Modeling of a Compact Dual Band and Flexible Elliptical-Shape Implantable Antenna in Multi-Layer Tissue Model

Round 1

Reviewer 1 Report

Scientific issues:

1. The literature on the subject is insufficiently reviewed in the Introduction.

2. Despite the fact that "In [10-16], several techniques are used to improve the gain and bandwidth." is written, these methods are not mentioned.

3. The literature review was insufficiently conducted, and the studies that have been published on this subject are not mentioned.

4. Before the paragraph that describes the study, there are only eight sentences in the introduction. The introduction lacks sufficient information.

5. It is stated that the proposed antenna is flexible, but it is not specified how the substrate enables this flexibility. In addition, there are no visuals to support the information on how the flexible structure functions. A classical microstrip antenna design is proposed.  It's just about "The idea behind the elliptical shape of the design is to make the implantable antenna flexible and more smooth for the patient." sentence.

6. The authors use the term "return loss" throughout their article. Nonetheless, the curves shown in Figure do not correspond to return loss. Return Loss values cannot ever be negative. These data may also be referred to as the reflection coefficient, scattering parameter, or s-parameter. Please check the following reference for more information:

Definition and Misuse of Return Loss [Report of the Transactions Editor-in-Chief]: https://doi.org/10.1109/MAP.2009.5162049

7. Instead of Figures 3a and 3b, it would be clearer and more appropriate to present the plot of S11 data between 0.2 and 3.5 GHz. Currently, the frequency range from 0.8 GHz to 2 GHz cannot be seen clearly. For a better understanding of dual band performance, the two graphs should be eliminated and a single graph should be presented for the frequency range of 0.2 GHz to 3.5 GHz. The causes of graph fluctuations should also be explained. S11 values cannot exceed 0 dB at any time.

8. In this study, only simulation was performed; no fabrication or measurements were conducted to compare the antenna's actual performance. This is a significant flaw. For instance, Fig. 3b demonstrates that the S11 value reaches -50 dB, and in the frequency range of approximately 2 GHz to 3.5 GHz, the S11 values of the antenna are around -10 dB or lower; however, it is unknown how this performance will translate to the manufacturing stage.

 

Format/Typoo/Grammar issues:

1.  The article's language should be improved. There are numerous grammatical and narrative errors in the English.

2. The images presented in the study are of low resolution and quality. The figure resolutions must be increased.

3. Figures 1, 5, 7, and 9 are direct screenshots from the CST program. These images should be generated in a separate program specifically for the article.

4. The red-colored texts should have their colors corrected.

5. The position of Table 2 on the page has been shifted to the left; this should be corrected. Additionally, the concept of Return Loss is employed incorrectly in this table. Check for instances of Return Loss throughout the article.

6. Table 1 is provided as an image. Consequently, it appears to be of poor quality. The table must be modified and incorporated into the text.

Author Response

Dear Reviewer;

thanks a lot for your effort and comments.

Regards to your comments 1-4, the literature review is expanded, and more details are presented about the gain enhancement techniques used in the related references.

For comment 5, the flexibility is obtained by choosing an elliptical shape antenna and avoiding sharp edges in the conventional rectangular shape implantable antennas.

Regards to comment 6, the return loss is replaced by reflection coefficient S11.

Based on comment 7, Fig.3a and Fig.3b are merged in a one figure and the frequency range is readjusted.

Regards to comment 8, we are very interested to build the design and make measurements. We asked for the materials required in our project but unfortunately, we have in Palestine many challenges due to political issues. It will take long time for the materials to arrive and sometimes our order is rejected.

 

 

In regard to format/grammar issues.

the language is revised, and the resolution of the figures is increased.

 

Reviewer 2 Report

Dear Authors,

*) Please provide results for a experimental prototype. AS it is not, the paper is weak since only simulation is concerned.

Thanks

Author Response

Dear The Reviewer;

Thanks a lot for your effort in revising my paper.

Regards to your comment, we are very interested to build the design and make measurements. We asked for the materials needed in our project but unfortunately, we have in Palestine many challenges due to political issues. It will take long time for the materials to arrive and sometimes our order is rejected.

Best Regards

 

Reviewer 3 Report

The authors present a flexible compact size elliptical-shaped implantable antenna with dual-band functionality. The antenna is proposed for biomedical application. However, according to the presented data, the antenna exhibits a high level of Specific Absorption Rate (SAR) than the standard acceptable SAR value suggested by WHO (World Health Organization) and FCC (Federal Communication Commission). Several modifications and concerns must be addressed before resubmission.

1.      The authors don’t show any measurement data along with the prototype of the proposed antenna. The authors should add the measurement data along with the proposed prototype to validate their work properly.

2.      The authors should simulate/measure the antenna according to the WHO and FCC guidelines for the SAR value. And, please compare the antenna’s SAR values with the standard values of WHO and FCC in a tabular form to show its suitability for actual usage.

3.      The proposed antenna geometry presented in Figure 1, is not clear. It seems the figure is a screenshot from the simulation software. Please provide a clear and understandable schematic for the antenna geometry which will fully represent the proposed antenna.

4.      Please improve the quality of Table 1. And keep the “MICS band” and “ISM band” at the center of the cell.

5.      The authors don’t compare the proposed work with the previous work available in the literature. Please compare the proposed work with the recently published similar works.

6.      The authors don’t follow the Journal template properly for the peer review. There is no page number and line numbers. The authors should format the article according to the journal’s template.

7.      Most of the Figures and Table 2 are highlighted in red color in the manuscript, which is unnecessary.

8.      Graph and title of Figure 7 should be on the same page.

 

9.      The references are not formatted accordingly to the journal template.

Author Response

Dear The Reviewer;

Thanks a lot for your comments.

Regards to comment 2, SAR values for this work in comparison with IEEE standard are presented in Table 1.

Comments 3, 4, 7 and 8, resolution for figures and tables is increased. Colors and titles are corrected and modified.

For comment 5, the main parameters for this work are compared to previous works in Table 3.

The Journal Template is used regards to comments 6, and 9.

Finally Regards to the 1st comment: we are very interested to build the design and make measurements. We asked for the materials needed in our project but unfortunately, we have in Palestine many challenges due to political issues. It will take long time for the materials to arrive and sometimes our order is rejected.

Best Regards

 

 

Round 2

Reviewer 1 Report

I appreciate the authors taking my comments into account.

It may be preferable to combine Figures 6 and 8 on a single graph with distinct line styles so that comparisons can be made and changes can be observed more clearly.

Author Response

thank you again for your comments in the second round.

both figures 6 and 8 are combined and presented in Fig.12.

a comparison between both skin and fat results is highlighted by a red color within the paper.

The proposed antenna is fabricated, and measured results are presented.

  best regards

 

Reviewer 3 Report

Most of the comments are not addressed properly.

The proposed work isn't validated through the measurement results. The authors were asked to add the measurement data and the proposed prototype to validate their work. However, the authors didn't add the measurement data.

The authors are also asked to simulate and measure the antenna according to the WHO and FCC guidelines for the SAR value. And to compare the antenna’s SAR values with the standard values of WHO and FCC in a tabular form to show its suitability for actual usage. The revised manuscript also doesn’t show any updates regarding those issues.

The revised manuscript doesn't show enough quality to be accepted for publication in Electronics.

 

Author Response

Thanks again for your comments in the second round that help in improving our work.

Regards to SAR values: we have already calculated the SAR values over (1g and 10g) for our proposed antenna.

The SAR values are also compared with EU limits (2W/Kg averaged over 10g) and FCC limits (1.6W/Kg averaged over 1g).

the maximum input power is calculated for our proposed antenna so that the SAR values do not exceed the standard limits, Table 1.

the proposed antenna is fabricated, Fig.6 and 7.

all modifications are highlighted as red color.

best regards

 

 

 

Round 3

Reviewer 3 Report

All the comments are addressed properly in the revised version. The manuscript has the potential to be accepted for publication in Electronics. Some minor updates are required before final submission.

1.      The authors didn’t format the manuscript properly for peer review. The line numbers are missing and an important section is also missing from the first page including the copyright section. Please format the manuscript according to the journal’s template properly for a smooth process from peer review to publication.

2.      All tables (Table 1, Table 2, and Table 3) in the manuscript are not properly formatted according to the journal’s template. Please update the table according to the journal’s template. And all data in the table are recommended to be centered in the table cell.

3.      In Table 1, there is an extra line space at the row indicating “SAR limits”. Please, remove this extra line spacing.

4.      Why Figure 12 is placed after the conclusion? Please put all the data before the conclusion section.

 

5.      The references are not formatted accordingly to the journal’s template. Please update the references according to the journal’s template.