CN116232367A - Extractor and communication equipment comprising same - Google Patents
Extractor and communication equipment comprising same Download PDFInfo
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- CN116232367A CN116232367A CN202310233945.7A CN202310233945A CN116232367A CN 116232367 A CN116232367 A CN 116232367A CN 202310233945 A CN202310233945 A CN 202310233945A CN 116232367 A CN116232367 A CN 116232367A
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/40—Circuits
Abstract
The present disclosure relates to an extractor and a communication device including the same. Wherein the extractor comprises a band pass filter connected between the common terminal and the first input/output terminal, and a band reject filter connected between the common terminal and the second input/output terminal; the band-pass filter is provided with N serial branches and M parallel branches, wherein N, M is a natural number; the first serial branch is closer to the common terminal than the first parallel branch, the first serial branch is the serial branch closest to the common terminal in the N serial branches, and the first parallel branch is the parallel branch closest to the common terminal in the M parallel branches; the impedance of the first series branch is greater than the impedance of the I-th series branch, wherein 1< I < N; the parallel branch closest to the first input/output terminal of the M parallel branches has the lowest resonant frequency relative to the other parallel branches, which have the same or similar resonant frequency.
Description
Technical Field
The present disclosure relates to a communication device, and more particularly, to a communication device including an extractor.
Background
A portable communication device, such as: the mobile phone, the notebook or the personal digital assistant needs to acquire and transmit signals, and different signals correspond to different communication modes and frequency ranges; for example: and a communication mode based on a cellular (cellular) mode, a communication mode based on a WIFI mode and a communication mode based on a GPS mode are adopted to achieve acquisition and emission of different signals. Extractors have been developed to accommodate the signal acquisition and transmission requirements of portable communication devices. As the commercial use of 5G increases, the demand for extractors increases.
Referring to fig. 1 and 2, fig. 1 is a block diagram illustrating a prior art extractor, and fig. 2 is a frequency response diagram of a band reject filter in the extractor shown in fig. 1. The extractor 10 includes a common terminal a, an input/output terminal B, an input/output terminal C, a band pass filter 20, and a band reject filter 30. The band pass filter 20 is connected between a common terminal a and an input/output terminal B, and the band reject filter 30 is connected between the common terminal a and an input/output terminal C, the common terminal a being further connected to the antenna section 40. The conventional design of a bandpass filter in an existing extractor as shown in fig. 2 introduces an abnormal zero at the passband edge of the bandstop filter, where "freq" is the frequency and "dB (S (3, 1))" is the insertion loss. It is therefore desirable to develop extractors with high performance.
Disclosure of Invention
The present disclosure is directed to the above technical problems, and is directed to an extractor, which avoids the technical defects of the extractor in the prior art, and successfully develops a high performance extractor for eliminating the abnormal zero point of the passband edge of a band stop filter.
A brief summary of the disclosure will be presented below in order to provide a basic understanding of some aspects of the disclosure. It should be understood that this summary is not an exhaustive overview of the disclosure. It is not intended to identify key or critical elements of the disclosure or to delineate the scope of the disclosure. Its purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
According to an aspect of the present disclosure, there is provided an extractor 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 reject filter connected between the common terminal and the second input/output terminal; the band-pass filter is provided with N series branches and M parallel branches, wherein N, M is a natural number; the first serial branch is closer to the common terminal than the first parallel branch, the first serial branch is the serial branch closest to the common terminal in the N serial branches, and the first parallel branch is the parallel branch closest to the common terminal in the M parallel branches; the impedance of the first series branch is greater than the impedance of the I-th series branch, wherein 1< I < N; the parallel branch closest to the first input/output terminal of the M parallel branches has the lowest resonant frequency relative to the other parallel branches, and the resonant frequencies of the other parallel branches are the same or similar.
Further, the impedance of the first serial 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 input impedance, j is imaginary unit, ω is frequency, a is resonator area, 2d is piezoelectric layer thickness, ε_zz is dielectric constant, and c_0 is capacitance.
Further, the band reject filter has P series branches and Q parallel branches, P, Q being a natural number; the series branch closest to the common terminal among the P series branches of the band-reject filter is closer to the common terminal than the parallel branch closest to the common terminal among the Q parallel branches.
Further, the number of parallel branches in the band-pass filter is at least 3 or more.
Further, each of the N series branches includes at least one series resonator, and an area of the series resonator in the first series branch is 1/2-2/3 of an area of the series resonator in the I-th series branch, where 1< I < N.
Further, the area A of the series resonators in the first series branch is 4.5 e-9.ltoreq.A.ltoreq.6e-9 square meters.
Further, the parallel branch closest to the first input/output terminal in the band-pass filter has the thickest mass-loading layer with respect to the other parallel branches, and the mass-loading layers of the other parallel branches have the same or similar thickness.
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 the other parallel branches have a first mass-loading layer.
Further, the extractor further comprises a first matching unit, and the first matching unit is connected with the external terminal and the common terminal and is used for matching the input impedance of the extractor.
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.
Further, the band-pass filter further includes a second matching unit connected to the first input/output terminal.
Further, the first matching unit and the second matching unit form coupling.
Further, the band-stop filter further includes a third matching unit connected to the first input/output terminal.
Further, an inductance and a resonance unit which are connected in series are arranged on a serial branch of the band-stop filter closest to the common terminal. According to another aspect of the present disclosure there is provided a communication device comprising an extractor of any one of the above.
The present disclosure improves the performance of an extractor by improving the structure of a band pass filter in the extractor to eliminate abnormal zero points at the channel edges of the band stop filter.
Drawings
The above and other objects, features and advantages of the present disclosure will be more readily appreciated by reference to the following description of the specific details of the disclosure taken in conjunction with the accompanying drawings. The drawings are only for the purpose of illustrating the principles of the present disclosure. The dimensions and relative positioning of the elements in the figures are not necessarily drawn to scale.
FIG. 1 is a block diagram showing the structure of an extractor of the prior art;
FIG. 2 is a graph of the frequency response of the band reject filter in the extractor of FIG. 1;
FIG. 3 shows a block diagram of an extractor in an embodiment of the present disclosure;
FIG. 4 shows a specific circuit block diagram of an extractor in an embodiment of the present disclosure;
FIG. 5 is a schematic diagram of the basic physical structure of a resonator included in the extractor shown in FIG. 4;
FIG. 6 shows a circuit configuration diagram of the comparative example extractor;
fig. 7 is a frequency response diagram of a band reject filter of an embodiment of the present disclosure and a comparative example.
Detailed Description
Exemplary disclosure of the present disclosure will be described hereinafter with reference to the accompanying drawings. In the interest of clarity and conciseness, not all features of an implementation of the present disclosure are described in the specification. It will be appreciated, however, that in the development of any such actual implementation, numerous implementation-specific decisions may be made to achieve the developers' specific goals, and that these decisions may vary from one implementation to another.
Here, it is also to be noted that, in order to avoid obscuring the present disclosure with unnecessary details, only device structures closely related to the scheme according to the present disclosure are shown in the drawings, while other details not greatly related to the present disclosure are omitted.
It is to be understood that the present disclosure is not limited to the described embodiments due to the following description with reference to the drawings. In the present disclosure, features between different embodiments may be substituted or borrowed where possible, and one or more features may be omitted in one embodiment.
In the embodiments of the present disclosure, an extractor capable of responding to cellular communication and responding to WIFI communication will be described as an example. It should be understood that the disclosed embodiments are not meant to be limiting as to extractors that can respond to other different wireless band communication modes.
Referring to fig. 3, fig. 3 shows a block diagram of an extractor 100 in an embodiment of the present disclosure. 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 the high-frequency signals based on the cellular method and the high-frequency signals based on the WIFI method to an external element (not shown) such as an antenna, and can transmit the high-frequency signals received by the external element such as the antenna to a radio frequency signal processing circuit (not shown). Specifically, the band-pass filter 300 passes WIFI signals having a wireless carrier frequency, and the band-reject filter 400 passes WIFI signals having the wireless carrier frequency and passes cellular signals of other wireless carrier frequencies.
The external terminal 101 is used for connecting external elements such as an antenna. The first matching unit 200 is connected in series between the external terminal 101 and the common terminal 102 for matching 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 reject filter 400 is connected between the common terminal 102 and the cellular signal transmission terminal 104.
Alternatively, the first matching unit 200 may be connected to the external terminal 101 in parallel, 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 provided in this way, the common terminal 102 can be used as an external terminal at the same time.
In a specific example, referring to fig. 4, fig. 4 shows a specific circuit diagram of an extractor according to an embodiment of the present disclosure, the first matching unit 200 in the extractor 100 may be formed by an inductor Lmc, 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.
Alternatively, the first matching unit 200 may alternatively be formed by connecting a plurality of inductors in series or in parallel, and one end of the first matching unit is connected to the external terminal 101, and the other end of the first matching unit is connected to the common terminal 102, so that the impedance between the band-pass filter 300 and the band-stop filter 400 is matched, and an insertion loss is prevented from being excessively bad.
Alternatively, the first matching unit 200 may be formed of one inductor or a plurality of inductors connected in series or parallel, and has one end connected to the common terminal 102 and the other end connected to the ground.
The band pass filter 300 comprises a series branch S1-S4, a parallel branch P1-P4, a second matching unit M1 and a plurality of connection nodes. Specifically, the connection node is a node between two adjacent series branches, a node between a series branch and the second matching unit M1.
The series branch S1 is disposed between the common terminal 102 and the connection node N1; the series branch S2 is arranged between the connection node N1 and the connection node N2; the series branch S3 is arranged between the connection node N2 and the connection node N3; the series branch S4 is arranged between the connection node N3 and the connection node N4; specifically, series leg S1 has a higher input impedance than series leg S2 and series leg S3. The second matching unit M1 is disposed between the connection node N4 and the WIFI signal transmission terminal 103.
Further, the series branch S1 includes a series resonant unit (not identified in the figure) including a series resonator S1; the series branch S2 comprises a series resonant unit (not identified in the figure) comprising a series resonator S2; the series branch S3 comprises a series resonant unit (not identified in the figure) comprising a series resonator S3; the series branch S4 comprises a series resonant unit (not identified in the figure) comprising a series resonator S4.
The parallel branch P1 is arranged between the connecting node N1 and the grounding end; the parallel branch P2 is arranged between the connecting node N2 and the grounding end; the parallel branch P3 is arranged between the connecting node N3 and the grounding end; the parallel branch P4 is arranged between the connection node N4 and ground.
Further, the parallel branch P1 includes a parallel resonance unit (not identified in the figure) including a parallel resonator P1; the parallel branch P2 includes a parallel resonance unit (not identified in the figure) including a parallel resonator P2; the parallel branch P3 includes a parallel resonance unit (not identified in the figure) including a parallel resonator P3; the parallel branch P4 includes a parallel resonance unit (not identified in the figure) including a parallel resonator P4. Specifically, the resonance frequency of the parallel resonator p1 is the same as or similar to the resonance frequency of the parallel resonator p2 and the resonance frequency of the parallel resonator p 3; 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 p 3.
Further, one end of the parallel resonator p1 is connected with the connection node N1, and the other end of the parallel resonator p1 is connected with the inductor L1 in series and then connected with the ground terminal; one end of the parallel resonator p2 is connected with the connecting node N2, and the other end of the parallel resonator p2 is connected with the inductor L2 in series and then connected with the grounding end; one end of the parallel resonator p3 is connected with the connecting node N3, and the other end of the parallel resonator p3 is connected with the inductor L3 in series and then connected with the grounding end; 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 inductor L4 in series and then to the ground.
Each resonator of the series branches S1-S4 and the parallel branches P1-P4 (i.e., the series resonators S1-S4 and the parallel resonators P1-P4) of the band-pass rejection filter 300 may be configured using bulk acoustic wave resonators.
It will be appreciated by those skilled in the art that although the series resonant unit and the parallel resonant unit of the band pass filter 300 in fig. 4 are constituted by a single resonator, the series resonant unit and the parallel resonant unit may include a plurality of resonators, and when the series resonant unit and the parallel resonant unit include a plurality of resonators, the plurality of resonators may be connected in series and/or in parallel.
The second matching unit M1 provided in fig. 4 is constituted by a single inductance Lm 1. Alternatively, the second matching unit M1 may be alternatively configured of a plurality of inductors in series or parallel for matching the impedance of the band-pass filter 300 itself.
Alternatively, the second matching unit M1 formed by the single inductor Lm1 or the second matching unit M1 formed by a plurality of series or parallel inductors may be further 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.
It will be appreciated by those skilled in the art that although the bandpass filter 300 provided in fig. 4 is a 4-series 4-parallel circuit configuration, the specific series-parallel order is not a specific limitation of the bandpass filter 300 in the present disclosure. For the band-pass filter 300, it is important to ensure that the series branch S1 of the band-pass filter 300 is closer to the common endpoint than the parallel branch P1 in terms of circuit configuration to increase the input impedance of the band-pass filter 300; and it is necessary to secure, in the circuit configuration of the band-pass filter 300, that the input impedance of the series branch S1 closest to the common terminal 102 is higher than the input impedance of the series branches S2 and S3 other than the series branch S4 closest to the WIFI signal transmission terminal 103.
Preferably, the band-pass filter 300 has more than or equal to 3 parallel branches in its circuit structure, in other words, it is necessary to ensure that there is at least one or more other parallel branches in the band-pass filter 300 between the parallel branch P1 closest to the common terminal 102 and the parallel branch P4 closest to the WIFI signal transmission terminal 103, and that the resonant frequency of the parallel resonator P1 in the parallel branch P1 closest to the common terminal 102 is the same as or similar to the resonant frequency of the parallel resonators P2-P3 in the other parallel branches P2-P3, and that the resonant frequency of the parallel resonator P4 in the parallel branch P4 closest to the WIFI signal transmission terminal 103 is smaller than the resonant frequency of the parallel resonators P1-P3 in the other parallel branches P1-P3.
With continued reference to fig. 4, the band reject filter 400 includes a series leg S5, a parallel leg P5, and a third matching unit M2.
Series leg S5 is disposed between common terminal 102 and cellular signal transmission terminal 104; parallel branch P5 is disposed between cellular signal transmission terminal 104 and ground; the third matching unit M2 is disposed between the cellular signal transmission terminal 104 and the ground.
Further, the series branch S5 includes a series resonant unit (not identified in the figure) including a series resonator S5, and an inductance L5; one end of the inductor L5 is connected with the common terminal 102, and the other end of the inductor L5 is connected with the series resonator s5 in series and then connected to the cellular signal transmission terminal 104; the composition of the series leg S5 further helps to cooperate with the bandpass filter 300 to eliminate outliers at the passband edges of the bandstop filter 400. The parallel branch P5 includes a parallel resonant unit (not shown) and an inductance L6, the parallel resonant 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 ground after being connected in series with the inductance L6.
It will be appreciated that although only one resonator is provided on both the series leg S5 and the parallel leg P5 in the circuit structure of the band-reject filter 400 provided in fig. 4, the series leg S5 of the band-reject filter 400 may alternatively comprise a plurality of resonators that may form a series resonant unit in series and/or in parallel. The parallel branch P5 of the band reject filter 400 may include a plurality of resonators that may form parallel resonant cells in series and/or parallel.
The third matching unit M2 is constituted by a single inductance Lm 2. Alternatively, the third matching unit M2 may be alternatively configured of a plurality of inductors in series or parallel for matching the impedance of the band reject filter 400 itself.
Further, although the band reject filter 400 in fig. 4 is a circuit structure of 1 series to 1 parallel, the specific series to parallel order is not a specific limitation of the band reject filter 401 in the present disclosure. For the circuit configuration of the band-reject filter 400, it is preferable to ensure that the series leg S5 of the band-pass filter is closer to the common endpoint than the parallel leg P5.
Each resonator in the series arm S5 and the parallel arm P5 of the band reject filter 400 may employ a bulk acoustic wave resonator, a surface acoustic wave resonator, or the like. The present disclosure is not particularly limited as to the type of band reject filter 400.
To sum up, to eliminate abnormal zero at the passband edge of the band stop filter 400 in the extractor, the performance of the extractor 100 is improved. The improvement of the band-pass filter disclosed by the disclosure comprises the following steps: first, the input impedance of the series branch S1 in the band-pass filter 300 is increased as much as possible without affecting the frequency response of the band-pass filter 300. More specifically, the input impedance of the series branch S1 is set to be higher than the input impedance of the other series branches S2 to S3 except for the series branch S4 closest to the WIFI signal transmission terminal 103. Second, the series branch S1 of the series branch of the band-pass filter 300 closest to the common terminal 102 is closer to the common terminal 102 than the parallel branch P1 of the parallel branch closest to the common terminal 102. Further, the resonance frequency of the parallel resonator P1 in the parallel branch P1 closest to the common terminal 102 in the band-pass filter 300 is the same as or similar to the resonance frequency 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 smaller than the resonance frequency of the parallel resonators P1-P3 in the other parallel branches P1-P3. Thereby successfully eliminating the abnormal zero at the passband edge of the band stop filter 400 and improving the performance of the extractor 100.
According to the circuit structure of the extractor 100 provided in fig. 4, how to raise the input impedance of the series arm S1 and adjust the resonant frequencies of the parallel resonators p1-p4 in the inventive concept of the present disclosure is further described in terms of device structure for the resonator included in the extractor 100, taking an air cavity thin film bulk acoustic resonator as an example.
Referring to fig. 5, fig. 5 is a schematic diagram showing a basic physical structure of a resonator included in the extractor shown in fig. 4. The air cavity thin 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.
Further, the lower electrode 1200, the piezoelectric layer 1300, and the upper electrode 1400 form a stacked structure, and an overlapping region between the upper electrode 1400, the piezoelectric layer 1300, and the lower electrode 1200 is an active region of the bulk acoustic wave resonator. The piezoelectric layer 1300 is made of a piezoelectric material having an electromechanical conversion capability, such as aluminum nitride, doped aluminum nitride, or titanate zirconate, etc., for realizing conversion between acoustic waves and electric signals.
As for the concept of increasing the impedance of the series arm S1 in the band pass filter 300 as much as possible without affecting the frequency response of the band pass filter 300, the present disclosure specifically describes how to increase the impedance of the series arm S1 by adjusting the size of the area of the series resonator S1 in the series arm S1 as an example in the structural implementation of the filter 300.
Since the specific formula for the impedance of the series branch S1 of the band-pass filter 300 is as follows:
wherein in formula 1, Z is input impedance, j is imaginary unit, ω is frequency, A is resonator area, 2d is piezoelectric layer thickness,
is the dielectric constant. C (C) 0 Is a capacitance value.
As can be seen from equation 1, the impedance of the series branch S1 of the band-pass filter 300 is related to the area of the series resonator S1, and the smaller the area of the series resonator S1 is, the larger the input impedance of the series branch S1 is. Therefore, in order to satisfy setting the input impedance of the series branch S1 to be higher than the input impedance of the other series branches S2 to S3 except for the series branch S4 closest to the WIFI signal transmission terminal 103, the area of the series resonator S1 in the series branch S1 is structurally adjustable. Specifically, the ratio R of the area of the series resonator S1 in the series arm S1 to the area of the series resonator S2 in the series arm S2, or the ratio R of the area of the series resonator S1 in the series arm S1 to the area of the series resonator S3 in the series arm S3 is set to 1/2.ltoreq.R.ltoreq.2/3. More specifically, the area a of the series resonator S1 in the series branch S1 may be set to 4.5e, for example -9 ≤A≤6e -9 Square meters.
It should be understood by those skilled in the art that, although the present disclosure describes how to increase the impedance of the series arm S1 by taking the adjustment of the area of the series resonator S1 in the series arm S1 as an example, one or more parameters affecting the impedance of the series arm S1 in equation 1 may be adjusted without further limitation of the present disclosure, without affecting the frequency response of the band pass filter, with reference to equation 1.
Regarding the concept of setting the resonance frequency of the parallel resonator p1 in the band-pass filter 300 to be the same or similar to the resonance frequency of the parallel resonator p2 and the resonance frequency of the parallel resonator p3, the resonance frequency of the parallel resonator p4 is smaller than the parallel resonators p1-p3, the resonance frequencies of the parallel resonators p1-p4 in the band-pass filter 300 are adjusted in such a manner that mass load layers of different thicknesses are provided in the parallel resonators p1-p4 in the present disclosure.
Specifically, in order to ensure a good matching in the passband of the bandpass filter 300 formed by the air cavity thin film bulk acoustic resonator 1000, the circuit configuration first needs to make the resonant frequency of the parallel resonators P1-P4 in the parallel branches P1-P4 in the bandpass filter lower than the resonant frequency of the series resonators S1-S4 in the series branches S1-S4. To meet the above requirement, a first mass-loaded layer (not shown) is formed on the upper electrode 1300 or the lower electrode 1200 of each parallel resonator p1-p4 of the band-pass filter, and the first load layer is disposed such that the resonance frequencies of the parallel resonators p1-p4 are the same or similar and lower than the resonance frequencies of each series resonator S1-S4 of the series branches S1-S4.
Then, a second mass-loaded layer (not shown) is further added to the parallel resonator P4 in the parallel branch P4, and the resonant frequency of the parallel resonator P4 is made lower than the resonant frequencies of the parallel resonators P1-P3 by the arrangement of the second mass-loaded layer.
In summary, by providing the first mass-loaded layer on the parallel resonators P1-P3 and providing the first mass-loaded layer and the second mass-loaded layer on the parallel resonator P4, it is achieved that the frequency of the parallel resonator P1 in the parallel branch P1 is the same as or similar to the frequency of the parallel resonator P2 in the parallel branch P2 and the frequency of the parallel resonator P3 in the parallel branch P3, and the frequency of the parallel resonator P1 in the parallel branch P1 is simultaneously higher than the frequency of the parallel resonator P4 in the parallel branch P4.
The first mass-loaded layer and the second mass-loaded layer may be composed of a metal such as Mo, au, or the like, for example. It will be appreciated that it is also possible to provide no multilayer mass-loading layer on the parallel resonator p4, but only by way of a single mass-loading layer, with a greater thickness than the mass-loading layers on the other parallel resonators p1-p3, so that the resonant frequency of the parallel resonator p4 is smaller than the resonant frequencies of the other parallel resonators p1-p 3.
In the embodiment of the present disclosure, by disposing the series branch S1 in the band-pass filter 300 closer to the common terminal 102 than the parallel branch P1 and reducing the area of the resonator S1 in the series branch S1 in the band-pass filter 300, the input impedance of the series branch S1 is increased; meanwhile, through the arrangement of the first mass load layer and the second mass load layer, the resonant frequency of each parallel resonator P1-P3 in the parallel branches P1-P3 in the band-pass filter 300 is set to be the same or similar, the resonant frequency of the parallel resonator P4 in the parallel branch P4 is lower than the resonant frequency of each parallel resonator P1-P3 in the parallel branches P1-P3, signals of the band-pass filter 300 can be prevented from flowing to the ground terminal through the parallel branch P1, and abnormal zero points are avoided at the edges of the pass band of the band-pass filter 400.
Further, the present disclosure takes the form of a comparative example to verify the improvement in the passband edge zero of the band reject filter 400 in the embodiments of the present disclosure.
Referring to fig. 6, fig. 6 shows a circuit configuration diagram of the comparative example extractor. The circuit structure of the comparative example extractor 100' is similar to that of the extractor 100 in fig. 4, and will not be described here. The series branches S2'-S4' and the parallel branches P2'-P4' of the bandpass filter in the comparative example are the same as the series branches S2-S4 and the parallel branches P2-P4 of the bandpass filter 300 according to the embodiment of the disclosure, and the same type of resonator is used, and the materials constituting the functional layers of the resonator are the same.
The resonator S1' in the series branch S1' of the band-pass filter 300' in the comparative example differs from the resonator S1 in the series branch S1 of the band-pass filter 300 of the embodiment of the present disclosure only in that:
(1) The ratio of the area a of the series resonator s1 of the band pass filter 300 in the embodiment 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.ltoreq.a/a'.ltoreq.2/3.
(2) The structure of the parallel resonator P1' of the parallel branch P1' of the band pass filter 300' in the comparative example is further provided with a second load layer in addition to the first load layer, relative to the structure of the parallel resonator P1 of the band pass filter 300 in the embodiment of the present disclosure.
Referring to fig. 7, fig. 7 is a frequency response diagram of a band-stop filter according to an embodiment of the present disclosure and a comparative example, wherein a dotted line is a frequency response of the band-stop filter according to the comparative example, a solid line is a frequency response of the band-stop filter provided by the present disclosure, a horizontal axis is frequency (in GHz), and a vertical axis is insertion loss (in dB). As can be seen in fig. 7: the passband edge of the band stop filter of the comparative example has an abnormal zero, and the present disclosure successfully eliminates the abnormal zero at the passband edge of the band stop filter. Therefore, the performance of the band-stop filter is improved through the design optimization of the band-pass filter, so that the performance of the extractor is successfully improved.
The extractor of the embodiments of the present disclosure may be widely used in communication devices, such as cell phones, personal digital assistants, electronic gaming devices, wearable terminals, and the like.
The present disclosure has been described in connection with specific embodiments, but it should be apparent to those skilled in the art that the description is intended to be illustrative and not limiting of the scope of the disclosure. Various modifications and alterations of this disclosure may be made by those skilled in the art in light of the spirit and principles of this disclosure, and such modifications and alterations are also within the scope of this disclosure.
Claims (15)
1. An extractor, 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 reject filter connected between the common terminal and the second input/output terminal;
the band-pass filter is provided with N series branches and M parallel branches, wherein N, M is a natural number;
the first serial branch is closer to the common terminal than the first parallel branch, the first serial branch is the serial branch closest to the common terminal in the N serial branches, and the first parallel branch is the parallel branch closest to the common terminal in the M parallel branches;
the impedance of the first series branch is greater than the impedance of the I-th series branch, wherein 1< I < N;
the parallel branch closest to the first input/output terminal of the M parallel branches has the lowest resonant frequency relative to the other parallel branches, and the resonant frequencies of the other parallel branches are the same or similar.
2. The extractor of claim 1 wherein: the impedance of the first series branch is calculated by an impedance formula; the impedance formula is Z=1/jωC 0 Wherein, the method comprises the steps of, wherein,
z is input impedance, j is imaginary unit, ω is frequency, A is resonator area, 2d is piezoelectric layer thickness, < >>
Is the dielectric constant, C 0 Is a capacitance value.
3. The extractor of claim 1 wherein: the band-reject filter has P series branches and Q parallel branches, P, Q being a natural number; 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.
4. An extractor according to claim 3, wherein: the number of parallel branches in the band pass filter is at least greater than or equal to 3.
5. An extractor according to claim 3, wherein: the N series branches each include at least one series resonator, the area of the series resonator in the first series branch being 1/2-2/3 of the area of the series resonator in the I-th series branch, where 1< I < N.
6. The extractor of claim 5 wherein: the area A of the series resonator in the first series branch is 4.5e -9 ≤A≤6e -9 Square meters.
7. The extractor of claim 1 wherein: the parallel branch closest to the first input/output terminal in the band-pass filter has the thickest mass-loading layer relative to the other parallel branches, which have the same or similar thickness.
8. The extractor of claim 7 wherein: the parallel resonators in the parallel branch closest to the first input/output terminal have 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.
9. The extractor according to any one of claims 1 to 8, characterized in that: the extractor further comprises a first matching unit, wherein the first matching unit is connected with the external terminal and the common terminal and is used for matching the input impedance of the extractor.
10. The extractor of claim 9 wherein: 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.
11. The extractor of claim 10 wherein: the band-pass filter further includes a second matching unit connected to the first input/output terminal.
12. The extractor of claim 11 wherein: the first matching unit and the second matching unit form coupling.
13. The extractor of claim 9 wherein: the band reject filter further comprises a third matching unit connected to the second input/output terminal.
14. The extractor of claim 9 wherein: the series branch of the band-reject filter closest to the common terminal is provided with an inductance and a resonance unit which are connected in series.
15. A communication device, characterized by: the communication device comprising the extractor of any of claims 1-14.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202310233945.7A CN116232367A (en) | 2023-03-13 | 2023-03-13 | Extractor and communication equipment comprising same |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202310233945.7A CN116232367A (en) | 2023-03-13 | 2023-03-13 | Extractor and communication equipment comprising same |
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| CN116232367A true CN116232367A (en) | 2023-06-06 |
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| CN202310233945.7A Pending CN116232367A (en) | 2023-03-13 | 2023-03-13 | Extractor and communication equipment comprising same |
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