Band-pass filter and communication equipment
By designing a specific topology for the bandpass filter and utilizing the connection of microstrip lines and short-circuited stubs, the problem of increased system complexity and size caused by cascaded filters was solved, achieving high selectivity, wide stopband, and high isolation, thus promoting the miniaturization and integration of communication equipment.
Patent Information
- Application Number
- CN202520299506.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2035-02-24
AI Technical Summary
Existing technologies that achieve wide stopband characteristics through cascaded filters increase the complexity and size of the system, which is not conducive to the miniaturization and integration of communication equipment.
Design a bandpass filter, including a substrate and a topology, which forms six transmission poles and six transmission zeros through a specially arranged microstrip line and short-circuit stubs, achieving high selectivity, wide stopband and high isolation, and a compact structure.
It achieves high flatness in the passband and high selectivity in the stopband, reducing the need for additional filters and contributing to the miniaturization and integration of communication systems.
Smart Images
Figure CN223771313U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The embodiment of the utility model relates to communication technical field, especially a kind of band-pass filter and communication equipment. BACKGROUND
[0002] In modern wireless communication system, band-pass filter as key component, undertakes the important task of frequency selection, filtering. With the continuous development of communication technology, the performance requirement of band-pass filter is also more and more high, especially in selectivity, stopband width and isolation, and wide stopband can provide wider frequency suppression range, reduce unnecessary signal interference. At present, the wideband band-pass filter with wide stopband characteristics is usually realized by cascading band-pass filter and low-pass filter
[0003] In the process of implementing the embodiments of the present application, the inventors have found that: by cascading filters to realize wide stopband characteristics, the complexity and volume of the system are increased, which is not conducive to the miniaturization and integration of communication equipment. UTILITY MODEL CONTENT
[0004] In view of the above problems, the embodiment of the utility model provides a kind of band-pass filter and communication equipment, overcome above-mentioned problem or at least partially solve above-mentioned problem.
[0005] To solve the above technical problems, one of the technical solutions adopted by the utility model is to provide a band-pass filter, comprising a substrate and a topology structure, the topology structure is arranged on the substrate, the topology structure includes an input end, a first parallel line, a second parallel line, a third parallel line, 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 first short-circuit stub, a second short-circuit stub, a third short-circuit stub, a fourth short-circuit stub and an output end, wherein the input end is connected with one end of the first parallel line, the other end of the first parallel line is connected with one end of the second parallel line and one end of the first microstrip line, the other end of the first microstrip line is connected with one end of the second microstrip line and one end of the third microstrip line, the other end of the second parallel line is connected with one end of the third microstrip line and one end of the fourth microstrip line, the other end of the fourth microstrip line is connected with one end of the fifth microstrip line and one end of the sixth microstrip line, the other end of the third parallel line is connected with the output end, one end of the first short-circuit stub, the second microstrip line, the third microstrip line and one end of the second short-circuit stub are connected in sequence, one end of the third short-circuit stub, the fifth microstrip line, the sixth microstrip line and one end of the fourth short-circuit stub are connected in sequence.
[0006] Optionally, the first parallel line and the third parallel line are symmetrically distributed about the second parallel line, the second microstrip line and the third microstrip line are symmetrically distributed about the first microstrip line, the first short-circuit stub and the second short-circuit stub are symmetrically distributed about the first microstrip line, and the fifth microstrip line and the sixth microstrip line are symmetrically distributed about the fourth microstrip line.
[0007] Optionally, the first parallel line, the second parallel line, the third parallel line, the second microstrip line, the third microstrip line, the fifth microstrip line, and the sixth microstrip line are parallel to each other and are perpendicular to the first microstrip line, the fourth microstrip line, the first short-circuit stub, the second short-circuit stub, the third short-circuit stub, and the fourth short-circuit stub.
[0008] Optionally, the electrical length of the first parallel line, the electrical length of the second parallel line, and the electrical length of the third parallel line are equal and each equal to a corresponding quarter wavelength at a center frequency of a passband, the electrical length of the first microstrip line and the electrical length of the fourth microstrip line are equal, the electrical length of the second microstrip line, the electrical length of the third microstrip line, the electrical length of the fifth microstrip line, and the electrical length of the sixth microstrip line are equal, the electrical length of the first short-circuit stub, the electrical length of the second short-circuit stub, the electrical length of the third short-circuit stub, and the electrical length of the fourth short-circuit stub are equal, and the sum of the electrical length of the first microstrip line, the electrical length of the second microstrip line, and the electrical length of the first short-circuit stub is greater than the electrical length of the second parallel line.
[0009] Optionally, the characteristic impedance of the second microstrip line, the characteristic impedance of the third microstrip line, the characteristic impedance of the fifth microstrip line, the characteristic impedance of the sixth microstrip line, the characteristic impedance of the first short-circuit stub, the characteristic impedance of the second short-circuit stub, the characteristic impedance of the third short-circuit stub, and the characteristic impedance of the fourth short-circuit stub are equal and each equal to twice the characteristic impedance of the first microstrip line and the characteristic impedance of the fourth microstrip line.
[0010] Optionally, the first parallel line includes a first transmission line, a second transmission line, and a third transmission line arranged in sequence and in parallel, the first transmission line and the third transmission line are connected to the input terminal, and the second transmission line is connected to one end of the second parallel line and one end of the first microstrip line.
[0011] Optionally, the third parallel line includes a fourth transmission line, a fifth transmission line, and a sixth transmission line arranged in sequence and in parallel, the fourth transmission line and the sixth transmission line are connected to the output terminal, and the fifth transmission line is connected to the other end of the second parallel line and one end of the fourth microstrip line.
[0012] Optionally, the second parallel line includes a seventh transmission line and an eighth transmission line arranged in parallel in sequence. The seventh transmission line is connected to one end of the second transmission line and the first microstrip line, and the eighth transmission line is connected to one end of the fifth transmission line and the fourth microstrip line.
[0013] Optionally, the other ends of the first short-circuited stub, the second short-circuited stub, the third short-circuited stub, and the fourth short-circuited stub are all grounded.
[0014] To solve the above-mentioned technical problems, another technical solution adopted by this utility model is to provide a communication device.
[0015] The beneficial effects of this utility model embodiment are as follows: Unlike the prior art, this utility model embodiment provides a bandpass filter and a communication device. The bandpass filter includes a substrate and a topology. The topology is disposed on the substrate and includes an input terminal, a first parallel line, a second parallel line, a third parallel line, 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 first short-circuit stub, a second short-circuit stub, a third short-circuit stub, a fourth short-circuit stub, and an output terminal. The input terminal is connected to one end of the first parallel line, and the other end of the first parallel line is connected to one end of the second parallel line and the first microstrip line. One end of a microstrip line is connected, and the other end of the first microstrip line is connected to one end of the second microstrip line and one end of the third microstrip line. The other end of the second parallel line is connected to one end of the third microstrip line and 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 and one end of the sixth microstrip line. The other end of the third parallel line is connected to the output terminal. One end of the first short-circuit stub, the second microstrip line, the third microstrip line, and one end of the second short-circuit stub are connected sequentially. One end of the third short-circuit stub, the fifth microstrip line, the sixth microstrip line, and one end of the fourth short-circuit stub are connected sequentially. With the above structure, the bandpass filter has six transmission poles in the passband, achieving high flatness in the passband. It has six transmission zeros in the stopband, achieving high selectivity, wide stopband, and high isolation. Moreover, the structure is compact, eliminating the need for cascading additional filters, which is beneficial for the miniaturization and integration of communication systems. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. 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 of a bandpass filter provided in an embodiment of the present invention;
[0018] Figure 2 This is a layout diagram of a bandpass filter provided in an embodiment of the present invention;
[0019] Figure 3 yes Figure 2 Parameter labeling diagram;
[0020] Figure 4 This is a simulation result diagram of the S-parameters of a bandpass filter provided in an embodiment of this utility model. Detailed Implementation
[0021] 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.
[0022] 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.
[0023] This application provides an embodiment of a bandpass filter, which includes a substrate (not shown) and a topology 100 disposed on the substrate.
[0024] For the above topology 100, please refer to Figure 1 The topology 100 includes an input terminal 10, a first parallel line 20, a second parallel line 21, a third parallel line 22, a first microstrip line 30, a second microstrip line 31, a third microstrip line 32, a fourth microstrip line 33, a fifth microstrip line 34, a sixth microstrip line 35, a first short-circuit stub 40, a second short-circuit stub 41, a third short-circuit stub 42, a fourth short-circuit stub 43, and an output terminal 50.
[0025] Specifically, input terminal 10 is connected to one end of the first parallel line 20, the other end of the first parallel line 20 is connected to one end of the second parallel line 21 and one end of the first microstrip line 30, the other end of the first microstrip line 30 is connected to one end of the second microstrip line 31 and one end of the third microstrip line 32, the other end of the second parallel line 21 is connected to one end of the third microstrip line 32 and one end of the fourth microstrip line 33, the other end of the fourth microstrip line 33 is connected to one end of the fifth microstrip line 34 and one end of the sixth microstrip line 35, the other end of the third parallel line 22 is connected to output terminal 50, one end of the first short-circuit stub 40, one end of the second microstrip line 31, one end of the third microstrip line 32 and one end of the second short-circuit stub 41 are connected in sequence, and one end of the third short-circuit stub, one end of the fifth microstrip line 34, one end of the sixth microstrip line 35 and one end of the fourth short-circuit stub 43 are connected in sequence.
[0026] In some embodiments, the other ends of the first short-circuit stub 40, the second short-circuit stub 41, the third short-circuit stub 42, and the fourth short-circuit stub 43 are all grounded.
[0027] In some embodiments, the first parallel line 20 and the third parallel line 22 are symmetrically distributed about the second parallel line 21, the second microstrip line 31 and the third microstrip line 32 are symmetrically distributed about the first microstrip line 30, the first short-circuit stub 40 and the second short-circuit stub 41 are symmetrically distributed about the first microstrip line 30, and the fifth microstrip line 34 and the sixth microstrip line 35 are symmetrically distributed about the fourth microstrip line 33.
[0028] In some embodiments, the first parallel line 20, the second parallel line 21, the third parallel line 22, the second microstrip line 31, the third microstrip line 32, the fifth microstrip line 34, and the sixth microstrip line 35 are parallel to each other and are all perpendicular to the first microstrip line 30, the fourth microstrip line 33, the first short-circuit stub 40, the second short-circuit stub 41, the third short-circuit stub 42, and the fourth short-circuit stub 43.
[0029] In some embodiments, the electrical lengths of the first parallel line 20, the second parallel line 21, and the third parallel line 22 are equal, and each is equal to a quarter wavelength corresponding to the center frequency of the passband. The electrical lengths of the first microstrip line 30 and the fourth microstrip line 33 are equal, the electrical lengths of the second microstrip line 31, the third microstrip line 32, the fifth microstrip line 34, and the sixth microstrip line 35 are equal, the electrical lengths of the first short-circuit stub 40, the second short-circuit stub 41, the third short-circuit stub 42, and the fourth short-circuit stub 43 are equal, and the sum of the electrical lengths of the first microstrip line 30, the second microstrip line 31, and the first short-circuit stub 40 is greater than the electrical length of the second parallel line 21.
[0030] In some embodiments, the characteristic impedances of the second microstrip line 31, the third microstrip line 32, the fifth microstrip line 34, the sixth microstrip line 35, the first short-circuit stub 40, the second short-circuit stub 41, the third short-circuit stub 42, and the fourth short-circuit stub 43 are equal, and each is twice the characteristic impedance of the first microstrip line 30 and the fourth microstrip line 33.
[0031] Regarding the first parallel line 20 mentioned above, please refer to some embodiments. Figure 1 and Figure 2 The first parallel line 20 includes a first transmission line 201, a second transmission line 202 and a third transmission line 203 arranged in parallel in sequence. The first transmission line 201 and the third transmission line 203 are both connected to the input terminal 10. The second transmission line 202 is connected to one end of the second parallel line 21 and one end of the first microstrip line 30.
[0032] Regarding the second parallel line 21 mentioned above, please refer to some embodiments. Figure 1 and Figure 2 The second parallel line 21 includes a seventh transmission line 211 and an eighth transmission line 212 arranged in parallel in sequence. The seventh transmission line 211 is connected to one end of the second transmission line 202 and the first microstrip line 30, and the eighth transmission line 212 is connected to one end of the fifth transmission line 222 and the fourth microstrip line 33.
[0033] Regarding the third parallel line 22 mentioned above, please refer to some embodiments. Figure 1 and Figure 2 The third parallel line 22 includes a fourth transmission line 221, a fifth transmission line 222 and a sixth transmission line 223 arranged in parallel in sequence. The fourth transmission line 221 and the sixth transmission line 223 are both connected to the output terminal 50. The fifth transmission line 222 is connected to the other end of the second parallel line 21 and one end of the fourth microstrip line 33.
[0034] This application also provides simulation embodiments of the above-mentioned bandpass filter; please refer to [link / reference]. Figure 2 and Figure 3 The substrate measures 37.2mm x 9.6mm, has a thickness of 0.813mm, a dielectric constant of 3.38, and a dielectric loss of 0.0022. A set of parameters for the topology 100 is set as follows:
[0035] l T =10.1mm,s T =0.1mm,w T =0.2mm,l p =10.1mm,s p =0.1mm,
[0036] w p=0.2mm, l1=4.2mm, w1=1.8mm, l2=5.5mm, w2=0.9mm,
[0037] l3 = 2.2 mm, w3 = 0.9 mm.
[0038] Among them, l T w T The physical lengths and widths of the first transmission line 201, the second transmission line 202, the third transmission line 203, the fourth transmission line 221, the fifth transmission line 222, and the sixth transmission line 223 are respectively, s T The physical spacing between adjacent transmission lines of the first transmission line 201, the second transmission line 202, and the third transmission line 203, and the physical spacing between adjacent transmission lines of the fourth transmission line 221, the fifth transmission line 222, and the sixth transmission line 223, l p w p The physical lengths and widths of the seventh transmission line 211 and the eighth transmission line 212 are s, respectively. p The physical spacing between the seventh transmission line 211 and the eighth transmission line 212 is given by l1 and w1, respectively, which are the physical lengths and widths of the first microstrip line 30 and the fourth microstrip line 33. The physical lengths and widths of the second microstrip line 31, the third microstrip line 32, the fifth microstrip line 34 and the sixth microstrip line 35 are given by l2 and w2, respectively. The physical lengths and widths of the first short-circuit branch, the second short-circuit stub 41, the third short-circuit stub 42 and the fourth short-circuit stub 43 are given by l3 and w3, respectively.
[0039] Please see Figure 4 , Figure 4 The above simulation results show the S-parameters. The passband range with a reflection coefficient less than -10dB is 2.2GHz to 7.08GHz, the passband center frequency is 4.64GHz, the absolute passband bandwidth is 4.88GHz, and the relative passband bandwidth is 105.2%. There are six transmission poles in the passband, corresponding to frequencies of 2.26GHz, 2.81GHz, 4.16GHz, 5.3GHz, 6.39GHz, and 7.01GHz, ensuring high passband flatness. There are six transmission zeros in the stopband, corresponding to frequencies of 0, 0.22GHz, 0.38GHz, 8.16GHz, 10.2GHz, and 10.68GHz, ensuring high selectivity, wide stopband, and high isolation of the filter.
[0040] In this embodiment, the bandpass filter achieves high flatness in the passband by setting a topology 100 on the substrate, with six transmission poles in the passband and six transmission zeros in the stopband, achieving high selectivity, wide stopband and high isolation. It also has a compact structure and does not require cascading additional filters, which is beneficial for the miniaturization and integration of communication systems.
[0041] This application also provides embodiments of communication devices, which include the bandpass filter described above. The structure and function of the bandpass filter can be found in the above embodiments, and 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 bandpass filter, characterized by, The bandpass filter comprises: a substrate; a topology disposed on the substrate, the topology comprising an input, a first parallel line, a second parallel line, a third parallel line, 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 first short-circuit stub, a second short-circuit stub, a third short-circuit stub, a fourth short-circuit stub, and an output; wherein the input is connected to one end of the first parallel line, the other end of the first parallel line is connected to one end of the second parallel line and 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 and one end of the third microstrip line, the other end of the second parallel line is connected to one end of the third microstrip line and 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 and one end of the sixth microstrip line, the other end of the third parallel line is connected to the output, one end of the first short-circuit stub, the second microstrip line, the third microstrip line, and one end of the second short-circuit stub are connected in sequence, one end of the third short-circuit stub, the fifth microstrip line, the sixth microstrip line, and one end of the fourth short-circuit stub are connected in sequence.
2. The bandpass filter of claim 1, wherein: the first parallel line and the third parallel line are symmetrically distributed about the second parallel line, the second microstrip line and the third microstrip line are symmetrically distributed about the first microstrip line, the first short-circuit stub and the second short-circuit stub are symmetrically distributed about the first microstrip line, and the fifth microstrip line and the sixth microstrip line are symmetrically distributed about the fourth microstrip line.
3. The bandpass filter of claim 1, wherein , the first parallel line, the second parallel line, the third parallel line, the second microstrip line, the third microstrip line, the fifth microstrip line, and the sixth microstrip line are parallel to each other and are perpendicular to the first microstrip line, the fourth microstrip line, the first short-circuit stub, the second short-circuit stub, the third short-circuit stub, and the fourth short-circuit stub.
4. The bandpass filter of claim 1, wherein , an electrical length of the first parallel line, an electrical length of the second parallel line, and an electrical length of the third parallel line are equal and each equal to a corresponding quarter wavelength at a center frequency of a passband; an electrical length of the first microstrip line is equal to an electrical length of the fourth microstrip line, an electrical length of the second microstrip line, an electrical length of the third microstrip line, an electrical length of the fifth microstrip line, and an electrical length of the sixth microstrip line are equal, an electrical length of the first short-circuit stub, an electrical length of the second short-circuit stub, an electrical length of the third short-circuit stub, and an electrical length of the fourth short-circuit stub are equal, and a sum of the electrical length of the first microstrip line, the electrical length of the second microstrip line, and the electrical length of the first short-circuit stub is greater than the electrical length of the second parallel line.
5. The bandpass filter of claim 4, wherein: The characteristic impedance of the second microstrip line, the characteristic impedance of the third microstrip line, the characteristic impedance of the fifth microstrip line, the characteristic impedance of the sixth microstrip line, the characteristic impedance of the first short-circuit stub, the characteristic impedance of the second short-circuit stub, the characteristic impedance of the third short-circuit stub, and the characteristic impedance of the fourth short-circuit stub are equal, and are all equal to twice the characteristic impedance of the first microstrip line and the characteristic impedance of the fourth microstrip line. 6.The bandpass filter of any one of claims 1-5, wherein, The first parallel line comprises a first transmission line, a second transmission line, and a third transmission line arranged in parallel in sequence, the first transmission line and the third transmission line are both connected with the input terminal, and the second transmission line is connected with one end of the second parallel line and one end of the first microstrip line. 7.The bandpass filter of claim 6, wherein, The third parallel line comprises a fourth transmission line, a fifth transmission line, and a sixth transmission line arranged in parallel in sequence, the fourth transmission line and the sixth transmission line are both connected with the output terminal, and the fifth transmission line is connected with the other end of the second parallel line and one end of the fourth microstrip line. 8.The bandpass filter of claim 7, wherein, The second parallel line comprises a seventh transmission line and an eighth transmission line arranged in parallel in sequence, the seventh transmission line is connected with the second transmission line and one end of the first microstrip line, and the eighth transmission line is connected with the fifth transmission line and one end of the fourth microstrip line. 9.The bandpass filter of any one of claims 1-5, wherein, The other end of the first short-circuit stub, the other end of the second short-circuit stub, the other end of the third short-circuit stub, and the other end of the fourth short-circuit stub are all grounded.
10. A communication device, characterized by A bandpass filter as claimed in any one of claims 1-9.