Topological structure, second-order broadband band-pass filter and communication equipment
A second-order broadband bandpass filter designed with a specific topology solves the problem of non-compact structure in broadband bandpass filters, achieving miniaturization and high selectivity, making it suitable for modern wireless communication systems.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-03-06
AI Technical Summary
Existing broadband bandpass filters are not compact in structure, which is not conducive to miniaturization and affects their use in modern wireless communication systems.
A topology design is adopted, including specific connection methods for input terminals, output terminals, transmission lines, microstrip lines and open stubs, to ensure the consistency of electrical length and characteristic impedance, and to implement a second-order broadband bandpass filter on the circuit board.
The filter achieves miniaturization, ensuring flatness and high selectivity within the passband. It has two transmission poles and two transmission zeros, improving the selectivity and compactness of the filter.
Smart Images
Figure CN223978070U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of topology technology, and in particular to a topology, a second-order broadband bandpass filter, and a communication device. Background Technology
[0002] With the rapid development of modern wireless communication technology, people's demand for broadband communication systems that can achieve high-speed data transmission is increasing, and it has become a key research object for practitioners in related fields. High-performance broadband bandpass filters have attracted the attention of many scholars and engineers, and have been studied in depth.
[0003] In the process of realizing this utility model, the inventors discovered that current wideband filters, when used to achieve high-speed data transmission, have a non-compact structure, which is not conducive to the miniaturization of the entire wideband filter and seriously affects its use in modern wireless communication systems. Utility Model Content
[0004] This utility model provides a topology, a second-order broadband bandpass filter, and a communication device. The main technical problem it solves is that the existing broadband bandpass filters are not compact enough and have insufficient miniaturization.
[0005] To solve the above-mentioned technical problems, the present invention provides a technical solution comprising: an input terminal, an output terminal, a first transmission line, a second transmission line, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a first open-circuit stub, and a second open-circuit stub; one end of the input terminal is connected to one end of the first transmission line, the other end of the first transmission line is connected to one end of the first microstrip line, the other end of the first microstrip line is connected to one end of the second microstrip line, the other end of the second microstrip line is connected to the first open-circuit stub, the output terminal is connected to one end of the second transmission line, the other end of the second transmission 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, and the other end of the fourth microstrip line is connected to the second open-circuit stub.
[0006] Optionally, the first transmission line and the second transmission line are arranged side by side at intervals along the first direction.
[0007] Optionally, the first transmission line, the second transmission line, the second microstrip line, and the fourth microstrip line are all arranged parallel to the second direction, and the first direction and the second direction are perpendicular.
[0008] Optionally, the first transmission line, the second transmission line, the second microstrip line, and the fourth microstrip line are all perpendicular to the first open stub, the second open stub, the first microstrip line, and the third microstrip line.
[0009] Optionally, the electrical length of the first transmission line is equal to the electrical length of the second transmission line; the electrical length of the first microstrip line is equal to the electrical length of the third microstrip line; the electrical length of the second microstrip line is equal to the electrical length of the fourth microstrip line; and the electrical length of the first open stub is equal to the electrical length of the second open stub.
[0010] Optionally, the sum of the electrical length of the first transmission line, the electrical length of the first microstrip line, the electrical length of the second microstrip line, and the electrical length of the first open stub is a quarter wavelength corresponding to the center frequency of the bandpass filter.
[0011] Optionally, the characteristic impedances of the first transmission line, the second transmission line, the first microstrip line, the second microstrip line, the third microstrip line, the fourth microstrip line, the first open-circuit stub, and the second open-circuit stub are all equal.
[0012] To solve the above-mentioned technical problems, another technical solution adopted by this utility model is to provide a second-order broadband bandpass filter, which is obtained through the above-mentioned topology design.
[0013] Optionally, the topology is disposed on a circuit board, the circuit board having a dielectric loss of 0.0022, a thickness of 0.813 mm, and a size of 13 mm * 5.8 mm.
[0014] To solve the above-mentioned technical problems, another technical solution adopted by this utility model is to provide a communication device, including the above-mentioned second-order broadband bandpass filter.
[0015] The beneficial effects of this utility model embodiment are as follows: Unlike existing technologies, this utility model embodiment provides a topology, a second-order broadband bandpass filter, and a communication device, specifically including: an input terminal, an output terminal, a first transmission line, a second transmission line, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a first open-circuit stub, and a second open-circuit stub; one end of the input terminal is connected to one end of the first transmission line, the other end of the first transmission line is connected to one end of the first microstrip line, the other end of the first microstrip line is connected to one end of the second microstrip line, the other end of the second microstrip line is connected to the first open-circuit stub, the output terminal is connected to one end of the second transmission line, the other end of the second transmission 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, and the other end of the fourth microstrip line is connected to the second open-circuit stub. The second-order broadband bandpass filter designed based on the above topology has two transmission poles in the passband. The two transmission poles ensure the flatness of the bandpass filter in the passband and also prove that the filter designed based on this topology is a second-order broadband bandpass filter. It also has two transmission zeros in the stopband. These two transmission poles can ensure the high selectivity of the filter, thereby ensuring the miniaturization characteristics of the second-order broadband bandpass filter. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the topology provided in an embodiment of the present utility model;
[0018] Figure 2 This is a schematic diagram of the layout of a second-order broadband bandpass filter based on topology design provided in an embodiment of this utility model;
[0019] Figure 3 This is a schematic diagram showing the layout of a second-order broadband bandpass filter based on topology design provided in this embodiment of the present invention.
[0020] Figure 4 This is a simulation result diagram of the S-parameters of a second-order broadband bandpass filter with changed s1, obtained based on topology design, provided by an embodiment of this utility model.
[0021] Figure 5 This is a simulation result diagram of the S-parameters of a second-order broadband bandpass filter with changed w1, obtained based on topology design, provided by an embodiment of this utility model.
[0022] Figure 6 This is a simulation result diagram of the S-parameters of a second-order broadband bandpass filter based on topology design provided in this embodiment of the present invention. Detailed Implementation
[0023] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this specification are for illustrative purposes only.
[0024] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.
[0025] Please see Figure 1 The topology 100 includes: an input terminal 101, an output terminal 102, a first transmission line 103, a second transmission line 104, a first microstrip line 105, a second microstrip line 106, a third microstrip line 107, a fourth microstrip line 108, a first open-circuit stub 109, and a second open-circuit stub 110. One end of the input terminal 101 is connected to one end of the first transmission line 103, the other end of the first transmission line 103 is connected to one end of the first microstrip line 105, the other end of the first microstrip line 105 is connected to one end of the second microstrip line 106, the other end of the second microstrip line 106 is connected to the first open-circuit stub 109, the output terminal 102 is connected to one end of the second transmission line 104, the other end of the second transmission line 104 is connected to one end of the third microstrip line 107, the other end of the third microstrip line 107 is connected to one end of the fourth microstrip line 108, and the other end of the fourth microstrip line 108 is connected to the second open-circuit stub 110.
[0026] In some embodiments, the first transmission line 103 and the second transmission line 104 are arranged side by side at intervals along the first direction Y, and the first transmission line 103 and the second transmission line 104 are arranged close together to ensure that the first transmission line 103 and the second transmission line 104 can achieve a coupling effect, thereby forming the passband and stopband characteristics of the broadband bandpass filter designed based on this topology 100, and ensuring that the structure of the broadband bandpass filter is compact.
[0027] In some embodiments, the first transmission line 103, the second transmission line 104, the second microstrip line 106 and the fourth microstrip line 108 are all arranged parallel to the second direction X, and the first direction Y and the second direction X are perpendicular.
[0028] Furthermore, the first transmission line 103, the second transmission line 104, the second microstrip line 106, and the fourth microstrip line 108 are all perpendicular to the first open-circuit stub 109, the second open-circuit stub 110, the first microstrip line 105, and the third microstrip line 107, and the first open-circuit stub 109, the second open-circuit stub 110, the first microstrip line 105, and the third microstrip line 107 are arranged along the second direction Y, and the first direction X and the second direction Y are perpendicular.
[0029] In some embodiments, the electrical length of the first transmission line 103 is equal to the electrical length of the second transmission line 104; the electrical length of the first microstrip line 105 is equal to the electrical length of the third microstrip line 107; the electrical length of the second microstrip line 106 is equal to the electrical length of the fourth microstrip line 108; and the electrical length of the first open stub 109 is equal to the electrical length of the second open stub 110.
[0030] Furthermore, the sum of the electrical lengths of the first transmission line 103, the first microstrip line 105, the second microstrip line 106, and the first open stub 109 is a quarter wavelength corresponding to the center frequency of the bandpass filter.
[0031] In some embodiments, the characteristic impedances of the first transmission line 103, the second transmission line 104, the first microstrip line 105, the second microstrip line 106, the third microstrip line 107, the fourth microstrip line 108, the first open stub 109, and the second open stub 110 are all equal.
[0032] This utility model provides a topology 100 including: an input terminal 101, an output terminal 102, a first transmission line 103, a second transmission line 104, a first microstrip line 105, a second microstrip line 106, a third microstrip line 107, a fourth microstrip line 108, a first open-circuit stub 109, and a second open-circuit stub 110; one end of the input terminal 101 is connected to one end of the first transmission line 103, the other end of the first transmission line 103 is connected to one end of the first microstrip line 105, the other end of the first microstrip line 105 is connected to one end of the second microstrip line 106, the other end of the second microstrip line 106 is connected to the first open-circuit stub 109, the output terminal 102 is connected to one end of the second transmission line 104, the other end of the second transmission line 104 is connected to one end of the third microstrip line 107, the other end of the third microstrip line 107 is connected to one end of the fourth microstrip line 108, and the other end of the fourth microstrip line 108 is connected to the second open-circuit stub 110. The broadband bandpass filter designed based on the above topology 100 has the advantage of miniaturization.
[0033] The broadband bandpass filter designed based on this topology 100 has six design parameters: the physical length l1 of the first transmission line 103 or the second transmission line 104, the physical length l2 of the first microstrip line 105 or the third microstrip line 107, the physical length l3 of the second microstrip line 106 or the fourth microstrip line 108, the physical length l4 of the first open stub 109 or the second open stub 110, the spacing s1 between the first transmission line 103 and the second transmission line 104, and the physical width w1 of the first transmission line 103, the second transmission line 104, the first microstrip line 105, the second microstrip line 106, the third microstrip line 107, the fourth microstrip line 108, the first open stub 109, and the second open stub 110. According to fundamental microwave theory, l1, l2, l3, and l4 determine the center frequency of the bandpass filter. Changing the values of l1, l2, l3, and l4 proportionally changes the center frequency of the bandpass filter inversely. s1 and w1 determine the performance of the filter.
[0034] To verify the concept of this utility model, a simulation experiment of a second-order broadband bandpass filter embodiment is also provided, as detailed below:
[0035] like Figure 2 and Figure 3As shown, the second-order broadband bandpass filter is designed using the aforementioned topology 100 and mounted on a circuit board. The specified dielectric loss of the circuit board is 0.0022, the thickness is 0.813 mm, and the dimensions of the circuit board are 13 mm * 5.8 mm. The specific dimensions of the topology 100 mounted on the circuit board are: l1 = 8.0 mm, l2 = 1.6 mm, l3 = 2.9 mm, l4 = 1.0 mm, s1 = 0.1 mm, w1 = 0.1 mm.
[0036] Figure 4 The effect of changing only s1 on filter performance is shown. Figure 4 It can be seen that as the value of parameter s1 increases, the operating bandwidth of the bandpass filter decreases, the reflection coefficient in the passband improves, and the isolation in the stopband improves.
[0037] Figure 5 The effect of changing only w1 on filter performance is shown. Figure 5 It can be seen that as the value of parameter w1 increases, the operating bandwidth of the bandpass filter decreases, the reflection coefficient in the passband improves, and the isolation in the stopband deteriorates.
[0038] In summary, the analysis shows that for filters designed based on this topology 100, as the values of parameters s1 and w1 increase, the operating bandwidth of the bandpass filter decreases, the reflection coefficient in the passband improves, and the stopband isolation deteriorates. Furthermore, regardless of how the parameters s1 and w1 are changed, the filter designed based on this topology 100 can only be a bandpass filter.
[0039] The simulation results of the S-parameters of the second-order broadband bandpass filter corresponding to the above typical dimensions are shown in the figure. Figure 6 It can be seen that its impedance bandwidth with a reflection coefficient less than -10dB ranges from 2.86 to 5.02 GHz, the passband center frequency is 3.94 GHz, the absolute passband bandwidth is 2.16 GHz, and the relative passband bandwidth is 54.8%. Furthermore, within the passband, there are two transmission poles located at 3.2 GHz and 4.66 GHz, respectively. These two transmission poles not only ensure the flatness of the passband filter but also directly prove that the filter designed based on this topology is a second-order bandpass filter. In the stopband, there are two transmission zeros located at 0 GHz and 8.07 GHz, respectively. These two transmission poles ensure the high selectivity of the filter.
[0040] Through the simulation examples of the above topology 100, it can be demonstrated that the wide passband filter designed based on the above topology 100 has the characteristic of miniaturization.
[0041] This utility model also provides a communication device embodiment, including the above-mentioned second-order broadband bandpass filter. For the specific structure and function of the above-mentioned second-order broadband bandpass filter, please refer to the above embodiments, which will not be repeated here.
[0042] It should be noted that while the preferred embodiments of this utility model are provided in the specification and accompanying drawings, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are not intended to impose additional limitations on the content of this utility model; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Furthermore, the above-described technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of this utility model specification. Moreover, those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A topology, characterized in that, The topology structure comprises: an input terminal, an output terminal, a first transmission line, a second transmission line, a first microstrip line, a second microstrip line, a third microstrip line, a fourth microstrip line, a first open stub and a second open stub; one end of the input terminal is connected to one end of the first transmission line, the other end of the first transmission line is connected to one end of the first microstrip line, the other end of the first microstrip line is connected to one end of the second microstrip line, the other end of the second microstrip line is connected to the first open stub, the output terminal is connected to one end of the second transmission line, the other end of the second transmission 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, and the other end of the fourth microstrip line is connected to the second open stub.
2. The topology structure according to claim 1, wherein the first transmission line and the second transmission line are arranged side by side along a first direction.
3. The topology structure according to claim 2, wherein the first transmission line, the second transmission line, the second microstrip line and the fourth microstrip line are arranged parallel along a second direction, and the first direction is perpendicular to the second direction.
4. The topology structure according to claim 3, wherein the first transmission line, the second transmission line, the second microstrip line and the fourth microstrip line are perpendicular to the first open stub, the second open stub, the first microstrip line and the third microstrip line.
5. The topology structure according to claim 1, wherein an electrical length of the first transmission line is equal to an electrical length of the second transmission line; an electrical length of the first microstrip line is equal to an electrical length of the third microstrip line; an electrical length of the second microstrip line is equal to an electrical length of the fourth microstrip line; and an electrical length of the first open stub is equal to an electrical length of the second open stub.
6. The topology structure according to claim 5, wherein a sum of the electrical length of the first transmission line, the electrical length of the first microstrip line, the electrical length of the second microstrip line and the electrical length of the first open stub is equal to a quarter wavelength corresponding to a center frequency of a band-pass filter.
7. The topology structure according to any one of claims 1-6, wherein a characteristic impedance of the first transmission line, a characteristic impedance of the second transmission line, a characteristic impedance of the first microstrip line, a characteristic impedance of the second microstrip line, a characteristic impedance of the third microstrip line, a characteristic impedance of the fourth microstrip line, a characteristic impedance of the first open stub and a characteristic impedance of the second open stub are equal.
8. A second order wideband bandpass filter characterized by, The topology structure is designed according to any one of claims 1-7.
9. The second-order wideband bandpass filter of claim 8, wherein, The topology structure is arranged on a circuit board, the circuit board has a dielectric loss of 0.0022, a thickness of 0.813 mm, and a size of 13 mm*5.8 mm.
10. A communication device comprising the second-order wideband band-pass filter according to claim 9.