Method for correcting loss index through eye pattern ratio

Abstract

The invention relates to a method for correcting a loss index through an eye diagram ratio. The method comprises the following steps: acquiring the minimum voltage amplitude of an input end and the minimum voltage amplitude of an output end of a target link; according to the minimum voltage amplitude of the input end and the minimum voltage amplitude of the output end, an initial loss value is calculated through a traditional loss formula; establishing a transmitting-receiving model to simulate and obtain the actual eye pattern height of a receiving end; calculating a proportionality coefficient of the actual eye height and the expected eye height; and correcting the initial loss value according to a proportionality coefficient to obtain a corrected loss value. According to the method, the initial loss value is calculated by using the traditional loss formula, passive simulation is performed on the target link to obtain the actual eye pattern height of the receiving end, and then the initial loss value is corrected according to the proportionality coefficient of the actual eye height and the expected eye height, so that the actual attenuation in the signal transmission process is considered; an indefinite loss index can be converted into an accurate and available loss value, and a reliable basis is provided for passive simulation.

Description

Technical Field

[0001] The invention relates to the field of high-speed serial signal simulation, and in particular to a method for correcting a loss index through an eye diagram ratio. Background Art

[0002] Printed Circuit Board (PCB) is a key part of the physical support of electronic products and signal transmission. Its performance is crucial to the stable operation of the entire electronic system. In most high-speed serial signal simulation projects, passive simulation is a common method. By obtaining the protocol loss index to be transmitted by the link, the channel routing length is determined to ensure the quality of signal transmission. For example, in the 28Gbps signal transmission protocol, the loss value of the 14GHz base frequency is -10dB, so the routing length can be planned based on -10dB. This is the conventional passive simulation method in the industry.

[0003] However, the passive loss indicators of some signal protocols are not clear, and only the minimum differential voltage amplitude at the output end and the minimum differential voltage amplitude at the receiving end are provided. In this case, the traditional approach is to divide the input and output voltage amplitudes and take the logarithm to obtain a loss dB value, and directly use this as a loss reference for passive simulation. For example, the signal rate is 10Gbps, the base frequency is 5GHz, the minimum differential voltage amplitude at the output end is 500mV, and the minimum differential voltage amplitude at the input end is 180mV. The output voltage amplitude is 1000mV, the input voltage amplitude is 360mV, and the loss is 20log(360 / 1000)=-8.87dB. Therefore, the industry plans the routing length based on -8.87dB.

[0004] However, when using the planned link to build an ideal transceiver model to simulate the eye diagram, and verifying whether the result at the receiving end is around 360mV after passing through the -8.87db loss channel when the output is 1000mV, it was found that the eye height of the eye diagram is only 282mV, which is a large deviation from the expected 360mV. It can be seen that the loss index calculated by the formula is too idealized and does not fully consider the actual attenuation of the signal in the complex transmission process, resulting in a large deviation between the design result and the actual application effect.

[0005] Therefore, how to convert such unclear loss indicators into accurate and usable loss values, and then perform reliable passive simulation, has become a key technical problem that needs to be solved urgently in the industry. Summary of the invention

[0006] In order to solve the problem in the prior art that when the passive loss index is unclear, the traditional method of determining the loss index is inaccurate, the present invention provides a method for correcting the loss index by eye diagram ratio, which improves the accuracy of loss index determination in high-speed serial signal simulation and ensures the signal transmission quality.

[0007] The technical solution of the present invention is as follows:

[0008] 1. A method for correcting loss indicators by eye diagram ratio, characterized in that it comprises the following steps:

[0009] Step 1, obtaining the minimum voltage amplitude at the input end and the minimum voltage amplitude at the output end of the target link;

[0010] Step 2: Calculate the initial loss value using a traditional loss formula according to the minimum voltage amplitude at the input end and the minimum voltage amplitude at the output end;

[0011] Step 3: Build a transceiver model to simulate and obtain the actual eye diagram height of the receiving end;

[0012] Step 4, calculate the ratio coefficient between the actual eye height and the expected eye height;

[0013] Step 5: Correct the initial loss value according to the proportional coefficient to obtain a corrected loss value.

[0014] As a preferred solution of the present invention, in step 2, the traditional loss formula is: L 0 =20×log 10 (V in / V out );

[0015] Among them, L 0 represents the initial loss value, V in Indicates the minimum voltage amplitude at the input terminal, V out Indicates the minimum voltage amplitude at the output.

[0016] As a preferred solution of the present invention, in step 4, the ratio coefficient between the actual eye height and the expected eye height is calculated, and the specific steps are: the value K obtained by dividing the actual eye height value by the expected eye height value is calculated as follows: K=H real / H ideal ;

[0017] Among them, H real Indicates the actual eye height, H ideal Indicates the expected eye height value.

[0018] Furthermore, in step 5, the initial loss value is corrected according to the proportional coefficient, and the specific steps are: multiplying the initial loss value by the proportional coefficient to obtain a corrected loss value, and the calculation formula is: L 1 =L0 ×K;

[0019] Among them, L 1 Indicates the corrected loss value.

[0020] As a preferred solution of the present invention, for differential signals, when obtaining the minimum voltage amplitude of the target link, the minimum voltage amplitude at the input end is equal to twice the minimum differential voltage amplitude at the receiving end, and the minimum voltage amplitude at the output end is twice the minimum differential voltage amplitude at the output end.

[0021] As a preferred embodiment of the present invention, the following steps are also included:

[0022] Step 6: adjusting link parameters based on the corrected loss value, resimulating, and obtaining an updated eye diagram;

[0023] Step 7: Compare the corrected eye height with the expected eye height to verify the result.

[0024] Furthermore, the specific steps of step 6 are: if the corrected loss value is less than the initial loss value, shorten the transmission line length; if the corrected loss value is greater than the initial loss value, increase the transmission line length, and the length step of each adjustment is dynamically adjusted according to the deviation between the simulation result and the expected value.

[0025] Furthermore, when comparing the verification results of the corrected eye height with the expected eye height in step 7, if the difference between the corrected eye height and the expected eye height exceeds the preset error range, the proportional coefficient is recalculated according to the size and direction of the difference, the initial loss value is corrected again, and steps 6 and 7 are repeated until the difference between the corrected eye height and the expected eye height is within the preset error range.

[0026] As a preferred solution of the present invention, in step 3, the simulation tool is ADS, and step 3 specifically includes the following steps:

[0027] Step 301: Use ADS software to create a transmission line model so that the transmission line meets the initial loss value at the target rate;

[0028] Step 302: Set a transmitter model and a receiver model at both ends of the transmission line model, start simulation and generate an eye diagram.

[0029] As a preferred solution of the present invention, step 301 specifically includes the following steps:

[0030] Step A: Start ADS software and create a schematic diagram;

[0031] Step B, setting the plate and stacking parameters;

[0032] Step C, placing transmission line elements and setting transmission line characteristic impedance;

[0033] Step D, preliminarily setting the transmission line length;

[0034] Step E: frequency domain simulation setting;

[0035] Step F: Run the simulation and adjust the transmission line length.

[0036] The step 302 specifically includes the following steps:

[0037] Step G, add the sending end model and the receiving end model;

[0038] Step H, the transmission line model connects the transceiver model and the transmission line;

[0039] Step I, setting eye diagram simulation parameters;

[0040] Step J: Run the eye diagram simulation.

[0041] The present invention according to the above scheme has the following beneficial effects:

[0042] The present invention first calculates the initial loss value using the traditional loss formula, performs passive simulation on the target link to obtain the actual eye diagram height of the receiving end, and then corrects the initial loss value according to the proportionality coefficient between the actual eye height and the expected eye height, thereby taking into account the actual attenuation during signal transmission, and being able to convert the unclear loss index into an accurate and usable loss value, providing a reliable basis for passive simulation.

[0043] Furthermore, the present invention is applicable to signal links of different rates, and can accurately determine the respective corrected loss values ​​according to the frequency characteristics of signals of different rates, thereby effectively solving the problem that traditional methods cannot accurately determine the loss index due to the different distribution of frequency components of signals of different rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flow chart of the method of the present invention;

[0045] Figure 2 This is the simulated eye diagram before loss value correction;

[0046] Figure 3 The simulated eye diagram after loss value correction;

[0047] Figure 4 The present invention is a method flow chart of a preferred embodiment. DETAILED DESCRIPTION

[0048] In order to better understand the purpose, technical scheme and technical effect of the present invention, the present invention is further explained in conjunction with the accompanying drawings and embodiments. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, it is stated that the embodiments described below are only used to explain the present invention and are not used to limit the present invention.

[0049] In some high-speed serial signal simulation projects, the passive loss index of the signal protocol is not clear, and only the minimum differential voltage amplitude at the output end and the minimum differential voltage amplitude at the receiving end are provided. However, since the traditional method does not fully consider the significant attenuation of the high-frequency part of the digital signal as a broadband signal when transitioning from a low-frequency code type to a high-frequency code type when calculating the loss index, the design result deviates greatly from the actual application effect. The present invention provides a method for correcting the loss index by eye diagram ratio, which improves the accuracy of determining the loss index in high-speed serial signal simulation and ensures the quality of signal transmission.

[0050] like Figure 1 As shown, a method for correcting a loss index by using an eye diagram ratio is characterized by comprising the following steps:

[0051] Step 1, obtaining the minimum voltage amplitude at the input end and the minimum voltage amplitude at the output end of the target link;

[0052] Step 2: Calculate the initial loss value using a traditional loss formula according to the minimum voltage amplitude at the input end and the minimum voltage amplitude at the output end;

[0053] Step 3: Build a transceiver model to simulate and obtain the actual eye diagram height of the receiving end;

[0054] Step 4, calculate the ratio coefficient between the actual eye height and the expected eye height;

[0055] Step 5: Correct the initial loss value according to the proportional coefficient to obtain a corrected loss value.

[0056] Step 6: adjusting link parameters based on the corrected loss value, resimulating, and obtaining an updated eye diagram;

[0057] Step 7: Compare the corrected eye height with the expected eye height to verify the result.

[0058] The present invention obtains the minimum input and output voltage amplitude of the target link, first calculates the initial loss value using the traditional loss formula, performs passive simulation on the target link to obtain the actual eye diagram height of the receiving end, then calculates the proportionality coefficient between the actual eye height and the expected eye height, and then corrects the initial loss value according to the proportionality coefficient between the actual eye height and the expected eye height. The actual attenuation in the signal transmission process is comprehensively considered, and the unclear loss index can be converted into an accurate and usable loss value, providing a reliable basis for passive simulation.

[0059] In the present invention, the traditional loss formula is: L 0 =20×log 10 (V in / V out ), where L 0 represents the initial loss value, V in Indicates the minimum voltage amplitude at the input terminal, V out Indicates the minimum voltage amplitude at the output. The formula is derived as follows:

[0060] In a circuit, the relationship between power and voltage is P = V 2 / R, when the signal is transmitted in the link, power loss will occur, and the loss is usually expressed in decibels (dB). The decibel calculation formula for power loss is L dB =10×log 10 (P 2 / P 1 ), P = V 2 Substituting / R into the power loss decibel formula, we can get L dB =10×log 10 (V 2 2 / V 2 1 )=20×log 10 (V 2 / V 1 ), when the loss is considered, it is expressed by the relationship between the input voltage and the output voltage, and L is obtained 0 =20×log 10 (V in / V out ). This formula reflects the attenuation of voltage amplitude when the signal is transmitted in the link, (V in / V out ) is larger, indicating that the voltage amplitude of the signal drops more from the input to the output, that is, the loss is greater. By taking the logarithm and multiplying it by 20, the change in voltage amplitude is converted into a loss value in decibels, which can more intuitively measure the degree of signal attenuation in the link.

[0061] It can be seen that the present invention can preliminarily estimate the possible loss of the link based on the existing voltage amplitude information, and provide an initial reference value for subsequent further analysis and correction.

[0062] In step 4, the ratio coefficient between the actual eye height and the expected eye height is calculated. The specific steps are: the value K obtained by dividing the actual eye height value by the expected eye height value is calculated as follows: K=H real / H ideal ; Among them, H real Indicates the actual eye height, H ideal Indicates the expected eye height value. The eye diagram is a direct reflection of the quality of high-speed serial signals. The eye height represents the effective amplitude of the signal at the receiving end. The actual eye height is the signal amplitude obtained after considering the actual link loss.

[0063] The present invention quantifies the deviation between the actual result obtained by eye diagram simulation after calculating the loss value using the traditional method and the ideal expectation by calculating the proportional coefficient between the actual eye height and the expected eye height, intuitively reflects the degree of difference between the actual result and the ideal expectation, and provides a key quantitative basis for the subsequent correction of the initial loss value, making the determination of the loss index more accurate, thereby improving the reliability of the entire high-speed serial signal simulation and design.

[0064] Different links have different effects on signal loss due to their different physical structures, material properties, etc. As can be seen from the above formula, the proportionality coefficient can be calculated based on the actual eye diagram simulation results of different links, so the present invention can adapt to links with various different characteristics.

[0065] It should be noted that the differential signal is composed of two complementary signals, and the voltage difference represents the information carried by the signal. The minimum differential voltage amplitude between the receiving end and the output end refers to the minimum voltage difference between the two complementary signals. The method of the present invention is applied to high-speed serial differential signal transmission links. When calculating the loss, it is usually necessary to consider the voltage amplitude change of the entire signal. When a signal is +V d / 2, the other signal is -V d / 2, the differential voltage amplitude is V d From the perspective of the overall voltage amplitude, the minimum voltage amplitude is equivalent to 2×(V d / 2)=V d , so the minimum voltage amplitude at the input end is equal to twice the minimum differential voltage amplitude at the receiving end, and the minimum voltage amplitude at the output end is twice the minimum differential voltage amplitude at the output end. For example, the minimum differential voltage amplitude at the receiving end is measured to be V 1 , the minimum differential voltage amplitude at the output is V 2 , then the minimum voltage amplitude at the input is 2V 1 , the minimum output voltage amplitude is 2V 2.

[0066] In a specific embodiment, taking a 10 Gbps signal as an example, the minimum output voltage amplitude V out =1000mV, minimum input voltage amplitude V in =360mV, according to the formula L 0 =20×log 10 (V in / V out ) can be calculated:

[0067] L 0 =20×log 10 (360 / 1000)=20×(-0.444)=-8.87dB; then the initial loss value is -8.87dB.

[0068] ADS software is used to create a transmission line model, so that the transmission line is -8.87dB at a rate of 10Gbps. Specifically, the following steps are included:

[0069] Step A: Start ADS software and create a schematic diagram;

[0070] Step B, setting the plate and stacking parameters;

[0071] Open the substrate library, select the appropriate plate model, set the plate's dielectric constant, dielectric loss tangent and other parameters according to the plate's actual characteristics; define the plate's stacking structure;

[0072] Step C, placing transmission line elements and setting transmission line characteristic impedance;

[0073] Select a transmission line component from the component library and place it in the schematic diagram; double-click the transmission line component and in the pop-up property setting window, set the characteristic impedance of the transmission line to 100 ohms;

[0074] Step D, preliminarily setting the transmission line length;

[0075] In the property setting window of the transmission line element, set an initial transmission line length. Since the final length needs to be adjusted according to the loss requirements, the initial length can be set to a rough value first;

[0076] Step E: frequency domain simulation setting;

[0077] Add an S-parameter simulation controller to the schematic diagram; set the simulation frequency range. If you are concerned about the base frequency of 5 GHz corresponding to the 10 Gbps rate, set the simulation frequency range to a suitable interval that includes 5 GHz, such as 1 GHz to 10 GHz; set the number of simulation points to ensure that there are enough sampling points near 5 GHz to accurately obtain the loss value;

[0078] Step F, running the simulation and adjusting the transmission line length;

[0079] Run the S parameter simulation and check the value of the S21 parameter (indicating transmission loss) at 5 GHz in the simulation results.

[0080] If the loss value at 5GHz is not equal to -8.87dB, adjust the length of the transmission line according to the simulation results. Generally speaking, the longer the transmission line, the greater the loss; the shorter the transmission line, the smaller the loss. Adjust the line length so that the loss value at 5GHz is equal to or close to -8.87dB.

[0081] At both ends of the created transmission line, set up an ideal transmitter model and an ideal receiver model respectively. The ideal transmitter model matches the characteristic impedance of the transmission line to ensure that the signal can be coupled from the transmitter to the transmission line with minimal reflection and distortion; the ideal receiver model is consistent with the impedance of the transmission line and the transmitter, and is used to receive the signal after transmission through the transmission line. It can ensure that the signal will not be reflected due to impedance mutation when entering the receiver, ensuring that the receiver can accurately receive the signal transmitted from the transmission line. Complete the construction of an ideal transceiver model for eye diagram simulation. The specific steps include:

[0082] Step G, add the sending end model and the receiving end model;

[0083] In the ADS schematic, select a suitable ideal transmitter model from the component library and set the parameters of the transmitter model, including the signal rate (such as 10Gbps), signal amplitude (corresponding to the minimum voltage amplitude at the output end), signal format, and impedance matching the transmission line; select a suitable ideal receiver model from the component library, and also the input impedance matching the transmission line;

[0084] Step H, the transmission line model connects the transceiver model and the transmission line;

[0085] Connect the output port of the transmitter model to the input port of the transmission line model, and connect the input port of the receiver model to the output port of the transmission line model to form a complete signal transmission link;

[0086] Step I, setting eye diagram simulation parameters;

[0087] Add an eye diagram simulation controller in ADS and set relevant simulation parameters, including simulation time and number of sampling points;

[0088] Step J, running eye diagram simulation;

[0089] Start the simulation. ADS simulates the entire process of a signal being sent from the transmitter, transmitted through the transmission line, and finally received by the receiver according to the set parameters, and generates an eye diagram.

[0090] Theoretically, when the output is 1000mV, after passing through the -8.87dB loss channel, the expected value at the receiving end is 360mV, and the eye diagram result should be the expected eye height H ideal =360mV, but the measured eye diagram at the receiving end shows: Heitght (eye height) is 0.282, Width (eye width) is 7.950E-11, refer to Figure 2 . That is, the actual eye height H real =282mV.

[0091] Calculate the ratio coefficient between the actual eye height and the expected eye height, K = 282 / 360 = 0.78, then correct the loss value:

[0092] L 1 =L 0 ×K=-8.87dB×0.78=-6.92dB.

[0093] ADS software is used to modify the line length in the transmission line model to make the transmission line -6.92dB at a rate of 10Gbps. When other conditions (such as board characteristics, laminate structure, etc.) remain unchanged, the longer the transmission line, the greater the attenuation experienced by the signal during transmission, and the higher the loss; conversely, the shorter the transmission line, the smaller the loss. Based on this, the line length can be shortened to adjust the loss of the transmission line from -8.87dB to -6.92dB at a rate of 10Gbps.

[0094] Reuse the transceiver model to simulate the eye diagram, and get the updated eye diagram display: Heitght (eye height) is 0.362, Width (eye width) is 8.500E-11, refer to Figure 3 From the eye diagram, we can see that the updated eye height is 362mV, which is very close to 360mV and meets the expected eye height. The trace length obtained is accurate.

[0095] like Figure 4As shown, in a preferred embodiment, when comparing the corrected eye height with the expected eye height verification result in step 7, if the difference between the corrected eye height and the expected eye height exceeds the preset error range, the proportional coefficient is recalculated according to the difference size and direction, and the initial loss value is corrected again, and steps 6 and 7 are repeated until the difference between the corrected eye height and the expected eye height is within the preset error range. For example, assuming that the link parameters such as the transmission line length are adjusted based on the initial corrected loss value of -6.92dB, the initial corrected eye height is only 320mV after re-simulation; if the preset error range is ±5%, then the error range between the initial corrected eye height and the expected eye height of 360mV exceeds 5%, then the proportional coefficient is calculated for the second time according to the initial corrected eye height and the expected eye height: 320 / 360=0.89, and the loss value is corrected again, and the secondary corrected loss value is -8.87dB×0.89=-7.89dB. Iterate again: adjust the link length again based on the secondary corrected loss value, repeat the simulation, and compare the new corrected eye height with the expected eye height again to determine whether the difference is within the preset error range, until the difference between the corrected eye height and the expected eye height falls within the preset error range.

[0096] In addition, the loss index calculated by the traditional method cannot be applied to different rates, because even if the baseband loss value is the same, the eye heights of signals at different rates are different due to the different distribution of frequency components. For example, for a 25Gbps signal, the output is 1000mV and the input is 360mV. The loss calculated by the traditional method is -8.87db@12.5GHz. The eye diagram of the loss is simulated to obtain an eye height of only 291mV. However, using the method of the present invention, the ratio coefficient between the actual eye height and the expected eye height becomes 291 / 360=0.8, and the corrected loss value is -8.87dB×0.8=-7.1dB. The line length in the transmission line model is modified using ADS software to make the transmission line -7.1dB at a rate of 25Gbps. The eye diagram is simulated using the transceiver model to obtain an eye diagram height of 359mV, which also meets the expected eye height.

[0097] It can be seen that the present invention is applicable to signal links of different rates, and can accurately determine the respective corrected loss values ​​according to the frequency characteristics of signals of different rates, effectively solving the problem that traditional methods cannot accurately determine the loss index due to the different distribution of frequency components of signals of different rates.

[0098] In summary, the present invention effectively solves the problem in the prior art that when the passive loss index is unclear, the traditional method for determining the loss index is inaccurate, significantly improves the accuracy of determining the loss index in high-speed serial signal simulation, and ensures the signal transmission quality. The present invention can also provide accurate loss indicators for signal links of different rates, ensuring that signals of various rates can be transmitted in a good state.

[0099] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for correcting loss indicators by eye diagram ratio, characterized in that: The following steps are involved: Step 1, obtaining the minimum voltage amplitude at the input end and the minimum voltage amplitude at the output end of the target link; Step 2: Calculate the initial loss value using the traditional loss formula; Step 3: Build a transceiver model to simulate and obtain the actual eye diagram height of the receiving end; Step 4, calculate the ratio coefficient between the actual eye height and the expected eye height; Step 5: Correct the initial loss value according to the proportional coefficient to obtain a corrected loss value.

2. The method for correcting loss index by eye diagram ratio according to claim 1, characterized in that: In step 2, the traditional loss formula is: L0=20×log 10 (V in / V out ); Among them, L0 represents the initial loss value, V in Indicates the minimum voltage amplitude at the input terminal, V out Indicates the minimum voltage amplitude at the output.

3. The method for correcting loss index by eye diagram ratio according to claim 1, characterized in that: In step 4, the ratio coefficient between the actual eye height and the expected eye height is calculated. The specific steps are: the value K obtained by dividing the actual eye height value by the expected eye height value is calculated as follows: K=H real / H ideal ; Among them, H real Indicates the actual eye height, H ideal Indicates the expected eye height value.

4. The method for correcting loss index by eye diagram ratio according to claim 3, characterized in that: In the step 5, the initial loss value is corrected according to the proportional coefficient, and the specific steps are: multiplying the initial loss value by the proportional coefficient to obtain a corrected loss value, and the calculation formula is: L1=L0×K; Wherein, L1 represents the corrected loss value.

5. The method for correcting loss index by eye diagram ratio according to claim 1, characterized in that: For differential signals, when obtaining the minimum voltage amplitude of the target link, the minimum voltage amplitude at the input end is equal to twice the minimum differential voltage amplitude at the receiving end, and the minimum voltage amplitude at the output end is twice the minimum differential voltage amplitude at the output end.

6. The method for correcting loss indicators by eye diagram ratio according to any one of claims 1 to 5, characterized in that: The following steps are also included: Step 6: adjusting link parameters based on the corrected loss value, resimulating, and obtaining an updated eye diagram; Step 7: Compare the corrected eye height with the expected eye height to verify the result.

7. The method for correcting loss index by eye diagram ratio according to claim 6, characterized in that: The specific steps of step 6 are: if the corrected loss value is less than the initial loss value, shorten the transmission line length; if the corrected loss value is greater than the initial loss value, increase the transmission line length, and the length step of each adjustment is dynamically adjusted according to the deviation between the simulation result and the expected value.

8. The method for correcting loss index by eye diagram ratio according to claim 6, characterized in that: When comparing the verification results of the corrected eye height with the expected eye height in step 7, if the difference between the corrected eye height and the expected eye height exceeds the preset error range, the proportional coefficient is recalculated according to the size and direction of the difference, the initial loss value is corrected again, and steps 6 and 7 are repeated until the difference between the corrected eye height and the expected eye height is within the preset error range.

9. The method for correcting loss index by eye diagram ratio according to claim 1, characterized in that: In step 3, the simulation tool is ADS, and step 3 specifically includes the following steps: Step 301: Use ADS software to create a transmission line model so that the transmission line meets the initial loss value at the target rate; Step 302: Set a transmitter model and a receiver model at both ends of the transmission line model, start simulation and generate an eye diagram.

10. The method for correcting loss index by eye diagram ratio according to claim 9, characterized in that: The step 301 specifically includes the following steps: Step A: Start ADS software and create a schematic diagram; Step B, setting the plate and stacking parameters; Step C, placing transmission line elements and setting transmission line characteristic impedance; Step D, preliminarily setting the transmission line length; Step E: frequency domain simulation setting; Step F, running the simulation and adjusting the transmission line length; The step 302 specifically includes the following steps: Step G, add the sending end model and the receiving end model; Step H, the transmission line model connects the transceiver model and the transmission line; Step I, setting eye diagram simulation parameters; Step J: Run the eye diagram simulation.

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