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Article
Peer-Review Record

Timing Analyses in FWE Evaluation

Appl. Sci. 2023, 13(24), 13008; https://doi.org/10.3390/app132413008
by Maria Sîrbu-Drăgan *, Diana Brînaru and Simona Halunga *
Reviewer 1: Anonymous
Reviewer 2: Anonymous
Appl. Sci. 2023, 13(24), 13008; https://doi.org/10.3390/app132413008
Submission received: 29 October 2023 / Revised: 1 December 2023 / Accepted: 2 December 2023 / Published: 6 December 2023
(This article belongs to the Special Issue Trends and Prospects for Wireless Sensor Networks and IoT)

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper presents time domain analysis of the simulation results of several transmission lines that use frequency dependent dielectrics. There are several lacks in the paper

1. There is no novelity in the paper. It looks as a basic engineering report. A research paper should have novel work.

2. The authors have cited basic references of websites and not discussed the research. I would highly suggest authors to have literature review of latest research papers  of dielectrics and understand the concept of research papers. Then present the novel research ahead of published work.

The authors states that "We performed simulations in the time domain using the eye diagram for the rates of 539 1GHz and 10 GHz and for the lengths of 120 mm and 250 mm. " Why do performed this simulations? What is the purpose and benefit of this research.

A research paper has a purpose and novel research which no one have done and is benefitual to the world. I dont want to discourage authors but i would suggest to read key papers of dielectric and understand the concept of research. Every research paper has a unique novelity. I suggest authors to  resubmit again after understanding the concept of research with the novel results which will benefit the research community.

Wish you best of luck for future papers.

Comments on the Quality of English Language

The quality of English is moderate. Can be increased. 

Author Response

Dear Reviewer,

 

Thank you for your review. All your remarks are valuable ones and we have taken them into consideration, helping us to increase the quality of our paper and to include all necessary aspects of scientific work. We hope that the paper is more clearly understandable now. Thank you again for your valuable review. For a better understanding, we include below the details of the manuscript reviews and our responses to the comments that include point-by-point explanations.

Point-by-point response to Comments and Suggestions of reviewer

Comment 1: There is no novelity in the paper. It looks as a basic engineering report. A research paper should have novel work.

Answer:

Thank you for this comment.

In the present work, we have made analyses in time domain starting from previous work presented in article "[1] Maria Drăgan, Diana Brînaru, Simona Halunga, Constraints of Fiber Weave Effect on High-Speed Circuits, 2022, 14th International Conference on Communications" where only frequencies domain analyses were accomplished. As mentioned in the Introduction chapter both time and frequency domain analyses have to be considered for a complete characterization of the influence of substrate over the circuit’s interconnections.

During the research, we studied multiple papers mentioned in the references chapter and none of them present detailed results in terms of jitter effect for microstrip and stripline technologies for traditional FR4 composite material but also for novel signal integrity oriented substrates type, N4000-13, used in simulation in the present work.

Also, the software we used for circuit design and obtaining results, called Microwave Office (MWO) from AWR, is a computer added design tool for RF and microwaves applications, but has no specific models for certain materials, nor dielectrics or conductor material. For instance, Simbeor, a program developed by Yuriy Shlepnev, a recognized expert in the field of high-frequency circuit design and signal integrity studies, is a dedicated software for signal integrity. The novelty in our work lies in implementing equations corresponding to the substrates used and apply them to achieve the desired circuits and results.

On the other hand, Microwave Office (MWO) from AWR DE is a general purpose tool with separate licensing options, either for microwave or for RF, with added on options for electromagnetic compatibility analyses. The benefit of MWO is the integration with the layout and is much easier to use. Simbeor is a niche program, not very popular and involves a higher cost for licensing and it can only be used for signal integrity problems. For signal integrity-dedicated programs, such as Simbeor software, the financial effort is much higher to acquire them.

In order to make those things clearer for the reader we completed the paper as follows.

 

 

We introduced new lines between lines 210-227:

The purpose of our article is to demonstrate the importance of determining the occurrence of jitter in high-speed circuits and reducing it for increasing the system performance.

The novelty of this work lies in:

  • implementing the equations for the substrates used in the working program, Microwave Office (MWO) from AWR DE;
  • highlighting the fiberglass effect on the system performances using eye diagrams;
  • checking the matching conditions via scattering parameters using Smith charts;
  • designing circuits, simulations, extracting data, and interpreting the results in this software, MWO from AWR DE, which is a work-oriented program for high-frequency applications, but it is not specific for modeling certain materials.

The main contribution consisted in the:

  • implementation of the circuits in the MWO design tool from AWR-DE;
  • selection of the specifications parameters for two substrates, a low-cost, conventional FR4 and a high-speed oriented substrate, N4000-13, from the data sheets;
  • implementation and analysis of the circuits;
  • extraction of data from these simulations, their analysis and interpretation of the results.

We introduced new lines between lines 439-445:

Jitter refers to the deviation or variability in the timing of signals in a communication system. It is a phenomenon characterized by small, rapid, and unpredictable variations in the timing of signal edges. Jitter can occur in various electronic and communication systems, affecting the accuracy and stability of signal transmission. In digital communications, jitter can lead to timing errors, signal distortion, and decreased system performance. Thus, managing and minimizing jitter is crucial in ensuring reliable and efficient data transfer, especially in high-speed communication systems.

We introduced new lines between lines 532-545:

Minimizing jitter in a system brings several benefits. Firstly, it enhances the overall reliability of signal transmission by reducing timing uncertainties, ensuring that data arrives at its destination consistently and predictably. This is particularly crucial in applications where precise timing is essential, such as telecommunications and data networking. Secondly, a low jitter value contributes to improved signal integrity, reducing the likelihood of timing errors and distortion. This is especially important in high-speed digital communication systems, where even small variations in signal timing can lead to data corruption. On the other hand, minimizing jitter is key to achieving stable and accurate synchronization between different components within a system. In scenarios like audio and video streaming or real-time data processing, maintaining a low jitter level helps prevent synchronization issues and ensures a smooth and seamless user experience.

In conclusion, achieving a minimal jitter value is essential for maintaining the reliability, integrity, and synchronization of signals in various communication and electronic systems.

 

Comment 2: The authors have cited basic references of websites and not discussed the research. I would highly suggest authors to have literature review of latest research papers  of dielectrics and understand the concept of research papers. Then present the novel research ahead of published work.

Answer:

Thank you for this comment.

The references chapter contain articles presented in renown journals or conferences dedicated to the signal integrity problems but also, the website of simulation software (Microwave Office) and, of course, the datasheets of the studied substrates. One by one, each paper mentioned in the References chapter was discussed in the Introduction section and also for comparison purpose of the obtained results.

The selection of the reference papers include both very new studies, e.g. 2023 year, but also well known books from specific literature with detailed synthesis of the analyzed parameters although the year of appearance is in ‘90s. It also includes references from authors that are recognized all around the world for their contributions in the field of high and very high frequency circuit design and analysis.

We introduced new lines between lines 200 - 209:

The subject of this research is of interest for high and very high-frequency circuit design industry, and its analysis, as shown by the references cited by this work. From those reference we may highlight [2], since one of its authors, Yuriy Shlepnev, is well-known in the circuit design industry, particularly in the field of simulations and analysis of paths for high and very high-frequency signals (HF and VHF). He is the founder and president of Simberian Inc., which develops the Simbeor software, and is world-wide recognized for his contributions to the field of Printed Circuit Board (PCB) trace design and for developing software tools that facilitate precise simulations of signal behavior in such environments. His works and presentations have often been featured at major conferences in the field.

 

Comment 3: The authors states that "We performed simulations in the time domain using the eye diagram for the rates of 539 1GHz and 10 GHz and for the lengths of 120 mm and 250 mm. " Why do performed this simulations? What is the purpose and benefit of this research.

Answer:

Thank you for this comment.

As per journal’s recommendation’s, the methods were described in detail starting with the schematics implemented in the simulation tool, codes written for the frequency domain dependent parameters, results presented as graphical representation but also tabular representation for highlighting the main interesting points, as minimum, maximum or cross-corners extracted from jitter analyses for easy understanding and clearness of the paper results. On the same idea we briefly described all the parameters that were used for characterization, e.g. insertion and return loss, or jitter, and appropriately cited articles for composite substrates patterns or timing skew where needed.

We introduced new lines between lines 681 - 686:

To highlight the influence of the high data rates, the frequency of the data source was varied from 1 GHz, small rates, to 10 GHz, high rates. The interconnection lengths selection, single ended or coupled, was made between 120 mm and 250 mm, since these are typical lengths on backplanes where signal integrity issues have to be considered. Higher frequencies and higher lengths will be analyzed in our future work.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors present a time-domain analysis of transmission lines with frequency-dependent dielectrics, focusing on the effects of fiberglass on system performance. They evaluate the circuit's matching conditions using Smith chart simulation and provide a time-domain analysis of the eye diagram. The study highlights the effect of increasing the rate on composite substrates for coupled or single-ended interconnects on PCBs.

The paper contributes insights into timing analyses of transmission lines using frequency-dependent dielectrics by considering composite substrates and their effect on high-speed design constraints. The authors highlight the importance of considering the fiber weave effect and its impact on system performance. Their findings can help PCB and system designers optimize their PCB designs for high-speed circuits and ensure signal integrity.

I have the following comments:

As the authors provide some references to previous studies, and highlights their findings, there is a lack of comprehensive comparison. It would be beneficial to further discuss and analyze the findings in relation to existing research in the field of signal integrity and timing analyses, perhaps, by providing a comparison table.

The authors briefly draw some conclusions and discuss time domain analysis, but there is a lack of in-depth discussion and interpretation of the results, lots of simulated eye diagram would be somehow refined. Further analysis and discussion of the findings could strengthen the paper's contribution to the scientific community.

The language of the paper can be improved further, inspecting typo and grammar errors. Here is a few example

"more costly, in comparison" -> "more costly in comparison"

"various analyses, including Acoustic Emission" -> "various analyses, including acoustic emission"

"Fiber glass" -> "Fiberglass"

"thick unsymmetric" -> "thick unsymmetrical"

"with different CFRP" -> "with different CFRPs"

"acoustic wave propagate with that in mind, the negative side effect are" -> "acoustic wave propagates; with that in mind, the negative side effects are"

 

Comments on the Quality of English Language

Editing may be required but mostly it is readable

Author Response

Dear Reviewer,

 

Thank you for your review. All your remarks are valuable ones and we have taken them into consideration, helping us to increase the quality of our paper and to include all necessary aspects of scientific work. We hope that the paper is more clearly understandable now. Thank you again for your valuable review. For a better understanding, we include below the details of the manuscript reviews and our responses to the comments that include point-by-point explanations.

Point-by-point response to Comments and Suggestions of reviewer

Comment 1: As the authors provide some references to previous studies, and highlights their findings, there is a lack of comprehensive comparison. It would be beneficial to further discuss and analyze the findings in relation to existing research in the field of signal integrity and timing analyses, perhaps, by providing a comparison table.

Answer:

Thank you for this comment.

The reference for [1] presents frequency type analysis for N4000-13 manly, FR4 was only used to be a composite type substrate, traditional one, mentioned as a well-known substrate. This can be verified on the results extracted from graphs representation for various lengths of coupled and uncoupled lines on microstrip and stripline technology.

In this paper, we introduced, for comparison purposes, two new references, [2] and [22], and we highlighted their findings that have a similar set of analyzed parameters at lines 308-330. We also mentioned the reason why we consider important to analyze the jitter and eye corners extracted from eye diagrams additional to differential and single ended skew.   

We introduced new lines between lines 308-330:

In [2] the authors present different patterns for very high speed bus designed in Double Data Rate (DDR) technologies – DDR5 that operates at 8.4 GT/s and DDR6 that works at 12.8 GT/s and analyses them in terms of delay and impedance variations, comparing different patterns of fiber weaves as 1030, 1080, 1078 and 3313 in terms of delay deviation exceedance and differential skew exceedance. Similar interconnections type are analyzed, single ended and differential PCB interconnects as it is analyzed in our systems. The main point of interest here is the variation of skew, but this should be completed with information regarding the jitter, eye corners figures in different substrates, microstrip and stripline. The results can be extracted easily from the eye diagrams making data rate, substrate type swappable as it will be demonstrated in chapter 3. The same 10 GHz data rate was of interest in article [2] and also the S parameters are indicated to be represented with the frequency variation to extract information about periodic response in terms of reflection coefficient. Additionally, in article [1], was demonstrated that insertion loss should be analyzed to highlight the influence of the attenuation over a certain length with the increase of frequency.

In [22] the authors turn their attention on fiber weave effect only for high-speed PCBs, and compare different fiber waves patterns, as 1035, 1078, 1080, and 2166 in terms of impedance fluctuations and phase difference on the traces at high data rates, over 56 Gbps. The dielectric constant fluctuation of different types of fiber weaves is analyzed for the mentioned patterns, affecting the impedance of the trace and signal propagation delay.  In this research the focus is oriented towards impedance fluctuation in time and phase difference in frequency, for rates up to 4 Gbps. Here also the study would be complete if additional information regarding jitter is provided.      

 

Comment 2: The authors briefly draw some conclusions and discuss time domain analysis, but there is a lack of in-depth discussion and interpretation of the results, lots of simulated eye diagram would be somehow refined. Further analysis and discussion of the findings could strengthen the paper's contribution to the scientific community.

Answer:

Thank you for this comment.

The results obtained in this work have been centralized in the tables presented in the appendix A, where we included 2 tables: Table A.1 for the values obtained in the case of microstrip technology for rise and fall times, and Table A.2 for the eye corners, and in Appendix B, where we also included 2 tables containing of course the same parameters as in tables A1 and A2, but for stripline technology. If you consider it is better to include them in the results chapter 3, please let us know. In addition to the tables in the appendices, in the Results and Discussions chapter, we presented the results obtained for jitter in Tables 1 and 2 for both technologies. To highlight the high data rates influence, the frequency was varied from 1 GHz, small rates, to 10 GHz, high rates.

We tried to clarify and expand the analysis and discussion in the paper by introducing new paragraphs as follows.

We introduced new lines between lines 373-388:

The eye diagrams are graphical representations used in signal processing and telecommunications to assess the quality and integrity of digital signals. They are particularly valuable in high-speed communication systems. An eye diagram is formed by overlaying multiple signal periods on top of each other, creating a visual representation of signal quality. The resulting pattern typically resembles an "eye," hence the name. The horizontal axis represents time, while the vertical axis represents signal amplitude.

Key aspects of eye diagrams include: opening width, rise and fall times, jitter and noise. The width of the "eye" opening provides an indication of signal timing and the potential for timing errors. Rise and fall times, often measured at the edges of the eye, represent the speed at which the signal transitions between its high and low states. Deviations from the ideal eye shape indicate the presence of jitter (timing variations) and noise, both of which can affect signal reliability.

The clearer and wider the eye opening, the better the signal quality. Engineers use eye diagrams to quickly assess and troubleshoot signal integrity issues, making them a valuable tool in optimizing communication systems, especially those operating at high data rates.

We introduced new lines between lines 580-634

The time domain analysis and frequency domain analysis are two distinct approaches in the study of signals and systems. The Time Domain Analysis is a method that examines the behavior of signals over time, focusing on how the signal varies over time and the temporal relationships between different signal events. The primary advantages of this analysis include detecting specific events within a time interval and evaluating the system's response over time. However, this method has limitations, such as not providing direct information about the frequency content of the signal.

Frequency Domain Analysis is a method that investigates the frequency content of signals, revealing the frequency components that make up a signal and their intensity. The advantages of frequency domain analysis lie in studying the frequency spectrum, identifying dominant frequencies, and evaluating how a system responds to different frequencies. However, it is limited in its inability to provide information about the timing or sequence of events over time.

Therefore, it is crucial to study both cases. Time domain analysis and frequency domain analysis offer different perspectives on system behavior. Combining both methods provides a more comprehensive understanding. Some faults or issues may be more evident in a time-domain analysis, while others may be better understood by exploring their frequency content. In the design and analysis of systems, understanding behavior in both domains can contribute to optimizing performance and stabilizing the system. By approaching both methods, more robust and complete conclusions can be drawn about the characteristics of the analyzed signals and systems.

Article [1] presents only frequency domain analyze. We have centralized the results obtained in article [1] in two tables, table 3 for reflections loss and table 4 for insertion loss.

Table 3. Jitter values for stripline lines extracted from simulations results

Technology type

Mode type

Reflection loss [dB]

Microstrip

Differential

41

Stripline

68

Microstrip

Common

46

Stripline

48

As mentioned in [1], a stripline interconnections presents improved reflection loss comparing to microstrip interconnections and, as can be seen in the table 3, we have a reduced value for reflection loss for stripline, 68 dB, compared to 41 dB for microstrip technology in differential mode. The difference is much lower between the two technology type for common mode, 48 dB vs. 46 dB.

Table 4. Jitter values for stripline lines extracted from simulations results

Technology type

Interconnections lengths [mm]

Insertion loss – Resonances Frequencies [GHz]

Microstrip

60

15

Stripline

12

Microstrip

120

9

22

Stripline

8

19

Microstrip

200

5

14

23

Stripline

3

11

19

27

Microstrip

250

4

11

19

26

Stripline

3

9

15

21

28

                       

As mentioned in [1], the number of resonance frequencies increase with the length of interconnection for both microstrip and stripline technology. As it was demonstrated, in case of stripline, we have additional frequencies of resonance compared to microstrip technology, 3 resonances for microstrip compared to 4 resonances for stripline at 200 mm or 4 resonances vs. 5 resonances for 250 mm for the same technologies, as it can be seen in table 4.

Besides frequency analyses we demonstrated that, despite the fact that the stripline technology is a more lossy medium it does not distort the signal as much as the microstrip variant especially with the increase of data rates. In chapter 3, we analyzed the corresponding substrates, FR4 and N4000-13, in time domain showing that the traditional FR4 substrate has an increase of the jitter with the increase of frequency for both microstrip and stripline interconnections much more important compared to N4000-13. The distortion of the signal is illustrated in the figure 13.a,b for microstrip at 1 GHz compared to 14.a,b for stripline at the same rate. With the increase of frequency, 10 GHz, the stripline wave form and the corresponding eye diagram presents low jitter, low overshoot and undershoot while for the microstrip lines these parameters increase. The values of the jitter are presented in table 1 for microstrip and in table 2 for stripline and transition rise and fall time and eye corners are summarized in appendix A and B for the two frequencies. The jitter values for microstrip at 1 GHz is 1.117 ps and that at 10 GHz is 1.2659 ps, showing an increasing of jitter of 11.76% compared to 1.8578 ps at 1 GHz and 1.9901 ps for 10 GHz for the stripline, meaning a 6.65% increase of the jitter with the increase of frequency.

The results presented in [1] together with the results from our present paper allows a complete study of a given material for both microstrip and stripline technology, as both frequency and time domain analysis will provide particularities either for reflection loss, insertion loss, number of resonance frequencies, jitter with the increase of data rates.

 

 

 

Comment 3: The language of the paper can be improved further, inspecting typo and grammar errors. Here is a few example...

Answer:

Thank you for this comment.

We have made all the changes suggested by you, plus a few more.

We made changes to lines:

  • Lines 32-33

"more costly, in comparison" -> "more costly in comparison"

  • Line 44

“Differential Skew Exceedance” -> “differential skew exceedance”

  • Lines 48-49

"various analyses, including Acoustic Emission" -> "various analyses, including acoustic emission"

  • Line 57

“Fiber glass" -> "Fiberglass"

  • Line 60

"thick unsymmetric" -> "thick unsymmetrical"

  • Lines 78-79

"with different CFRP" -> "with different CFRPs"

  • Line 81

"acoustic wave propagate with that in mind, the negative side effect are" -> "acoustic wave propagates; with that in mind, the negative side effects are"

  • Line 91

“composite overwrapped pressure vessels” -> “Composite Overwrapped Pressure Vessels”

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have worked on the comments however the quality of the paper can be increased. The scientific contribution is very low however it can be increased by working abit.

Literature review is very less. I would highly suggest to add the key papers. Citing should be done of peer reviewed papers rather than the websites. It is more authentic.

Rest I would suggest to give some practical evaluation of the key concept.

The article should be proofread and quality of technical writing should be enhanced.

Comments on the Quality of English Language

The article should be proofread and quality of technical writing should be enhanced.

Author Response

Dear Reviewer,

 

Thank you for your review. All your remarks are valuable ones and we have taken them into consideration, helping us to increase the quality of our paper and to include all necessary aspects of scientific work. We hope that the paper is more clearly understandable now. Thank you again for your valuable review. For a better understanding, we include below the details of the manuscript reviews and our responses to the comments that include point-by-point explanations.

Point-by-point response to Comments and Suggestions of reviewer

Comment: Literature review is very less. I would highly suggest to add the key papers. Citing should be done of peer reviewed papers rather than the websites. It is more authentic.

Rest I would suggest to give some practical evaluation of the key concept.

The article should be proofread and quality of technical writing should be enhanced.

 

Answer:

Thank you for this comment.

In order to make those things clearer for the reader we completed the paper as follows.

We have added new and recent references that suits to our work.

[37] Songzuo Liu, Habib Hussain Zuberi, Yi Lou, Muhmmad Bilal Farooq, Shahabuddin Shaikh & Waleed Raza, M-ary nonlinear sine chirp spread spectrum for underwater acoustic communication based on virtual time-reversal mirror method, EURASIP Journal on Wireless Communications and Networking, 2021

[41] Kartheek Nalla, Amendra Koul, Seungyong Baek, Mike Sapozhnikov, Giorgi Maghlakelidze, Jun Fan, Measurement and correlation-based methodology for estimating worst-case skew due to glass weave effect, 2017 IEEE International Symposium on Electromagnetic Compatibility & Signal/Power Integrity (EMCSI), 2017

[42] Alex Manukovsky, Yuriy Shlepnev, Shimon Mordooch3, Quantification of Delay and Skew Uncertainty due to Fiber Weave Effect in PCB Interconnects, 2023 IEEE 32nd Conference on Electrical Performance of Electronic Packaging and Systems (EPEPS), 2023

[43] Gang Qiao, Tianlong Ma, Songzuo Liu, Muhammad Bilal, A frequency hopping pattern inspired bionic underwater acoustic communication, Physical Communication, 2021

[44] Xuefei Ma, Waleed Raza, Zhiqiang Wu, Muhammad Bilal, Ziqi Zhou, Amir Ali, A Nonlinear Distortion Removal Based on Deep Neural Network for Underwater Acoustic OFDM Communication with the Mitigation of Peak to Average Power Ratio, Applied Sciences, Special Issue Underwater Acoustic Communications and Networks, 2020

 

We introduced new lines between lines 327-329:

The interconnections are modeled as a transmission channel with a transfer function in frequency domain, represented by parameter S21 or IL and its corresponding in time domain that can be obtained via a similar procedure as in article [37].

We introduced new lines between lines 615-626:

For a given interconnection on a PCB, we can evaluate the skew that is unintentionally induced in a differential pair due to misalignment of conductors and glass fiber bundles in PCB substrates [41], the delay uncertainty caused by FWE in sin-gle-ended and differential variants measuring Delay Deviation Exceedance and Differential Skew Exceedance defined in article [42] as probabilities of exceeding a certain limit and are derivate from 3D EM analysis of traces over composite dielectric with glass fiber bundles in resin. In [42] is demonstrated that wider traces will see less variation of these metrics compared to narrow traces and is recommended to apply the proposed numerical experiment on each particular case. We can also evaluate the crosstalk due to a tight separation between routes, this behavior is evaluated via S parameters, with detection of a signal from a trace to another, even if the power level is small enough. This traditional technique is widely use for electromagnetic and acoustic communications as in [43, 44].

Comment:Rest I would suggest to give some practical evaluation of the key concept.

The article should be proofread and quality of technical writing should be enhanced.

Thank you for this comment. We verified again the quality of technical writing, and we hope it is better now.  The practical evaluation of key concept is given in the conclusions section rows 668-690.

First, we checked the matching of the circuits with the help of the  distribution parameters that we represented on the Smith chart. We noticed how these parameters are located in the middle of the Smith chart, which means that the circuits are matched. In order to check the performance of the circuits, we performed simulations in the time domain using the eye diagram representation. We simulated the circuits at three different frequency rates (1GHz, 10 GHz and 30 GHz) for two-line lengths (60 mm and 250 mm). Comparing these results, we noticed that the circuits designed in strip-line technology offer better performances, the simulation results being more favorable. This happens because in the case of microstrip technology, the transmission is done through the air, and this leads to the appearance of coupling on the neighboring line. Based on the obtained eye diagrams, we were able to extract data about the rise time and the fall time. It was highlighted how with the increase of the frequency rate (from 1GHz to 10 GHz), the transition from the upper front to the lower levels is no longer done through a single point as it happens at a rate of 1 GHz. Also, we demonstrated how with the increase of the frequency rate, the upper and lower levels exceed the eye mask. Given the results we noticed that N4000-13 presents a lower variation of the rise and fall time for microstrip technology, 16.67%, comparing to FR4 substrate, 27.50% (values obtained for ). We noticed that the jitter values are lower for circuits with N4000-13 material compared to circuits with FR4 material. The simulations showed that for stripline technology the jitter for N4000-13 presents a lower increase in comparison to microstrip technology (6.65% vs. 11.76%) with the increase of frequency. For microstrip the jitter is lower comparing to stripline technology, but the influence of the frequency increase has lower impact on N4000-13 substrate.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have addressed all my concerns and have greatly revised the paper. I have a few more comments that need to be considered before publication.

Firstly, Tables 3 and 4 are titled as jitter values, but they present IL and RL values.

 

  1. It is better to remove the text (P.5/L214) "implementing the equations for the substrates used in the working program, Mi-214 Crowave Office (MWO) from AWR DE" as it is not a novelty but an activity towards developing novelty.
  2. Accordingly, the text (P.5/L222) "implementation of the circuits in the MWO design tool from AWR-DE;" seems to be redundant as it is implementation.
  3. It is better to refer to the source of Fig.3 if it is not created by the authors.

 

 

 

 

 

 

Comments on the Quality of English Language

There is no need to review the revised version again. It can be published directly.

Author Response

Dear Reviewer,

 

Thank you for your review. All your remarks are valuable ones and we have taken them into consideration, helping us to increase the quality of our paper and to include all necessary aspects of scientific work. We hope that the paper is more clearly understandable now. Thank you again for your valuable review. For a better understanding, we include below the details of the manuscript reviews and our responses to the comments that include point-by-point explanations.

Point-by-point response to Comments and Suggestions of reviewer

Comment 1: Firstly, Tables 3 and 4 are titled as jitter values, but they present IL and RL values.

Answer:

Thank you for this comment.

We modified the line 607:

Table 3. S parameters for stripline and microstrip

We modified the line 613:

Table 4. Insertion loss for stripline and microstrip for various interconnections' lengths

 

Comment 2: It is better to remove the text (P.5/L214) "implementing the equations for the substrates used in the working program, Mi-214 Crowave Office (MWO) from AWR DE" as it is not a novelty but an activity towards developing novelty.

Comment 3: Accordingly, the text (P.5/L222) "implementation of the circuits in the MWO design tool from AWR-DE;" seems to be redundant as it is implementation.

Answer:

Thank you for this comment.

We modified and introduced new lines between lines 214-220:

The novelty of this work lies in:

  • highlighting the fiberglass effect on the system performances using eye diagrams;
  • checking the matching conditions via scattering parameters using Smith charts;
  • designing circuits, simulations, extracting data, and interpreting the results in this software, MWO from AWR DE, which is a work-oriented program for high-frequency applications, but it is not specific for modeling certain materials, and accomplish this behavior by implementing the equations for the substrates used in the design tool.

 

Comment 4: It is better to refer to the source of Fig.3 if it is not created by the authors.

Answer:

Thank you for this comment.

We modified the lines 263-265:

Figure 3. Fiber weave styles. Loose weaves (left) create greater skew and impedance variations in a board compared to a tight weave (right) [17]

 

 

Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have worked hard and improved the quality of paper and now it is appropriate to be published.

Comments on the Quality of English Language

I would suggest proofreading the whole paper and try to enhance the quality of English as much as possible.

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