Design method of high-order ultra-wideband filter and terminal

Abstract

The application provides a design method and a terminal of a high-order ultra-wideband filter, comprising: obtaining the number of transmission poles and performance parameters of the filter; obtaining a corresponding topological structure according to the number of transmission poles of the filter, and obtaining a corresponding structure transmission characteristic function according to the topological structure; calculating a corresponding target transmission characteristic function according to the performance parameters; and calculating characteristic impedance parameters of the topological structure according to the characteristics that the structure transmission characteristic function and the target transmission characteristic function are identical. Compared with the synthesis method of the prior art, the application establishes a direct mathematical relationship between the target transmission characteristic and the structure transmission characteristic of the filter, the characteristic parameters of the filter can be directly obtained through the target transmission characteristic, and there is no redundancy of the characteristic parameters, that is, the step of constantly approximating the target transmission characteristic by the structure transmission characteristic function is not needed, the tedious and lengthy digital calculation process is avoided, and thus the filter design process is simplified.

Description

Technical Field

[0001] This invention relates to the field of filter technology, and in particular to a design method and terminal for a high-order ultra-wideband filter. Background Technology

[0002] A filter is a frequency-selective device. It attenuates electrical signals within one or a few frequency ranges (bands) very little, allowing these signals to pass through smoothly; while it attenuates electrical signals in other frequency bands very much, thereby blocking these signals from passing through as much as possible.

[0003] Currently, the insertion attenuation method or the operating parameter method are commonly used for the synthesis design of passive filters. This design method includes three steps: (1) specifying an ideal attenuation characteristic; (2) approximating this characteristic with a realizable rational function; and (3) applying network synthesis theory to synthesize this function into a practical network. The actual characteristics of the filter designed according to this synthesis method are very close to the pre-specified characteristics. However, this synthesis method requires tedious and lengthy numerical calculations and cannot directly obtain the design parameters from the pre-specified filter performance parameters. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a design method and terminal for a high-order ultra-wideband filter, thereby simplifying the filter design process.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A design method for a high-order ultrawideband filter includes the following steps:

[0007] S1. Obtain the number of transmission poles and performance parameters of the filter;

[0008] S2. Obtain the corresponding topology based on the number of transmission poles of the filter, and obtain the corresponding structural transmission characteristic function based on the topology;

[0009] S3. Calculate the corresponding target transmission characteristic function based on the performance parameters;

[0010] S4. Based on the fact that the structural transmission characteristic function and the target transmission characteristic function are identical, calculate the characteristic impedance parameters of the topology.

[0011] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows:

[0012] A design terminal for a high-order ultrawideband filter includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it performs the following steps:

[0013] S1. Obtain the number of transmission poles and performance parameters of the filter;

[0014] S2. Obtain the corresponding topology based on the number of transmission poles of the filter, and obtain the corresponding structural transmission characteristic function based on the topology;

[0015] S3. Calculate the corresponding target transmission characteristic function based on the performance parameters;

[0016] S4. Based on the fact that the structural transmission characteristic function and the target transmission characteristic function are identical, calculate the characteristic impedance parameters of the topology.

[0017] The beneficial effects of this invention are as follows: Based on the basic principle of the synthesis method, the target transmission characteristic is predetermined, and then an implementable structural transmission characteristic function is used to approximate this target transmission characteristic. Compared with the synthesis method of the prior art, this invention establishes a direct mathematical relationship between the target transmission characteristic and the structural transmission characteristic of the filter. The characteristic impedance parameter uniquely corresponding to the topology can be directly obtained through the target transmission characteristic, and there is no redundancy of the characteristic impedance parameter. That is, there is no need to perform the step of continuously approximating the target transmission characteristic with the structural transmission characteristic function, thus avoiding the tedious and lengthy digital calculation process and simplifying the filter design process. Attached Figure Description

[0018] Figure 1 A flowchart illustrating the steps of a design method for a high-order ultrawideband filter provided in an embodiment of the present invention;

[0019] Figure 2 The topology transmission characteristic curves (N=1) for different ripples when N is an odd number are provided in the embodiments of the present invention.

[0020] Figure 3 The topology transmission characteristic curves (N=1) for different bandwidths when N is an odd number are provided in the embodiments of the present invention.

[0021] Figure 4 The topology transmission characteristic curves (N=2) are provided for the embodiment of the present invention when N is an even number and the structure transmission characteristics correspond to different ripples.

[0022] Figure 5 The topology transmission characteristic curves (N=2) for different bandwidths when N is an even number are provided in the embodiments of the present invention.

[0023] Figure 6 This is a schematic diagram of a topological structure when N is an odd number, provided as an embodiment of the present invention.

[0024] Figure 7 This is a schematic diagram of a topological structure when N is an even number, provided by an embodiment of the present invention.

[0025] Figure 8 The equivalent transformation diagram of the second-order narrowband Chebyshev bandpass filter LC circuit and parallel lines provided in the embodiments of the present invention;

[0026] Figure 9 Equivalent transformation diagram of parallel LC circuit and short-circuit stub provided in embodiments of the present invention;

[0027] Figure 10 An LC circuit for a (3N+2) order narrowband Chebyshev bandpass filter;

[0028] Figure 11 A schematic diagram of the design terminal for a high-order ultra-wideband filter provided in an embodiment of the present invention;

[0029] Label Explanation:

[0030] 1. A design terminal for a high-order ultra-wideband filter; 2. Memory; 3. Processor. Detailed Implementation

[0031] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0032] Please refer to Figure 1 This invention provides a design method for a high-order ultra-wideband filter, comprising:

[0033] S1. Obtain the number of transmission poles and performance parameters of the filter;

[0034] S2. Obtain the corresponding topology based on the number of transmission poles of the filter, and obtain the corresponding structural transmission characteristic function based on the topology;

[0035] S3. Calculate the corresponding target transmission characteristic function based on the performance parameters;

[0036] S4. Based on the fact that the structural transmission characteristic function and the target transmission characteristic function are identical, calculate the characteristic impedance parameters of the topology.

[0037] As can be seen from the above description, the beneficial effects of the present invention are as follows: Based on the basic principle of the synthesis method, the target transmission characteristic is predetermined, and then an implementable structural transmission characteristic function is used to approximate this target transmission characteristic; compared with the synthesis method of the prior art, the present invention establishes a direct mathematical relationship between the target transmission characteristic and the structural transmission characteristic of the filter. The characteristic impedance parameter uniquely corresponding to the topology can be directly obtained through the target transmission characteristic, and there is no redundancy of the characteristic impedance parameter. That is, there is no need to perform the step of continuously approximating the target transmission characteristic with the structural transmission characteristic function, thus avoiding the tedious and lengthy digital calculation process and simplifying the filter design process.

[0038] Furthermore, the number of transmission poles is represented as 3N+2, and the topology includes odd-numbered topology and even-numbered topology;

[0039] S2 includes:

[0040] Determine whether N in the number of transmission poles is odd or even;

[0041] If N is odd, then an odd-numbered topology is obtained, and the odd-numbered structure transmission characteristic function is calculated based on the odd-numbered topology.

[0042] If N is even, then an even-numbered topology is obtained, and the even-numbered structure transmission characteristic function is calculated based on the even-numbered topology.

[0043] As described above, the number of transmission poles determines the specific structure and transmission characteristics of the filter. Therefore, different topologies need to be selected for different numbers of transmission poles to ensure that the actual characteristics of the final filter are consistent with the pre-defined transmission characteristics, thereby improving the design effect of the filter.

[0044] Furthermore, the calculation of the odd-number topology transmission characteristic function based on the odd-number topology specifically involves:

[0045]

[0046] Wherein, θ is the electrical length of short-circuited branches and parallel lines in an odd-numbered topology;

[0047]

[0048] The This is a functional relationship between the characteristic impedance parameters of the odd-numbered topology; The characteristic impedance parameter of the odd-numbered topology;

[0049] The specific steps for calculating the even-number topology transmission characteristic function are as follows:

[0050]

[0051] Wherein, θ is the electrical length of short-circuit stubs and parallel lines in an even-numbered topology;

[0052]

[0053] The This is a functional relationship between the characteristic impedance parameters of the even-numbered topology and... is the characteristic impedance parameter of the even-numbered topology.

[0054] As can be seen from the above description, a mathematical relationship between the structural transmission characteristics and its characteristic impedance parameters can be established based on the topology, that is, the corresponding structural transmission characteristic formula can be obtained based on the characteristic impedance parameters.

[0055] Furthermore, the target transmission characteristic function includes odd-numbered target transmission characteristic functions and even-numbered target transmission characteristic functions;

[0056] Specifically, S3 is:

[0057] Calculate the odd-target transmission characteristic function corresponding to the number of transmission zeros of the filter based on the performance parameters:

[0058]

[0059] in,

[0060] Alternatively, the even-number target transmission characteristic function corresponding to the number of transmission zeros of the filter can be calculated based on the performance parameters:

[0061]

[0062] in,

[0063] The f(ε,θ) c ) represents the functional relationship between the performance parameters.

[0064] As described above, obtaining the predefined target transmission characteristics and organizing and summarizing them enables the mathematical identity between the target transmission characteristics and the structural transmission characteristics, facilitating the direct establishment of a mathematical relationship between the two in the later stages and simplifying the mathematical calculation process.

[0065] Furthermore, S4 specifically includes:

[0066] Let the structural transmission characteristic function be equal to the target transmission characteristic function. Based on the basic principle of equality, establish a system of equations with the characteristic impedance parameter as an unknown and the performance parameter as a known. Solve the system of equations to obtain the value of the characteristic impedance parameter.

[0067] As described above, the structural transmission characteristics are based on the mathematical relationship of the characteristic impedance parameters of the topology, while the target transmission characteristics are based on the mathematical relationship of the predefined filter performance parameters. Therefore, by making them equal, the mathematical relationship between the filter performance parameters and the topology characteristic parameters can be obtained. When the filter performance parameter values ​​are determined, the corresponding characteristic impedance parameters can be directly obtained based on their identity relationship, without the need to continuously try to approximate the parameters, simplifying the mathematical calculation process and improving the design efficiency of the filter.

[0068] Please refer to Figure 11 Another embodiment of the present invention provides a design terminal for a high-order ultra-wideband filter, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it performs the following steps:

[0069] S1. Obtain the number of transmission poles and performance parameters of the filter;

[0070] S2. Obtain the corresponding topology based on the number of transmission poles of the filter, and obtain the corresponding structural transmission characteristic function based on the topology;

[0071] S3. Calculate the corresponding target transmission characteristic function based on the performance parameters;

[0072] S4. Based on the fact that the structural transmission characteristic function and the target transmission characteristic function are identical, calculate the characteristic impedance parameters of the topology.

[0073] As can be seen from the above description, the beneficial effects of the present invention are as follows: Based on the basic principle of the synthesis method, the target transmission characteristic is predetermined, and then an implementable structural transmission characteristic function is used to approximate this target transmission characteristic; compared with the synthesis method of the prior art, the present invention establishes a direct mathematical relationship between the target transmission characteristic and the structural transmission characteristic of the filter. The characteristic impedance parameter uniquely corresponding to the topology can be directly obtained through the target transmission characteristic, and there is no redundancy of the characteristic impedance parameter. That is, there is no need to perform the step of continuously approximating the target transmission characteristic with the structural transmission characteristic function, thus avoiding the tedious and lengthy digital calculation process and simplifying the filter design process.

[0074] Furthermore, the number of transmission poles is represented as 3N+2, and the topology includes odd-numbered topology and even-numbered topology;

[0075] S2 includes:

[0076] Determine whether N in the number of transmission poles is odd or even;

[0077] If N is odd, then an odd-numbered topology is obtained, and the odd-numbered structure transmission characteristic function is calculated based on the odd-numbered topology.

[0078] If N is even, then an even-numbered topology is obtained, and the even-numbered structure transmission characteristic function is calculated based on the even-numbered topology.

[0079] As described above, the number of transmission poles determines the specific structure and transmission characteristics of the filter. Therefore, different topologies need to be selected for different numbers of transmission poles to ensure that the actual characteristics of the final filter are consistent with the pre-defined transmission characteristics, thereby improving the design effect of the filter.

[0080] Furthermore, the calculation of the odd-number topology transmission characteristic function based on the odd-number topology specifically involves:

[0081]

[0082] Wherein, θ is the electrical length of short-circuited branches and parallel lines in an odd-numbered topology;

[0083]

[0084] The This is a functional relationship between the characteristic impedance parameters of the odd-numbered topology; The characteristic impedance parameter of the odd-numbered topology;

[0085] The specific steps for calculating the even-number topology transmission characteristic function are as follows:

[0086]

[0087] Wherein, θ is the electrical length of short-circuit stubs and parallel lines in an even-numbered topology;

[0088]

[0089] The This is a functional relationship between the characteristic impedance parameters of the even-numbered topology and... is the characteristic impedance parameter of the even-numbered topology.

[0090] As can be seen from the above description, a mathematical relationship between the structural transmission characteristics and its characteristic impedance parameters can be established based on the topology, that is, the corresponding structural transmission characteristic formula can be obtained based on the characteristic impedance parameters.

[0091] Furthermore, the target transmission characteristic function includes odd-numbered target transmission characteristic functions and even-numbered target transmission characteristic functions;

[0092] Specifically, S3 is:

[0093] Calculate the odd-target transmission characteristic function corresponding to the number of transmission zeros of the filter based on the performance parameters:

[0094]

[0095] in,

[0096] Alternatively, the even-number target transmission characteristic function corresponding to the number of transmission zeros of the filter can be calculated based on the performance parameters:

[0097]

[0098] in,

[0099] The f(ε,θ) c ) represents the functional relationship between the performance parameters.

[0100] As described above, obtaining the predefined target transmission characteristics and organizing and summarizing them enables the mathematical identity between the target transmission characteristics and the structural transmission characteristics, facilitating the direct establishment of a mathematical relationship between the two in the later stages and simplifying the mathematical calculation process.

[0101] Furthermore, S4 specifically includes:

[0102] Let the structural transmission characteristic function be equal to the target transmission characteristic function. Based on the basic principle of equality, establish a system of equations with the characteristic impedance parameter as an unknown and the performance parameter as a known. Solve the system of equations to obtain the value of the characteristic impedance parameter.

[0103] As described above, the structural transmission characteristic is a mathematical relationship based on the characteristic impedance parameters of the topology, while the target transmission characteristic is a mathematical relationship based on the predefined filter performance parameters. By setting the structural transmission characteristic equal to the target transmission characteristic, the mathematical relationship between the filter performance parameters and the topology characteristic parameters can be obtained. When the filter performance parameter values ​​are determined, the corresponding characteristic parameters can be directly obtained based on their mathematical relationship, eliminating the need for continuous parameter approximation, simplifying the mathematical calculation process, and improving the filter design efficiency.

[0104] This invention provides a design method and terminal for a high-order ultra-wideband filter, which can be applied to the manufacturing of ultra-wideband filters, simplifying the design process. The following specific embodiments illustrate this method:

[0105] Please refer to Figures 1 to 10 Embodiment 1 of the present invention is as follows:

[0106] A design method for a high-order ultrawideband filter includes:

[0107] S1. Obtain the number of transmission poles and performance parameters of the filter;

[0108] S2. Obtain the corresponding topology based on the number of transmission poles of the filter, and obtain the corresponding structure transmission characteristic function based on the topology; wherein, the number of transmission poles is represented as 3N+2, and the topology includes odd-numbered topologies and even-numbered topologies.

[0109] Specifically, S2 includes:

[0110] S21. Determine whether N in the number of transmission poles is odd or even.

[0111] S22. If N is an odd number, then obtain the odd topology and calculate the odd structure transmission characteristic function based on the odd topology.

[0112] Specifically, S22 is:

[0113]

[0114] In the formula, θ is the electrical length of short-circuited branches and parallel lines in an odd-numbered topology;

[0115]

[0116] The This is a functional relationship between the characteristic impedance parameters of the odd-numbered topology; is the characteristic impedance parameter of the odd-numbered topology.

[0117] S23. If N is even, then obtain the even topology and calculate the even structure transmission characteristic function based on the even topology.

[0118] Specifically, S23 is:

[0119]

[0120] In the formula, θ is the electrical length of short-circuited branches and parallel lines in an even-numbered topology;

[0121]

[0122] The This is a functional relationship between the characteristic impedance parameters of the even-numbered topology and... is the characteristic impedance parameter of the even-numbered topology.

[0123] In this embodiment, both the odd-numbered topology and the even-numbered topology are symmetrical structures.

[0124] Specifically, since odd-numbered topologies are symmetrical, their transmission characteristics can be expressed as follows:

[0125]

[0126] in,

[0127]

[0128] In the formula, B T and C T These are the elements of the ABCD matrix of this topology. This topology can be obtained by multiplying the ABCD matrices of its various cascaded structures:

[0129]

[0130]

[0131] in,

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140] Based on the calculation formula of the ABCD matrix above, its B... T and C T Substituting the array elements into formula (2), and after a series of calculations, the transmission characteristic function of the odd-numbered structure can be obtained as follows:

[0141]

[0142] Here, N is an odd number, and

[0143]

[0144] Similarly, since even-numbered topologies are symmetric, their transmission characteristics can also be expressed by formulas (1) and (2). In this case, the ABCD matrix of the topology can be calculated using the following formula:

[0145]

[0146]

[0147] in,

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156] Based on the calculation formula of the ABCD matrix above, its B... T and C T Substituting the array elements into formula (2), and after a series of calculations, the transmission characteristics of the even-numbered structure can be obtained as follows:

[0157]

[0158] Here, N is an even number, and

[0159]

[0160] S3. Calculate the corresponding target transmission characteristic function based on the performance parameters; wherein, the target transmission characteristic function includes odd-numbered target transmission characteristic functions and even-numbered target transmission characteristic functions;

[0161] Specifically, S3 is:

[0162] Calculate the odd-target transmission characteristic function corresponding to the number of transmission zeros of the filter based on the performance parameters:

[0163]

[0164] in,

[0165] Alternatively, the even-number target transmission characteristic function corresponding to the number of transmission zeros of the filter can be calculated based on the performance parameters:

[0166]

[0167] in,

[0168] The f(ε,θ) c ) represents the functional relationship between the performance parameters.

[0169] In this embodiment, the target transmission characteristic of the (3N+2)th order Chebyshev bandpass filter can be expressed as:

[0170]

[0171] in,

[0172] F L =εcos(nφ+qξ) (6)

[0173] In the prior art, formulas (5) and (6) can represent the transmission characteristics of Chebyshev bandpass filters with arbitrary bandwidth and ripple. If both odd-numbered and even-numbered topologies can be used to design Chebyshev bandpass filters with arbitrary bandwidth and ripple, then the transmission characteristics of the odd-numbered structure and the even-numbered structure must maintain an identity with formula (6). Therefore, n and q must be (N+1) and (2N+1) respectively.

[0174] When N is odd, its odd-target transmission characteristic function can be expressed as:

[0175]

[0176] in

[0177]

[0178] When N is even, its even-number target transmission characteristics can be expressed as:

[0179]

[0180] in,

[0181]

[0182] The f(ε,θ) c ) represents the functional relationship between the performance parameters.

[0183] S4. Based on the fact that the structural transmission characteristic function and the target transmission characteristic function are identical, calculate the characteristic impedance parameters of the topology.

[0184] Specifically, S4 is:

[0185] Let the structural transmission characteristic function be equal to the target transmission characteristic function. Based on the basic principle of equality, establish a system of equations with the characteristic impedance parameter as an unknown and the performance parameter as a known. Solve the system of equations to obtain the value of the characteristic impedance parameter.

[0186] When the filter performance ε and FBW / θ c Given that the coefficients of the function θ in formulas (7) and (8) are... or It is a constant. Therefore, when N is odd, let the odd-numbered structure transmission characteristic (i.e., formula (3)) be equal to the odd-numbered target transmission characteristic (i.e., formula (7)). According to the basic principle of equality, the coefficients in formula (3) are constant. To be related to the coefficients in formula (7) If they remain consistent, then:

[0187] Depend on

[0188]

[0189] g'0=f0(ε,θ c )

[0190] have to

[0191]

[0192] By analogy, establish a system of (3N+3) / 2 equations containing (3N+3) / 2 unknowns;

[0193] Similarly, when N is even, let the transmission characteristics of the even-number structure (i.e., formula (4)) be equal to the transmission characteristics of the even-number target (i.e., formula (8)). According to the basic principle of equality, the coefficients in formula (4) To be related to the coefficients in formula (8) By keeping each equation consistent, a system of (3N+4) / 2 equations containing (3N+4) / 2 unknowns is established.

[0194] By solving the system of equations for both odd and even N, the unique solution to the characteristic parameter Z of the filter can be obtained.

[0195] To verify the feasibility of the design method, Tables 1 and 2 below show the characteristic impedance values ​​of Chebyshev bandpass filters with different ripple and bandwidth when N is equal to 1 and 2, respectively.

[0196] Table 1. Characteristic impedance values ​​corresponding to different ripple and bandwidth when N=1.

[0197] FBW (%) 133.3 133.3 133.3 100 66.6 <![CDATA[L A (dB)]]> 0.02 0.06 0.1 0.1 0.1 <![CDATA[θ c ]]> 30° 30° 30° 45° 60° ε 0.068 0.118 0.153 0.153 0.153 <![CDATA[Z1]]> 54.4 52.4 52.6 26.2 13.4 Z 0 oo(Ω) 12.9 16.3 18.3 35.6 70.7 Z 0 oe(Ω) 107.7 116.3 122.2 134.4 165.5

[0198] Table 2 Characteristic impedance values ​​corresponding to different ripple and bandwidth when N=2

[0199] FBW (%) 133.3 133.3 133.3 100 66.6 <![CDATA[L A (dB)]]> 0.02 0.06 0.1 0.1 0.1 <![CDATA[θ c ]]> 30° 30° 30° 45° 60° ε 0.068 0.118 0.153 0.153 0.153 <![CDATA[Z1]]> 44.35 44.99 45.8 23.3 12.2 Z 0 oo(Ω) 14.31 17.57 19.7 37.7 74.1 Z 0 oe(Ω) 107.8 116.62 122.8 135.6 168.4 Z 1 oo(Ω) 24.62 27.5 29.5 52.3 95.1 Z 1 oe(Ω) 107.8 114.7 120.8 134.7 171.4

[0200] According to Table 2, when N=2, the performance parameters of the ultra-wideband filter to be designed are: when FBW=133.3%, θ c =30°, L A =0.02dB, ε=0.068; Substituting the above performance parameters into the even-numbered target transmission characteristics, where the coefficients g0, g1, and g2 in the even-numbered target transmission characteristics are all constants, such that g0=g'0, g1=g1', g2=g'2, then:

[0201]

[0202]

[0203]

[0204] Solving the above system of equations yields Z1 = 54.4 Ω.

[0205] Substituting the characteristic impedance values ​​in Table 1 into the corresponding odd-numbered structure transmission characteristics, the transmission characteristic curves are as follows: Figure 2 and Figure 3 As shown.

[0206] Substituting the characteristic impedance values ​​from Table 2 into the corresponding even-numbered structure transmission characteristics, the transmission characteristic curves are as follows: Figure 4 and Figure 5 As shown.

[0207] In this embodiment, the topology includes multiple parallel coupled lines, multiple short-circuited stubs, and input / output feeders; refer to Figure 6 The odd-numbered topology is symmetrical about a short-circuit branch located in the middle, with the vertical line as the center; refer to Figure 7 The even-numbered topology is symmetrically structured with a horizontal straight line used for parity-even modulus analysis, positioned in the middle as a parallel coupling line. For example... Figure 8 As shown, the above topology is obtained by performing an equivalent transformation based on the LC circuit of a (3N+2) order narrowband Chebyshev bandpass filter. The equivalent transformation relationship is as follows: Figure 9 and Figure 10As shown. Since the above topology is derived from the LC circuit of a narrowband Chebyshev bandpass filter, it cannot be determined whether the above topology is equally applicable to the design of a broadband Chebyshev bandpass filter. To verify whether the above topology is equally applicable to the design of a broadband Chebyshev bandpass filter, the target transmission characteristic used in this design method is a Chebyshev bandpass filter with arbitrary bandwidth and ripple. By calculating, organizing, and summarizing the structural transmission characteristics, it is determined whether the structural transmission characteristics of the topology can be consistent with the target transmission characteristics. If so, it indicates that the topology can be applied to a Chebyshev bandpass filter with arbitrary bandwidth and ripple.

[0208] Please refer to Figure 11 Embodiment two of the present invention is as follows:

[0209] A design terminal 1 for a high-order ultra-wideband filter includes a memory 2, a processor 3, and a computer program stored in the memory 2 and running on the processor 3. When the processor 3 executes the computer program, it implements any of the steps in Embodiment 1.

[0210] In summary, the present invention provides a design method and terminal for a high-order ultra-wideband filter. Based on the fundamental principles of the synthesis method, it predefines the target transmission characteristics and then approximates these characteristics using an implementable structural transmission characteristic function. Compared to the synthesis method in existing technologies, the present invention designs corresponding topologies based on the number of transmission poles of the filter, thereby directly designing the filter based on the topology. Simultaneously, it establishes a direct mathematical relationship between the filter's target transmission characteristics and structural transmission characteristics. The structural transmission characteristics are mathematical expressions based on the characteristic parameters of the topology, while the target transmission characteristics are mathematical expressions based on the predetermined filter performance parameters. Therefore, by making them equal, the mathematical relationship between the filter performance parameters and the topology characteristic parameters can be obtained. When the filter performance parameter values ​​are determined, the corresponding characteristic parameters can be directly obtained based on their mathematical relationship, eliminating the need for continuous parameter approximation, simplifying the mathematical calculation process, improving filter design efficiency, and simplifying the filter design method. Furthermore, this design method is applicable not only to the design of narrowband Chebyshev bandpass filters but also to the design of wideband filters. That is, the design method provided by the present invention can be used to design Chebyshev bandpass filters with arbitrary bandwidth and ripple.

[0211] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A design method for a high-order ultrawideband filter, characterized in that, include: S1. Obtain the number of transmission poles and performance parameters of the filter; S2. Obtain the corresponding topology based on the number of transmission poles of the filter, and obtain the corresponding structural transmission characteristic function based on the topology; S3. Calculate the corresponding target transmission characteristic function based on the performance parameters; S4. Based on the fact that the structural transmission characteristic function and the target transmission characteristic function are identical, calculate the characteristic impedance parameters of the topology; The number of transmission poles is represented as 3N+2, and the topology includes odd-numbered topology and even-numbered topology; S2 includes: Determine whether N in the number of transmission poles is odd or even; If N is odd, then an odd-numbered topology is obtained, and the odd-numbered structure transmission characteristic function is calculated based on the odd-numbered topology. If N is even, then obtain the even-number topology and calculate the even-number structure transmission characteristic function based on the even-number topology; The calculation of the odd-structure transmission characteristic function based on the odd-numbered topology is specifically as follows: ； Wherein, θ is the electrical length of short-circuited branches and parallel lines in an odd-numbered topology; , The This is a functional relationship between the characteristic impedance parameters of the odd-numbered topology; The characteristic impedance parameter of the odd-numbered topology; The specific steps for calculating the even-number topology transmission characteristic function are as follows: ； Wherein, θ is the electrical length of short-circuit stubs and parallel lines in an even-numbered topology; , The This is a functional relationship between the characteristic impedance parameters of the even-numbered topology and... The characteristic impedance parameter of the even-numbered topology; The target transmission characteristic function includes odd-numbered target transmission characteristic functions and even-numbered target transmission characteristic functions; Specifically, S3 is: Calculate the odd-target transmission characteristic function corresponding to the number of transmission zeros of the filter based on the performance parameters: ； in, ; Alternatively, the even-number target transmission characteristic function corresponding to the number of transmission zeros of the filter can be calculated based on the performance parameters: ； in, ; The This is a functional relationship with respect to the performance parameters.

2. The design method of a high-order ultrawideband filter according to claim 1, characterized in that, Specifically, S4 is: Let the structural transmission characteristic function be equal to the target transmission characteristic function. Based on the basic principle of equality, establish a system of equations with the characteristic impedance parameter as an unknown and the performance parameter as a known. Solve the system of equations to obtain the value of the characteristic impedance parameter.

3. A design terminal for a high-order ultra-wideband filter, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it performs the following steps: S1. Obtain the number of transmission poles and performance parameters of the filter; S2. Obtain the corresponding topology based on the number of transmission poles of the filter, and obtain the corresponding structural transmission characteristic function based on the topology; S3. Calculate the corresponding target transmission characteristic function based on the performance parameters; S4. Based on the fact that the structural transmission characteristic function and the target transmission characteristic function are identical, calculate the characteristic impedance parameters of the topology; The number of transmission poles is represented as 3N+2, and the topology includes odd-numbered topology and even-numbered topology; S2 includes: Determine whether N in the number of transmission poles is odd or even; If N is odd, then an odd-numbered topology is obtained, and the odd-numbered structure transmission characteristic function is calculated based on the odd-numbered topology. If N is even, then obtain the even-number topology and calculate the even-number structure transmission characteristic function based on the even-number topology; The calculation of the odd-structure transmission characteristic function based on the odd-numbered topology is specifically as follows: ； Wherein, θ is the electrical length of short-circuited branches and parallel lines in an odd-numbered topology; , The This is a functional relationship between the characteristic impedance parameters of the odd-numbered topology; The characteristic impedance parameter of the odd-numbered topology; The specific steps for calculating the even-number topology transmission characteristic function are as follows: ； Wherein, θ is the electrical length of short-circuit stubs and parallel lines in an even-numbered topology; , The This is a functional relationship between the characteristic impedance parameters of the even-numbered topology and... The characteristic impedance parameter of the even-numbered topology; The target transmission characteristic function includes odd-numbered target transmission characteristic functions and even-numbered target transmission characteristic functions; Specifically, S3 is: Calculate the odd-target transmission characteristic function corresponding to the number of transmission zeros of the filter based on the performance parameters: ； in, ; Alternatively, the even-number target transmission characteristic function corresponding to the number of transmission zeros of the filter can be calculated based on the performance parameters: ； in, ; The This is a functional relationship with respect to the performance parameters.

4. The design terminal for a high-order ultra-wideband filter according to claim 3, characterized in that, Specifically, S4 is: Let the structural transmission characteristic function be equal to the target transmission characteristic function. Based on the basic principle of equality, establish a system of equations with the characteristic impedance parameter as an unknown and the performance parameter as a known. Solve the system of equations to obtain the value of the characteristic impedance parameter.

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