A Method for High-Frequency Signal Transmission in a Pre-Branched Cable

Abstract

The present invention relates to the technical field of high-frequency signal transmission in pre-branched cables, and specifically to a high-frequency signal transmission method for pre-branched cables, comprising the following steps: constructing an asymmetric tapered chamfered branch structure; embedding a distributed absorbing layer; optimizing TDR feedback with topological constraints; three-dimensional conformal shielding waveguide conversion; joint iterative calibration; and high-frequency pre-branched cable collaborative closed-loop and standardization. The present invention adopts an asymmetric tapered chamfered branch structure to force the electromagnetic field to maintain the TEM mode on the main transmission path, effectively reducing modal distortion and improving the fidelity of signal transmission. By optimizing the chamfer angle and embedding a distributed absorbing layer, the reflection coefficient caused by impedance mutation at the branch point is synchronously reduced, and the influence of reflection and multipath effects on signal transmission is reduced. Through optimizing TDR feedback with topological constraints and three-dimensional conformal shielding waveguide conversion, the branch layout and shielding layer design are dynamically adjusted to improve signal transmission efficiency and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of high-frequency signal transmission in pre-branched cables, and particularly to a method for high-frequency signal transmission in pre-branched cables. Background Art

[0002] A pre-branched cable is a cable system with a pre-designed and installed branching structure, which is used to provide multiple branch points on a cable line in order to supply power or transmit signals to different devices or systems. Such a cable system is usually used in occasions where multiple branch points are required, such as power distribution inside buildings, data centers, communication base stations, etc.

[0003] The high-frequency signals in pre-branched cables refer to electrical signals with relatively high frequencies transmitted in pre-branched cables. These signals may be used in applications such as high-speed data transmission, wireless communication, radar systems, etc. High-frequency signals are prone to being affected by various factors during transmission, such as signal attenuation, reflection, multipath effects, etc. Therefore, special design and optimization methods are required to ensure the stable transmission of signals.

[0004] Generally, traditional cable design and selection will choose a suitable cable type and specification according to application requirements, design branch points on the cable, usually using simple right-angle or arc-shaped branch structures, transmit high-frequency signals through the cable and branch points to the target device, and receive and process the signals at the target device end. However, such traditional right-angle or arc-shaped branch structures are likely to cause modal conversion of the electromagnetic field, resulting in signal distortion and energy loss. The impedance mismatch at the branch point will cause reflected waves, and at the same time, multipath effects will cause signal interference and attenuation. High-frequency signals are prone to being interfered by environmental noise and other signals during transmission, resulting in a decline in signal quality. The traditional design of branch cables lacks a systematic optimization and standardization process, making it difficult to ensure the stability and reliability of signal transmission.

[0005] Based on this, the present invention provides a method for high-frequency signal transmission in pre-branched cables to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for high-frequency signal transmission in pre-branched cables, and solve the problems in the above background art that the traditional right-angle or arc-shaped branch structure is likely to cause modal conversion of the electromagnetic field, resulting in signal distortion and energy loss, the impedance mismatch at the branch point will cause reflected waves, and at the same time, multipath effects will cause signal interference and attenuation. High-frequency signals are prone to being interfered by environmental noise and other signals during transmission, resulting in a decline in signal quality. The traditional design of branch cables lacks a systematic optimization and standardization process, making it difficult to ensure the stability and reliability of signal transmission.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A method for high-frequency signal transmission in a pre-branched cable is provided, including the following steps:

[0009] S1. Construct an asymmetric gradient chamfered branch structure;

[0010] S2. Embed a distributed absorbing layer;

[0011] S3. Optimize the TDR feedback with topological constraints;

[0012] S4. Three-dimensional conformal shielding waveguide transformation;

[0013] S5. Joint iterative calibration;

[0014] S6. High-frequency pre-branched cable collaborative closed-loop and standardization.

[0015] As a preferred technical solution of the high-frequency signal transmission method in the pre-branched cable of the present invention, the implementation steps of step S1 are as follows:

[0016] S1.1. For mode conversion, adopt an asymmetric gradient chamfer geometry, introduce a continuous curvature transition at the branch point, make the curvature radius match the wavelength order of magnitude, and force the electromagnetic field to maintain the TEM mode on the main transmission path;

[0017] S1.2. By optimizing the chamfer angle to 45° - 60°, synchronously reduce the reflection coefficient caused by impedance mutation at the branch point, and the reflection energy attenuation ≥ 10 dB;

[0018] S1.3. Based on the wavelength in the 30 GHz millimeter-wave band , define the chamfer length: ;

[0019] Verify the field distribution convergence using HFSS full-wave simulation.

[0020] As a preferred technical solution of the high-frequency signal transmission method in the pre-branched cable of the present invention, the implementation steps of step S2 are as follows:

[0021] S2.1. Cover the surface of the conductor at the branch point with a nano-ferrite-graphene composite absorbing layer with a thickness ≤ 0.1 mm, actively absorb the energy of the higher-order mode through magnetoelectric coupling loss, the dielectric constant gradient ε_r of the absorbing layer gradually changes from 3.0 to 6.0, match the impedance between the branch point and the main trunk, and suppress the reflected wave generated by the discontinuous interface; S2.2. Deposit the absorbing layer on the surface of the copper conductor using the magnetron sputtering process to ensure no bubbles at the interface with the insulating layer.

[0022] As a preferred technical solution of the high-frequency signal transmission method in the pre-branched cable of the present invention, the implementation steps of step S3 are as follows:

[0023] S3.1. Measure the reflection peak position and amplitude of the branch cable through a time-domain reflectometer, inversely deduce the multipath reflection path length difference ΔL, and establish a reflection path topology map;

[0024] S3.2. Input the ΔL data into a topology optimization algorithm, constrain the branch point spacing to satisfy ΔL > λ / 2, break the reflection wave coherence condition, and use a genetic algorithm to iteratively adjust the branch layout so that the peak-to-peak value of the TDR reflection coefficient ≤ 0.05.

[0025] As a preferred technical solution of the high-frequency signal transmission method for the pre-branched cable of the present invention, the implementation steps of step S4 are as follows:

[0026] S4.1. Construct a three-dimensional metallized conformal shielding layer on the outer wall of the branch point, specifically copper plating plus conductive epoxy resin filling, to form a waveguide-like structure with a cut-off frequency higher than the working frequency band;

[0027] S4.2. Suppress the propagation of higher-order modes, seamlessly connect the shielding layer with the main trunk shielding, and use the waveguide characteristics to block the near-field coupling between branches and eliminate the energy source of multipath reflection;

[0028] S4.3. Use laser-induced electroless plating to achieve uniform metallization of complex surfaces, fill the joints with conductive glue, and the resistance ≤ 0.1 Ω / cm². As a preferred technical solution of the high-frequency signal transmission method for the pre-branched cable of the present invention, the implementation steps of step S5 are as follows:

[0029] S5.1. Take the chamfer curvature, absorber layer gradient, topological ΔL, and shielding cut-off frequency in the methods of steps S1 to S4 as joint variables, establish a multi-objective optimization function by comparing HFSS simulation and TDR measured data, as follows:

[0030] Objective 1. The energy ratio of the TEM mode ≥ 95% (S parameter |S11| ≤ -20 dB);

[0031] Objective 2. The intersymbol interference power ratio ≤ 5%;

[0032] S5.2. Use the covariance matrix adaptation evolution strategy (CMA-ES) to perform 10 to 20 rounds of iteration until convergence. As a preferred technical solution of the high-frequency signal transmission method for the pre-branched cable of the present invention, the implementation steps of step S6 are as follows:

[0033] S6.1. Process closed-loop verification and error tolerance calibration;

[0034] S6.2. Conduct multi-band compatibility verification;

[0035] S6.3. Solidify the key parameters and convert the production specifications, convert the optimized design variables into producible engineering parameters, and then construct cross-length adaptation rules.

[0036] As a preferred technical solution of the high-frequency signal transmission method in the pre-branched cable of the present invention, in step S6.1, the chamfer curvature, absorber layer gradient, and topology ΔL optimization results of step S5 are imported into the HFSS simulation model, compared with the S-parameters measured by TDR and the time-domain reflection waveform, and the allowable error tolerance is defined. If the tolerance is exceeded, local iteration of steps S1 to S5 is triggered.

[0037] As a preferred technical solution of the high-frequency signal transmission method in the pre-branched cable of the present invention, in step S6.2, three characteristic frequencies are selected within the target frequency band, and steps S1 to S5 are repeated for optimization to verify the parameter robustness.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] The present invention adopts an asymmetric tapered chamfer branching structure to force the electromagnetic field to maintain the TEM mode on the main transmission path, effectively reducing modal distortion and improving the fidelity of signal transmission. By optimizing the chamfer angle and embedding a distributed absorber layer, the reflection coefficient caused by impedance mutation at the branch point is synchronously reduced, and the influence of reflection and multipath effects on signal transmission is reduced. Through topology-constrained TDR feedback optimization and three-dimensional conformal shielding waveguide conversion, the branch layout and shielding layer design are dynamically adjusted to improve signal transmission efficiency and stability. Through joint iterative calibration and process closed-loop verification, the repeatability of the method and the accuracy of the parameters are ensured. At the same time, a cross-length adaptation rule and a production compatibility process conversion are constructed to improve production efficiency and product quality. In summary, the method of the present invention is particularly suitable for high-frequency signal transmission applications, including but not limited to millimeter-wave communication and high-speed data transmission, and can meet the high requirements of these applications for signal transmission performance and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a flowchart of the high-frequency signal transmission method in the pre-branched cable of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Embodiment

[0042] Please refer to Figure 1 , the present invention provides a high-frequency signal transmission method for a pre-branched cable, including the following steps:

[0043] S1. Construct an asymmetric tapered chamfer branching structure;

[0044] In this embodiment, it should also be noted that the implementation steps of step S1 are as follows:

[0045] S1.1. For modal conversion, an asymmetric tapered chamfer geometry is adopted, and a curvature continuous transition is introduced at the branch point to match the curvature radius with the wavelength order of magnitude, forcing the electromagnetic field to maintain the TEM mode on the main transmission path.

[0046] S1.2. By optimizing the chamfer angle to 45° - 60°, the reflection coefficient caused by impedance mutation at the branch point is synchronously reduced, and the reflected energy attenuation ≥ 10 dB.

[0047] S1.3. Based on the wavelength of the 30 GHz millimeter - wave band , the chamfer length is defined as: ; The HFSS full - wave simulation is used to verify the convergence of the field distribution.

[0048] S2. Embedding of the distributed absorbing layer;

[0049] In this embodiment, it should also be noted that the implementation steps of step S2 are as follows:

[0050] S2.1. A nano - ferrite - graphene composite absorbing layer with a thickness ≤ 0.1 mm is covered on the surface of the branch - point conductor. The high - order mode energy is actively absorbed through magnetoelectric coupling loss. The dielectric constant gradient ε_r of the absorbing layer gradually changes from 3.0 to 6.0 to match the impedance between the branch point and the main trunk, and suppress the reflected wave generated by the discontinuous interface.

[0051] S2.2. The magnetron sputtering process is used to deposit the absorbing layer on the surface of the copper conductor to ensure no bubbles at the interface with the insulating layer.

[0052] S3. Topology - constrained TDR feedback optimization;

[0053] In this embodiment, it should also be noted that the implementation steps of step S3 are as follows:

[0054] S3.1. The position and amplitude of the reflection peak of the branch cable are measured by a time - domain reflectometer, and the length difference ΔL of the multipath reflection paths is deduced inversely to establish a reflection - path topology map.

[0055] S3.2. The ΔL data is input into the topology optimization algorithm. The distance between branch points is constrained to satisfy ΔL > λ / 2 to break the coherent condition of the reflected wave. The genetic algorithm is used to iteratively adjust the branch layout to make the peak - to - peak value of the TDR reflection coefficient ≤ 0.05.

[0056] S4. Three - dimensional conformal shielding waveguide conversion;

[0057] In this embodiment, it should also be noted that the implementation steps of step S4 are as follows:

[0058] S4.1. Construct a three-dimensional metallized conformal shielding layer on the outer wall of the branch point, specifically by copper plating and filling with conductive epoxy resin to form a waveguide-like structure with a cut-off frequency higher than the operating frequency band.

[0059] S4.2. Suppress the propagation of higher-order modes. The shielding layer is seamlessly connected to the main trunk shielding, and the waveguide characteristics are used to block the near-field coupling between branches and eliminate the source of multipath reflection energy.

[0060] S4.3. Use laser-induced electroless plating to achieve uniform metallization of complex surfaces, fill the joints with conductive glue, and the resistance ≤ 0.1 Ω / cm².

[0061] S5. Joint iterative calibration;

[0062] In this embodiment, it should also be noted that the implementation steps of step S5 are as follows:

[0063] S5.1. Take the chamfer curvature, absorber layer gradient, topological ΔL, and shielding cut-off frequency in the methods of steps S1 to S4 as joint variables, establish a multi-objective optimization function by comparing the HFSS simulation and TDR measured data, as follows:

[0064] Objective 1. The energy ratio of the TEM mode ≥ 95% (S parameter |S11| ≤ -20 dB);

[0065] Objective 2. The inter-symbol interference power ratio ≤ 5%;

[0066] S5.2. Use the covariance matrix adaptation evolution strategy (CMA-ES) to perform 10 to 20 rounds of iteration until convergence.

[0067] S6. High-frequency pre-branched cable collaborative closed-loop and standardization.

[0068] In this embodiment, it should also be noted that the implementation steps of step S6 are as follows:

[0069] S6.1. Process closed-loop verification and error tolerance calibration;

[0070] S6.2. Conduct multi-band compatibility verification;

[0071] S6.3. Solidify key parameters and convert production specifications, convert the optimized design variables into producible engineering parameters, and then construct cross-length adaptation rules.

[0072] In this embodiment, it should also be noted that in step S6.1, the optimization results of the chamfer curvature, absorber layer gradient, and topological ΔL in step S5 are imported into the HFSS simulation model, compared with the S parameters and time-domain reflection waveforms measured by TDR, and the allowable error tolerance is defined. If the tolerance is exceeded, local iteration of steps S1 to S5 is triggered.

[0073] In this embodiment, it should also be noted that in step S6.2, three characteristic frequencies are selected within the target frequency band, and steps S1 to S5 are repeated for optimization to verify the parameter robustness. Embodiment

[0074] In practical applications, the method for high-frequency signal transmission in the pre-branched cable of the present invention specifically includes the following steps:

[0075] (1) Design an asymmetric tapered chamfered branch structure to suppress mode conversion and at the same time reduce the reflection at the branch point, achieving the co-suppression of the two problems;

[0076] By step (1), an asymmetric tapered chamfered branch structure is constructed. Through the asymmetric tapered chamfer geometry, the electromagnetic field is forced to maintain the TEM mode on the main transmission path, suppressing mode conversion, effectively reducing mode distortion, and improving the fidelity of signal transmission;

[0077] 1.1) The chamfer parameters are matched with the wavelength

[0078] Calculation of the radius of curvature:

[0079] According to the operating frequency (such as 30 GHz, λ = 10 mm), it is determined that the radius of curvature R of the chamfer needs to satisfy:

[0080] ;

[0081] Among them, the dielectric ε_r = 2.3, then R ≥ 2.1 mm, and R = 2.5 mm is taken;

[0082] Optimization of the tapered angle:

[0083] Piecewise linear taper (asymmetric) is adopted. The chamfer angle θ1 on the main transmission path side = 45° (slow taper to reduce mode distortion), and θ2 on the branch side = 60° (steep taper to reduce reflection);

[0084] Verification of electromagnetic field constraint:

[0085] Set in HFSS:

[0086] Boundary condition: The radiation boundary is extended to outside λ / 4;

[0087] Mesh division: The mesh size in the curvature region ≤ λ / 20 (0.5 mm);

[0088] Excitation port: The number of wave port modes is 5 to ensure that high-order modes are captured;

[0089] Through step 1.1), for mode conversion, an asymmetric tapered chamfer geometry is adopted, introducing a continuous transition of curvature, making the radius of curvature match the wavelength order of magnitude, ensuring the smooth transition of the electromagnetic field and reducing energy loss;

[0090] 1.2) Chamfer-Absorbing Layer Joint Modeling

[0091] Material Interface Optimization:

[0092] Preset a 50-μm groove on the chamfer surface and embed a nano-ferrite-graphene composite absorbing layer (with a ratio of Fe3O4:C = 3:7). Match the impedance through the interface gradient ε_r gradually changing from 2.5 to 5.0;

[0093] Use laser etching to process grooves on the surface of the copper conductor, magnetron sputter deposit the absorbing layer (sputtering power 200 W, Ar gas flow rate 20 sccm), and then anneal at 300 °C to eliminate stress;

[0094] Optimize the chamfer angle to 45° - 60° through step 1.2), synchronously reduce the reflection coefficient caused by impedance mutation at the branch point, significantly reduce the reflected energy, and improve the signal transmission efficiency;

[0095] 1.3) Reflection Suppression Verification

[0096] Time Domain Reflectometer (TDR) Test:

[0097] Inject a step signal with a 1-ps rising edge into a single branch point and measure the reflection coefficient Γ;

[0098] If Γ > -15 dB, adjust the chamfer angle θ2 to 65°;

[0099] If Γ ≤ -15 dB and the field distribution converges, enter the topology optimization stage;

[0100] Define the chamfer length based on the wavelength in the 30 GHz millimeter-wave band through step 1.3), and use HFSS full-wave simulation to verify the convergence of the field distribution to ensure the accuracy of the design and optimize the signal transmission performance;

[0101] (2) Embedding Distributed Absorbing Layers;

[0102] Through step (2) of embedding distributed absorbing layers, cover a nano-ferrite-graphene composite absorbing layer on the surface of the branch point conductor, actively absorb the energy of higher-order modes, effectively suppress higher-order modes, and reduce signal interference;

[0103] 2.1) Cover a nano-ferrite-graphene composite absorbing layer with a thickness ≤ 0.1 mm on the surface of the branch point conductor, actively absorb the energy of higher-order modes through magnetoelectric coupling loss, and the dielectric constant gradient ε_r of the absorbing layer gradually changes from 3.0 to 6.0 to match the impedance between the branch point and the main trunk and suppress the reflected wave generated by the discontinuous interface;

[0104] Cover an absorbing layer with a thickness ≤ 0.1 mm through step 2.1), and the dielectric constant gradient of the absorbing layer changes gradually to match the impedance between the branch point and the main trunk, reduce the reflected wave caused by impedance mismatch, and improve the signal transmission quality;

[0105] 2.2) Deposit an electromagnetic wave absorbing layer on the surface of the copper conductor by using the magnetron sputtering process to ensure no bubbles at the interface with the insulating layer;

[0106] By depositing the electromagnetic wave absorbing layer through the process in step 2.2) using the magnetron sputtering process, ensure no bubbles at the interface between the electromagnetic wave absorbing layer and the insulating layer, and improve the stability and reliability of the electromagnetic wave absorbing layer;

[0107] (3) Topology-constrained TDR feedback optimization, inversely deduce the multipath routes from the measured reflection data, and dynamically adjust the branch layout to destroy the coherence condition;

[0108] Through the topology-constrained TDR feedback optimization in step (3), inversely deduce the multipath routes from the measured reflection data, dynamically adjust the branch layout, destroy the coherence condition of the reflected waves, and reduce the multipath reflection interference;

[0109] 3.1) TDR multipath route inversion algorithm

[0110] Data acquisition:

[0111] Inject TDR pulses (pulse width 10 ps, amplitude 5 V) at all branch ports of the cable, and record the time series t1, t2,... t of the reflected waveforms at each port n ;

[0112] Path difference calculation:

[0113] Extract the time difference Δt of the reflection peaks through the cross-correlation algorithm, and inversely deduce the path length difference ΔL = Δt × vp (vp is the signal propagation speed, taking 0.7c);

[0114] Constraint condition: Force ΔL > λ / 2 (ΔL > 5 mm at 30 GHz);

[0115] By establishing a topological map of the reflection paths in step 3.1), inversely deduce the path length difference ΔL of the multipath reflections, providing accurate data support for topological optimization;

[0116] 3.2) Genetic algorithm topological optimization

[0117] Coding rule:

[0118] Encode the branch position coordinates (x, y, z) and length L into a chromosome, and each gene represents a branch parameter. Specifically, x ∈ [0, L_total], and the fitness function is:

[0119] ;

[0120] In the formula, α = 0.6, β = 0.4, Γ_i is the reflection coefficient of each branch point, and ΔL_j is the path difference;

[0121] Iteration strategy:

[0122] Population size: 50;

[0123] Crossover rate: 0.8, mutation rate: 0.05;

[0124] Termination condition: The change in F is less than 1% for 5 consecutive generations or the total number of iterations is ≥ 100;

[0125] Through step 3.2), use the genetic algorithm to iteratively adjust the branch layout, constrain the branch point spacing to satisfy ΔL > λ / 2, optimize the branch layout, and reduce reflection interference;

[0126] 3.3) Dynamic feedback adjustment

[0127] Fine-tuning of branch length:

[0128] If there are still branch pairs with ΔL ≤ λ / 2 after optimization, use a piezoelectric ceramic micro-displacement device with an accuracy of ±0.01 mm to stretch / compress the branch cable until ΔL > λ / 2;

[0129] Adaptive correction of the shielding layer:

[0130] For the moved branch points, reinforce the shielding layer by laser-induced electroless plating (plating thickness ≥ 2 μm, resistance ≤ 0.05 Ω / sq);

[0131] (4) Three-dimensional conformal shielding waveguide conversion

[0132] Through step (4) three-dimensional conformal shielding waveguide conversion, construct a three-dimensional metallized conformal shielding layer on the outer wall of the branch point to form a waveguide-like structure, block the near-field coupling between branches, and eliminate the source of multipath reflection energy;

[0133] 4.1) Construct a three-dimensional metallized conformal shielding layer on the outer wall of the branch point, specifically copper plating plus conductive epoxy resin filling, to form a waveguide-like structure with a cut-off frequency higher than the working frequency band;

[0134] Through step 4.1) construct a three-dimensional metallized conformal shielding layer with a cut-off frequency higher than the working frequency band, effectively suppress the propagation of high-order modes, and improve the signal transmission stability;

[0135] 4.2) Suppress the propagation of high-order modes, seamlessly connect the shielding layer with the main trunk shielding, and use the waveguide characteristics to block the near-field coupling between branches to eliminate the source of multipath reflection energy;

[0136] Through step 4.2) the shielding layer is seamlessly connected with the main trunk shielding, and the waveguide characteristics are used to block the near-field coupling between branches to reduce the mutual interference between signals;

[0137] 4.3) Use laser-induced electroless plating to achieve uniform metallization of complex surfaces, fill the seams with conductive glue, and the resistance ≤ 0.1 Ω / cm²;

[0138] Through step 4.3), laser-induced electroless plating is used to achieve uniform metallization of complex curved surfaces, conductive adhesive is filled at the joints, and the resistance is ≤ 0.1 Ω / cm², improving the conductivity and reliability of the shielding layer;

[0139] (5) Joint iterative calibration

[0140] Through step (5) joint iterative calibration, the chamfer curvature, absorber layer gradient, topological ΔL, and shielding cut-off frequency are used as joint variables for optimization. Through multi-objective optimization, the overall performance of signal transmission is improved;

[0141] 5.1) Take the chamfer curvature, absorber layer gradient, topological ΔL, and shielding cut-off frequency in the methods of steps S1 to S4 as joint variables. By comparing the HFSS simulation with the measured TDR data, establish a multi-objective optimization function as follows:

[0142] Objective 1. The energy ratio of TEM mode ≥ 95% (S parameter |S11| ≤ -20 dB);

[0143] Objective 2. The inter-symbol interference power ratio ≤ 5%;

[0144] Through step 5.1) to establish a multi-objective optimization function, by comparing the HFSS simulation with the measured TDR data, ensure the accuracy and reliability of the optimization results;

[0145] 5.2) Adopt the covariance matrix adaptation evolution strategy (CMA-ES) for 10 to 20 rounds of iteration until convergence;

[0146] Specifically, the implementation process is as follows:

[0147] Chamfer design → Initial TDR measurement: After completing steps 1.1) to 1.3), obtain the initial reflection data Γ and ΔL;

[0148] Topology optimization → Chamfer correction: If the output branch position of the genetic algorithm conflicts with the chamfer curvature, when the curvature radius < 2.1 mm, return to step 1.1 to adjust the chamfer parameters;

[0149] Final verification: Perform full-band sweep (26.5 - 33.5 GHz) on the optimized cable, requirements:

[0150] The TEM mode ratio ≥ 95% (measured by a mode analyzer);

[0151] The inter-symbol interference power ratio ≤ 3% (calculated by an error rate tester);

[0152] Among them, it should also be noted that:

[0153] The chamfer curvature matches the wavelength: Avoid edge field distortion caused by insufficient curvature. When the measured R = 2.5 mm, the high-order mode suppression ratio is increased by 12 dB;

[0154] TDR inversion accuracy control uses Gaussian pulse fitting algorithm to improve the path difference resolution to 0.1mm level;

[0155] Genetic algorithm acceleration, the introduction of GPU parallel computing (CUDA acceleration), reduces the iteration time of 100 generations from 2 hours to 8 minutes;

[0156] In step 5.2), the covariance matrix adaptive evolution strategy is used to iterate until convergence, and the parameters such as the chamfer curvature and the absorbing layer gradient are optimized to improve the optimization efficiency and ensure the optimality of the optimization results;

[0157] (6) Closing loop and standardization of high-frequency pre-branch cable collaborative design process

[0158] Through step (6) high frequency pre-branch cable coordinated closed loop and standardization, through process closed loop verification and error tolerance calibration, the repeatability of the method is ensured, and through standardized processes, production efficiency and product quality are improved;

[0159] 6.1) Process closed-loop verification and error tolerance calibration

[0160] Comparison of simulation and measured data:

[0161] The chamfer curvature, absorbing layer gradient, and topology ΔL optimization results of step (5) are imported into the HFSS simulation model, compared with the S parameters (|S11|, |S21|) and time domain reflection waveform measured by TDR, and the allowable error tolerance is defined:

[0162] a. The error between simulation and measured TEM mode energy is ≤±2%;

[0163] b. Peak-to-peak deviation of reflection coefficient ≤±0.02;

[0164] c. If the deviation is exceeded, trigger the local iteration of steps (1) to (5), and only adjust the deviation variable;

[0165] Multi-band compatibility verification:

[0166] Select 28 GHz, 30 GHz, and 32 GHz characteristic frequencies within the target frequency band, repeat optimization steps (1) to (5), and verify parameter robustness.

[0167] Through step 6.1) process closed-loop verification and error tolerance calibration, the optimization results are imported into the HFSS simulation model and compared with the TDR measured data to ensure the accuracy and reliability of the design parameters;

[0168] 6.2) Key parameter solidification and production specification conversion

[0169] Parameter mapping table generation:

[0170] Convert the optimized design variables into producible engineering parameters. The cross-length adaptation rule is as follows:

[0171] For different total cable lengths L_total, define the relationship between the chamfer length L and L_total through a piecewise function: ;

[0172] Conduct multi-band compatibility verification through step 6.2). Select characteristic frequencies within the target frequency band, repeat the optimization process, verify the robustness of the parameters, and improve the applicability of the product;

[0173] 6.3) Production Compatibility Process Conversion

[0174] Chamfering Machining Process Adaptation:

[0175] Convert the chamfer surface data optimized by HFSS into a five-axis CNC machining program:

[0176] Tool Path Generation: Based on asymmetric chamfer angles (θ1 = 45°, θ2 = 60°), use contour layer milling;

[0177] Surface Roughness Control: Ra ≤ 0.8μm to prevent high-frequency skin depth fluctuations;

[0178] Shielding Layer Production Line Adaptation:

[0179] Convert the laser-induced electroless plating parameters into production line equipment instructions:

[0180] Plating Solution Formula: CuSO4 80g / L + H2SO4 20g / L + Additive JGB-5 3mL / L;

[0181] Laser Parameters: Wavelength 532nm, Power 50W, Scanning Speed 2mm / s;

[0182] Through step 6.3), solidify the conversion of key parameters and production specifications, convert the optimized design variables into producible engineering parameters, provide accurate technical guidance for production, and improve production efficiency;

[0183] 6.4) Design-Manufacturing Coupling

[0184] Linkage Rule Manual:

[0185] Compile a table of parameter coupling relationships between steps to clarify the priority of conflict resolution:

[0186] Version Control and Iteration Trigger:

[0187] Define the design version number rule, VerX.Y.Z, where X = frequency band, Y = topological complexity, Z = number of iterations, and set the revision trigger conditions;

[0188] a. The operating frequency changes by ≥ ±10%;

[0189] b. When new materials are introduced, the dielectric constant changes by ≥ ±15%;

[0190] c. The production yield for three consecutive batches is < 95%;

[0191] Through the design - production coupling in step 6.4), compile a table of parameter coupling relationships between steps, clarify the priority of conflict resolution, ensure seamless connection between design and production, and improve the overall performance of the product;

[0192] Through this step, by using simulation - measurement comparison and error calibration, ensure the repeatability of the method, convert the theoretically optimized parameters into executable process instructions, avoid the "design - manufacturing gap", solidify the multi - step linkage rules through documentation, prevent global performance degradation caused by local optimization, and ensure the coordinated solution of mode conversion and multipath reflection through process standardization. Embodiment

[0193] In practical applications, the actual application process of the high - frequency signal transmission method for the pre - branched cable of the present invention is as follows:

[0194] Design an asymmetric tapered chamfered branch structure: Adopt an asymmetric tapered chamfer geometric design for the branch structure to ensure that the electromagnetic field maintains the TEM mode on the main transmission path, suppress mode conversion, calculate the chamfer curvature radius according to the operating frequency, and optimize the chamfer angle to reduce the reflection coefficient at the branch point. Use HFSS full - wave simulation to verify the convergence of the field distribution and ensure the accuracy of the design.

[0195] Embed a distributed absorbing layer: Cover the surface of the branch - point conductor with a nano - ferrite - graphene composite absorbing layer, actively absorb the energy of high - order modes through magnetoelectric coupling loss, ensure that there are no bubbles between the absorbing layer and the conductor surface, and improve the stability and reliability of the absorbing layer.

[0196] TDR feedback optimization with topological constraints: Measure the reflection peak position and amplitude of the branched cable through a time - domain reflectometer (TDR), use the cross - correlation algorithm to inversely deduce the path - length difference of multipath reflection paths, establish a topological map of the reflection paths, and use the genetic algorithm to iteratively adjust the branch layout to ensure that the branch - point spacing meets specific conditions to disrupt the coherent conditions of the reflected waves and reduce multipath reflection interference.

[0197] Three - dimensional conformal shielding waveguide conversion: Construct a three - dimensional metallized conformal shielding layer on the outer wall of the branch point to form a waveguide - like structure, suppress the propagation of high - order modes, ensure seamless connection between the shielding layer and the main trunk shielding, use the waveguide characteristics to block the near - field coupling between branches, and use laser - induced chemical plating to achieve uniform metallization of complex surfaces to ensure the conductivity and reliability of the shielding layer.

[0198] Joint iterative calibration: Taking chamfer curvature, absorber layer gradient, topological layout, and shielding cut-off frequency as joint variables, a multi-objective optimization function is established by comparing HFSS simulation data with TDR measured data. The covariance matrix adaptation evolution strategy (CMA-ES) is used for iterative optimization until convergence to ensure the optimal overall performance of signal transmission.

[0199] Closed-loop and standardization of the co-design process for high-frequency pre-branched cables: Import the optimization results into the HFSS simulation model, compare with TDR measured data, define the allowable error tolerance to ensure the accuracy and reliability of design parameters. Select characteristic frequencies within the target frequency band, repeat the optimization process to verify the robustness of parameters. Convert the optimized design variables into producible engineering parameters, construct cross-length adaptation rules, and convert the design parameters into production line equipment instructions to ensure the compatibility and efficiency of the production process. Compile a table of parameter coupling relationships between steps, clarify the priority of conflict resolution to ensure seamless connection between design and production. Define the design version number rule and set the revision trigger conditions for local iteration or overall optimization when needed.

[0200] Through the above actual application steps, the present invention can effectively solve the problems of mode conversion and multi-path reflection in high-frequency signal transmission in pre-branched cables, improve the stability and reliability of signal transmission, and is applicable to the fields of high-frequency communication and data transmission.

[0201] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0202] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A method for transmitting high frequency signals in a pre-branching cable, characterized in that: The following steps are involved: S1. Construct an asymmetric gradient chamfered branch structure; S2. Embedded distributed absorbing layer; S3. Perform topology-constrained TDR feedback optimization; S4. Implement three-dimensional conformal shielding waveguiding; S5. Perform joint iterative calibration; S6. High frequency pre-branch cable coordinated closed loop and standardization; The implementation steps of step S1 are: S1.

1. For mode conversion, an asymmetric gradient chamfer geometry is used to introduce a continuous transition of curvature at the branch point, so that the radius of curvature matches the wavelength order, forcing the electromagnetic field to maintain the TEM mode on the main transmission path; S1.

2. By optimizing the chamfer angle to 45°~60°, the reflection coefficient caused by impedance mutation at the branch point is simultaneously reduced, and the reflected energy attenuation is ≥10dB; S1.

3. Based on the wavelength λ≈10mm in the 30GHz millimeter wave band, define the chamfer length: L = λ / 4; Use HFSS full-wave simulation to verify the convergence of field distribution; The implementation steps of step S2 are: S2.

1. Cover the branch point conductor surface with a nano-ferrite-graphene composite absorbing layer with a thickness of ≤0.1mm, actively absorb the high-order mode energy through magneto-electric coupling loss, and the dielectric constant gradient of the absorbing layer gradually changes from 3.0 to 6.0, matching the branch point and trunk impedance, and suppressing the reflected waves generated by the discontinuous interface; S2.

2. Use magnetron sputtering process to deposit the absorbing layer on the surface of the copper conductor to ensure that there are no bubbles at the interface with the insulating layer; The implementation steps of step S3 are: S3.

1. Use a time domain reflectometer to measure the reflection peak position and amplitude of the branch cable, inversely calculate the multipath reflection path length difference ΔL, and establish a reflection path topology map; S3.

2. Input the ΔL data into the topology optimization algorithm, constrain the branch point spacing to satisfy ΔL>λ / 2, destroy the reflected wave coherence condition, and use the genetic algorithm to iteratively adjust the branch layout so that the peak-to-peak value of the TDR reflection coefficient is ≤0.05; The implementation steps of step S4 are: S4.

1. Construct a three-dimensional metalized conformal shielding layer on the outer wall of the branch point, specifically a copper plating layer plus a conductive epoxy resin filling, to form a waveguide-like structure with a cutoff frequency higher than the working frequency band; S4.

2. Suppress the propagation of high-order modes, seamlessly connect the shielding layer with the trunk shielding, use the waveguide characteristics to block the near-field coupling between branches, and eliminate the source of multipath reflection energy; S4.

3. Laser-induced chemical plating is used to achieve uniform metallization of complex curved surfaces, and conductive glue is filled at the joints, with a resistance of ≤0.1Ω / cm 2 ; The implementation steps of step S5 are: S5.

1. Take the chamfer curvature, absorbing layer gradient, topology ΔL and shielding cutoff frequency in the method of steps S1 to S4 as joint variables, compare the HFSS simulation with the TDR measured data, and establish a multi-objective optimization function as follows: Target 1. TEM mode energy ratio ≥ 95%; Objective 2. Inter-symbol interference power ratio ≤ 5%; S5.

2. Use the covariance matrix adaptive evolution strategy for 10 to 20 rounds of iterations until convergence; The implementation steps of step S6 are: S6.

1. Process closed-loop verification and error tolerance calibration; S6.

2. Perform multi-band compatibility verification; S6.

3. Conversion of key parameters and production specifications, converting optimized design variables into producible engineering parameters, and then constructing cross-length adaptation rules.

2. A method for transmitting high frequency signals in a pre-branching cable according to claim 1, characterized in that: In step S6.1, the chamfer curvature, absorbing layer gradient, and topology ΔL optimization results of step S5 are imported into the HFSS simulation model, compared with the S parameters and time domain reflection waveform measured by TDR, and the allowable error tolerance is defined. If the error exceeds the tolerance, local iteration of steps S1 to S5 is triggered.

3. A method for transmitting high frequency signals in a pre-branching cable according to claim 1, characterized in that: In step S6.2, three characteristic frequencies are selected within the target frequency band, and steps S1 to S5 are repeated for optimization to verify parameter robustness.

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