A topology, bandstop filter and communication device

Abstract

The embodiment of the present application relates to the technical field of filter, in particular to a kind of topology structure, band elimination filter and communication device, including input, output, first microstrip line, second microstrip line, third microstrip line, fourth microstrip line, fifth microstrip line, sixth microstrip line, seventh microstrip line, eighth microstrip line, first open stub, second open stub, third open stub, fourth open stub, fifth open stub and sixth open stub, first microstrip line and first open stub are connected to input, second microstrip line and second open stub are connected to output, first microstrip line, second microstrip line, third microstrip line and fourth microstrip line are connected together, fifth microstrip line, third microstrip line and sixth microstrip line are connected together. By the above mode, the embodiment of the present application can make that band elimination filter has the characteristic of high selectivity.

Description

Technical Field

[0001] The present invention relates to the field of filter technology, and in particular to a topology, a band-stop filter, and a communication device. Background Technology

[0002] With the development of modern communication technology, people's demand for information transmission is gradually increasing. However, spectrum resources are relatively limited, and various communication systems and modes are becoming increasingly similar or even overlapping in frequency space. This necessitates that each communication system possess strong anti-interference capabilities to prevent interference from other systems. Furthermore, with the increasing high-density integration of electronic devices, future communication systems will trend towards miniaturization. Therefore, the miniaturization and high selectivity of filters have gradually become a research hotspot in communication technology.

[0003] However, in the process of realizing this invention, the inventors discovered that most band-stop filters on the market have poor selectivity. The topology of the band-stop filter plays a crucial role in the performance of the band-stop filter. Therefore, the performance of the band-stop filter can be improved by improving the topology. Summary of the Invention

[0004] In view of the above problems, embodiments of the present invention provide a topology that overcomes or at least partially solves the above problems.

[0005] According to one aspect of the present invention, a topology is provided, including 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, an eighth microstrip line, a first open-circuit stub, a second open-circuit stub, a third open-circuit stub, a fourth open-circuit stub, a fifth open-circuit stub, and a sixth open-circuit stub. In this configuration, the first end of the first microstrip line and one end of the first open-circuit stub are both connected to the input terminal; the first end of the second microstrip line and one end of the second open-circuit stub are both connected to the output terminal; the second ends of the first, second, third, and fourth microstrip lines are connected together; the first ends of the fifth, third, and sixth microstrip lines are connected together; the second end of the fifth microstrip line is connected to one end of the third open-circuit stub; the second end of the sixth microstrip line is connected to one end of the fourth open-circuit stub; the first ends of the seventh, fourth, and eighth microstrip lines are connected together; the second end of the seventh microstrip line is connected to one end of the fifth open-circuit stub; and the second end of the eighth microstrip line is connected to one end of the sixth open-circuit stub.

[0006] In some embodiments, the first open-circuit spur is bent to form a first left open-circuit portion and a second left open-circuit portion, a first end of the first left open-circuit portion is connected to the input terminal, and a second end of the first left open-circuit portion is connected to one end of the second left open-circuit portion. The second open-circuit spur is bent to form a first right open-circuit portion and a second right open-circuit portion, a first end of the first right open-circuit portion is connected to the output terminal, and a second end of the first right open-circuit portion is connected to one end of the second right open-circuit portion.

[0007] In some embodiments, the third microstrip line and the fourth microstrip line are on the same straight line. With the straight line as the axis, the first microstrip line and the second microstrip line are symmetrically arranged, the input terminal and the output terminal are symmetrically arranged, the first open-circuit stub and the second open-circuit stub are symmetrically arranged, the fifth microstrip line and the sixth microstrip line are symmetrically arranged, the third open-circuit stub and the fourth open-circuit stub are symmetrically arranged, the seventh microstrip line and the eighth microstrip line are symmetrically arranged, and the fifth open-circuit stub and the sixth open-circuit stub are symmetrically arranged. This makes the topology spatially compact and structurally simple, which is beneficial for miniaturization and simplified design.

[0008] In some embodiments, the first and third microstrip lines are perpendicular, the fifth and seventh microstrip lines are parallel to the first microstrip line, the third and fifth open-circuit stubs are parallel to the third microstrip line, the first left open-circuit portion is parallel to the first microstrip line, and the second left open-circuit portion is perpendicular to the first left open-circuit portion. This is beneficial for improving the performance of filters based on the aforementioned topology.

[0009] In some embodiments, the topology satisfies the following conditions: the characteristic impedances of the first microstrip line, the second microstrip line, the first open-circuit stub, and the second open-circuit stub are all Z1; the characteristic impedances of the third and fourth microstrip lines are both Z2; and the characteristic impedances of the fifth, sixth, seventh, and eighth microstrip lines, the third open-circuit stub, the fourth open-circuit stub, the fifth open-circuit stub, and the sixth open-circuit stub are all 2*Z2. This simplifies the design of filters based on this topology.

[0010] In some embodiments, the topology satisfies: Θ1=Θ2=Θ9=Θ 10 Θ 11 +Θ5=Θ 12 +Θ6,Θ 13 +Θ7=Θ 14+Θ8, where Θ1 is the electrical length of the first microstrip line, Θ2 is the electrical length of the second microstrip line, Θ5 is the electrical length of the fifth microstrip line, Θ6 is the electrical length of the sixth microstrip line, Θ7 is the electrical length of the seventh microstrip line, Θ8 is the electrical length of the eighth microstrip line, and Θ9 is the electrical length of the first open-circuit stub. 10 The electrical length of the second open-circuit stub, Θ 11 The electrical length of the third open-circuit stub, Θ 12 The electrical length of the fourth open-circuit stub, Θ 13 The electrical length of the fifth open branch, Θ 14 This is the electrical length of the sixth open-circuit stub. This is beneficial for improving the performance of filters based on this topology.

[0011] In some embodiments, the topology satisfies: Θ3+Θ 11 +Θ5=Θ4+Θ 13 +Θ7, where Θ3 is the electrical length of the third microstrip line and Θ4 is the electrical length of the fourth microstrip line. This improves the performance of filters based on this topology.

[0012] According to one aspect of the present invention, a band-stop filter is provided, including the topology described above.

[0013] In some embodiments, the electrical lengths of the first microstrip line, the second microstrip line, the first open-circuit stub, and the second open-circuit stub are all quarter-wavelengths corresponding to the center frequency of the stopband of the band-stop filter. This is beneficial for improving the performance of filters based on the aforementioned topology.

[0014] According to one aspect of the present invention, a communication device is provided, including the band-stop filter described above.

[0015] The beneficial effects of the embodiments of the present invention are as follows: Unlike the prior art, the embodiments of the present invention provide a topology, a band-stop filter, and a communication device. The topology 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, an eighth microstrip line, a first open-circuit stub, a second open-circuit stub, a third open-circuit stub, a fourth open-circuit stub, a fifth open-circuit stub, and a sixth open-circuit stub. Through symmetry, transmission line bending, and corresponding layout, the band-stop filter based on the topology has three transmission zeros in the stopband and five transmission poles in the two passbands adjacent to the stopband, giving the band-stop filter high selectivity. 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 invention;

[0018] Figure 2 This is a schematic diagram of the layout of a band-stop filter provided in an embodiment of the present invention;

[0019] Figure 3 The figure shows the S-parameter simulation results of the band-stop filter provided in this embodiment of the invention under a set of optimized parameters.

[0020] The reference numerals in the detailed embodiments are as follows:

[0021] 1000, Band-stop filter;

[0022] 100. Topology;

[0023] 10. Input terminal; 11. Output terminal; 12. First microstrip line; 13. Second microstrip line; 14. Third microstrip line; 15. Fourth microstrip line; 16. Fifth microstrip line; 17. Sixth microstrip line; 18. Seventh microstrip line; 19. Eighth microstrip line; 20. First open-circuit stub; 21. Second open-circuit stub; 22. Third open-circuit stub; 23. Fourth open-circuit stub; 24. Fifth open-circuit stub; 25. Sixth open-circuit stub;

[0024] 201. First left-hand opening section; 202. Second left-hand opening section;

[0025] 211. First right-hand opening section; 212. Second right-hand opening section. Detailed Implementation

[0026] To facilitate understanding of the present invention, 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.

[0027] 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 invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0028] Please see Figure 1-2 The topology 100 includes an input terminal 10, an output terminal 11, a first microstrip line 12, a second microstrip line 13, a third microstrip line 14, a fourth microstrip line 15, a fifth microstrip line 16, a sixth microstrip line 17, a seventh microstrip line 18, an eighth microstrip line 19, a first open-circuit stub 20, a second open-circuit stub 21, a third open-circuit stub 22, a fourth open-circuit stub 23, a fifth open-circuit stub 24, and a sixth open-circuit stub 25. The first end of the first microstrip line 12 and the first open-circuit stub 20 are both connected to the input terminal 10. The first end of the second microstrip line 13 and the first end of the second open-circuit stub 21 are both connected to the output terminal 11. The second ends of the first microstrip line 12, the second end of the second microstrip line 13, the first end of the third microstrip line 14, and the first end of the fourth microstrip line 15 are all connected together. The first ends of the fifth microstrip line 16, the second end of the third microstrip line 14, and the first end of the sixth microstrip line 17 are all connected together. The second end of the fifth microstrip line 16 is connected to one end of the third open-circuit stub 22. The second end of the sixth microstrip line 17 is connected to one end of the fourth open-circuit stub 23. The first ends of the seventh microstrip line 18, the second end of the fourth microstrip line 15, and the first end of the eighth microstrip line 19 are all connected together. The second end of the seventh microstrip line 18 is connected to one end of the fifth open-circuit stub 24. The second end of the eighth microstrip line 19 is connected to one end of the sixth open-circuit stub 25.

[0029] In some embodiments, the third microstrip line 14 and the fourth microstrip line 15 are on the same straight line. With the straight line as the axis, the first microstrip line 12 and the second microstrip line 13 are symmetrically arranged, the input terminal 10 and the output terminal 11 are symmetrically arranged, the first open-circuit stub 20 and the second open-circuit stub 21 are symmetrically arranged, the fifth microstrip line 16 and the sixth microstrip line 17 are symmetrically arranged, the third open-circuit stub 22 and the fourth open-circuit stub 23 are symmetrically arranged, the seventh microstrip line 18 and the eighth microstrip line 19 are symmetrically arranged, and the fifth open-circuit stub 24 and the sixth open-circuit stub 25 are symmetrically arranged. This makes the topology 100 spatially compact and structurally simple, which is beneficial for miniaturization and simplified design.

[0030] For the first open branch 20 mentioned above, the first open branch 20 is bent to form a first left open section 201 and a second left open section 202. The first end of the first left open section 201 is connected to the input terminal 10, and the second end of the first left open section 201 is connected to one end of the second left open section 202.

[0031] For the second open branch 21 mentioned above, the second open branch 21 is bent to form a first right open section 211 and a second right open section 212. The first end of the first right open section 211 is connected to the output terminal 11, and the second end of the first right open section 211 is connected to one end of the second right open section 212.

[0032] In some embodiments, the first microstrip line 12 and the third microstrip line 14 are perpendicular, the fifth microstrip line 16 and the seventh microstrip line 18 are parallel to the first microstrip line 12, the third open-circuit stub 22 and the fifth open-circuit stub 24 are parallel to the third microstrip line 14, the first left open-circuit portion 201 is parallel to the first microstrip line 12, and the second left open-circuit portion 202 is perpendicular to the first left open-circuit portion 201. This improves the performance of the filter based on the topology 100.

[0033] In some embodiments, the topology 100 satisfies the following conditions:

[0034] (1) The characteristic impedances of the first microstrip line 12, the second microstrip line 13, the first open-circuit stub 20, and the second open-circuit stub 21 are all Z1. The characteristic impedances of the third microstrip line 14 and the fourth microstrip line 15 are all Z2. The characteristic impedances of the fifth microstrip line 16, the sixth microstrip line 17, the seventh microstrip line 18, the eighth microstrip line 19, the third open-circuit stub 22, the fourth open-circuit stub 23, the fifth open-circuit stub 24, and the sixth open-circuit stub 25 are all 2*Z2. The principle for setting the parameters of the topology 100 is to maximize Z1 and minimize Z2. This is beneficial for the filter based on the topology 100 to have high stopband isolation, low passband insertion loss, and good flatness.

[0035] (2)Θ1=Θ2=Θ9=Θ 10 Θ 11 +Θ5=Θ 12 +Θ6,Θ 13 +Θ7=Θ 14 +Θ8,

[0036] Θ3+Θ 11 +Θ5=Θ4+Θ 13+Θ7, where Θ1 is the electrical length of the first microstrip line 12, Θ2 is the electrical length of the second microstrip line 13, Θ3 is the electrical length of the third microstrip line 14, Θ4 is the electrical length of the fourth microstrip line 15, Θ5 is the electrical length of the fifth microstrip line 16, Θ6 is the electrical length of the sixth microstrip line 17, Θ7 is the electrical length of the seventh microstrip line 18, Θ8 is the electrical length of the eighth microstrip line 19, and Θ9 is the electrical length of the first open-circuit stub 20. 10 The electrical length of the second open-circuit branch 21, the Θ 11 The electrical length of the third open-circuit branch 22, the Θ 12 The electrical length of the fourth open branch 23, the Θ 13 The electrical length of the fifth open branch 24, the Θ 14 This is the electrical length of the sixth open stub 25. This is beneficial for improving the performance of the filter based on the aforementioned topology 100.

[0037] The present invention also provides an embodiment of a band-stop filter 1000, wherein the band-stop filter 1000 includes the above-described topology 100, and the band-stop filter 1000 designed based on the above-described topology 100 also has the following relationship:

[0038] (1)Θ1=Θ2=Θ9=Θ 10 =0.25*λ, where Θ1 is the electrical length of the first microstrip line 12, Θ2 is the electrical length of the second microstrip line 13, and Θ9 is the electrical length of the first open-circuit stub 20. 10 The electrical length of the second open-circuit stub 21 is given by λ, where λ is the wavelength corresponding to the center frequency of the stopband of the band-stop filter 1000. This improves the performance of the band-stop filter 1000.

[0039] (2)Θ 11 +Θ5+Θ3=Θ 12 +Θ6+Θ3=Θ 13 +Θ7+Θ4=Θ 14 +Θ8+Θ4=0.5*λ, where Θ3 is the electrical length of the third microstrip line 14, Θ4 is the electrical length of the fourth microstrip line 15, Θ5 is the electrical length of the fifth microstrip line 16, Θ6 is the electrical length of the sixth microstrip line 17, Θ7 is the electrical length of the seventh microstrip line 18, and Θ8 is the electrical length of the eighth microstrip line 19. 11 The electrical length of the third open-circuit branch 22, the Θ 12 The electrical length of the fourth open branch 23, the Θ 13 The electrical length of the fifth open branch 24, the Θ 14The electrical length of the sixth open stub 25 is given by λ, where λ is the wavelength corresponding to the center frequency of the stopband of the band-stop filter 1000. This improves the performance of the band-stop filter 1000.

[0040] (3) The physical width of the first left open section 201 is equal to the physical width of the second left open section 202; the physical width of the third microstrip line 14 is equal to the physical width of the fourth microstrip line 15; the physical widths of the fifth microstrip line 16, the sixth microstrip line 17, the seventh microstrip line 18, and the eighth microstrip line 19 are all equal; and the physical widths of the third open stub 22, the fourth open stub 23, the fifth open stub 24, and the sixth open stub 25 are all equal. This facilitates the simplified design of the band-stop filter 1000.

[0041] (4) W1 = W2, W3 = 2 * W4 = 2 * W5, where W1 is the physical width of the first left open section 201, W2 is the physical width of the first microstrip line 12, W3 is the physical width of the third microstrip line 14, W4 is the physical width of the fifth microstrip line 16, and W5 is the physical width of the third open stub 22. This design simplifies the design of the band-stop filter 1000.

[0042] In some embodiments, the band-stop filter 1000 is designed on a circuit board with a dielectric constant of 3.38, a dielectric loss of 0.0022, and a thickness of 0.813 mm. The overall dimensions of the circuit board are 23.0 mm * 12.5 mm. It is understood that the dielectric constant, dielectric loss, thickness, and dimensions of the circuit board are not limited to the above values ​​and can be adjusted according to requirements. Assumption: L 1H L is the physical length of the first left-hand open section 201. 1V L1 is the physical length of the second left open section 202, L2 is the physical length of the first microstrip line 12, L3 is the physical length of the third microstrip line 14, L4 is the physical length of the fourth microstrip line 15, L5 is the physical length of the fifth microstrip line 16, L6 is the physical length of the seventh microstrip line 18, L7 is the physical length of the third open stub 22, and L8 is the physical length of the fifth open stub 24.

[0043] As we know from basic microwave knowledge, synchronously changing L by the same amount 1H L 1V The values ​​of L2, L3, L4, L5, L6, L7, and L8 can be inversely linearly adjusted to control the operating frequency range of the stopband of the band-stop filter 1000. Therefore, there are only two parameters that affect the performance of the band-stop filter 1000, namely W1 and W3.

[0044] In some typical embodiments, one set of optimized dimensional parameters is: L 1H =7.9mm, L 1V =0.9mm, L2=8.8mm, L3=6.0mm, L4=5.1mm, L5=9.6mm, L6=9.6mm, L7=3.5mm, L8=4.4mm, W1=W2=0.1mm, W3=2W4=2W5=1.4mm. The simulation results of the band-stop filter 1000 designed with the above parameters are as follows: Figure 3 As shown in the figure, the stopband range with isolation greater than 20dB is from 1.934GHz to 8.588GHz, the stopband center frequency is 5.261GHz, the absolute bandwidth is 6.654GHz, and the relative bandwidth is 126.5%. Furthermore, there are three transmission zeros within the stopband, located at 2.502GHz, 5.508GHz, and 8.264GHz. Adjacent to the stopband are two passbands, each containing five transmission poles located at 0GHz, 0.443GHz, 9.525GHz, 10.589GHz, and 11.707GHz. These three transmission zeros and poles not only ensure the high isolation characteristics of the stopband and the low insertion loss and flatness of the passband, but also guarantee the high selectivity of the 1000 sidebands of the band-stop filter. It can be understood that the parameter L... 1H L 1V L2, L3, L4, L5, L6, L7, L8, W1, W2, W3, W4 and W5 are not limited to the above values ​​and can be adjusted according to needs.

[0045] In this embodiment of the invention, the topology 100 includes an input terminal 10, an output terminal 11, a first microstrip line 12, a second microstrip line 13, a third microstrip line 14, a fourth microstrip line 15, a fifth microstrip line 16, a sixth microstrip line 17, a seventh microstrip line 18, an eighth microstrip line 19, a first open-circuit stub 20, a second open-circuit stub 21, a third open-circuit stub 22, a fourth open-circuit stub 23, a fifth open-circuit stub 24, and a sixth open-circuit stub 25. With the straight line containing the third microstrip line 14 and the fourth microstrip line 15 as the axis, the first microstrip line 12 and the second microstrip line 13 are symmetrically arranged, the input terminal 10 and the output terminal 11 are symmetrically arranged, and the first open-circuit stub 20 and the second open-circuit stub 25 are... The stub 21 is symmetrically arranged, the fifth microstrip line 16 and the sixth microstrip line 17 are symmetrically arranged, the third open-circuit stub 22 and the fourth open-circuit stub 23 are symmetrically arranged, the seventh microstrip line 18 and the eighth microstrip line 19 are symmetrically arranged, and the fifth open-circuit stub 24 and the sixth open-circuit stub 25 are symmetrically arranged. The first open-circuit stub 20 and the second open-circuit stub 21 are bent, making the topology 100 compact. This is beneficial for the small size and simplified design of the band-stop filter 1000. Based on the topology 100, the band-stop filter 1000 only needs to be designed with two parameters to have the characteristics of wide bandwidth, high selectivity and low insertion loss in the passband.

[0046] The present invention also provides an embodiment of a communication device, the communication device including the above-mentioned band-stop filter 1000. The function and structure of the band-stop filter 1000 can be referred to the above embodiment, and will not be repeated here.

[0047] It should be noted that while the preferred embodiments of the present invention are given in the specification and accompanying drawings, the present invention 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 the present invention; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of the present invention. 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 the present invention 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, comprises: 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, an eighth microstrip line, a first open-circuit stub, a second open-circuit stub, a third open-circuit stub, a fourth open-circuit stub, a fifth open-circuit stub and a sixth open-circuit stub; wherein a first end of the first microstrip line and one end of the first open-circuit stub are both connected to the input end, a first end of the second microstrip line and one end of the second open-circuit stub are both connected to the output end, a second end of the first microstrip line, a second end of the second microstrip line, a first end of the third microstrip line and a first end of the fourth microstrip line are commonly connected, a first end of the fifth microstrip line, a second end of the third microstrip line and a first end of the sixth microstrip line are commonly connected, a second end of the fifth microstrip line is connected to one end of the third open-circuit stub, a second end of the sixth microstrip line is connected to one end of the fourth open-circuit stub, a first end of the seventh microstrip line, a second end of the fourth microstrip line and a first end of the eighth microstrip line are commonly connected, a second end of the seventh microstrip line is connected to one end of the fifth open-circuit stub, and a second end of the eighth microstrip line is connected to one end of the sixth open-circuit stub; the first open-circuit stub is bent to form a first left open-circuit part and a second left open-circuit part, a first end of the first left open-circuit part is connected to the input end, and a second end of the first left open-circuit part is connected to one end of the second left open-circuit part; the second open-circuit stub is bent to form a first right open-circuit part and a second right open-circuit part, a first end of the first right open-circuit part is connected to the output end, and a second end of the first right open-circuit part is connected to one end of the second right open-circuit part; The topologies satisfy: the characteristic impedance of the first microstrip line, the characteristic impedance of the second microstrip line, the characteristic impedance of the first open stub, and the characteristic impedance of the second open stub are all Z 1. The characteristic impedance of the third microstrip line and the characteristic impedance of the fourth microstrip line are both Z 2. The characteristic impedance of the fifth microstrip line, the characteristic impedance of the sixth microstrip line, the characteristic impedance of the seventh microstrip line, the characteristic impedance of the eighth microstrip line, the characteristic impedance of the third open stub, the characteristic impedance of the fourth open stub, the characteristic impedance of the fifth open stub, and the characteristic impedance of the sixth open stub are all Z 2.

2. The topology structure according to claim 1, wherein: the third microstrip line and the fourth microstrip line are on the same straight line, the first microstrip line and the second microstrip line are symmetrically arranged about the straight line as an axis, the input end and the output end are symmetrically arranged, the first open-circuit stub and the second open-circuit stub are symmetrically arranged, the fifth microstrip line and the sixth microstrip line are symmetrically arranged, the third open-circuit stub and the fourth open-circuit stub are symmetrically arranged, the seventh microstrip line and the eighth microstrip line are symmetrically arranged, and the fifth open-circuit stub and the sixth open-circuit stub are symmetrically arranged.

3. The topology structure according to claim 2, wherein: the first microstrip line is perpendicular to the third microstrip line, the fifth microstrip line, the seventh microstrip line and the first microstrip line are parallel, the third open-circuit stub, the fifth open-circuit stub and the third microstrip line are parallel, the first left open-circuit part is parallel to the first microstrip line, and the second left open-circuit part is perpendicular to the first left open-circuit part.

4. The topology of claim 1, wherein, The topology satisfies: Θ 1= Θ 2= Θ 9= Θ 10 , Θ 11 + Θ 5= Θ 12 + Θ 6, Θ 13 + Θ 7= Θ 14 + Θ 8 The Θ 1 is an electrical length of a first microstrip line, the Θ 2 is an electrical length of a second microstrip line, the Θ 5 is an electrical length of a fifth microstrip line, the Θ 6 is an electrical length of a sixth microstrip line, the Θ 7 is an electrical length of a seventh microstrip line, the Θ 8 is an electrical length of an eighth microstrip line, the Θ 9 is an electrical length of a first open-circuited stub, the Θ 10 is an electrical length of a second open-circuited stub, the Θ 11 is an electrical length of a third open-circuited stub, the Θ 12 is an electrical length of a fourth open-circuited stub, the Θ 13 is an electrical length of a fifth open-circuited stub, the Θ 14 is an electrical length of a sixth open-circuited stub.

5. The topology of claim 4, wherein, The topology satisfies: Θ 3+ Θ 11 + Θ 5= Θ 4+ Θ 13 + Θ 7 The Θ 3 is the electrical length of a third microstrip line, the Θ 4 is the electrical length of a fourth microstrip line.

6. A band reject filter characterized by, comprises the topology structure according to any one of claims 1-5.

7. The band-stop filter according to claim 6, wherein: electrical lengths of the first microstrip line, the second microstrip line, the first open-circuit stub and the second open-circuit stub are all one-quarter of a wavelength corresponding to a center frequency of a stop band of the band-stop filter.

8. A communication device, characterized by comprises the band-stop filter according to any one of claims 6-7.

Images