CN117335110A - High roll-off filter and multiplexer - Google Patents
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- 230000000052 comparative effect Effects 0.000 description 6
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P7/00—Resonators of the waveguide type
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Abstract
The invention relates to the technical field of electronics, in particular to a high roll-off filter and a multiplexer, wherein the resonant frequency of a first resonator is smaller than the anti-resonant frequency of a third resonator by arranging a first resonator group and a second resonator group, the anti-resonant frequency of the first resonator is equal to the resonant frequency of the second resonator, and the frequency of a first resonant point of an equivalent resonant curve formed by the first resonator and the second resonator is equal to the anti-resonant frequency of the third resonator, so that the passband of the filter is flatter and the echo is better; meanwhile, the filter curve has a suppression point with better suppression effect under the double impedance action of the first resonator and the second resonator, and the slope between the first resonance point and the first anti-resonance point of the equivalent resonance curve is larger than the slope between the resonance point and the anti-resonance point of the first resonator, so that the roll-off speed of the filter is faster, the width of the isolation zone area at the edge of the filter is reduced, and the communication quality of an edge channel is improved.
Description
Technical Field
The application belongs to the technical field of electronics, and particularly relates to a high roll-off filter and a multiplexer.
Background
With the rapid development of communication systems, communication channels are increasingly crowded, and the isolation zone area between the channels needs to be further reduced. For example, for two filters, the narrower the isolation zone region between the filters, the better the communication quality of the edge channel will be. Therefore, how to narrow the isolation zone region, i.e. how to roll off the edge of the filter faster is a key to improve the communication quality of the filter edge channel.
At present, acoustic wave filters and multiplexers are widely used because of lower insertion loss, higher rejection, narrower isolation bands, and smaller size than other types of filters and multiplexers, wherein the acoustic wave filter is composed of a plurality of series resonators and a plurality of parallel resonators alternately cascaded. However, when the antiresonant frequency point of the parallel resonator of the acoustic wave filter is higher than the resonant frequency point of the series resonator, the insertion loss in the middle of the pass band of the filter curve of the acoustic wave filter is low, and the insertion loss on both sides of the pass band is high, so that the pass band takes a "unimodal" shape, the pass band flatness is low, the echo is deteriorated, and the isolation band region of the edge of the acoustic wave filter is wide, and the communication quality of the edge channel of the acoustic wave filter is poor.
Disclosure of Invention
In order to solve the above-mentioned prior art problems, the present invention provides a high roll-off filter and a multiplexer, which have the following technical schemes:
in a first aspect, embodiments of the present application provide a high roll-off filter, including:
the first resonator group comprises a plurality of resonators which are sequentially connected in series, and the second resonator group comprises a plurality of resonators which are sequentially connected in parallel at two ends of each resonator of the first resonator group;
the first resonator is the resonator with the lowest resonance frequency in the first resonator group, the second resonator is any resonator except the first resonator in the first resonator group, the third resonator is the resonator with the highest resonance frequency in the second resonator group, the anti-resonance frequency of the first resonator is equal to that of the second resonator, the resonance frequency of the first resonator is smaller than that of the third resonator, the equivalent resonance curve of the first resonator and the resonance curve of the second resonator comprises a first resonance point and a first anti-resonance point, the frequency of the first resonance point is equal to that of the third resonator, and the frequency of the first anti-resonance point is equal to that of the first resonator.
In one embodiment, a first end of the first resonator group is for inputting a signal and a second end of the first resonator group is for outputting a signal.
In one embodiment, the first end of the second resonator group is connected to the first resonator group and the second end of the second resonator group is grounded.
In one embodiment, the resonance frequencies of the individual resonators of the first resonator group are different.
In one embodiment, the frequency difference between the resonance frequency of each resonator of the first resonator group and the anti-resonance frequency thereof is greater than a preset frequency difference.
In one embodiment, there is a first intersection point and a second intersection point between the resonance curve of the first resonator and the resonance curve of the second resonator, the frequency of the first intersection point being smaller than the frequency of the second intersection point.
In one embodiment, the frequency of the first resonance point is equal to the frequency of the first intersection point.
In one embodiment, the equivalent resonance curve further includes a second resonance point and a second antiresonance point, the second resonance point having a frequency equal to the frequency of the second intersection point, the second antiresonance point having a frequency equal to the antiresonance frequency of the second resonator.
In one embodiment, the second resonator is the resonator with the highest resonant frequency in the first resonator group.
In a second aspect, embodiments of the present application provide a multiplexer, including:
a number of the high roll-off filters of the first aspect.
The invention has the beneficial effects that the first resonator group comprising a plurality of resonators connected in series in sequence and the second resonator group comprising a plurality of resonators connected in parallel at two ends of each resonator of the first resonator group in sequence are arranged, wherein the resonance frequency of the first resonator is smaller than the anti-resonance frequency of the third resonator, and the anti-resonance frequency of the first resonator is equal to the resonance frequency of the second resonator, so that the first resonator and the second resonator form an equivalent resonance curve, the frequency of a first resonance point of the equivalent resonance curve is increased compared with the resonance frequency of the first resonator, and the frequency of the first resonance point is equal to the anti-resonance frequency of the third resonator, thereby enabling the passband of the filter to be flatter and the echo to be better; meanwhile, the frequency of the first anti-resonance point, the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator are equal, the filter curve has a suppression point with better suppression effect under the dual impedance action of the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator, and the slope between the first resonance point and the first anti-resonance point of the equivalent resonance curve is larger than the slope between the resonance point and the anti-resonance point of the first resonator, so that the roll-off speed of the filter is faster, namely the width of an isolation zone area at the edge of the filter is reduced, and the communication quality of an edge channel is improved.
Drawings
In the drawings, the same reference numerals refer to the same or similar parts or elements throughout the several views unless otherwise specified. The figures are not necessarily drawn to scale. It is appreciated that these drawings depict only some embodiments according to the disclosure and are not therefore to be considered limiting of its scope.
Fig. 1 is a schematic structural diagram of a high roll-off filter according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a high roll-off filter according to an embodiment of the present application, shown in FIG. 1;
FIG. 3 is a schematic diagram of a high roll-off filter according to an embodiment of the present application;
fig. 4 is a graph showing a comparison of a filter curve of the high roll-off filter according to the embodiment of the present application with a filter curve of a comparative example.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
In a first aspect, embodiments of the present application provide a high roll-off filter. Fig. 1 shows a schematic structure of a high roll-off filter according to an embodiment of the present application. As shown in fig. 1, the high roll-off filter may include:
the first resonator group comprises a plurality of resonators which are sequentially connected in series, and the second resonator group comprises a plurality of resonators which are sequentially connected in parallel at two ends of each resonator of the first resonator group.
The anti-resonance frequency of the first resonator is equal to that of the second resonator, the resonance frequency of the first resonator is smaller than that of the third resonator, the resonance curve of the first resonator and the resonance curve of the second resonator are equivalent to an equivalent resonance curve, the equivalent resonance curve comprises a first resonance point and a first anti-resonance point, the frequency of the first resonance point is equal to that of the third resonator, the frequency of the first anti-resonance point is equal to that of the first resonator, the first resonator is the resonator with the lowest resonance frequency in the first resonator group, the second resonator is any resonator except the first resonator in the first resonator group, and the third resonator is the resonator with the highest resonance frequency in the second resonator group.
It is understood that the high roll-off filter provided with the first resonator group and the second resonator group of the embodiments of the present application has the same structure as the acoustic wave filter. Fig. 1 shows a first resonator group (resonator 11, resonator 12, resonator 13, resonator 14, resonator 15) with 5 resonators connected in series in sequence, and a second resonator group (resonator 21, resonator 22, resonator 23, resonator 24) with 4 resonators connected in parallel in sequence across each resonator of the first resonator group. When the resonance frequency of the first resonator is equal to the antiresonance frequency of the third resonator, the flatness of the filter curve in the whole passband frequency range is high, and the echo is good; when the resonance frequency of the first resonator is smaller than the antiresonance frequency of the third resonator, the insertion loss in the middle of the passband of the filter curve is lower, and the insertion loss at two sides of the passband is higher, so that the passband can be in a 'single-peak' shape, the passband flatness is low, the echo is deteriorated, the isolation band area at the edge of the acoustic wave filter is wider, and the communication quality of the edge channel of the acoustic wave filter is poor. Based on the above, the anti-resonance frequency of the first resonator is equal to the resonance frequency of the second resonator, so that an equivalent resonance curve is formed between the first resonator and the second resonator, the frequency of the first resonance point of the equivalent resonance curve is increased compared with that of the first resonator, and the frequency of the first resonance point is equal to that of the third resonator, thereby enabling the passband of the filter to be flatter and the echo to be better; meanwhile, as the frequency of the first anti-resonance point, the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator are equal, the filter curve F2 has a suppression point with better suppression effect under the dual impedance action of the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator (compared with the independent action of the anti-resonance frequency of the first resonator), and as the slope between the first resonance point and the first anti-resonance point of the equivalent resonance curve is larger than the slope between the resonance point and the anti-resonance point of the first resonator, the electromechanical coupling coefficient is smaller, so that the roll-off speed of the filter is faster, namely the width of an isolation zone area at the edge of the filter is reduced, and the communication quality of an edge channel is improved.
Fig. 2 shows a filter curve F2 of the high roll-off filter according to the embodiment of the present application, and a resonance curve 11 of the first resonator, a resonance curve 15 of the second resonator, a resonance curve 21 of the third resonator, and an equivalent resonance curve 10, wherein the abscissa indicates the frequency, the ordinate indicates the insertion loss on the left side, and the ordinate indicates the impedance on the right side. Specifically, referring to fig. 2, the first resonator has a resonance frequency fs1 and the first resonator has an antiresonance frequency fp1; the resonance frequency of the second resonator is fs5, and the antiresonance frequency of the second resonator is fp5; the resonance frequency of the third resonator is fs, and the antiresonance frequency of the third resonator is fp; the frequency of the first resonance point of the equivalent resonance curve 10 is fs10 'and the frequency of the first antiresonant point is fp10'. Wherein the resonance frequency fs of the third resonator determines the isolation region on the left side of the filter curve F2; the frequency fs10' of the first resonance point of the equivalent resonance curve 10 is shifted to the right compared to the resonance frequency fs1 of the first resonator and is equal to the antiresonance frequency fp of the third resonator. The antiresonant frequency fp1 of the first resonator, the frequency fp10' of the first antiresonant point of the equivalent resonance curve 10, and the resonant frequency fs5 of the second resonator are equal, and the corresponding frequency values are represented as the suppression point n1 on the filter curve F2. From the foregoing, it can be seen that the suppression point n1 has a better suppression effect (compared to the single effect of the anti-resonance frequency of the first resonator) under the dual impedance effect of the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator, so that the insertion loss at the suppression point n1 is lower, i.e., the roll-off speed of the right frequency of the filter curve F2 is faster, and the isolation band region is narrower.
With continued reference to fig. 1, optionally, in some embodiments, a first end of the first resonator group is for an input signal and a second end of the first resonator group is for an output signal.
Further, in some embodiments, a first end of the second resonator group is connected to the first resonator group and a second end of the second resonator group is grounded.
Optionally, in some embodiments, the resonance frequencies of the individual resonators of the first resonator group are not identical.
Specifically, fig. 3 shows a filter curve F2 of the high roll-off filter and a resonance curve of each resonator according to the embodiment of the present application, wherein the abscissa is frequency, the left ordinate is insertion loss, and the right ordinate is impedance. Referring to fig. 3, taking the structure of the high roll-off filter shown in fig. 1 as an example, the resonant frequencies of the five resonators in the first resonator group are fs1, fs2, fs3, fs4, fs5, respectively, and the antiresonant frequencies of the five resonators in the first resonator group are fp1, fp2, fp3, fp4, fp5, respectively. Wherein fs1 < fs2 < fs3 < fs4 < fs5, fp1 < fp2 < fp3 < fp4 < fp5. The resonance points corresponding to the different resonance frequencies fs1, fs2, fs3, fs4, fs5 make the filter curve F2 flatter at the passband, while the different antiresonance frequencies fp1, fp2, fp3, fp4, fp5 make the suppression frequency range of the filter curve F2 on the right side of the passband wider and the suppression effect better. As can be seen from fig. 2 and 3, the antiresonant frequency fp1 and the resonant frequency fs5 correspond to the suppression point n1 of the filter curve F2, the antiresonant frequency fp2 corresponds to the suppression point n2, the antiresonant frequency fp3 corresponds to the suppression point n3, the antiresonant frequency fp4 corresponds to the suppression point n4, and the antiresonant frequency fp5 corresponds to the suppression point n5. It is understood that the number of resonators and the connection order of the resonators in the embodiments of the present application are not limited to the number of resonators and the connection order of the resonators shown in fig. 1.
Further, in some embodiments, a frequency difference between the resonance frequency of each resonator of the first resonator group and the anti-resonance frequency thereof is greater than a preset frequency difference.
It can be understood that, since the resonant frequencies of the resonators of the first resonator group are different, and the frequency difference between the resonant frequency and the anti-resonant frequency thereof is greater than the preset frequency difference, the filter curve F2 is suppressed more widely in the near-stop band.
Referring to fig. 2, optionally, in some embodiments, there is a first intersection point m1 and a second intersection point m2 between the resonance curve of the first resonator and the resonance curve of the second resonator.
Wherein the frequency of the first intersection point m1 is smaller than the frequency of the second intersection point m2. It can be understood that the number of intersections between the resonance curves of the first resonator and the resonance curves of the second resonator is equal to the number of resonance points of the equivalent resonance curves formed by the first resonator and the second resonator, and the frequency of each resonance point of the equivalent resonance curves is equal to the frequency of the corresponding intersection point; meanwhile, as the anti-resonance frequency of the first resonator is not equal to that of the second resonator, the anti-resonance frequency of the first resonator and the anti-resonance frequency of the second resonator respectively correspond to an anti-resonance point on an equivalent resonance curve. The equivalent resonance curve has two resonance points and two anti-resonance points.
Further, the frequency of the first resonance point is equal to the frequency of the first intersection point m 1.
Further, the equivalent resonance curve further includes a second resonance point and a second antiresonance point, the frequency of the second resonance point is equal to the frequency of the second intersection point m2, and the frequency of the second antiresonance point is equal to the antiresonance frequency of the second resonator.
Optionally, in some embodiments, the second resonator is a resonator with a highest resonant frequency in the first resonator group.
Fig. 4 shows a graph comparing the filter curve F2 of the embodiment of the present application with the filter curve F3 of the comparative example. The anti-resonant frequency of the first resonator and the resonant frequency of the second resonator in the comparative example are not equal, that is, the resonant curve of the first resonator and the resonant curve of the second resonator cannot form an equivalent resonant curve, and the other resonant curves are the same as the setting in the embodiment of the present application. As can be seen from fig. 4, the suppression point n11 of the filter curve F2 on the right side of the passband of the present embodiment of application is lower in frequency than the suppression point n12 of the filter curve F3 of the comparative example, and has a faster roll-off speed, i.e., a narrower isolation region, and the roll-off speed on the left side of the passband of the filter curve F2 of the present embodiment of application is also faster. Meanwhile, the filter curve F2 has a suppression point with better suppression effect under the dual impedance action of the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator, and the resonance frequencies of the resonators of the first resonator group are different, and the frequency difference between the resonance frequency and the self anti-resonance frequency is larger than the preset frequency difference value, so that the filter curve F2 is suppressed more widely in the near stop band. As shown in fig. 4, the overall insertion loss of the filter curve F2 at the frequency interval between n12 and n14 in the embodiment of the present application is below-50 dB, that is, the near-stop band rejection frequency of the filter curve F2 is between n12 and n14, while the near-stop band rejection frequency of the filter curve F3 in the comparative example is between n12 and n13, which is narrower than the near-stop band rejection frequency of the filter curve F2 in the embodiment of the present application. In addition, the filter curve F2 of the embodiments of the present application is more deeply suppressed than the filter curve F3 of the comparative example in the frequency range of n15-n16 on the left side of the passband.
In summary, in the embodiment of the present application, by providing the first resonator group including a plurality of resonators connected in series in turn, and the second resonator group including a plurality of resonators connected in parallel at two ends of each resonator of the first resonator group in turn, wherein the resonant frequency of the first resonator is smaller than the anti-resonant frequency of the third resonator, and the anti-resonant frequency of the first resonator is equal to the resonant frequency of the second resonator, so that the first resonator and the second resonator form an equivalent resonant curve, and the frequency of the first resonant point of the equivalent resonant curve is increased compared with the resonant frequency of the first resonator, and is equal to the anti-resonant frequency of the third resonator, thereby making the passband of the filter flatter and the echo better; meanwhile, the frequency of the first anti-resonance point, the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator are equal, the filter curve has a suppression point with better suppression effect under the dual impedance action of the anti-resonance frequency of the first resonator and the resonance frequency of the second resonator, and the slope between the first resonance point and the first anti-resonance point of the equivalent resonance curve is larger than the slope between the resonance point and the anti-resonance point of the first resonator, so that the roll-off speed of the filter is faster, namely the width of an isolation zone area at the edge of the filter is reduced, and the communication quality of an edge channel is improved.
In a second aspect, embodiments of the present application provide a multiplexer, including:
a number of the high roll-off filters of the first aspect.
In the description of embodiments of the present invention, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", or a third "may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.
In describing embodiments of the present invention, it should be noted that the term "coupled" should be interpreted broadly, unless otherwise indicated and limited thereto, such as being either fixedly coupled, detachably coupled, or integrally coupled; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In the description of embodiments of the invention, a particular feature, structure, material, or characteristic may be combined in any suitable manner in one or more embodiments or examples.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (10)
1. A high roll-off filter, comprising:
the first resonator group comprises a plurality of resonators which are sequentially connected in series, and the second resonator group comprises a plurality of resonators which are sequentially connected in parallel at two ends of each resonator of the first resonator group;
the first resonator is the resonator with the lowest resonance frequency in the first resonator group, the second resonator is any one of the resonators except the first resonator in the first resonator group, the third resonator is the resonator with the highest resonance frequency in the second resonator group, the anti-resonance frequency of the first resonator is equal to that of the second resonator, the resonance frequency of the first resonator is smaller than that of the third resonator, the equivalent resonance curve of the first resonator and that of the second resonator comprises a first resonance point and a first anti-resonance point, the frequency of the first resonance point is equal to that of the third resonator, and the frequency of the first anti-resonance point is equal to that of the first resonator.
2. The high roll-off filter of claim 1, wherein a first end of the first resonator group is for an input signal and a second end of the first resonator group is for an output signal.
3. The high roll-off filter of claim 2, wherein a first end of the second resonator group is connected to the first resonator group and a second end of the second resonator group is grounded.
4. The high roll-off filter of claim 1, wherein the resonant frequencies of the individual resonators of the first resonator group are different.
5. The high roll-off filter of claim 4, wherein a frequency difference between a resonance frequency of each resonator of the first resonator group and an anti-resonance frequency thereof is greater than a preset frequency difference.
6. The high roll-off filter of claim 1, wherein there is a first intersection point and a second intersection point between the resonance curve of the first resonator and the resonance curve of the second resonator, the frequency of the first intersection point being less than the frequency of the second intersection point.
7. The high roll-off filter of claim 6, wherein the frequency of the first resonance point is equal to the frequency of the first intersection point.
8. The high roll-off filter of claim 6, wherein the equivalent resonance curve further comprises a second resonance point and a second antiresonance point, the second resonance point having a frequency equal to the frequency of the second intersection point, the second antiresonance point having a frequency equal to the antiresonance frequency of the second resonator.
9. The high roll-off filter of claim 1, wherein the second resonator is a resonator of the first resonator group having a highest resonant frequency.
10. A multiplexer, comprising:
a number of high roll-off filters as claimed in any of claims 1-9.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311631239.4A CN117335110B (en) | 2023-12-01 | 2023-12-01 | High roll-off filter and multiplexer |
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| CN202311631239.4A CN117335110B (en) | 2023-12-01 | 2023-12-01 | High roll-off filter and multiplexer |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1296454A2 (en) * | 2001-09-25 | 2003-03-26 | TDK Corporation | SAW element and SAW device |
| CN1739237A (en) * | 2003-01-20 | 2006-02-22 | 皇家飞利浦电子股份有限公司 | Resonator filter structure having equal resonance frequencies |
| JP2016054374A (en) * | 2014-09-03 | 2016-04-14 | 株式会社村田製作所 | Variable resonant circuit and variable filter circuit |
| CN109831177A (en) * | 2018-12-20 | 2019-05-31 | 天津大学 | A kind of more stop-band filters and its implementation |
| CN111953317A (en) * | 2019-05-14 | 2020-11-17 | 三星电机株式会社 | Filter comprising acoustic wave resonators |
| CN116781035A (en) * | 2023-06-29 | 2023-09-19 | 锐石创芯(重庆)科技有限公司 | Filter, multiplexer and RF front-end module |
-
2023
- 2023-12-01 CN CN202311631239.4A patent/CN117335110B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1296454A2 (en) * | 2001-09-25 | 2003-03-26 | TDK Corporation | SAW element and SAW device |
| CN1739237A (en) * | 2003-01-20 | 2006-02-22 | 皇家飞利浦电子股份有限公司 | Resonator filter structure having equal resonance frequencies |
| JP2016054374A (en) * | 2014-09-03 | 2016-04-14 | 株式会社村田製作所 | Variable resonant circuit and variable filter circuit |
| CN109831177A (en) * | 2018-12-20 | 2019-05-31 | 天津大学 | A kind of more stop-band filters and its implementation |
| CN111953317A (en) * | 2019-05-14 | 2020-11-17 | 三星电机株式会社 | Filter comprising acoustic wave resonators |
| CN116781035A (en) * | 2023-06-29 | 2023-09-19 | 锐石创芯(重庆)科技有限公司 | Filter, multiplexer and RF front-end module |
Non-Patent Citations (4)
| Title |
|---|
| SERGII LITVINTSEV ET AL: ""Method of stopband expansion for pseudocombline bandpass filters"", 《2020 IEEE UKRAINIAN MICROWAVE WEEK（UKRMW）》 * |
| 刘思奇等: ""一种高滚降宽阻带低通微带滤波器"", 《微波学报》, vol. 36, no. 3, pages 87 - 91 * |
| 刘蕾蕾等: ""基片集成波导准感性窗滤波器的设计与实现"", 《微波学报》, vol. 27, no. 4, pages 65 - 67 * |
| 李守湛等: ""频率可调带通-带阻可切换滤波器的设计"", 《压电与声光》, vol. 45, no. 4, pages 554 - 559 * |
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| CN117335110B (en) | 2024-04-05 |
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