific to the present disclosure can be made during the development of any such implementation of the present disclosure in order to achieve the specific goals of the developer, and these decisions may vary with different implementations of the present disclosure.

[0030] Here, it should also be noted that in order to avoid obscuring the present disclosure due to unnecessary details, only the device structures closely related to the solution according to the present disclosure are shown in the drawings, while other details less related to the present disclosure are omitted.

[0031] It should be understood that the present disclosure is not limited to the described embodiments only due to the following description with reference to the drawings. In the present disclosure, where feasible, features between different embodiments may be replaced or borrowed, and one or more features may be omitted in one embodiment.

[0032] In the embodiment of the present disclosure, an extractor capable of responding to cellular communication and WIFI communication is taken as an example for illustration. It should be understood that the embodiment of the present disclosure does not mean a limitation on extractors capable of responding to other different wireless frequency band communication methods.

[0033] Please refer to Figure 3 , Figure 3The structural block diagram of the extractor 100 in the embodiments of the present disclosure is shown. The extractor 100 includes an external terminal 101, a first matching unit 200, a common terminal 102, a band-pass filter 300, a WIFI signal transmission terminal 103, a band-stop filter 400, and a cellular signal transmission terminal 104. The extractor 100 can transmit high-frequency signals based on the cellular mode and high-frequency signals based on the WIFI mode to external components such as an antenna (not shown), and can also transmit the high-frequency signals received by external components such as an antenna to a radio frequency signal processing circuit (not shown). Specifically, the band-pass filter 300 allows the WIFI signal with a wireless carrier frequency to pass through, and the band-stop filter 400 blocks the WIFI signal with this wireless carrier frequency and allows cellular signals with other wireless carrier frequencies to pass through.

[0034] The external terminal 101 is used to connect external components such as an antenna. The first matching unit 200 is connected in series between the external terminal 101 and the common terminal 102 and is used to match the input impedance of the extractor 100. The band-pass filter 300 is connected between the common terminal 102 and the WIFI signal transmission terminal 103. The band-stop filter 400 is connected between the common terminal 102 and the cellular signal transmission terminal 104.

[0035] Alternatively, the first matching unit 200 can also be connected to the external terminal 101 in a parallel manner, that is, one end of the first matching unit 200 is connected to the common terminal 102, and the other end of the first matching unit 200 is connected to the ground terminal. When the first matching unit 200 is arranged in this way, the common terminal 102 can be used as the external terminal at the same time.

[0036] In a specific embodiment, please refer to Figure 4 , Figure 4 which shows the specific circuit structure diagram of the extractor in the embodiments of the present disclosure. The first matching unit 200 in the extractor 100 can be composed of an inductor Lmc, and one end of the inductor Lmc is connected to the external terminal 101, and the other end of the inductor Lmc is connected to the common terminal 102.

[0037] Alternatively, the first matching unit 200 can also be replaced by a plurality of inductors connected in series or in parallel, and one end of it is connected to the external terminal 101 and the other end is connected to the common terminal 102, so as to match the impedance between the band-pass filter 300 and the band-stop filter 400 and avoid excessive insertion loss.

[0038] Alternatively, the first matching unit 200 can be composed of an inductor or a plurality of inductors connected in series or in parallel, and one end of it is connected to the common terminal 102 and the other end is connected to the ground terminal.

[0039] The band-pass filter 300 includes series branches S1 - S4, parallel branches P1 - P4, a second matching unit M1, and a plurality of connection nodes. Specifically, the connection nodes are the nodes between two adjacent series branches and the nodes between a series branch and the second matching unit M1.

[0040] The series branch S1 is disposed between the common terminal 102 and the connection node N1; the series branch S2 is disposed between the connection node N1 and the connection node N2; the series branch S3 is disposed between the connection node N2 and the connection node N3; the series branch S4 is disposed between the connection node N3 and the connection node N4. Specifically, the series branch S1 has a higher input impedance compared to the series branches S2 and S3. The second matching unit M1 is disposed between the connection node N4 and the WIFI signal transmission terminal 103.

[0041] Further, the series branch S1 includes a series resonance unit (not labeled in the figure), and the series resonance unit includes a series resonator s1; the series branch S2 includes a series resonance unit (not labeled in the figure), and the series resonance unit includes a series resonator s2; the series branch S3 includes a series resonance unit (not labeled in the figure), and the series resonance unit includes a series resonator s3; the series branch S4 includes a series resonance unit (not labeled in the figure), and the series resonance unit includes a series resonator s4.

[0042] The parallel branch P1 is disposed between the connection node N1 and the ground terminal; the parallel branch P2 is disposed between the connection node N2 and the ground terminal; the parallel branch P3 is disposed between the connection node N3 and the ground terminal; the parallel branch P4 is disposed between the connection node N4 and the ground terminal.

[0043] Further, the parallel branch P1 includes a parallel resonance unit (not labeled in the figure), and the parallel resonance unit includes a parallel resonator p1; the parallel branch P2 includes a parallel resonance unit (not labeled in the figure), and the parallel resonance unit includes a parallel resonator p2; the parallel branch P3 includes a parallel resonance unit (not labeled in the figure), and the parallel resonance unit includes a parallel resonator p3; the parallel branch P4 includes a parallel resonance unit (not labeled in the figure), and the parallel resonance unit includes a parallel resonator p4. Specifically, the resonance frequency of the parallel resonator p1 is the same as or approximately the same as the resonance frequencies of the parallel resonator p2 and the parallel resonator p3; the resonance frequency of the parallel resonator p4 is lower than the resonance frequencies of the parallel resonator p1, the parallel resonator p2, and the parallel resonator p3.

[0044] Further, one end of the parallel resonator p1 is connected to the connection node N1, and the other end of the parallel resonator p1 is connected to the ground terminal after being connected in series with the inductor L1; one end of the parallel resonator p2 is connected to the connection node N2, and the other end of the parallel resonator p2 is connected to the ground terminal after being connected in series with the inductor L2; one end of the parallel resonator p3 is connected to the connection node N3, and the other end of the parallel resonator p3 is connected to the ground terminal after being connected in series with the inductor L3; one end of the parallel resonator p4 is connected to the connection node N4, and the other end of the parallel resonator p4 is connected to the ground terminal after being connected in series with the inductor L4.

[0045] Each resonator (i.e., the series resonators s1 - s4 and the parallel resonators p1 - p4) in the series branches S1 - S4 and the parallel branches P1 - P4 of the band - pass and band - stop filter 300 can be formed by a bulk acoustic wave resonator.

[0046] Those skilled in the art can understand that although Figure 4 the series resonance unit and the parallel resonance unit of the band - pass filter 300 in

[0047] Figure 4 are composed of a single resonator, the series resonance unit and the parallel resonance unit can also include multiple resonators. When the series resonance unit and the parallel resonance unit include multiple resonators, the multiple resonators can be connected in series and / or in parallel.

[0048] Alternatively, the second matching unit M1 composed of a single inductor Lm1 or the second matching unit M1 composed of multiple inductors connected in series or in parallel can also be connected between the node N4 and the ground terminal; an inductive coupling is formed between the first matching unit 200 and the second matching unit M1.

[0049] Those skilled in the art can understand that although Figure 4 the band - pass filter 300 provided in

[0050] Preferably, the circuit structure of the band - pass filter 300 has three or more parallel branches. In other words, it is necessary to ensure that there is at least one other parallel branch between the parallel branch P1 closest to the common terminal 102 and the parallel branch P4 closest to the WIFI signal transmission terminal 103 in the band - pass filter 300. And the resonance frequency of the parallel resonator p1 in the parallel branch P1 closest to the common terminal 102 is the same as or approximately the same as the resonance frequencies of the parallel resonators p2 - p3 in the other parallel branches P2 - P3. The resonance frequency of the parallel resonator p4 in the parallel branch P4 closest to the WIFI signal transmission terminal 103 is less than the resonance frequencies of the parallel resonators p1 - p3 in the other parallel branches P1 - P3.

[0051] Continuing to refer to Figure 4 , the band - stop filter 400 includes a series branch S5, a parallel branch P5, and a third matching unit M2.

[0052] The series branch S5 is disposed between the common terminal 102 and the cellular signal transmission terminal 104; the parallel branch P5 is disposed between the cellular signal transmission terminal 104 and the ground terminal; the third matching unit M2 is disposed between the cellular signal transmission terminal 104 and the ground terminal.

[0053] Furthermore, the series branch S5 includes a series resonance unit (not labeled in the figure) and an inductor L5. The series resonance unit includes a series resonator s5; one end of the inductor L5 is connected to the common terminal 102, and the other end of the inductor L5 is connected to the series resonator s5 in series and then connected to the cellular signal transmission terminal 104. The composition of the series branch S5 is more helpful for cooperating with the band - pass filter 300 to eliminate the abnormal zero points at the pass - band edge of the band - stop filter 400. The parallel branch P5 includes a parallel resonance unit (not labeled in the figure) and an inductor L6. The parallel resonance unit includes a parallel resonator p5. One end of the parallel resonator p5 is connected to the cellular signal transmission terminal 104, and the other end of the parallel resonator p5 is connected to the inductor L6 in series and then connected to the ground terminal.

[0054] It can be understood that although Figure 4 in the circuit structure of the band - stop filter 400 provided, there is only one resonator on both the series branch S5 and the parallel branch P5, alternatively, the series branch S5 of the band - stop filter 400 can include multiple resonators, and these multiple resonators can form a series resonance unit in a series and / or parallel manner. The parallel branch P5 of the band - stop filter 400 can include multiple resonators, and these multiple resonators can form a parallel resonance unit in a series and / or parallel manner.

[0055] The third matching unit M2 is composed of a single inductor Lm2. Alternatively, the third matching unit M2 can also be replaced by a structure formed by multiple inductors connected in series or parallel to match the impedance of the band-stop filter 400 itself.

[0056] Furthermore, although Figure 4 the band-stop filter 400 in

[0057] has a circuit structure of 1 series and 1 parallel, the specific order of series and parallel is not specifically limited for the band-pass filter 401 in this disclosure. For the circuit structure of the band-stop filter 400, preferably, it is ensured that the series branch S5 of the band-pass filter is closer to the common end point than the parallel branch P5.

[0058] In summary, in order to eliminate the abnormal zero points at the passband edge of the band-stop filter 400 in the extractor and improve the performance of the extractor 100. The improvements to the band-pass filter in this disclosure include: First, without affecting the frequency response of the band-pass filter 300, the input impedance of the series branch S1 in the band-pass filter 300 is increased as much as possible. More specifically, the input impedance of the series branch S1 is set to be higher than the input impedances of the other series branches S2 - S3 except for the series branch S4 closest to the WIFI signal transmission terminal 103. Second, the series branch S1 in the series branches of the band-pass filter 300 that is closest to the common terminal 102 is closer to the common terminal 102 than the parallel branch P1 in the parallel branches that is closest to the common terminal 102. In addition, the resonance frequencies of the parallel resonators p1 in the parallel branch P1 closest to the common terminal 102 in the band-pass filter 300 are the same as or approximately the same as the resonance frequencies of the parallel resonators p2 - p3 in the other parallel branches P2 - P3, and the resonance frequency of the parallel resonator p4 in the parallel branch P4 closest to the WIFI signal transmission terminal 103 is less than the resonance frequencies of the parallel resonators p1 - p3 in the other parallel branches P1 - P3. Thus, the abnormal zero points at the passband edge of the band-stop filter 400 are successfully eliminated, and the performance of the extractor 100 is improved.

[0059] According to Figure 4 the circuit structure of the extractor 100 provided in

[0060] Please refer to Figure 5 , Figure 5 For Figure 4The extractor shown is a schematic diagram of the basic physical structure of the resonator. The air cavity film bulk acoustic resonator 1000 includes at least a carrier 1100, a cavity 1110 formed in the carrier, a lower electrode 1200, an upper electrode 1400, and a piezoelectric layer 1300 sandwiched between the upper and lower electrodes.

[0061] Furthermore, lower electrode 1200, piezoelectric layer 1300, and upper electrode 1400 form a stacked structure. The overlapping region between upper electrode 1400, piezoelectric layer 1300, and lower electrode 1200 constitutes the active region of the BAW resonator. Piezoelectric layer 1300 is made of a piezoelectric material with electromechanical transduction capabilities, such as aluminum nitride, doped aluminum nitride, or zirconate titanate, to achieve conversion between acoustic waves and electrical signals.

[0062] Regarding the concept of increasing the impedance of the series branch S1 in the bandpass filter 300 as much as possible without affecting the frequency response of the bandpass filter 300, the present disclosure uses the adjustment of the area size of the series resonator s1 in the series branch S1 as an example in the structural implementation of the filter 300 to specifically illustrate how to increase the impedance of the series branch S1.

[0063] As for the impedance of the series branch S1 of the bandpass filter 300, its specific formula is as follows:

[0064]

[0065] Where, in Equation 1, Z is the input impedance, j is the imaginary unit, ω is the frequency, A is the area of the resonator, 2d is the thickness of the piezoelectric layer, is the dielectric constant. C0 is the capacitance value.

[0066] According to formula 1, the impedance of the series branch S1 of the bandpass filter 300 is related to the area of the series resonator s1. The smaller the area of the series resonator s1, the larger the input impedance of the series branch S1. Therefore, in order to meet the requirement that the input impedance of the series branch S1 is set to be higher than the input impedance of the other series branches S2-S3 except the series branch S4 closest to the WIFI signal transmission terminal 103, the area of the series resonator s1 in the series branch S1 can be adjusted in terms of structural implementation. Specifically, the ratio R of the area of the series resonator s1 in the series branch S1 to the area of the series resonator s2 in the series branch S2, or the ratio R of the area of the series resonator s1 in the series branch S1 to the area of the series resonator s3 in the series branch S3 is set to 1 / 2≤R≤2 / 3. More specifically, the area A of the series resonator s1 in the series branch S1 can be set to 4.5e -9 ≤A≤6e -9 square meters.

[0067] Those skilled in the art should understand that although the adjustment of the area of the series resonator s1 in the series branch S1 is used as an example in the present disclosure to illustrate how to increase the impedance of the series branch S1, without affecting the frequency response of the band-pass filter, reference can also be made to Equation 1 to adjust one or more other parameters in Equation 1 that affect the impedance of the series branch S1, and the present disclosure does not further limit it.

[0068] For the concept of setting the resonance frequencies of the parallel resonators p1, p2, and p3 in the band-pass filter 300 to be the same or approximately the same, and the resonance frequency of the parallel resonator p4 to be less than that of the parallel resonators p1 - p3, in the present disclosure, different thicknesses of mass loading layers are provided in the parallel resonators p1 - p4 to adjust the resonance frequencies of the parallel resonators p1 - p4 in the band-pass filter 300.

[0069] Specifically, for the band-pass filter 300 composed of the air cavity thin film bulk acoustic wave resonator 1000, in order to ensure good matching within the passband, in the circuit structure, it is first necessary to make the resonance frequencies of the parallel resonators p1 - p4 in the parallel branches P1 - P4 of the band-pass filter lower than the resonance frequencies of the series resonators s1 - s4 in the series branches S1 - S4. To meet the above requirements, a first mass loading layer (not shown) is formed on the upper electrode 1300 or the lower electrode 1200 of the parallel resonators p1 - p4 in each parallel branch of the band-pass filter. By setting the first loading layer, the resonance frequencies of the parallel resonators p1 - p4 are made the same or approximately the same, and lower than the resonance frequencies of the series resonators s1 - s4 in the series branches S1 - S4.

[0070] Then, a second mass loading layer (not shown) is further added to the parallel resonator p4 in the parallel branch P4. By setting the second mass loading layer, the resonance frequency of the parallel resonator p4 is made lower than the resonance frequencies of the parallel resonators p1 - p3.

[0071] In summary, by providing a first mass loading layer on the parallel resonators p1 - p3 and a first mass loading layer and a second mass loading layer on the parallel resonator p4, the frequency of the parallel resonator p1 in the parallel branch P1 is made the same or approximately the same as the frequencies of the parallel resonators p2 in the parallel branch P2 and the parallel resonator p3 in the parallel branch P3, and at the same time, the frequency of the parallel resonator p1 in the parallel branch P1 is higher than the frequency of the parallel resonator p4 in the parallel branch P4.

[0072] The first mass loading layer and the second mass loading layer can be composed of metals such as Mo, Au, etc. It can be understood that the multi-layer mass loading layer may not be provided on the parallel resonator p4, and only by means of a single mass loading layer, with a thickness thicker than that of the mass loading layers on the other parallel resonators p1-p3, so that the resonance frequency of the parallel resonator p4 is less than that of the other parallel resonators p1-p3.

[0073] In the embodiments of the present disclosure, by setting the series branch S1 in the band-pass filter 300 to be closer to the common terminal 102 than the parallel branch P1, and reducing the area of the resonator s1 in the series branch S1 of the band-pass filter 300, the input impedance of the series branch S1 is increased; at the same time, by setting the first mass loading layer and the second mass loading layer, the resonance frequencies of the parallel resonators p1-p3 in the parallel branches P1-P3 of the band-pass filter 300 are set to be the same or approximately the same, and the resonance frequency of the parallel resonator p4 in the parallel branch P4 is lower than the resonance frequencies of the parallel resonators p1-p3 in the parallel branches P1-P3, which can prevent the signal of the band-pass filter 300 from flowing to the ground terminal through the parallel branch P1, and avoid generating abnormal zeros at the passband edge of the band-stop filter 400.

[0074] Furthermore, the present disclosure uses the form of a comparative example to verify the improvement of the zero point at the passband edge of the band-stop filter 400 in the embodiments of the present disclosure.

[0075] Please refer to Figure 6 , Figure 6 which shows the circuit structure diagram of the comparative example extractor. For the comparative example extractor 100', its circuit structure is similar to that of the extractor 100 in Figure 4 and will not be elaborated here. In the comparative example, the series branches S2'-S4' and the parallel branches P2'-P4' of the band-pass filter use the same type of resonators as the series branches S2-S4 and the parallel branches P2-P4 of the band-pass filter 300 in the embodiments of the present disclosure, and the materials of the functional layers constituting the resonators are the same.

[0076] The difference between the resonator s1' in the series branch S1′ of the band-pass filter 300' in the comparative example and the resonator s1 in the series branch S1 of the band-pass filter 300 in the embodiments of the present disclosure is only that:

[0077] (1) The ratio of the area A of the series resonator s1 of the band-pass filter 300 in the embodiments of the present disclosure to the area A' of the series resonator s1′ of the band-pass filter 300' in the comparative example is set to 1 / 2 ≤ A / A′ ≤ 2 / 3.

[0078] (2) In the comparison example, with respect to the structure of the parallel resonator p1' of the parallel branch P1' of the band-pass filter 300', in addition to providing a first load layer, a second load layer is further provided as compared with the structure of the parallel resonator p1 of the band-pass filter 300 in the embodiment of the present disclosure.

[0079] Please refer to Figure 7 , Figure 7 FIG. is the frequency response diagram of the band-stop filter of the embodiment of the present disclosure and the comparative example. Among them, the dashed line is the frequency response of the band-stop filter of the comparative example, and the solid line is the frequency response of the band-stop filter provided by the present disclosure. The horizontal axis is the frequency (unit: GHz), and the vertical axis is the insertion loss (unit: dB). As can be seen from Figure 7 : There are abnormal zeros at the passband edge of the band-stop filter in the comparative example, while the present disclosure has successfully eliminated the abnormal zeros at the passband edge of the band-stop filter. It can be seen that through the design optimization of the band-pass filter in the present disclosure, the performance of the band-stop filter is improved, and thus the performance of the extractor is successfully enhanced.

[0080] The extractor of the embodiment of the present disclosure can be widely applied to communication devices, and exemplary communication devices are mobile phones, personal digital assistants, electronic game devices, wearable terminals, etc.

[0081] The present disclosure has been described in conjunction with specific implementation schemes, but those skilled in the art should understand that these descriptions are exemplary and not a limitation on the protection scope of the present disclosure. Those skilled in the art can make various variations and modifications to the present disclosure according to the spirit and principle of the present disclosure, and these variations and modifications are also within the scope of the present disclosure.

Claims

1. An extractor, characterized in that, Comprising: An external terminal, a common terminal, a first input / output terminal, a second input / output terminal, a band-pass filter connected between the common terminal and the first input / output terminal, and a band-stop filter connected between the common terminal and the second input / output terminal; The band-pass filter has N series branches and M parallel branches, and each series branch and parallel branch includes a bulk acoustic wave resonator, where N and M are natural numbers greater than or equal to 4; The first series branch is closer to the common terminal than the first parallel branch. The first series branch is the series branch closest to the common terminal among the N series branches, and the first parallel branch is the parallel branch closest to the common terminal among the M parallel branches; The input impedance of the first series branch is higher than that of the other series branches except the Nth series branch; Among the M parallel branches, the parallel branch closest to the first input / output terminal has the lowest resonance frequency compared to the other parallel branches, and the resonance frequencies of the other parallel branches are the same or approximately the same; The band-stop filter has P series branches and Q parallel branches, where P and Q are natural numbers; the series branch closest to the common terminal among the P series branches of the band-stop filter is closer to the common terminal than the parallel branch closest to the common terminal among the Q parallel branches; the series branch closest to the common terminal among the P series branches of the band-stop filter includes a bulk acoustic wave resonator and an inductor.

2. The extractor according to claim 1, wherein: The impedance of the first series branch is calculated by the impedance formula; the impedance formula is Z = 1 / jωC0, where, Z is the input impedance, j is the imaginary unit, ω is the frequency, A is the area of the resonator, 2d is the thickness of the piezoelectric layer, is the dielectric constant, and C0 is the capacitance value.

3. The extractor according to claim 1, wherein: Each of the N series branches includes at least one series resonator, and the area of the series resonator in the first series branch is 1 / 2 - 2 / 3 of the area of the series resonator in the Ith series branch, where 1 < I < N.

4. The extractor according to claim 3, characterized in that: The area A of the series resonator in the first series branch is 4.5e -9 ≤ A ≤ 6e -9 square meters.

5. The extractor according to claim 1, characterized in that: Among the parallel branches of the band-pass filter, the parallel branch closest to the first input / output terminal has the thickest mass loading layer compared to the other parallel branches, and the thicknesses of the mass loading layers of the other parallel branches are the same or approximately the same.

6. The extractor according to claim 5, characterized in that: The parallel resonator in the parallel branch closest to the first input / output terminal has a first mass loading layer and a second mass loading layer, and the parallel resonators in the other parallel branches have a first mass loading layer.

7. The extractor according to any one of claims 1-6, characterized in that: The extractor further has a first matching unit, which is connected to the external terminal and the common terminal for matching the input impedance of the extractor.

8. The extractor according to claim 7, characterized in that: The first matching unit is connected in series between the external terminal and the common terminal; or the first matching unit is connected in parallel between the common terminal and the ground terminal.

9. The extractor according to claim 8, characterized in that: The band-pass filter further includes a second matching unit, which is connected to the first input / output terminal.

10. The extractor according to claim 9, characterized in that: The first matching unit and the second matching unit form a coupling.

11. The extractor according to claim 7, wherein: The band-stop filter further includes a third matching unit, which is connected to the second input / output terminal.

12. A communication device, characterized in that: The communication device includes the extractor according to any one of claims 1 - 11.

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