CN114725635B - Dual-frequency balance filter - Google Patents
Dual-frequency balance filter Download PDFInfo
- Publication number
- CN114725635B CN114725635B CN202210486712.3A CN202210486712A CN114725635B CN 114725635 B CN114725635 B CN 114725635B CN 202210486712 A CN202210486712 A CN 202210486712A CN 114725635 B CN114725635 B CN 114725635B
- Authority
- CN
- China
- Prior art keywords
- impedance
- branch
- resonator
- sub
- pair
- 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.)
- Active
Links
- 230000005284 excitation Effects 0.000 claims abstract description 12
- 230000001629 suppression Effects 0.000 claims abstract description 11
- 230000000694 effects Effects 0.000 claims abstract description 6
- 230000008878 coupling Effects 0.000 claims description 20
- 238000010168 coupling process Methods 0.000 claims description 20
- 238000005859 coupling reaction Methods 0.000 claims description 20
- 238000005452 bending Methods 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 claims description 5
- 238000013461 design Methods 0.000 abstract description 7
- 238000004891 communication Methods 0.000 description 8
- 239000000758 substrate Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 2
- 230000036039 immunity Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- BTGZYWWSOPEHMM-UHFFFAOYSA-N [O].[Cu].[Y].[Ba] Chemical compound [O].[Cu].[Y].[Ba] BTGZYWWSOPEHMM-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910021521 yttrium barium copper oxide Inorganic materials 0.000 description 1
Classifications
-
- 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
- H01P1/201—Filters for transverse electromagnetic waves
- H01P1/203—Strip line filters
- H01P1/20309—Strip line filters with dielectric resonator
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
The application provides a dual-frequency balance filter, which comprises a pair of input feeder structures and a pair of output feeder structures which are symmetrically arranged, and a first step impedance resonator and a second step impedance resonator which are symmetrically arranged; wherein the pair of input feed line structures are connected with the first step impedance resonator and the pair of output feed line structures are connected with the second step impedance resonator to provide electromagnetic excitation; the first step impedance resonator and the second step impedance resonator are symmetrical structures and comprise a step impedance body and a first branch knot arranged at the center of the step impedance body, so that two frequency bands are generated under the electromagnetic excitation effect and used for common mode frequency suppression of the two frequency bands. The dual-frequency balance filter has a simple structure when realizing multiple frequency bands, flexibly regulates and controls each frequency band, enhances the design flexibility and improves the suppression degree of common mode noise.
Description
Technical Field
The disclosed embodiments of the present application relate to the field of wireless communication technology, and more particularly, to a dual-frequency balanced filter.
Background
Currently, deployment of large-scale wireless communication networks and small-sized wireless communication terminals provide high-quality and intelligent communication services. However, high density wireless communication networks and highly integrated circuits greatly challenge the robustness of communication systems, with the immunity to electromagnetic interference of radio frequency front-end device systems being the most critical. Compared with the traditional unbalanced device for processing single-ended signals, the balanced circuit has a unique physical topological structure, can effectively inhibit various environmental noises and electronic noises generated by circuit components, can solve the problem of electromagnetic interference (EMI) between communication devices, and greatly improves the signal-to-noise ratio of a receiver and the efficiency of a transmitter.
Therefore, in increasingly complex electromagnetic environments, it is of great importance to design a highly selective balanced filter with excellent noise immunity. In addition, to better meet the multi-service requirements of modern wireless communication, it is important to research and design a balance filter with multiple operating frequency bands.
Disclosure of Invention
According to an embodiment of the present application, a dual-band balanced filter is provided to solve the above-mentioned problems.
In accordance with aspects of the present application, an exemplary dual-band balanced filter is disclosed. The exemplary dual-band balanced filter includes a pair of input feed line structures and a pair of output feed line structures arranged symmetrically and first and second stepped impedance resonators arranged symmetrically; wherein the pair of input feed line structures are connected with the first step impedance resonator and the pair of output feed line structures are connected with the second step impedance resonator to provide electromagnetic excitation; the first step impedance resonator and the second step impedance resonator are symmetrical structures and comprise a step impedance body and a first branch knot arranged at the center of the step impedance body, so that two frequency bands are generated under the electromagnetic excitation effect and used for common mode frequency suppression of the two frequency bands.
In some embodiments, the dual-frequency balance filter further comprises a first connecting line and a second connecting line which are symmetrically arranged and are connected with the first step impedance resonator and the second step impedance resonator; the first step impedance resonator and the second step impedance resonator each further comprise a pair of second branches arranged on the step impedance body and spaced from the first branches; the first connecting wire and the second connecting wire are used for providing magnetic coupling between the first step impedance resonator and the second step impedance resonator, and the gap coupling between the two ends of the step impedance body of the first step impedance resonator and the two ends of the step impedance body of the second step impedance resonator and between the pair of second branches of the first step impedance resonator and the pair of second branches of the second step impedance resonator is provided, so that the electric coupling between the first step impedance resonator and the second step impedance resonator is provided, and two sides of the two frequency bands respectively have a transmission zero point.
In some embodiments, the first branch is a symmetrical T-shaped structure including a first sub-branch and a second sub-branch connected between the stepped impedance body center and the first sub-branch center for common mode frequency rejection of the two frequency bands.
In some embodiments, the equivalent impedance of the first sub-branch is the same as the equivalent impedance of the second sub-branch.
In some embodiments, the equivalent impedance of the first sub-branch is the same as the equivalent impedance of the first connection line or the second connection line.
In some embodiments, the stepped impedance body includes a first impedance portion, two second impedance portions symmetrically disposed, two fourth impedance portions symmetrically disposed, and two fourth impedance portions symmetrically disposed, wherein a center of the first impedance portion is a center of the stepped impedance body, and the first impedance portion, the second impedance portion, the third impedance portion, and the fourth impedance portion are sequentially connected from the center of the stepped impedance body; each second branch of the pair of second branches is connected to a connection portion of the first impedance portion and the second impedance portion.
In some embodiments, the second branch comprises a third sub-branch and a fourth sub-branch, wherein the fourth sub-branch is connected to the third sub-branch and an equivalent impedance of the fourth sub-branch is different from an equivalent impedance of the third sub-branch; the third impedance part and the fourth impedance part are subjected to bending treatment, so that the fourth impedance part and the fourth sub-branch are positioned on the same straight line to be commonly used for the gap coupling.
In some embodiments, the equivalent impedance of the third sub-branch is the same as the equivalent impedance of the second impedance section; the equivalent impedance of the fourth sub-branch is the same as the equivalent impedance of the fourth impedance section.
In some embodiments, the pair of input feed line structures comprises a first input feed line and a second input feed line symmetrically disposed, and the pair of output feed line structures comprises a first output feed line and a second output feed line symmetrically disposed; wherein the first input feeder line and the first output feeder line correspond to the first connecting line, and the second input feeder line and the second output feeder line correspond to the second connecting line.
In some embodiments, the first input feed line, the first output feed line, and the first connection line are collinear; the second input feeder line, the second output feeder line and the second connecting line are located in another straight line.
The beneficial effects of this application are: the first step impedance resonator and the second step impedance resonator both comprise step impedance bodies so as to generate two frequency bands under the action of electromagnetic excitation, so that the dual-frequency balance filter with a simple structure and multiple frequency bands can be realized, each frequency band can be flexibly regulated and controlled, the design flexibility is enhanced, and the first branch arranged in the center of the step impedance bodies is included in the first step impedance resonator and the second step impedance resonator so as to be used for common mode frequency suppression of the two frequency bands, the suppression degree of common mode noise is improved, and the dual-frequency balance filter with good performance and multiple frequency bands is realized.
These and other objects of the present application will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures and drawings.
Drawings
Fig. 1 is a schematic structural diagram of a dual-frequency balanced filter according to an embodiment of the present application;
fig. 2 is a graph of scattering parameters of a dual-frequency balanced filter according to an embodiment of the present application.
Detailed Description
Certain terms are used throughout the description and claims to refer to particular components. As will be appreciated by those skilled in the art, electronic device manufacturers may refer to a component by different names. The components are not distinguished by name herein, but rather by function. In the following description and claims, the terms "include" and "comprise" are defined as open-ended terms, and thus should be interpreted to mean "include, but not limited to …". In addition, the term "coupled" is intended to mean either an indirect electrical connection or a direct electrical connection. Thus, when one device is coupled to another device, then the connection may be a direct electrical connection or an indirect electrical connection via other devices and connections.
Fig. 1 is a schematic structural diagram of a dual-frequency balance filter according to an embodiment of the present application. The dual-frequency balanced filter 100 includes a pair of input feed line structures 110 and a pair of output feed line structures 120 arranged symmetrically, and a first stepped impedance resonator 130 and a second stepped impedance resonator 140 arranged symmetrically.
The symmetrical arrangement of the pair of input feed line structures 110 and the pair of output feed line structures 120 and the first step impedance resonator 130 and the second step impedance resonator 140 may be arranged according to practical circuit design considerations. In the present embodiment, the pair of input feeder structures 110 and the pair of output feeder structures 120, and the first step impedance resonator 130 and the second step impedance resonator 140 are disposed vertically symmetrically, i.e. the symmetry direction is the vertical direction. In other embodiments, the pair of input feeder structures 110 and the pair of output feeder structures 120 and the first step impedance resonator 130 and the second step impedance resonator 140 may also be symmetrically disposed about a tilt line.
Wherein a pair of input feed line structures 110 are connected to a first step impedance resonator 130 and a pair of output feed line structures 120 are connected to a second step impedance resonator 140 to provide electromagnetic excitation.
The first step impedance resonator 130 and the second step impedance resonator 140 are symmetrical structures, and each include a step impedance body a and a first branch b disposed at the center of the step impedance body a, so as to generate two frequency bands under the electromagnetic excitation effect, and are used for common mode frequency suppression of the two frequency bands.
The symmetry direction of the symmetry structure may be perpendicular to the symmetry direction of the symmetrically disposed first and second step-impedance resonators 130 and 140. For example, if the symmetry direction of the first step impedance resonator 130 and the second step impedance resonator 140 which are symmetrically arranged is a vertical direction, the symmetry direction of the symmetrical structure is a horizontal direction, i.e., the symmetrical structure is horizontally symmetrically arranged.
The stepped impedance body a is a symmetrical half-wavelength resonator, and under electromagnetic excitation, the stepped impedance body a of the first stepped impedance resonator 130 and the second stepped impedance resonator 140 can generate 2 frequencies, each frequency forms a frequency band, and the center frequencies of the two frequency bands are sequentially increased. The first branch b is arranged in the center of the stepped impedance body a and is used for common mode frequency suppression of two frequency bands.
In this embodiment, the first step impedance resonator 130 and the second step impedance resonator 140 each include a step impedance body a to generate two frequency bands under the electromagnetic excitation effect, so as to implement the multi-band dual-frequency balance filter 100 with a simple structure, flexibly regulate each frequency band, enhance the design flexibility, and the first step impedance resonator 130 and the second step impedance resonator 140 each include a first branch b disposed in the center of the step impedance body a for common mode frequency suppression of the two frequency bands, thereby improving the suppression degree of common mode noise and implementing the multi-band dual-frequency balance filter 100 with good performance.
As described above, the stepped impedance body a of the first stepped impedance resonator 130 and the second stepped impedance resonator 140 generates two frequency bands under the electromagnetic excitation, and the first stub b of the first stepped impedance resonator 130 and the second stepped impedance resonator 140 disposed at the center of the stepped impedance body a is used for common mode frequency rejection of the two frequency bands. In some embodiments, the first step impedance resonator 130 and the second step impedance resonator 140 each further include a pair of second branches c disposed on the step impedance body a and spaced apart from the first branch b; the dual-frequency balanced filter further includes a first connection line 150 and a second connection line 160, which are symmetrically disposed, and are connected to the first step impedance resonator 130 and the second step impedance resonator 140.
The first connection line 150 and the second connection line 160 are used for providing magnetic coupling between the first step impedance resonator 130 and the second step impedance resonator 140, and gap coupling between two ends of the step impedance body a of the first step impedance resonator 130 and two ends of the step impedance body a of the second step impedance resonator 140 and gap coupling between a pair of second branches c of the first step impedance resonator 130 and a pair of second branches c of the second step impedance resonator 140, and providing electric coupling between the first step impedance resonator 130 and the second step impedance resonator 140, so that two sides of two frequency bands respectively have a transmission zero point.
The first branch b is arranged at the center of the step impedance body a, and the pair of second branches c and the first branch b are arranged at intervals, so that the pair of second branches c are arranged at two opposite ends of the step impedance body a and are symmetrically arranged. The symmetry direction of the pair of second branches c is the same as the symmetry direction of the stepped impedance body a.
Gap coupling is commonly achieved between two ends of the step impedance body a of the first step impedance resonator 130 and two ends of the step impedance body a of the second step impedance resonator 140 and between a pair of second branches c of the first step impedance resonator 130 and a pair of second branches c of the second step impedance resonator 140, that is, a gap between two ends of the step impedance body a of the first step impedance resonator 130 and two ends of the step impedance body a of the second step impedance resonator 140 is the same as a gap between a pair of second branches c of the first step impedance resonator 130 and a pair of second branches c of the second step impedance resonator 140.
Due to the gap coupling and the electric coupling, two sides of the two frequency bands generated by the step impedance body a are respectively provided with a transmission zero, the frequency band selectivity is improved, and the performance of the double-frequency balance filter is improved.
The symmetry direction of the first connection line 150 and the second connection line 160 symmetrically disposed may be a horizontal direction, which is the same as the symmetry direction of the stepped impedance body a. Meanwhile, the first connection line 150 and the second connection line 160 are also vertically symmetrical, that is, the symmetrical directions of the first connection line 150 and the second connection line 160 are vertical directions.
As described above, the first branch b of the first and second stepped impedance resonators 130 and 140 disposed at the center of the stepped impedance body a is used for common mode frequency rejection of two frequency bands. In some embodiments, the first branch b is a symmetrical T-shaped structure including a first sub-branch b1 and a second sub-branch b2 connected between the center of the stepped impedance body a and the center of the first sub-branch b1 for common mode frequency rejection of two frequency bands.
The symmetry direction of the first branch b is the same as the symmetry direction of the first step impedance resonator 130 or the second step impedance resonator 140, i.e., the symmetry direction of the above-described symmetry structure. For example, the symmetry direction of the first step impedance resonator 130 or the second step impedance resonator 140 is a horizontal direction, and the symmetry direction of the first branch b is also a horizontal direction. For another example, the symmetry direction of the first stepped impedance resonator 130 or the second stepped impedance resonator 140 is a tilt line, and the symmetry direction of the first branch b is also a tilt line, that is, both are symmetrical about the tilt line.
In some examples, the equivalent impedance of the first sub-branch b1 is the same as the equivalent impedance of the second sub-branch b 2. The equivalent impedance of the first sub-branch b1 is the same as that of the second sub-branch b2, i.e., the physical widths of the first sub-branch b1 and the second sub-branch b2 are the same.
In some embodiments, the equivalent impedance of the first sub-branch b1 is the same as the equivalent impedance of the first connection line 150 or the second connection line 160. The equivalent impedance of the first sub-branch b1 and the first connection line 150 or the second connection line 160 is the same, i.e., the physical width of the first sub-branch b1 and the first connection line 150 or the second connection line 160 is the same, wherein the first connection line 150 and the second connection line 160 are symmetrically arranged, and the equivalent impedance of the first connection line 150 and the second connection line 160 is the same, i.e., the physical width is the same.
As described above, the stepped impedance body a is a symmetrical half-wavelength resonator, and in some embodiments, the stepped impedance body a includes a first impedance portion a1, two second impedance portions a2 symmetrically disposed, two third impedance portions a3 symmetrically disposed, and two fourth impedance portions a4 symmetrically disposed, where the center of the first impedance portion a1 is the center of the stepped impedance body a, and the first impedance portion a1, the second impedance portion a2, the third impedance portion a3, and the fourth impedance portion a4 are sequentially connected from the center of the stepped impedance body a; each second branch c of the pair of second branches c is connected to a connection portion of the first impedance portion a1 and the second impedance portion a 2.
The equivalent impedances of the first impedance part a1, the second impedance part a2, the third impedance part a3 and the fourth impedance part a4 are different from each other, and are sequentially connected from the center of the stepped impedance body a, namely the stepped impedance body a is in a four-stage step, so that the central frequency of two frequency bands can be adjusted, and the flexibility of designing double frequency bands can be improved. In the present embodiment, the equivalent impedance of the first impedance portion a1, the second impedance portion a2, the third impedance portion a3, and the fourth impedance portion a4 decreases in order, that is, the physical widths of the first impedance portion a1, the second impedance portion a2, the third impedance portion a3, and the fourth impedance portion a4 increase in order.
As described above, the pair of second branches c are spaced from the first branch b, and each second branch c of the pair of second branches c is connected to a junction between the first impedance portion a1 and the second impedance portion a2, and in some embodiments, the second branch c includes a third sub-branch c1 and a fourth sub-branch c2, wherein the fourth sub-branch c2 is connected to the third sub-branch c1, and an equivalent impedance of the fourth sub-branch c2 is different from an equivalent impedance of the third sub-branch c 1; the third impedance portion a3 and the fourth impedance portion a4 are subjected to bending processing such that the fourth impedance portion a4 and the fourth sub-branch c2 are positioned in the same line to be commonly used for slot coupling.
The equivalent impedance of the fourth sub-branch c2 is different from that of the third sub-branch c1, i.e., the physical widths of the fourth sub-branch c2 and the third sub-branch c1 are different.
The third impedance portion a3 and the fourth impedance portion a4 are subjected to bending treatment, that is, the third impedance portion a3 is bent once, so that the third impedance portion a3 is vertically arranged with the second impedance portion a2, and the fourth impedance portion a4 is bent once, so that the fourth impedance portion a4 is vertically arranged with the third impedance portion a3, and therefore the fourth impedance portion a4 and the fourth sub-branch c2 are located on the same straight line, the first step impedance resonator 130 and the fourth impedance portion a4 and the fourth sub-branch c2 of the second step impedance resonator 140 are commonly used for slot coupling, the performance of each frequency band of the dual-frequency balance filter 100 is improved, miniaturization is achieved, and manufacturing cost is reduced.
Note that bending of the third impedance portion a3 and the fourth impedance portion a4 once indicates bending the third impedance portion a3 and the fourth impedance portion a4 once by 90 degrees, respectively, so that the third impedance portion a3 is disposed perpendicular to the second impedance portion a2, and so that the fourth impedance portion a4 is disposed perpendicular to the third impedance portion a 3.
In some examples, the equivalent impedance of the third sub-branch c1 is the same as the equivalent impedance of the second impedance portion a 2; the equivalent impedance of the fourth sub-branch c2 is the same as that of the fourth impedance section a 4. The equivalent impedance of the third sub-branch c1 is the same as that of the second impedance portion a2, and the equivalent impedance of the fourth sub-branch c2 is the same as that of the fourth impedance portion a4, that is, the physical widths of the third sub-branch c1 and the second impedance portion a2 are the same, and the equivalent impedance of the fourth sub-branch c2 and the physical width of the fourth impedance portion a4 are the same.
As mentioned above, the pair of input feed line structures 110 are symmetrically disposed, e.g., vertically symmetrically disposed, with the pair of output feed line structures 120, and in some embodiments, the pair of input feed line structures 110 are themselves symmetrically disposed, and the pair of output feed line structures 120 are themselves symmetrically disposed. For example, the pair of input feed line structures 110 are themselves horizontally symmetrical, and as a result of the pair of input feed line structures 110 being vertically symmetrical to the pair of output feed line structures 120, the pair of input feed line structures 110 are also themselves horizontally symmetrical.
Specifically, in some embodiments, the pair of input feed line structures 110 includes a first input feed line 111 and a second input feed line 112 that are symmetrically disposed, and the pair of output feed line structures 120 includes a first output feed line 121 and a second output feed line 122 that are symmetrically disposed, wherein the first input feed line 111 and the first output feed line 121 correspond to the first connection line 150, and the second input feed line 112 and the second output feed line 122 correspond to the second connection line 160. In the present embodiment, the symmetrical arrangement of the first and second input feed lines 111 and 112 and the first and second output feed lines 121 and 122 is a horizontal lower upper symmetrical arrangement, but the present application is not limited thereto, and it may be arranged according to practical circuit design considerations.
One end of each of the first input feeder 111, the second input feeder 112, the first output feeder 121, and the second output feeder 122 is used to implement tap coupling, and the other end is an input port/output port. The other ends of the first input feeder 111 and the second input feeder 112 serve as input ports to be fed with electromagnetic signals, and the other ends of the first output feeder 121 and the second output feeder 122 serve as output ports to be fed with electromagnetic signals. Note that the arrangement of the input port and the output port is merely illustrative, and the input port and the output port may be reversed.
The first input feeder 111 and the first output feeder 121 correspond to the first connection line 150, and the second input feeder 112 and the second output feeder 122 correspond to the second connection line 160, which facilitates the magnetic coupling between the first step impedance resonator 130 and the second step impedance resonator 140 using the first connection line 150 and the second connection line 160.
The equivalent impedance of the first input feed line 111, the second input feed line 112, the first output feed line 121, and the second output feed line 122 is 50 ohms.
As described above, the first input feed line 111 corresponds to the first connection line 150 with the first output feed line 121, the second input feed line 112 corresponds to the second connection line 160 with the second output feed line 122, and in some embodiments, the first input feed line 111, the first output feed line 121, and the first connection line 150 are positioned in the same line; the second input feed line 112, the second output feed line 122, and the second connection line 160 are located in another straight line.
The first input feeder 111, the first output feeder 121, and the first connection line 150 are positioned in the same straight line, and the second input feeder 112, the second output feeder 122, and the second connection line 160 are positioned in another straight line, which further facilitates the magnetic coupling between the first stepped impedance resonator 130 and the second stepped impedance resonator 140 using the first connection line 150 and the second connection line 160.
Further, in some embodiments, the dual-frequency balanced filter 100 includes a pair of input feed line structures 110 and a pair of output feed line structures 120 that are symmetrically disposed and a first step impedance resonator 130 and a second step impedance resonator 140 that are symmetrically disposed. That is, a dielectric substrate is used to fabricate the dual-band balanced filter 100. The dielectric substrate can be a high-temperature superconductive dielectric substrate made of magnesium oxide, the upper surface and the lower surface of the high-temperature superconductive dielectric substrate are made of yttrium barium copper oxide superconductive films, the dielectric constant is 9.78, the thickness is 0.5mm, at the moment, the loss of the dual-frequency balance filter 100 is small, the quality factor is high, and therefore, the dual-frequency balance filter 100 has better effect when applied to the dual-frequency balance filter 100 and the like, and is stable to use and long in service time. Of course, it is within the understanding of those skilled in the art that the dielectric substrate may also be used to fabricate the dual-band balanced filter 100 with other parameters, which are not limited herein.
As shown in fig. 2, a graph of scattering parameters of a dual-frequency balance filter according to an embodiment of the present application is shown. For the dual-band balanced filter 100 of the above embodiment, when a dielectric substrate is used for manufacturing, the center frequencies of two frequency bands are 1.48GHz and 4.25GHz respectively, the insertion loss of the frequency bands is less than 0.1dB, the return loss is greater than 20dB, the insertion loss of the common mode is greater than 25dB, that is, the common mode noise suppression is better than 25dB, two sides of the two frequency bands have a transmission zero respectively, and the selectivity of the frequency bands is improved.
Those skilled in the art will readily appreciate that many modifications and variations are possible in the device and method while maintaining the teachings of the present application. Accordingly, the above disclosure should be viewed as limited only by the scope of the appended claims.
Claims (9)
1. A dual-band balanced filter, comprising:
a pair of input feed line structures and a pair of output feed line structures symmetrically arranged, and a first step impedance resonator and a second step impedance resonator symmetrically arranged;
wherein the pair of input feed line structures are connected with the first step impedance resonator and the pair of output feed line structures are connected with the second step impedance resonator to provide electromagnetic excitation;
the first step impedance resonator and the second step impedance resonator are symmetrical structures and comprise a step impedance body and a first branch knot arranged in the center of the step impedance body so as to generate two frequency bands under the electromagnetic excitation effect and used for common mode frequency suppression of the two frequency bands;
the dual-frequency balance filter further includes:
the first connecting wire and the second connecting wire are symmetrically arranged and are connected with the first step impedance resonator and the second step impedance resonator;
the first step impedance resonator and the second step impedance resonator each further comprise a pair of second branches arranged on the step impedance body and spaced from the first branches;
the first connecting wire and the second connecting wire are used for providing magnetic coupling between the first step impedance resonator and the second step impedance resonator, and the gap coupling between the two ends of the step impedance body of the first step impedance resonator and the two ends of the step impedance body of the second step impedance resonator and between the pair of second branches of the first step impedance resonator and the pair of second branches of the second step impedance resonator is provided, so that the electric coupling between the first step impedance resonator and the second step impedance resonator is provided, and two sides of the two frequency bands respectively have a transmission zero point.
2. The dual-band balanced filter of claim 1, wherein the first branch is a symmetrical T-shaped structure including a first sub-branch and a second sub-branch connected between the step impedance body center and the first sub-branch center for common mode frequency rejection of the two frequency bands.
3. The dual-band balanced filter of claim 2, wherein,
the equivalent impedance of the first sub-branch is the same as the equivalent impedance of the second sub-branch.
4. The dual-band balanced filter of claim 2, wherein,
the equivalent impedance of the first sub-branch is the same as the equivalent impedance of the first connecting line or the second connecting line.
5. The dual-band balanced filter according to claim 1, wherein the stepped impedance body includes a first impedance portion, two second impedance portions symmetrically disposed, two third impedance portions symmetrically disposed, and two fourth impedance portions symmetrically disposed, wherein a center of the first impedance portion is a center of the stepped impedance body, and the first impedance portion, the second impedance portion, the third impedance portion, and the fourth impedance portion are sequentially connected from the center of the stepped impedance body;
each second branch of the pair of second branches is connected to a connection portion of the first impedance portion and the second impedance portion.
6. The dual-band balanced filter of claim 5, wherein,
the second branch comprises a third sub-branch and a fourth sub-branch, wherein the fourth sub-branch is connected with the third sub-branch, and the equivalent impedance of the fourth sub-branch is different from the equivalent impedance of the third sub-branch;
the third impedance part and the fourth impedance part are subjected to bending treatment, so that the fourth impedance part and the fourth sub-branch are positioned on the same straight line to be commonly used for the gap coupling.
7. The dual-band balanced filter of claim 6, wherein,
the equivalent impedance of the third sub-branch is the same as that of the second impedance part;
the equivalent impedance of the fourth sub-branch is the same as the equivalent impedance of the fourth impedance section.
8. A dual-band balanced filter as claimed in any one of claims 1 to 7,
the pair of input feeder structures comprises a first input feeder and a second input feeder which are symmetrically arranged, and the pair of output feeder structures comprises a first output feeder and a second output feeder which are symmetrically arranged;
wherein the first input feeder line and the first output feeder line correspond to the first connecting line, and the second input feeder line and the second output feeder line correspond to the second connecting line.
9. The dual-band balanced filter of claim 8, wherein,
the first input feeder line, the first output feeder line and the first connecting line are positioned on the same straight line;
the second input feeder line, the second output feeder line and the second connecting line are located in another straight line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210486712.3A CN114725635B (en) | 2022-05-06 | 2022-05-06 | Dual-frequency balance filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210486712.3A CN114725635B (en) | 2022-05-06 | 2022-05-06 | Dual-frequency balance filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114725635A CN114725635A (en) | 2022-07-08 |
| CN114725635B true CN114725635B (en) | 2024-01-30 |
Family
ID=82231251
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210486712.3A Active CN114725635B (en) | 2022-05-06 | 2022-05-06 | Dual-frequency balance filter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114725635B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115149229B (en) * | 2022-07-15 | 2024-02-20 | 华东交通大学 | Balanced filter |
| CN115425377B (en) * | 2022-09-29 | 2023-09-08 | 河南科技大学 | Double-passband balance filter based on loading of ring resonator |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010081292A (en) * | 2008-09-26 | 2010-04-08 | Kyocera Corp | Branching filter, and wireless communication mudule and wireless communication device using the same |
| WO2015003652A1 (en) * | 2013-07-12 | 2015-01-15 | 中兴通讯股份有限公司 | Dbr filter and dbr duplexer |
| CN109524749A (en) * | 2018-11-23 | 2019-03-26 | 西安交通大学 | A kind of double-passband filter with trap characteristic |
| CN112103610A (en) * | 2020-10-22 | 2020-12-18 | 南通大学 | Balanced multimode band-pass filter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6791431B2 (en) * | 2002-09-03 | 2004-09-14 | Broadcom Corporation | Compact balun with rejection filter for 802.11a and 802.11b simultaneous operation |
-
2022
- 2022-05-06 CN CN202210486712.3A patent/CN114725635B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010081292A (en) * | 2008-09-26 | 2010-04-08 | Kyocera Corp | Branching filter, and wireless communication mudule and wireless communication device using the same |
| WO2015003652A1 (en) * | 2013-07-12 | 2015-01-15 | 中兴通讯股份有限公司 | Dbr filter and dbr duplexer |
| CN109524749A (en) * | 2018-11-23 | 2019-03-26 | 西安交通大学 | A kind of double-passband filter with trap characteristic |
| CN112103610A (en) * | 2020-10-22 | 2020-12-18 | 南通大学 | Balanced multimode band-pass filter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114725635A (en) | 2022-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114725635B (en) | Dual-frequency balance filter | |
| JP4904197B2 (en) | Unbalanced feed broadband slot antenna | |
| CN109904607B (en) | Simple and compact wide-stopband filtering patch antenna | |
| US7528676B2 (en) | Balun circuit suitable for integration with chip antenna | |
| CN110444840B (en) | Double-frequency differential band-pass filter based on stub load resonator | |
| CN109755702B (en) | Four-frequency differential band-pass filter | |
| JP4904196B2 (en) | Unbalanced feed broadband slot antenna | |
| JP3101460B2 (en) | Dielectric filter and duplexer using the same | |
| WO2001084665A1 (en) | Filtering device and method | |
| US6720849B2 (en) | High frequency filter, filter device, and electronic apparatus incorporating the same | |
| CN107275740A (en) | It is a kind of that there is the dual-frequency power divider for transmitting null character | |
| CN113131108B (en) | Balance filter | |
| CN209626392U (en) | Quadravalence cross-coupling ceramic dielectric filter | |
| US6072376A (en) | Filter with low-noise amplifier | |
| CN115149229B (en) | Balanced filter | |
| US6670865B2 (en) | Method and apparatus for low loss high frequency transmission | |
| CN110137644B (en) | High-selectivity wide-stop-band balance filter based on slot line | |
| US9048547B2 (en) | Air loop antenna for shared AM/FM | |
| CN114284677A (en) | High-selectivity broadband inverse filtering power divider based on three-wire coupling | |
| CN109524749B (en) | Double-passband filter with notch characteristic | |
| JPH05145316A (en) | Filter antenna system | |
| CN117767901B (en) | Open stub loaded band reject filter | |
| CN113708026B (en) | Differential 90-degree Scheffman phase shifter based on slot line | |
| CN117293502A (en) | Double-frequency balance filter based on composite left and right hands | |
| US6617942B1 (en) | Hybrid multi-pole gain zero filter element |
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 |