CN111200419A - Filter, duplexer, high-frequency front-end circuit and communication device - Google Patents
Filter, duplexer, high-frequency front-end circuit and communication device Download PDFInfo
- Publication number
- CN111200419A CN111200419A CN202010046418.1A CN202010046418A CN111200419A CN 111200419 A CN111200419 A CN 111200419A CN 202010046418 A CN202010046418 A CN 202010046418A CN 111200419 A CN111200419 A CN 111200419A
- Authority
- CN
- China
- Prior art keywords
- series
- parallel
- inductors
- inductor
- branch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004891 communication Methods 0.000 title claims abstract description 16
- 239000003990 capacitor Substances 0.000 claims description 57
- 230000008878 coupling Effects 0.000 claims description 14
- 238000010168 coupling process Methods 0.000 claims description 14
- 238000005859 coupling reaction Methods 0.000 claims description 14
- 238000003780 insertion Methods 0.000 abstract description 14
- 230000037431 insertion Effects 0.000 abstract description 14
- 238000010586 diagram Methods 0.000 description 26
- 101100194362 Schizosaccharomyces pombe (strain 972 / ATCC 24843) res1 gene Proteins 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 230000001939 inductive effect Effects 0.000 description 7
- 238000010897 surface acoustic wave method Methods 0.000 description 7
- 101100194363 Schizosaccharomyces pombe (strain 972 / ATCC 24843) res2 gene Proteins 0.000 description 5
- 238000013461 design Methods 0.000 description 5
- 230000001629 suppression Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 239000010408 film Substances 0.000 description 3
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- WSMQKESQZFQMFW-UHFFFAOYSA-N 5-methyl-pyrazole-3-carboxylic acid Chemical compound CC1=CC(C(O)=O)=NN1 WSMQKESQZFQMFW-UHFFFAOYSA-N 0.000 description 1
- PIGFYZPCRLYGLF-UHFFFAOYSA-N Aluminum nitride Chemical compound [Al]#N PIGFYZPCRLYGLF-UHFFFAOYSA-N 0.000 description 1
- 229910003334 KNbO3 Inorganic materials 0.000 description 1
- 229910003327 LiNbO3 Inorganic materials 0.000 description 1
- 229910012463 LiTaO3 Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- UKDIAJWKFXFVFG-UHFFFAOYSA-N potassium;oxido(dioxo)niobium Chemical compound [K+].[O-][Nb](=O)=O UKDIAJWKFXFVFG-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- MAKDTFFYCIMFQP-UHFFFAOYSA-N titanium tungsten Chemical compound [Ti].[W] MAKDTFFYCIMFQP-UHFFFAOYSA-N 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/70—Multiple-port networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source
- H03H9/703—Networks using bulk acoustic wave devices
- H03H9/706—Duplexers
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
The invention relates to the technical field of filters, in particular to a filter, a duplexer, a high-frequency front-end circuit and a communication device, wherein the filter comprises a first series branch and a plurality of parallel branches, wherein the first series branch is positioned between the input end and the output end of the filter; one end of the parallel branch is positioned on the first series branch, the other end of the parallel branch is grounded, the filter also comprises at least one second series branch positioned between the input end and the output end of the filter, and the second series branch comprises an inductor; and for the whole formed by the first series branch and the second series branch, at least 1 acoustic wave resonator exists in the whole, and the acoustic wave resonator is connected in series with the inductor in the series branch where the acoustic wave resonator is located. The filter that this technical scheme provided helps improving the filter roll-off characteristic, reduces the insertion loss characteristic near resonator series resonance frequency point, and improves the far-band rejection characteristic of filter.
Description
Technical Field
The present invention relates to the field of filter technologies, and in particular, to a filter, a duplexer, a high-frequency front-end circuit, and a communication device.
Background
With the development of wireless communication applications, the demand for data transmission rate is higher and higher, and the data transmission rate corresponds to high utilization rate of spectrum resources and spectrum complexity. The complexity of the communication protocol imposes strict requirements on various performances of the radio frequency system, and the radio frequency filter plays a crucial role in the radio frequency front-end module and can filter out-of-band interference and noise so as to meet the requirements of the radio frequency system and the communication protocol on the signal to noise ratio.
Rf filters are mainly used in wireless communication systems, such as rf front-ends of base stations, mobile phones, computers, satellite communication, radar, electronic countermeasure systems, and the like. The main performance indicators of the rf filter are insertion loss, out-of-band rejection, power capacity, linearity, device size and cost. The good filter performance can improve the data transmission rate, the service life and the reliability of the communication system to a certain extent. It is crucial to design a high performance, simplified filter for a wireless communication system. At present, a small-sized filtering device capable of meeting the use requirement of a communication terminal is mainly a piezoelectric acoustic wave filter, and resonators constituting the acoustic wave filter mainly include: FBAR (Film Bulk Acoustic Resonator), SMR (solid Mounted Resonator), and SAW (Surface Acoustic wave). Among them, filters manufactured based on the bulk acoustic wave principle FBAR and SMR (collectively referred to as BAW, bulk acoustic wave resonator) have advantages of lower insertion loss, faster roll-off characteristics, and the like, compared to filters manufactured based on the surface acoustic wave principle SAW.
The broadband filter is generally implemented by using an LC filter, and a low temperature co-fired ceramic (LTCC) material is widely used in the LC filter because of its advantages of low cost, good performance, high reliability, and the like. However, due to the limitation of the Q value of LTCC, it has a general performance in terms of insertion loss, out-of-band rejection and roll-off; meanwhile, due to the existence of a lead-Inductor (lead-Inductor), the LTCC has poor far-band rejection characteristics.
Disclosure of Invention
In view of the above, it is a primary object of the present invention to provide a filter, a duplexer, a high-frequency front-end circuit, and a communication apparatus, which are useful for improving the roll-off characteristics of the filter, reducing the insertion loss characteristics near the series resonance frequency point of the resonator, and improving the far-band rejection characteristics of the filter.
To achieve the above object, according to one aspect of the present invention, there is provided a filter including a first series branch between an input and an output of the filter, and a plurality of parallel branches; one end of the parallel branch is positioned on the first series branch, the other end of the parallel branch is grounded, the filter also comprises at least one second series branch positioned between the input end and the output end of the filter, and the second series branch comprises an inductor; and for the whole formed by the first series branch and the second series branch, at least 1 acoustic wave resonator exists in the whole, and the acoustic wave resonator is connected in series with the inductor in the series branch.
Optionally, the first series branch comprises two inductors connected in series, and a capacitor is connected between the two inductors in series; the second series branch comprises two inductors which are connected in series, and an acoustic wave resonator is connected between the two inductors in series; the parallel branch comprises two parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor.
Optionally, the first series branch comprises two series resonant units connected in series, each series resonant unit comprising a capacitor and an inductor connected in series; the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series; the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the three parallel resonance units are respectively connected with an input end series branch node, a series resonance unit connecting node and an output end series branch node, and the other ends of the three parallel resonance units are grounded.
Optionally, the first series branch comprises two series resonant units connected in series, each series resonant unit comprising a capacitor and an inductor connected in series; the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series; the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor; one end of the other parallel resonance unit is connected with the connection node of the series resonance unit, the other end of the parallel resonance unit is connected with an inductor, and the inductor is grounded.
Optionally, the first series branch comprises two series resonant units connected in series, each series resonant unit comprising a capacitor and an inductor connected in series; the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series; the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the three parallel resonance units are respectively connected with an input end series branch node, a series resonance unit connecting node and an output end series branch node, the other ends of the three parallel resonance units are respectively connected with the inductors, and the three inductors are grounded.
Optionally, the first series branch comprises two series resonant units connected in series, each series resonant unit comprising a capacitor and an inductor connected in series; the second series branch comprises two inductors which are connected in series, two acoustic wave resonators with different frequencies are connected between the two inductors in series, and the two acoustic wave resonators are connected in parallel; the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor; one end of the other parallel resonance unit is connected with the connection node of the series resonance unit, the other end of the parallel resonance unit is connected with an inductor, and the inductor is grounded.
Optionally, the first series branch includes two inductors connected in series, and two acoustic wave resonators with different frequencies are connected in series between the two inductors, and the two acoustic wave resonators are connected in series; the second series branch comprises two inductors which are connected in series, and a capacitor is connected between the two inductors in series; the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor; one end of the other parallel resonance unit is connected with a connection node between the acoustic wave resonators, the other end of the other parallel resonance unit is connected with an inductor, and the inductor is grounded.
Optionally, the first series branch comprises two series resonant units connected in series, each series resonant unit comprising a capacitor and an inductor connected in series; the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series; the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises an acoustic wave resonator and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end series branch node and an output end series branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with a grounding inductor; one end of the other parallel resonance unit is connected with the connection node of the series resonance unit, the other end of the parallel resonance unit is connected with an inductor, and the inductor is grounded.
The first series branch comprises two series resonance units which are connected in series, and each series resonance unit comprises a capacitor and an inductor which are connected in series;
the second series branch comprises two inductors which are connected in series, and an acoustic wave resonator is connected between the two inductors in series;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, one end of each parallel resonance unit is respectively connected to the input end serial branch node, the serial resonance unit connection node and the output end serial branch node, and the other end of each parallel resonance unit is respectively connected to the inductor; the inductors connected with the parallel resonance units connected with the connection nodes of the series resonance units are grounded, the inductors connected with the other two parallel resonance units are respectively connected with the grounded inductors, and the nodes between the two inductors and the grounded inductors are connected through the first inductor.
Optionally, a coupling structure is formed by mutual inductance between two inductors connected to two parallel resonant units connected to the input end series branch node and the output end series branch node.
According to another aspect of the present invention, there is provided a duplexer including the above filter.
In yet another aspect of the present invention, a high frequency front end circuit is provided, which includes the above filter.
According to still another aspect of the present invention, there is provided a communication apparatus including the above filter.
The invention has the following beneficial effects:
(1) an acoustic wave resonator is arranged on a first series branch or a second series branch between an input end series branch node and an output end series branch node, and the high Q characteristic of the acoustic wave resonator is utilized to ensure that an area between Fs and Fp is used for forming a rapid roll-off edge of the filter, so that the roll-off characteristic of the filter is effectively improved;
(2) by utilizing the low impedance characteristic near the series resonance frequency Fs of the acoustic wave resonator, the insertion loss characteristic of the filter near the resonator Fs is improved to the maximum extent;
(3) the series inductance is introduced into the parallel branch to form series resonance at the far band, and coupling is added between the introduced series inductances, so that the far band rejection characteristic of the filter is effectively improved, and the design flexibility is greatly increased.
Drawings
For purposes of illustration and not limitation, the present invention will now be described in accordance with its preferred embodiments, particularly with reference to the accompanying drawings, in which:
FIG. 1a is an electrical notation of a piezoelectric acoustic wave resonator;
FIG. 1b is a diagram of an equivalent electrical model of a piezoelectric acoustic wave resonator;
FIG. 2 is a relationship between resonator impedance and fs and fp;
FIG. 3 is a schematic cross-sectional view of a bulk acoustic wave resonator structure;
FIG. 4 is a circuit configuration diagram of a comparative example;
fig. 5 is a schematic diagram of a topology of a filter provided in the present embodiment;
fig. 6 is a schematic topology structure diagram of the first embodiment provided in this embodiment;
fig. 7 is a schematic view of a topology structure of a second example provided in the present embodiment;
FIG. 8 is an equivalent circuit diagram of a series branch circuit irrespective of a parallel branch circuit condition for a comparative example circuit configuration;
FIG. 9 is an equivalent circuit diagram of the circuit configuration of the first embodiment without considering the parallel branch;
fig. 10 is a graph comparing the impedance frequency characteristics of the acoustic wave resonator and the impedance frequency characteristics of the comparative example series arm 400 and the first embodiment series arm 401;
FIG. 11 is a comparison of the roll-off characteristics of the first embodiment and the second embodiment;
FIG. 12 is a diagram of a parallel branch circuit of a comparative example;
FIG. 13 is a diagram showing a parallel branch circuit configuration of the second embodiment;
FIG. 14 is a graph comparing the far band suppression characteristics of the first and second embodiments;
fig. 15 shows out-of-band rejection characteristics corresponding to series inductance values of different parallel branches in the second embodiment when M is 0;
fig. 16 is a schematic diagram of the topology of a filter provided in the third embodiment;
fig. 17 is a schematic diagram of the topology of a filter provided in the fourth embodiment;
fig. 18 is a schematic diagram of a topology of a filter provided in the fifth embodiment;
fig. 19 is a schematic diagram of the topology of a filter provided in the sixth embodiment;
fig. 20 is a schematic diagram of the topology of a filter provided in the seventh embodiment;
FIG. 21 shows the out-of-band rejection characteristics for different inductive couplings M when the parallel branch series inductance is equal to 0.15 nH;
fig. 22 is a three-dimensional circuit model of the second embodiment.
Detailed Description
Fig. 1a is an electrical symbol of the piezoelectric acoustic wave resonator, fig. 1b is a diagram of an equivalent electrical model thereof, and the electrical model is simplified to a resonant circuit composed of Lm, Cm and C0 without considering loss terms. According to the resonance condition, the resonance circuit has two resonance frequency points: one is fs when the impedance value of the resonant circuit reaches a minimum value, and fs is defined as a series resonance frequency point of the resonator; and the other is fp when the impedance value of the resonant circuit reaches a maximum value, and fp is defined as a parallel resonance frequency point of the resonator. Wherein the content of the first and second substances,
and fs is smaller than fp; at the same time, the effective electromechanical coupling coefficient Kt of the resonator is defined2eff (hereinafter abbreviated as Kt)2) It can be expressed in fs and fp:
fig. 2 is a relationship between resonator impedance and fs and fp. Under a certain specific frequency, the larger the effective electromechanical coupling coefficient is, the larger the frequency difference between fs and fp is, i.e. the farther the two resonant frequency points are, the larger Kt is2The resonator can meet the design requirements of a wide bandwidth filter. Meanwhile, the impedance amplitude of the resonator at fs is defined as Rs, which is the minimum value in the impedance curve of the resonator; the magnitude of the impedance of the resonator at fp is defined as Rp, which is the maximum value in the impedance curve of the resonator. Rs and Rp are important parameters describing resonance loss characteristics, and when Rs is smaller and Rp is larger, the loss of the resonator is smaller, the Q value is higher, and the insertion loss characteristics of the filter are better.
Fig. 3 is a schematic cross-sectional view of a structure of a thin film bulk acoustic resonator, 61 is a semiconductor substrate material, 65 is an air cavity obtained by etching, a bottom electrode 63 of the thin film bulk acoustic resonator is deposited on the semiconductor substrate 61, 62 is a piezoelectric thin film material, and 64 is a top electrode. The area outlined by the dashed line is the overlapping area of the 65 air cavity, the 64 top electrode, the 63 bottom electrode and the 62 piezoelectric layer, which is the effective resonance area. The top electrode and the bottom electrode may be made of gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium Tungsten (TiW), aluminum (Al), titanium (Ti), or the like; the material of the piezoelectric layer may be aluminum nitride (AlN), zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO3), Quartz (Quartz), potassium niobate (KNbO3), lithium tantalate (LiTaO3), or the like. The thickness of the piezoelectric film is typically less than 10 microns. The aluminum nitride film is polycrystalline or monocrystalline, and the growth method is sputtering or Metal Organic Chemical Vapor Deposition (MOCVD).
Fig. 4 is a circuit structure diagram (comparative example) of a conventional LC filter 100, as shown in fig. 4, two capacitors connected in series are provided between an input end series branch node P1 and an output end series branch node P2, which are respectively C1 and C2, an inductor L1 is provided between the input end series branch node P1 and an input end T1, an inductor L2 is provided between the output end series branch node P2 and an output end T2, the input end series branch node P1, a line between the capacitors C1 and C2, and the output end series branch node P2 are respectively connected to a parallel branch, the parallel branch includes a capacitor C3 and an inductor L3 connected in parallel, a capacitor C4 and an inductor L4 connected in parallel, a capacitor C5 and an inductor L5 connected in parallel, and the other ends of the three parallel branches are grounded.
The conventional LC filter has general performances such as insertion loss, out-of-band rejection, roll-off and the like due to the limitation of the Q value of the LTCC, and the LTCC has poor far-band rejection characteristics due to the existence of a lead-Inductor (LED).
In view of the defects in the above comparative examples, the present embodiment proposes a new filter, which adds a series branch to the existing filter, and sets an acoustic wave filter on any one series branch to form a combined filter.
Fig. 5 is a schematic diagram of a topology of a filter according to this embodiment, and as shown in fig. 5, the first series branch includes two inductors L0 connected in series, and a capacitor C1 connected in series between the two inductors L0; the second series branch comprises two inductors L0 connected in series, and a series acoustic wave resonator RES1 is connected between the two inductors L0; the parallel branch comprises two parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, C2, C3, L3 and L4 in the figure, the two parallel resonance units are respectively connected with an input end series branch node P1 and an output end series branch node P2, the other ends of the two parallel resonance units are respectively connected with inductors L5 and L6, and one ends of the two inductors L5 and L6 are connected with a grounding inductor LM together (the node P3). In this structure, the parallel branch includes two parallel resonant units, wherein the filter may further include three parallel resonant units, and fig. 6 is a schematic view of a topology structure of a filter having another structure according to this embodiment; in the figure, the first series branch comprises two series resonant units connected in series, each series resonant unit comprises a capacitor and an inductor connected in series, and C2 and C3 are connected with L0; the second series branch comprises two inductors L0 connected in series, and an acoustic wave resonator RES1 is connected between the two inductors L0 in series; the parallel branch comprises three parallel resonant units, each parallel resonant unit comprises a capacitor and an inductor which are connected in parallel, such as C4 and L3, C5 and L4, C6 and L5 which are connected in parallel in the figure; the three parallel resonant cells are connected to the input end series branch node P1, the series resonant cell connection node, and the output end series branch node P2, respectively, and the other ends are grounded.
As shown in fig. 7, the first series branch comprises two series resonant cells connected in series, each series resonant cell comprising a capacitor and an inductor connected in series, two L0, C2 and C3 respectively; the second series branch comprises two inductors L0 connected in series, and an acoustic wave resonator RES1 is connected between the two inductors in series; the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the capacitors and the inductors are respectively C4 and L3, C5 and L4, and C6 and L5 which are connected in parallel, the two parallel resonance units are respectively connected with an input end series branch node P1 and an output end series branch node P2, the other ends of the two parallel resonance units are respectively connected with an inductor L6 and an inductor L8, and one ends of the two inductors are commonly connected with a grounding inductor LM; one end of the other parallel resonant cell is connected to the series resonant cell connection node, and the other end is connected to an inductor L7, which is grounded.
Fig. 8 is an equivalent circuit diagram 400 of the series branch of the comparative circuit structure 100 without considering the parallel branch, in which the inductor LE is the equivalent inductance of the series branch and the capacitor CE is the equivalent capacitance of the series branch. Taking the topology of the filter disclosed in fig. 6 as a first embodiment (embodiment 1), fig. 9 is an equivalent circuit diagram 401 of the circuit structure 300 of the first embodiment without considering the parallel branches, where the inductor LE is an equivalent inductor of the series branch, the capacitor CE is an equivalent capacitor of the series branch, and 2L0 represents the series inductor of the input and output terminals.
As shown in fig. 10, in which a solid line is an impedance frequency characteristic curve of the resonator RES in fig. 9, and a DOT broken line is an impedance frequency characteristic curve of the equivalent circuit shown in fig. 9, the series resonator frequency Fs of the resonator after the resonator RES is connected in series to the equivalent inductance is shifted to a low frequency side, and since the series equivalent inductance is relatively small, the series resonance frequency Fs of the equivalent circuit 401 is hardly changed, and the parallel resonator frequency Fp of the resonator after the resonator RES is connected in parallel to the equivalent capacitance is shifted to a low frequency side. In summary, the equivalent Kt of the resonator is caused by the introduction of the equivalent inductor and the equivalent capacitor in the equivalent circuit shown in 4012And decreases. The DASH dotted line is an impedance frequency characteristic curve of the equivalent circuit shown in fig. 8, and since the equivalent inductance LE is small, the series resonator point is located at a higher frequency.
As shown in fig. 11 in which a thin solid line is a solid line of the impedance frequency characteristic curve of the equivalent circuit shown in fig. 9, a thick solid line is an insertion loss characteristic curve of the first embodiment, and a broken line is an insertion loss characteristic curve of the comparative example, the pass band edge roll-off characteristics of the embodiment are significantly improved relative to the comparative example because the region between Fs and Fp is ensured for forming the fast roll-off edge of the filter due to the high Q characteristics of the BAW/SAW resonator (acoustic wave resonator); meanwhile, as shown by the dotted rectangular box in fig. 11, since the second series branch is connected across the input terminal node P1 and the output terminal node P2, the low impedance characteristic in the vicinity of the series resonance frequency Fs of the BAW/SAW resonator can minimize the insertion loss in the corresponding passband band.
Fig. 12 shows a parallel branch circuit structure 501 of a comparative example, which is composed of an inductor L and a capacitor C connected in parallel with each other; the topology of the filter disclosed in fig. 7 is taken as a second embodiment, and fig. 13 shows a parallel branch circuit structure 502 of the second embodiment (embodiment 2), which is formed by connecting an inductor L1 and a capacitor C1 in parallel with each other and then connecting an inductor L2 in series.
As shown in fig. 14, in which a thick implementation represents the insertion loss characteristic curve of embodiment 2, and a thin solid line represents the impedance frequency characteristic curve of the parallel branch circuit in the second embodiment shown in fig. 13; the thick broken line is an insertion loss characteristic curve of example 1, and the thin broken line is an impedance frequency characteristic curve of the parallel branch circuit of the first embodiment shown in fig. 12. Since the inductor L2 in the parallel branch circuit of the second embodiment introduces series resonance, a suppression zero is generated at the far band, and the far band suppression characteristic of the filter is effectively improved.
As shown in fig. 15, the change rule of the out-of-band rejection characteristic of the filter is shown along with the change of the inductance of the series inductor L2 in the parallel branch. As the inductance of inductor L2 increases, the damping zero at the far band moves toward the low frequency end.
In addition to the first embodiment and the second embodiment, the topological structure of the filter in this embodiment further includes the following embodiments.
Fig. 16 is a schematic diagram of a topology of a filter provided in a third embodiment, as shown in fig. 16, a first series branch includes two series resonant cells connected in series, each series resonant cell includes two capacitors and inductors connected in series, respectively L0, C2 and C3; the second series branch comprises two inductors L0 connected in series, between which an acoustic wave resonator RES1 is connected in series.
The parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel and are respectively C4, L3, C5, L4, C6 and L5, the three parallel resonance units are respectively connected with an input end series branch node P1, a series resonance unit connecting node and an output end series branch node P2, the other ends of the three parallel resonance units are respectively connected with the inductors L6, L7 and L8, and the three inductors are grounded.
Fig. 17 is a schematic diagram of a topology of a filter provided in a fourth embodiment, as shown in fig. 17, a first series branch includes two series resonant cells connected in series, each series resonant cell includes a capacitor and an inductor connected in series, two L0, C2 and C3; the second series branch comprises two inductors L0 connected in series, two acoustic wave resonators with different frequencies are connected between the two inductors in series, and the two acoustic wave resonators are connected in parallel and are RES1 and RES 2; wherein the frequencies of the resonator RES1 and the resonator RES2 are different from each other.
The parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel and are respectively C4, L3, C5, L4, C6 and L5, the two parallel resonance units are respectively connected with an input end series branch node P1 and an output end series branch node P2, the other ends of the two parallel resonance units are respectively connected with an inductor L6 and an inductor L8, and one ends of the two inductors are commonly connected with a grounding inductor LM; one end of the other parallel resonant cell is connected to the series resonant cell connection node, and the other end is connected to an inductor L7, which is grounded.
Fig. 18 is a schematic diagram of a topology of a filter provided in a fifth embodiment, as shown in fig. 18, a first series branch includes two inductors L0 connected in series, two acoustic wave resonators RES1 and RES2 with different frequencies are connected in series between the two inductors, and the two acoustic wave resonators are connected in series; the second series branch comprises two inductors L0 connected in series, and a capacitor C1 connected in series between the two inductors;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, C4, L3, C5, L4, C6 and L5, the two parallel resonance units are respectively connected with an input end series branch node P1 and an output end series branch node P2, the other ends of the two parallel resonance units are respectively connected with inductors L6 and L8, and one ends of the two inductors are commonly connected with a grounding inductor LM; one end of the other parallel resonant unit is connected to a connection node between the acoustic wave resonators, and the other end is connected to an inductance L7, which is grounded. In this embodiment, the capacitance in the series unit of the first series arm is replaced by the acoustic wave resonator RES1 and the resonator RES2, and the roll-off characteristic on the right side of the filter pass band is improved.
Fig. 19 is a schematic diagram of a topology of a filter provided in a sixth embodiment, as shown in fig. 19, a first series branch includes two series resonant cells connected in series, each series resonant cell includes a capacitor and an inductor connected in series, two L0, C2 and C3; the second series branch comprises two inductors L0 connected in series, between which an acoustic wave resonator RES1 is connected in series.
The parallel branch comprises three parallel resonance units, each parallel resonance unit comprises an acoustic wave resonator and an inductor which are connected in parallel and respectively include RES2, L3, RES3, L4, RES4 and L5, the two parallel resonance units are respectively connected with an input end series branch node P1 and an output end series branch node P2, the other ends of the two parallel resonance units are respectively connected with inductors L6 and L8, and one ends of the two inductors are commonly connected with a grounding inductor LM; one end of the other parallel resonant cell is connected to the series resonant cell connection node, and the other end is connected to an inductor L7, which is grounded. In this embodiment, the capacitance in the parallel resonance unit is replaced by BAW/SAW resonators, resonator RES2, resonator RES3, and resonator RES4, which are different in resonator frequency from each other, for improving the roll-off characteristic on the left side of the filter passband.
Fig. 20 is a schematic diagram of the topology of a filter provided in the seventh embodiment; as shown in fig. 20, the first series branch includes two series resonant cells connected in series, each series resonant cell including a capacitor and an inductor connected in series, two inductors L0, C2, and C3; the second series branch comprises two inductors L0 connected in series, between which an acoustic wave resonator RES1 is connected in series.
The parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel and are respectively C4, L3, C5, L4, C6 and L5, one end of each parallel resonance unit is respectively connected to an input end series branch node P1, a series resonance unit connection node and an output end series branch node P2, and the other end of each parallel resonance unit is respectively connected with an inductor L6, an inductor L7 and an inductor L8; wherein, an inductor L7 connected with the parallel resonant unit connected with the connection node of the series resonant unit is grounded, inductors L6 and L8 connected with the other two parallel resonant units are respectively connected with a grounding inductor LM, and nodes P3 and P6 between the two inductors L6 and L8 and the grounding inductor LM are connected through a first inductor L9.
In this embodiment, a coupling structure is added to the parallel branch between the input end series branch node P1 and the output end series branch node P2, such as an inductive coupling M shown in fig. 16, where the inductive coupling M can improve the far-band rejection characteristic of the filter. Taking the second embodiment as an example, an inductive coupling M is added between the series inductor L6 of the input-end parallel branch and the series inductor L8 of the output-end parallel branch, and the magnitude of the inductive coupling M corresponds to the insertion loss characteristic curve of the second embodiment, as shown in fig. 21, the added coupled combined rejection zeros are separated into two rejection zeros at high and low frequencies, and the larger the inductive coupling amount is, the farther the two rejection zeros are apart. In conclusion, by changing the inductance of the inductor L2 and adding the inductance coupling between the series inductance L6 of the input-end parallel branch and the series inductance L8 of the output-end parallel branch, the out-of-band rejection index requirements of different frequency bands can be met, and the design flexibility is increased to a great extent.
In this embodiment, the filter may be implemented by LTCC, discrete device, IPD, or other forms, and is preferably implemented by LTCC, which has the advantages of low cost, good performance, high reliability, and the like. As shown in fig. 22, a schematic diagram 800 of a three-dimensional structure implemented by the second embodiment based on LTCC is shown, where 86 is a reference plane, 80 is a resonator RES1, 83 of the second series branch is an LTCC dielectric material, 81 is a device input terminal, 82 is an output terminal of the device, P1 corresponds to a node P4 in the circuit diagram of the second embodiment, P2 corresponds to a node P5 in the circuit diagram of the second embodiment, a distance S between a node P1 and the node P2 corresponds to a series inductance in the parallel branch, a higher S generates a lower frequency of a position where a far-band suppression zero is located, a parameter H corresponds to an inductance LM in the second embodiment, and a higher H generates a larger inductive coupling M between the series inductance L6 representing the input-side parallel branch and the series inductance L8 representing the output-side parallel branch, and the two suppression zeros are further apart.
The present embodiment also provides a duplexer, a high frequency front end circuit and a communication device, including one or more of the filters in the above embodiments.
The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations, and substitutions may occur depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (13)
1. A filter comprises a first series branch and a plurality of parallel branches, wherein the first series branch is positioned between an input end and an output end of the filter; one end of the parallel branch is positioned on the first series branch, the other end is grounded, the device is characterized in that,
the filter also comprises at least one second series branch which is positioned between the input end and the output end of the filter, and the second series branch comprises an inductor;
and for the whole formed by the first series branch and the second series branch, at least 1 acoustic wave resonator exists in the whole, and the acoustic wave resonator is connected in series with the inductor in the series branch where the acoustic wave resonator is located.
2. The filter of claim 1, wherein the first series branch comprises two inductors connected in series, and a capacitor is connected in series between the two inductors;
the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series;
the parallel branch comprises two parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor.
3. The filter according to claim 1, characterized in that the first series branch comprises two series resonant cells in series, each series resonant cell comprising a capacitor and an inductor in series;
the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the three parallel resonance units are respectively connected with an input end series branch node, a series resonance unit connection node and an output end series branch node, and the other ends of the three parallel resonance units are grounded.
4. The filter according to claim 1, characterized in that the first series branch comprises two series resonant cells in series, each series resonant cell comprising a capacitor and an inductor in series;
the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor; one end of the other parallel resonance unit is connected with the connection node of the series resonance unit, the other end of the parallel resonance unit is connected with an inductor, and the inductor is grounded.
5. The filter according to claim 1, characterized in that the first series branch comprises two series resonant cells in series, each series resonant cell comprising a capacitor and an inductor in series;
the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the three parallel resonance units are respectively connected with an input end serial branch node, a serial resonance unit connecting node and an output end serial branch node, the other ends of the three parallel resonance units are respectively connected with the inductors, and the three inductors are grounded.
6. The filter according to claim 1, characterized in that the first series branch comprises two series resonant cells in series, each series resonant cell comprising a capacitor and an inductor in series;
the second series branch comprises two inductors which are connected in series, two acoustic wave resonators with different frequencies are connected between the two inductors in series, and the two acoustic wave resonators are connected in parallel;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor; one end of the other parallel resonance unit is connected with the connection node of the series resonance unit, the other end of the parallel resonance unit is connected with an inductor, and the inductor is grounded.
7. The filter according to claim 1, characterized in that the first series branch comprises two series inductors, two acoustic wave resonators with different frequencies are connected in series between the two inductors, and the two acoustic wave resonators are connected in series;
the second series branch comprises two inductors connected in series, and a capacitor is connected between the two inductors in series;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end serial branch node and an output end serial branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with the grounding inductor; one end of the other parallel resonance unit is connected with a connection node between the acoustic wave resonators, the other end of the other parallel resonance unit is connected with an inductor, and the inductor is grounded.
8. The filter according to claim 1, characterized in that the first series branch comprises two series resonant cells in series, each series resonant cell comprising a capacitor and an inductor in series;
the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises an acoustic wave resonator and an inductor which are connected in parallel, the two parallel resonance units are respectively connected with an input end series branch node and an output end series branch node, the other ends of the two parallel resonance units are respectively connected with the inductors, and one ends of the two inductors are jointly connected with a grounding inductor; one end of the other parallel resonance unit is connected with the connection node of the series resonance unit, the other end of the parallel resonance unit is connected with an inductor, and the inductor is grounded.
9. The filter according to claim 1, characterized in that the first series branch comprises two series resonant cells in series, each series resonant cell comprising a capacitor and an inductor in series;
the second series branch comprises two inductors connected in series, and an acoustic wave resonator is connected between the two inductors in series;
the parallel branch comprises three parallel resonance units, each parallel resonance unit comprises a capacitor and an inductor which are connected in parallel, one end of each parallel resonance unit is respectively connected to an input end serial branch node, a serial resonance unit connection node and an output end serial branch node, and the other end of each parallel resonance unit is respectively connected to the inductor; the inductors connected with the parallel resonance units connected with the connection nodes of the series resonance units are grounded, the inductors connected with the other two parallel resonance units are respectively connected with the grounded inductors, and the nodes between the two inductors and the grounded inductors are connected through the first inductor.
10. The filter according to any of claims 2 or 4 to 9, wherein a mutual inductance between two inductances connected to two parallel resonant cells connected to the input and output series branch nodes forms a coupling structure.
11. A duplexer comprising a filter according to any one of claims 1 to 10.
12. A high frequency front end circuit comprising a filter according to any one of claims 1 to 10.
13. A communication device comprising a filter according to any one of claims 1 to 10.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010046418.1A CN111200419B (en) | 2020-01-16 | 2020-01-16 | Filter, duplexer, high-frequency front-end circuit and communication device |
| PCT/CN2020/140941 WO2021143520A1 (en) | 2020-01-16 | 2020-12-29 | Filter, duplexer, high-frequency front-end circuit, and communication apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010046418.1A CN111200419B (en) | 2020-01-16 | 2020-01-16 | Filter, duplexer, high-frequency front-end circuit and communication device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111200419A true CN111200419A (en) | 2020-05-26 |
| CN111200419B CN111200419B (en) | 2021-08-10 |
Family
ID=70746356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010046418.1A Active CN111200419B (en) | 2020-01-16 | 2020-01-16 | Filter, duplexer, high-frequency front-end circuit and communication device |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN111200419B (en) |
| WO (1) | WO2021143520A1 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111641488A (en) * | 2020-05-28 | 2020-09-08 | 苏州汉天下电子有限公司 | Duplexer |
| CN112350684A (en) * | 2020-10-29 | 2021-02-09 | 诺思(天津)微***有限责任公司 | Acoustic wave filter, multiplexer and communication equipment |
| CN112688660A (en) * | 2020-11-27 | 2021-04-20 | 中国电子科技集团公司第十三研究所 | FBAR filter circuit design |
| WO2021143520A1 (en) * | 2020-01-16 | 2021-07-22 | 诺思(天津)微***有限责任公司 | Filter, duplexer, high-frequency front-end circuit, and communication apparatus |
| WO2021238970A1 (en) * | 2020-05-28 | 2021-12-02 | 诺思(天津)微***有限责任公司 | Filter, duplexer, multiplexer, and communication device |
| CN114465601A (en) * | 2022-04-13 | 2022-05-10 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| WO2022217971A1 (en) * | 2021-04-16 | 2022-10-20 | 苏州汉天下电子有限公司 | Lc filter |
| CN117543174A (en) * | 2023-12-25 | 2024-02-09 | 苏州汰砾微波技术有限公司 | Broadband frequency division duplexer |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1190823A (en) * | 1997-02-12 | 1998-08-19 | 冲电气工业株式会社 | Surface acoustic filter with decay pole produced by impedance circuit |
| CN1773849A (en) * | 2004-11-10 | 2006-05-17 | 三星电子株式会社 | Monolithic RF filter and integrated circuit |
| CN102365784A (en) * | 2009-02-09 | 2012-02-29 | 联合大学公司 | Reflectionless filters |
| CN102725959A (en) * | 2010-01-28 | 2012-10-10 | 株式会社村田制作所 | Tunable filter |
| CN104737447A (en) * | 2012-10-24 | 2015-06-24 | 株式会社村田制作所 | Filter device |
| CN105580274A (en) * | 2013-09-26 | 2016-05-11 | 株式会社村田制作所 | Resonator and high-frequency filter |
| CN109831176A (en) * | 2018-12-05 | 2019-05-31 | 天津大学 | A kind of piezoelectric acoustic-wave filter and duplexer |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5042663B2 (en) * | 2007-02-21 | 2012-10-03 | 日本碍子株式会社 | Ladder type piezoelectric filter |
| CN102638239A (en) * | 2012-04-17 | 2012-08-15 | 南京航空航天大学 | Capacitive coupling lumped parameter three-band pass filter |
| CN108123698A (en) * | 2018-02-08 | 2018-06-05 | 武汉衍熙微器件有限公司 | A kind of wave filter with Out-of-band rejection |
| CN109547042B (en) * | 2018-12-19 | 2020-12-22 | 天津大学 | Radio frequency front end structure and terminal of multi-channel transmitter and wireless communication equipment |
| CN111200419B (en) * | 2020-01-16 | 2021-08-10 | 诺思(天津)微***有限责任公司 | Filter, duplexer, high-frequency front-end circuit and communication device |
-
2020
- 2020-01-16 CN CN202010046418.1A patent/CN111200419B/en active Active
- 2020-12-29 WO PCT/CN2020/140941 patent/WO2021143520A1/en active Application Filing
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1190823A (en) * | 1997-02-12 | 1998-08-19 | 冲电气工业株式会社 | Surface acoustic filter with decay pole produced by impedance circuit |
| CN1773849A (en) * | 2004-11-10 | 2006-05-17 | 三星电子株式会社 | Monolithic RF filter and integrated circuit |
| CN102365784A (en) * | 2009-02-09 | 2012-02-29 | 联合大学公司 | Reflectionless filters |
| CN102725959A (en) * | 2010-01-28 | 2012-10-10 | 株式会社村田制作所 | Tunable filter |
| CN104737447A (en) * | 2012-10-24 | 2015-06-24 | 株式会社村田制作所 | Filter device |
| CN105580274A (en) * | 2013-09-26 | 2016-05-11 | 株式会社村田制作所 | Resonator and high-frequency filter |
| CN109831176A (en) * | 2018-12-05 | 2019-05-31 | 天津大学 | A kind of piezoelectric acoustic-wave filter and duplexer |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021143520A1 (en) * | 2020-01-16 | 2021-07-22 | 诺思(天津)微***有限责任公司 | Filter, duplexer, high-frequency front-end circuit, and communication apparatus |
| CN111641488A (en) * | 2020-05-28 | 2020-09-08 | 苏州汉天下电子有限公司 | Duplexer |
| WO2021238970A1 (en) * | 2020-05-28 | 2021-12-02 | 诺思(天津)微***有限责任公司 | Filter, duplexer, multiplexer, and communication device |
| CN112350684A (en) * | 2020-10-29 | 2021-02-09 | 诺思(天津)微***有限责任公司 | Acoustic wave filter, multiplexer and communication equipment |
| CN112688660A (en) * | 2020-11-27 | 2021-04-20 | 中国电子科技集团公司第十三研究所 | FBAR filter circuit design |
| WO2022217971A1 (en) * | 2021-04-16 | 2022-10-20 | 苏州汉天下电子有限公司 | Lc filter |
| CN114465601A (en) * | 2022-04-13 | 2022-05-10 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| CN114465601B (en) * | 2022-04-13 | 2022-08-12 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| CN117543174A (en) * | 2023-12-25 | 2024-02-09 | 苏州汰砾微波技术有限公司 | Broadband frequency division duplexer |
| CN117543174B (en) * | 2023-12-25 | 2024-06-21 | 苏州汰砾微波技术有限公司 | Broadband frequency division duplexer |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111200419B (en) | 2021-08-10 |
| WO2021143520A1 (en) | 2021-07-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111200419B (en) | Filter, duplexer, high-frequency front-end circuit and communication device | |
| US8063717B2 (en) | Duplexer having resonator filters | |
| US8125298B2 (en) | Acoustic wave filter, duplexer using the acoustic wave filter, and communication apparatus using the duplexer | |
| US8902020B2 (en) | Resonator filter with multiple cross-couplings | |
| JP4654220B2 (en) | Filter structure including a piezoelectric resonator | |
| JP4326063B2 (en) | Monolithic filter using thin film bulk acoustic wave device and minimal passive element to control the shape and width of passband response | |
| WO2021203761A1 (en) | Filter, multiplexer, and communication device | |
| JP4468185B2 (en) | Cavity filter structure with equal resonant frequency | |
| CN111327288B (en) | Bulk acoustic wave resonator, ultra-narrow band filter, duplexer and multiplexer | |
| CN103959647A (en) | Ladder-type elastic wave filter and antenna duplexer using same | |
| EP1503498A1 (en) | Surface acoustic wave device and communications apparatus | |
| KR20060121950A (en) | Surface acoustic wave filter and antenna common unit employing it | |
| JP2006513662A5 (en) | ||
| CN112073018B (en) | Duplexer, multiplexer, and communication device | |
| CN114301419A (en) | Acoustic matrix filter and radio using the same | |
| KR20020029922A (en) | Bulk accoustic wave filter | |
| WO2021147633A1 (en) | Filter, duplexer, high-frequency front-end circuit, and communication apparatus | |
| CN111628745B (en) | Signal transmission line, duplexer, multiplexer, and communication apparatus | |
| CN115473509A (en) | Filter, multiplexer and electronic equipment | |
| US20220337223A1 (en) | Hybrid resonators | |
| CN111130498A (en) | Duplexer | |
| CN111342806B (en) | Piezoelectric filter having lamb wave resonator, duplexer, and electronic device | |
| US10651822B2 (en) | Multiplexer | |
| CN215344517U (en) | Broadband filter, multiplexer, and electronic device | |
| JPH11340779A (en) | Surface acoustic wave filter, duplexer, and communication equipment device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: The invention relates to a filter, a duplexer, a high-frequency front-end circuit and a communication device Effective date of registration: 20210908 Granted publication date: 20210810 Pledgee: Tianjin TEDA Haihe intelligent manufacturing industry development fund partnership (L.P.) Pledgor: ROFS MICROSYSTEM(TIANJIN) Co.,Ltd. Registration number: Y2021980009034 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PP01 | Preservation of patent right |
Effective date of registration: 20240130 Granted publication date: 20210810 |
|
| PP01 | Preservation of patent right |