PONE-D-23-09968Dual Polarized 8-port Sub 6 GHz 5G MIMO Antenna for Smart Phone and Portable Wireless ApplicationsPLOS ONE

Dear Dr. Muhammad,

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: N/A

Reviewer #3: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: No

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This research work demonstrated and practically implemented a mobile phone antenna with dual-polarization capabilities which is a potential candidate for 5G MIMO communications. The antenna layout includes two-port microstrip feed lines with ground plane diamond slots placed at each of the PCB’s four corners. From this reviewer’s point of view promising results have been achieved and well discussed in the well-organized manuscript. So, the results have been experimentally validated and highlighted by providing a fair comparison with state-of-the-art. Although the concept and idea of this work were found interesting and they seem attractive for the scientific society, authors are requested to carefully address the following comments to improve the quality of the manuscript prior to final recommendation.

1) Please add the applied design method of the proposed MIMO antenna to the title.

2) Please explain some information about the advantage of the proposed decoupling method in the abstract section.

3) Average radiation gain and efficiency can be added to the abstract section.

4) Introduction section can be improved by adding more explanations along with proper references. For example, more discussions on 5g MIMO antennas are requested. Also, to realize MIMO antennas, isolation between the radiation elements are very important which need to be discussed. There are various decoupling methods which can be briefly mentioned. Below are helpful suggestions.

(i) 5G MIMO antenna

"H-shaped Eight-Element Dual-band MIMO Antenna for Sub-6 GHz 5G Smartphone Applications", IEEE Access, vol. 10, pp. 85619-85629, 2022.

"An Innovative Antenna Array with High Inter Element Isolation for Sub-6 GHz 5G MIMO Communication Systems", Scientific Reports, 12, 7907, 2022.

"mmWave Four-Element MIMO Antenna for Future 5G Systems", Applied Sciences, 12(9), 4280, 2022.

"Uni-Planar MIMO Antenna for Sub-6 GHz 5G Mobile Phone Applications", Applied Sciences, 12(8), 3746, 2022.

"Multiple Elements MIMO Antenna System with Broadband Operation for 5th Generation Smart Phones", IEEE Access, vol. 10, pp. 38446-38457, 2022.

“Novel MIMO Antenna System for Ultra Wideband Applications”, Applied Sciences, 12(7), 3684, 2022.

“A high gain multiband offset MIMO antenna based on a planar log-periodic array for Ku/K-band applications”, Scientific Reports, 12, 4044 (2022).

"A Compact CPW-Fed Ultra-Wideband Multi-Input-Multi-Output (MIMO) Antenna for Wireless Communication Networks,", IEEE Access, vol. 10, pp. 25278-25289, 2022.

"Printed Closely Spaced Antennas Loaded by Linear Stubs in a MIMO Style for Portable Wireless Electronic Devices", Electronics, 10(22), 2848, 2021.

"MIMO Antenna System for Modern 5G Handheld Devices with Healthcare and High Rate Delivery" Sensors, 21(21), 7415, 2021.

(ii) Decoupling methods to realize MIMO antennas

"A Comprehensive Survey on "Various Decoupling Mechanisms with Focus on Metamaterial and Metasurface Principles Applicable to SAR and MIMO Antenna Systems"", IEEE Access, vol. 8, pp. 192965-193004, 2020.

“Study on Isolation and Radiation Behaviours of a 34×34 Array-Antennas Based on SIW and Metasurface Properties for Applications in Terahertz Band Over 125-300 GHz”, Optik, International Journal for Light and Electron Optics, Volume 206, March 2020, 163222.

"Isolation Enhancement of Densely Packed Array Antennas with Periodic MTM-Photonic Bandgap for SAR and MIMO Systems", IET Microwaves, Antennas & Propagation, Volume 14, Issue 3, February 2020, pp. 183 - 188.

"Surface Wave Reduction in Antenna Arrays Using Metasurface Inclusion for MIMO and SAR Systems", Radio Science, 54, 1067–1075, 2019.

"Mutual-Coupling Isolation Using Embedded Metamaterial EM Bandgap Decoupling Slab for Densely Packed Array Antennas", IEEE Access, vol. 7, pp. 5182–51840, April 29, 2019.

"Mutual Coupling Suppression Between Two Closely Placed Microstrip Patches Using EM-Bandgap Metamaterial Fractal Loading", IEEE Access, vol. 7, Page(s): 23606 – 23614, March 5, 2019.

"Interaction Between Closely Packed Array Antenna Elements Using Metasurface for Applications Such as MIMO Systems and Synthetic Aperture Radars", Radio Science, Volume53, Issue11, November 2018, Pages 1368-1381.

“Antenna Mutual Coupling Suppression Over Wideband Using Embedded Periphery Slot for Antenna Arrays”, Electronics, 2018, 7(9), 198.

“Study on Isolation Improvement Between Closely Packed Patch Antenna Arrays Based on Fractal Metamaterial Electromagnetic Bandgap Structures”, IET Microwaves, Antennas & Propagation, Volume 12, Issue 14, 28 November 2018, p. 2241 – 2247.

“Meta-surface Wall Suppression of Mutual Coupling between Microstrip Patch Antenna Arrays for THz-band Applications”, Progress in Electromagnetics Research Letters, Vol. 75, page 105-111, 2018.

5) Design process of the proposed single antenna should be elaborated in depth. Please explain why authors have realized diagonal rectangular slots on the back? How were its dimensions optimized?

6) Quality of the plots are poor, they need to be improved.

7) More discussions on the surface current distributions should be added.

8) The feeding mechanism of the MIMO antenna should be explained in detail.

9) In comparison table 2 please add the terms “applied design method, radiation gain, and design complexity” as well to make it more comprehensive.

10) Please extend the conclusion by adding more numerical results and achievements.

11) Reference part needs to be improved as per above mentioned suggestions.

Reviewer #2: 1. An 8-port MIMO antenna for smartphone application is proposed.

2. Author need top carry out a systematic literature review to establish the technical contribution and need for the proposed work.

Please refer below paper for the same: Design and Analysis of Wideband Flexible Self-Isolating MIMO Antennas for Sub-6 GHz 5G and WLAN Smartphone Terminals

3. Also authors should refer to some latest sub-6 GHz MIMO antennas and do a thorough comparison to establish the novel contribution:

a. Compact wideband four element optically transparent MIMO antenna for mm-wave 5G applications

b. Multiband hybrid MIMO DRA for Sub‐6 GHz 5G and WiFi‐6 applications

c. Dual-band and dual-polarization CPW Fed MIMO antenna for fifth-generation mobile communications technology at 28 and 38 GHz

d. Wideband flexible/transparent connected-ground MIMO antennas for sub-6 GHz 5G and WLAN applications

4. Improve the quality of all the figures (Use vector software like origin or MATLAB to plot the results for better quality)

5. Show the coordinate axis next to the antenna geometry.

6. In Fig 6(a), gain should be in dBi and not dB.

7. For such configuration, the number of input ports increases significantly.

8. Present selected data in some of the graphs for brevity of data.

9. Fig 15 is not at all clear.

10. Authors should carry out SAR analysis.

Reviewer #3: The article "Dual Polarized 8-port Sub 6 GHz 5G MIMO Antenna for Smart Phone and Portable

Wireless Applications" need major revision to process to next level

1) The design orientation and associated mathematical formulation is missing in the paper

2) Figure captions not given with numbers for review

3) For eight ports, the transmission coefficient results shown are of low quality and data in zig zag.

4) Human phantom model is used in the work for analysis. I have not found any type SAR readings and related matter.

5) The CCL and Diversity Gain and TARC parameters for MIMO was not discussed and presented

6) 2D plots with several combinations without any analysis is presented

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes: Dr. B T P Madhav

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Dual Polarized 8-port Sub 6 GHz 5G MIMO Antenna for Smart Phone and Portable Wireless Applications

PONE-D-23-09968R1

Dear Dr. Muhammad,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Yuan-Fong Chou Chau

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: N/A

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Appropriate modifications have been applied as per requested to improve the quality of the manuscript to an acceptable level.

Reviewer #2: 1. The comments give by the reviewers are addressed and implemented properly.

2. The manuscript is good to be published in its present form.

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If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

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