Topological structure, filter and communication equipment
The novel topology structure for wideband filters addresses the lack of narrow passband characteristics by enhancing transmission quality through balanced electrical lengths and impedances, achieving high isolation and low insertion loss.
Patent Information
- Application Number
- CN202422361462.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-09-26
AI Technical Summary
Existing wide stopband filters lack narrow pass characteristics in the stopband range, limiting the transmission quality of multifunction signals.
A topology is designed, including the input, output, microstrip lines and open branches, and a combination of specific lengths and characteristic impedances to form a wide stopband filter with narrow pass characteristics.
The high selectivity of wide stopband filters in the stopband is achieved, and the transmission quality of multifunction signals is improved.
Smart Images
Figure CN223109209U_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present utility model relate to the field of communication technologies, and particularly to a topological structure, a filter, and a communication device. Background Art
[0002] In order to solve the contradiction between limited spectrum resources and the growing demand for information transmission, scientific researchers have developed radio frequency systems that can operate in different frequency ranges and communication modes to more efficiently utilize spectrum resources. In the above radio frequency systems, a wide-stopband filter with high selectivity has become one of the key components.
[0003] During the implementation of this application, the inventors found that: currently, within the stopband range, the wide-stopband filter does not have a narrow-pass characteristic (the narrow-pass characteristic means that the filter can allow signals required within a specific frequency range to pass through within a relatively narrow frequency range, and does not allow signals not required within other frequency ranges to pass through), resulting in the inability of the wide-stopband filter to transmit signals within the stopband range, which limits the transmission quality of multi-functional signals. Summary of the Utility Model
[0004] The main technical problem to be solved by embodiments of the present utility model is to provide a topological structure, a filter, and a communication device that can have a narrow-pass characteristic.
[0005] To solve the above technical problem, one technical solution adopted by embodiments of the present utility model is: to provide a topological structure, including an input end, an output end, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line, a seventh microstrip line, a first open stub, a second open stub, and a third open stub. Among them, one end of the second microstrip line is respectively connected to one end of the first microstrip line, one end of the sixth microstrip line, and one end of the seventh microstrip line. The other end of the first microstrip line is connected to the input end. The other end of the sixth microstrip line is respectively connected to the second open stub and the third open stub. The other end of the seventh microstrip line is connected to the output end. The other end of the second microstrip line is connected to one end of the third microstrip line. The other end of the third microstrip line is connected to one end of the fourth microstrip line. The other end of the fourth microstrip line is connected to one end of the fifth microstrip line. The other end of the fifth microstrip line is connected to the first open stub.
[0006] In some embodiments, the first microstrip line, the third microstrip line, the fifth microstrip line, the seventh microstrip line, the second open stub, and the third open stub are parallel to each other and are all perpendicular to the second microstrip line, the fourth microstrip line, the sixth microstrip line, and the first open stub.
[0007] In some embodiments, the first microstrip line and the seventh microstrip line are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line or the perpendicular bisector of the sixth microstrip line, the second open stub and the third open stub are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line or the perpendicular bisector of the sixth microstrip line, and the input end and the output end are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line or the perpendicular bisector of the sixth microstrip line.
[0008] In some embodiments, the electrical length of the first microstrip line is equal to the electrical length of the seventh microstrip line, and both are a quarter wavelength corresponding to the center frequency of the stopband filter.
[0009] In some embodiments, the sum of the electrical lengths of the second microstrip line, the third microstrip line, the fourth microstrip line, the fifth microstrip line, and the first open stub is a half wavelength corresponding to the center frequency of the stopband filter.
[0010] In some embodiments, the sum of the electrical lengths of the sixth microstrip line and the second open stub is a quarter wavelength corresponding to the center frequency of the stopband filter.
[0011] In some embodiments, the sum of the electrical lengths of the sixth microstrip line and the third open stub is a quarter wavelength corresponding to the center frequency of the stopband filter.
[0012] In some embodiments, the characteristic impedance of the first microstrip line is equal to the characteristic impedance of the seventh microstrip line, the characteristic impedances of the second microstrip line, the third microstrip line, the fourth microstrip line, the fifth microstrip line, and the first open stub are equal, and the characteristic impedance of the second open stub is equal to the characteristic impedance of the third open stub.
[0013] To solve the above technical problems, another technical solution adopted in the embodiments of the present invention is: to provide a filter including the above topological structure.
[0014] To solve the above technical problems, another technical solution adopted in the embodiments of the present invention is: to provide a communication device including the above filter.
[0015] The beneficial effects of the embodiments of the present utility model are as follows: Different from the prior art, the embodiments of the present utility model provide a topological structure, including an input end, an output end, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line, a seventh microstrip line, a first open stub, a second open stub, and a third open stub. Among them, one end of the second microstrip line is respectively connected to one end of the first microstrip line, one end of the sixth microstrip line, and one end of the seventh microstrip line. The other end of the first microstrip line is connected to the input end. The other end of the sixth microstrip line is respectively connected to the second open stub and the third open stub. The other end of the seventh microstrip line is connected to the output end. The other end of the second microstrip line is connected to one end of the third microstrip line. The other end of the third microstrip line is connected to one end of the fourth microstrip line. The other end of the fourth microstrip line is connected to one end of the fifth microstrip line. The other end of the fifth microstrip line is connected to the first open stub. Through the above method, the wide-stopband filter designed based on this topological structure has a narrow-pass characteristic, which can improve the transmission quality of multifunctional signals. Brief Description of the Drawings
[0016] In order to more clearly illustrate the technical solutions in the specific embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to actual scale.
[0017] Figure 1 is a schematic structural diagram of the topological structure provided by the embodiments of the present utility model Figure 1 ;
[0018] Figure 2 is a schematic structural diagram of the topological structure provided by the embodiments of the present utility model Figure 2 ;
[0019] Figure 3 is an S-parameter simulation result diagram of the topological structure provided by the embodiments of the present utility model;
[0020] Figure 4 is an equivalent structural diagram of the odd-mode form of the topological structure provided by the embodiments of the present utility model;
[0021] Figure 5 is an equivalent structural diagram of the even-mode form of the topological structure provided by the embodiments of the present utility model.
[0022] Description of the Reference Numerals:
[0023] 10 Input end;
[0024] 20 Output end;
[0025] 31st first microstrip line, 32nd second microstrip line, 33rd third microstrip line, 34th fourth microstrip line, 35th fifth microstrip line, 36th sixth microstrip line, 37th seventh microstrip line, 38th eighth microstrip line, 39th ninth microstrip line, 310th tenth microstrip line, 311th eleventh microstrip line, 312th twelfth microstrip line;
[0026] 41st first open stub, 42nd second open stub, 43rd third open stub, 44th fourth open stub;
[0027] 100 Topology structure. Detailed implementation manner
[0028] For the convenience of understanding the present utility model, the present utility model will be described in more detail below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is expressed as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is expressed as "connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "upper", "lower", "inner", "outer", "vertical", "horizontal", etc. used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.
[0029] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs. The terms used in this specification in the description of the present utility model are only for the purpose of describing specific embodiments and are not used to limit the present utility model. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.
[0030] The present utility model provides a topology structure 100. Please refer to Figure 1, the topological structure 100 includes an input end 10, an output end 20, a first microstrip line 31, a second microstrip line 32, a third microstrip line 33, a fourth microstrip line 34, a fifth microstrip line 35, a sixth microstrip line 36, a seventh microstrip line 37, a first open stub 41, a second open stub 42, and a third open stub 43. Among them, one end of the second microstrip line 32 is respectively connected to one end of the first microstrip line 31, one end of the sixth microstrip line 36, and one end of the seventh microstrip line 37. The other end of the first microstrip line 31 is connected to the input end 10. The other end of the sixth microstrip line 36 is respectively connected to the second open stub 42 and the third open stub 43. The other end of the seventh microstrip line 37 is connected to the output end 20. The other end of the second microstrip line 32 is connected to one end of the third microstrip line 33. The other end of the third microstrip line 33 is connected to one end of the fourth microstrip line 34. The other end of the fourth microstrip line 34 is connected to one end of the fifth microstrip line 35. The other end of the fifth microstrip line 35 is connected to the first open stub 41.
[0031] Specifically, the first microstrip line 31, the third microstrip line 33, the fifth microstrip line 35, the seventh microstrip line 37, the second open stub 42, and the third open stub 43 are parallel to each other and are all perpendicular to the second microstrip line 32, the fourth microstrip line 34, the sixth microstrip line 36, and the first open stub 41. Moreover, the first microstrip line 31 and the seventh microstrip line 37 are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line 32 or the perpendicular bisector of the sixth microstrip line 36. The second open stub 42 and the third open stub 43 are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line 32 or the perpendicular bisector of the sixth microstrip line 36. The input end 10 and the output end 20 are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line 32 or the perpendicular bisector of the sixth microstrip line 36.
[0032] For the above-mentioned first microstrip line 31 and seventh microstrip line 37, among them, the electrical length of the first microstrip line 31 is equal to the electrical length of the seventh microstrip line 37, and both are equal to one-quarter wavelength corresponding to the center frequency of the stopband filter.
[0033] For the above-mentioned second microstrip line 32, third microstrip line 33, fourth microstrip line 34, fifth microstrip line 35, and first open stub 41, among them, the sum of the electrical lengths of the second microstrip line 32, the third microstrip line 33, the fourth microstrip line 34, the fifth microstrip line 35, and the first open stub 41 is equal to one-half wavelength corresponding to the center frequency of the stopband filter.
[0034] For the above-mentioned sixth microstrip line 36 and second open stub 42, among them, the sum of the electrical length of the sixth microstrip line 36 and the electrical length of the second open stub 42 is equal to one-quarter wavelength corresponding to the center frequency of the stopband filter.
[0035] For the above-mentioned sixth microstrip line 36 and third open stub 43, the sum of the electrical lengths of the sixth microstrip line 36 and the third open stub 43 is a quarter wavelength corresponding to the center frequency of the stopband filter.
[0036] In addition, the characteristic impedance of the first microstrip line 31 is equal to that of the seventh microstrip line 37, the characteristic impedances of the second microstrip line 32, the third microstrip line 33, the fourth microstrip line 34, the fifth microstrip line 35 and the first open stub 41 are equal, and the characteristic impedance of the second open stub 42 is equal to that of the third open stub 43.
[0037] For the convenience of the reader's understanding, the following provides a simulation example of the topology 100:
[0038] Please refer to Figure 2 , the topology 100 is disposed on a circuit board (not shown in the figure). The size of the circuit board (not shown in the figure) is 23.0 mm * 10.8 mm, the thickness is 0.813 mm, the dielectric constant is 3.38, and the dielectric loss is 0.0022. The specific parameters of the topology 100 are: l1 = 9.3 mm, l2 = 4.75 mm, l3 = 6.1 mm, l4 = 2.5 mm, l5 = 13.4 mm, l6 = 3.3 mm, l7 = 1.7 mm, l8 = 7.6 mm, w1 = 0.1 mm, w2 = 0.8 mm, w3 = 0.2 mm, w4 = 0.1 mm. Please refer to Figure 3, The figure shows the results obtained from the simulation experiment based on the above dimensions and parameters. The simulation results of the S parameters are shown in the figure. Specifically: the stopband range with an isolation greater than 20 dB is 1.624 GHz - 8.656 GHz, the center frequency of the stopband is 5.14 GHz, the absolute bandwidth is 7.032 GHz, and the relative bandwidth is 136.8%. In addition, there are three transmission zeros in the stopband, located at 1.74 GHz, 5.28 GHz, and 8.521 GHz respectively; there are two passbands beside the stopband, and there are five transmission poles in the passbands, located at 0 GHz, 0.943 GHz, 9.36 GHz, 10.061 GHz, and 10.633 GHz respectively. Through the above three transmission zeros and five transmission poles, not only the high isolation characteristics of the stopband and the low insertion loss and flatness of the passband are ensured, but also the high selectivity characteristics of the sidebands of the band-stop filter are ensured. In addition, there are two passbands with relatively narrow bandwidths in the stopband. Among them, for the first passband, the passband range with a reflection coefficient less than -10 dB is 2.891 GHz - 3.029 GHz, the center frequency of the passband is 2.96 GHz, the absolute bandwidth is 0.138 GHz, and the relative bandwidth is 4.66%; for the second passband, the passband range with a reflection coefficient less than -10 dB is 7.093 GHz - 7.207 GHz, the center frequency of the passband is 7.15 GHz, the absolute bandwidth is 0.114 GHz, and the relative bandwidth is 1.59%.
[0039] Through the simulation example of the above topological structure 100, it can be proved that the wide-stopband filter designed based on the above topological structure 100 has the narrow-pass characteristic.
[0040] An embodiment of the present invention provides a topological structure 100, including an input end 10, an output end 20, a first microstrip line 31, a second microstrip line 32, a third microstrip line 33, a fourth microstrip line 34, a fifth microstrip line 35, a sixth microstrip line 36, a seventh microstrip line 37, a first open stub 41, a second open stub 42, and a third open stub 43. Among them, one end of the second microstrip line 32 is respectively connected to one end of the first microstrip line 31, one end of the sixth microstrip line 36, and one end of the seventh microstrip line 37. The other end of the first microstrip line 31 is connected to the input end 10. The other end of the sixth microstrip line 36 is respectively connected to the second open stub 42 and the third open stub 43. The other end of the seventh microstrip line 37 is connected to the output end 20. The other end of the second microstrip line 32 is connected to one end of the third microstrip line 33. The other end of the third microstrip line 33 is connected to one end of the fourth microstrip line 34. The other end of the fourth microstrip line 34 is connected to one end of the fifth microstrip line 35. The other end of the fifth microstrip line 35 is connected to the first open stub 41. In this way, the wide-stopband filter designed based on this topological structure 100 has the narrow-pass characteristic and can improve the transmission quality of multifunctional signals.
[0041] The present utility model further provides an embodiment of a filter. The filter includes the above-mentioned topological structure 100. For the specific structure and function of the above-mentioned topological structure 100, reference can be made to the above-mentioned embodiment, and details will not be repeated here.
[0042] For the convenience of readers' understanding, the following provides the idea of designing a wide stopband filter with narrow pass characteristics based on the above-mentioned topological structure 100, which is as follows:
[0043] Assume that the characteristic impedance of the first microstrip line 31 is equal to that of the seventh microstrip line 37, and both are Z1; the characteristic impedances of the second microstrip line 32, the third microstrip line 33, the fourth microstrip line 34, the fifth microstrip line 35, and the first open stub 41 are equal, all being Z2; the characteristic impedance of the sixth microstrip line 36 is Z3; the characteristic impedances of the second open stub 42 and the third open stub 43 are equal, and both are 2Z3. In addition, since the above-mentioned topological structure 100 is equivalent to a left-right symmetric structure, the wide stopband pass filter designed based on the above-mentioned topological structure 100 can be analyzed by the odd-even mode analysis method. The analysis process is as follows:
[0044] First, obtain the odd-mode form of the topological structure 100. Please refer to Figure 4 , the odd-mode form is that one end of the first microstrip line 31 is connected to the input terminal 10, and the other end of the first microstrip line 31 is grounded. When the input admittance Y ino is zero, two odd-mode transmission poles of the topological structure 100 can be obtained. The frequencies corresponding to the two odd-mode transmission poles are respectively:
[0045] f op1 = 0
[0046] f op2 = 2f0
[0047] where f0 is the center frequency of the band-stop filter.
[0048] Then, obtain the even-mode form of the topological structure 100. Please refer to Figure 5, the even - mode form is that one end of the eighth microstrip line 38 is successively connected to the ninth microstrip line 39, the tenth microstrip line 310, the eleventh microstrip line 311 and the fourth open - circuit stub 44, and the other end of the eighth microstrip line 38 is connected to the first microstrip line 31 and the twelfth microstrip line 312. One end of the first microstrip line 31 far from the eighth microstrip line 38 is connected to the input end 10, and one end of the twelfth microstrip line 312 far from the eighth microstrip line 38 is connected to the second open - circuit stub 42. Among them, the electrical length of the eighth microstrip line 38 is equal to the electrical length of the second microstrip line 32, the electrical length of the ninth microstrip line 39 is equal to the electrical length of the third microstrip line 33, the electrical length of the tenth microstrip line 310 is equal to the electrical length of the fourth microstrip line 34, the electrical length of the eleventh microstrip line 311 is equal to the electrical length of the fifth microstrip line 35, the electrical length of the twelfth microstrip line 312 is equal to the electrical length of the sixth microstrip line 36, and the electrical length of the fourth open - circuit stub 44 is equal to the electrical length of the first open - circuit stub 41; the characteristic impedance of the eighth microstrip line 38, the characteristic impedance of the ninth microstrip line 39, the characteristic impedance of the tenth microstrip line 310, the characteristic impedance of the eleventh microstrip line 311 and the characteristic impedance of the fourth open - circuit stub 44 are equal, all being 2Z2; the characteristic impedance of the twelfth microstrip line 312 is 2Z3. When the input admittance Y ine is infinite, it can be obtained that the topological structure 100 has five even - mode transmission poles, which are respectively:
[0049]
[0050] Among them:
[0051]
[0052] Finally, calculate the transmission zeros of the topological structure 100. Specifically, multiply the ABCD matrices of the cascaded resonators that make up the topological structure 100 in sequence to obtain the ABCD matrix corresponding to the topological structure 100; convert the ABCD matrix of the topological structure 100 into the corresponding S matrix. When |S21| = 0, it can be obtained that this topological structure 100 has three transmission zeros, and the frequencies corresponding to the three transmission zeros are respectively:
[0053]
[0054] f z2 = f0
[0055]
[0056] From the above analysis, it can be seen that the topological structure 100 has two odd - mode transmission poles, five even - mode transmission poles, and three transmission zeros. Regardless of how the values of the parameters Z1, Z2, and Z3 change, the relative positions of these transmission zero - poles, that is, f op1 < f ep1 < f z1 < fep2 <f z2 <f ep3 <f z3 <f ep4 <f op2 <f ep5 , which will not change. Therefore, the filter designed based on this topological structure 100 is a wide-stopband filter with narrow-pass characteristics.
[0057] The present utility model also provides an embodiment of a communication device. The communication device includes the above filter. For the specific structure and function of the above filter, reference may be made to the above embodiment, and details are not described herein again.
[0058] The above are only the embodiments of the present utility model, and do not limit the patent scope of the present utility model. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present utility model.
Claims
1. A topological structure, characterized in that, It includes an input terminal, an output terminal, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a sixth microstrip line, a seventh microstrip line, a first open stub, a second open stub, and a third open stub; Wherein, one end of the second microstrip line is respectively connected to one end of the first microstrip line, one end of the sixth microstrip line, and one end of the seventh microstrip line. The other end of the first microstrip line is connected to the input terminal. The other end of the sixth microstrip line is respectively connected to the second open stub and the third open stub. The other end of the seventh microstrip line is connected to the output terminal. The other end of the second microstrip line is connected to one end of the third microstrip line. The other end of the third microstrip line is connected to one end of the fourth microstrip line. The other end of the fourth microstrip line is connected to one end of the fifth microstrip line. The other end of the fifth microstrip line is connected to the first open stub.
2. The topological structure according to claim 1, wherein The first microstrip line, the third microstrip line, the fifth microstrip line, the seventh microstrip line, the second open stub, and the third open stub are parallel to each other and are all perpendicular to the second microstrip line, the fourth microstrip line, the sixth microstrip line, and the first open stub.
3. The topological structure according to claim 1, wherein The first microstrip line and the seventh microstrip line are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line or the perpendicular bisector of the sixth microstrip line. The second open stub and the third open stub are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line or the perpendicular bisector of the sixth microstrip line. The input terminal and the output terminal are symmetrically arranged with respect to the perpendicular bisector of the second microstrip line or the perpendicular bisector of the sixth microstrip line.
4. The topological structure according to claim 1, wherein The electrical length of the first microstrip line is equal to the electrical length of the seventh microstrip line, and both are equal to one-quarter of the wavelength corresponding to the center frequency of the stopband filter.
5. The topological structure according to claim 1, wherein The sum of the electrical lengths of the second microstrip line, the third microstrip line, the fourth microstrip line, the fifth microstrip line, and the first open stub is equal to one-half of the wavelength corresponding to the center frequency of the stopband filter.
6. The topological structure according to claim 5, wherein The sum of the electrical lengths of the sixth microstrip line and the second open stub is equal to one-quarter of the wavelength corresponding to the center frequency of the stopband filter.
7. The topological structure according to claim 1, wherein The sum of the electrical lengths of the sixth microstrip line and the third open stub is equal to one-quarter of the wavelength corresponding to the center frequency of the stopband filter.
8. The topological structure according to claim 7, wherein The characteristic impedance of the first microstrip line is equal to the characteristic impedance of the seventh microstrip line. The characteristic impedances of the second microstrip line, the third microstrip line, the fourth microstrip line, the fifth microstrip line, and the first open stub are equal. The characteristic impedance of the second open stub is equal to the characteristic impedance of the third open stub.
9. A filter, characterized in that, It includes the topological structure according to any one of claims 1-8.
10. A communication device, characterized in that, Comprising a filter as described in claim 9.