Design of 2.5 Bit Programmable Metasurface Unit Cell for Electromagnetic Manipulation

Round 1

Reviewer 1 Report

The authors of the paper proposed a reflective metasurface structure with 2.5-bit operating states. The operating frequency of this device was set at 5 GHz. The design process requires consideration of a number of factors that affect high phase resolution. The authors therefore proposed the use of genetic algorithms in the initial design and optimisation of the chip. The idea seems all the more interesting as the experimental verification results are promising.

The literature has been selected correctly. Individual articles have been analysed in detail. The methodology has been presented in a complete manner. The different phases of design are well described and documented.

I have a few comments that I feel should be included in the final version of the manuscript:

1. are the equivalent parameters of the P-I-N diode derived from measurements (if so, this process should be described) or from catalogue data?

2. what is the rationale behind the assumed population value of 50?

3) What is the physical sense of quoting the phase value to 3 decimal places (Table 2)?

4. was the measuring set calibrated prior to the main measurements and were the wire parameters taken into account in the measurement process?

In conclusion, in my opinion the paper can be published after minor corrections.

Overall, the article was written in understandable language, although it should be checked for English and editing.

In my opinion, a scientific text should be written in the passive voice.

Example detailed remarks:

1. Line 16 - "we conctruct...." - better elaborate

2. Line 30 - "we often hope...." - vernacular

3. Line 56 - "hot research direction" - this does not sound good in a scientific text

Line 328 - please add "s" to the "imulation"

Line 359-360 and 362-363 - the same text in Conclusion

Author Response

Dear Reviewer:

Thank you very much for reading our manuscript carefully and we are grateful for your suggestions. According to your kind comments, we have added more descriptions about the novelty of the work to the revised manuscript. Modifications and supplements are highlighted in the revised manuscript.

Best wishes!

Yours sincerely

Jian Ren, on behalf of all authors.

Author Response File: Author Response.pdf

Reviewer 2 Report

In the manuscript " Design of 2.5-Bit Programmable Metasurface Unit Cell for Electromagnetic Manipulation," the authors proposed a reflection-type programmable metasurface unit cell loaded with four-pin diodes with 2.5-bit operating states. The paper needs modifications, and I recommend accepting the manuscript with significant revisions. 

1.                  How does the programmability of the metasurface unit cell contribute to its diversity in EM applications?

2.                  How does the phase response quantization accuracy affect the beamforming capabilities of antenna arrays, especially in scenarios with complex signal environments?

3.                  How does the metasurface unit cell handle various EM frequencies, and what considerations were deemed to ensure broad functionality?

4.                  Are there tradeoffs between achieving high phase response quantization accuracy in antenna array designs and other performance parameters, such as power consumption or cost?

5.                  What are the main challenges faced in designing and implementing a 2.5-bit programmable metasurface unit cell, and how were they addressed?

6.                  Can you explain the relationship between quantization errors and the accuracy of beam steering in antenna arrays during scanning operations?

7.                   How does the 2.5-bit resolution impact the accuracy and flexibility of EM manipulation using the metasurface unit cell?

8.                   Are there specific beamforming algorithms or strategies that are more robust to quantize errors in beam scanning?

9.                   Compare your proposed array antenna with relevant works. It's advised to add a comparison table.

Author Response

Dear Reviewer:

Thank you very much for reading our manuscript carefully and we are grateful for your suggestions. According to your kind comments, we have added more descriptions about the novelty of the work to the revised manuscript. Modifications and supplements are highlighted in the revised manuscript.

Best wishes!

Yours sincerely

Jian Ren, on behalf of all authors.

Author Response File: Author Response.pdf

Reviewer 3 Report

Authors should add efficiency of the metasurface antenna.

Add more states of the reconfigurable metasurface antenna.

Add comparison of with and without the diodes metasurface antenna performance

Technical english writing must improve 

Author Response

Dear Reviewer:

Thank you very much for reading our manuscript carefully and we are grateful for your suggestions. According to your kind comments, we have added more descriptions about the novelty of the work to the revised manuscript. Modifications and supplements are highlighted in the revised manuscript.

Best wishes!

Yours sincerely

Jian Ren, on behalf of all authors.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Thanks to the authors. They answered all concerns, and the manuscript now looks better than it was and can be accepted in its current form.

Reviewer 3 Report

The authors have revised the manuscript satisfactorily.  Thanks for a revised version.

Authors should double-check the typos and grammar