A Mechanically Controlled Switchable Wideband Frequency–Selective Rasorber/Absorber

Round 1

Reviewer 1 Report

The authors present a discussion on mechanically-controlled switchable wideband frequency-selective absorber for communication technologies and radar. Overall the paper is good and well presented. There are a few concerns that need to be addressed.

1) S-parameters need to be presented in dB.

2) Please change the figures 2, 3, 7(b), 9 and 10b y-axis scale in dB 

3) How you have optimized the dimension of the unit cell? can you brief on it.

4) Which type of waveguide medium setup for excitation is followed to analyze the unit cell? Mater slave boundary condition or floquet  port analysis or wave port analysis?

5) On what basis do you arrive at the dimension of the unit cell? There is no mathematical equation which describes it in the paper.

6) Model design explanation needs to be detailed it is very superficial. You need to explain the waveguide analysis of this structure.

7) What is the effect we increase or decrease the square slot gap width?

8) How the square slot is positioned?

9) Fabrication model is needed to validate the simulated results.

10) Comparison of this absorber needs to be done with the similar type available in the literature.

Author Response

Dear Reviewer,

Thank you very much for providing us with detailed instructions regarding resubmission requirements.

Please find below our response to the comments and the corresponding changes we made to the manuscript; the changes are highlighted in red.

Yours sincerely,

Dr. Liansheng Wang (On behalf of all authors)

Response to the Reviewer I:

1.S-parameters need to be presented in dB.

We have changed the figures 2, 3, 7(b), 9, 10(b) and 11(b) y-axis scale in dB in the revision

2.Please change the figures 2, 3, 7(b), 9 and 10b y-axis scale in dB

We have changed the figures 2, 3, 7(b), 9, 10(b) and 11(b) y-axis scale in dB in the revision

3.How you have optimized the dimension of the unit cell? can you brief on it.

The method of parameter scanning is adopted to optimize the size parameters of the unit cell. We have added the expression in the revision.

4.Which type of waveguide medium setup for excitation is followed to analyze the unit cell? Mater slave boundary condition or floquet port analysis or wave port analysis?

The floquet port analysis is followed to analyze the unit cell. We have added the expression in the revision.

5.On what basis do you arrive at the dimension of the unit cell? There is no mathematical equation which describes it in the paper.

Based on our former research and similar report on rasorber/absorber[17,18], the method of parameter scanning is adopted to optimize the size parameters of the unit cell. We arrive at the dimension of the unit cell. We have added the expression in the revision.

[17]Qian G X, Zhao J M, Ren X M, Chen K, Jiang T, Feng Y J, Liu Y. Switchable Broadband Dual-Polarized Frequency-Selective Rasorber/Absorber. IEEE Antennas Wireless Propag. Lett,2019,18(12):2508-2512.

[18]Wang L S, Xia D Y,Fu Q H, Ding X Y, Wang Y. An electrically switchable wideband metamaterial absorber based on graphene at P band. Open Physics,2021,19: 460–466.

6.Model design explanation needs to be detailed it is very superficial. You need to explain the waveguide analysis of this structure.

We have detailed explained the model design in the revision.

The commercial electromagnetic simulation software Microwave Studio CST is used to simulate the unit cell. During the simulation process, the boundary condition at x and y direction is set as unit cell and the boundary condition at z-direction is set as open. The incident wave is along the z-direction, the electric and magnetic field of the incident wave is along the y and x-direction, respectively. The floquet port analysis is followed to analyze the unit cell. The frequency solver is used to calculate the electromagnetic properties of the unit cell.

We have added the expression in the revision.

7.What is the effect we increase or decrease the square slot gap width?

The bandwidth of the switchable rasorber/ absorber with the absorption over 90% and the transmission frequency is almost the same at different square slot gap width. We have added the results in the revision.

8.How the square slot is positioned?

The square slot is positioned at the metal plate of the third layer

9.Fabrication model is needed to validate the simulated results.

I am very sorry. Due to our experimental condition, we cannot carry out fabrication and experiment.

10.Comparison of this absorber needs to be done with the similar type available in the literature.

So far, most of the above-mentioned rasorber/absorbers are based on switchable PIN diodes, we firstly present a mechanically-controlled switchable wideband frequency-selective rasorber/absorber with the transmission window inside the absorption band based on frequency selective surface and the rotatable metal plate. Compared on the switchable rasorber/absorber based on PIN diodes[12,17], it has the advantages of simple, reliable and accurate control method with the application values on the communication and radar station.

[12]  Han Y, Che W, Xiu X, Yang W, and Christopoulos C. Switchable low-profile broadband frequency-selective rasorber/absorber based on slot arrays. IEEE Trans. Antennas Propag, 65(12): 6998–7008(2017).

[17]Qian G X, Zhao J M, Ren X M, Chen K, Jiang T, Feng Y J, Liu Y. Switchable Broadband Dual-Polarized Frequency-Selective Rasorber/Absorber. IEEE Antennas Wireless Propag. Lett,2019,18(12):2508-2512.

We have added the expression in the revision.

Author Response File: Author Response.pdf

Reviewer 2 Report

The presented article is interesting and it shows the recent trends for a mechanically-controlled switchable wideband frequency-selective rasorber/absorber with the transmission window inside the absorption band. The paper describes a wide experimental activity, but it lacks in many measurement-related points of views, that must be enhanced, considering the focus of the journal. The manuscript is well-written and worthwhile for publication. Irrespective of all the above-mentioned features.

Following have to be addressed,

1. The introduction is of good quality. if the intended application is related to radar detection systems, it may be necessary to list the competing switchable rasorber/absorber for radar systems or make a table of comparison of the proposed work with other published works.

2. Figure 2 and 3 presented the results of the S-parameter, but these results are simulated or measured. The authors are requested to compare simulated and measured results.

3. In the manuscript, authors presented the relative impedance in the figure 4. So, it is encouraged to mention if the results from the simulation or the measurement.

3. There are numerous grammatical and formatting errors in the manuscript. Not mentioning individually. Please correct all such errors

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

Thank you very much for providing us with detailed instructions regarding resubmission requirements.

Please find below our response to the comments and the corresponding changes we made to the manuscript; the changes are highlighted in red.

Yours sincerely,

Dr. Liansheng Wang (On behalf of all authors)

Response to the Reviewer II

1.The introduction is of good quality. if the intended application is related to radar detection systems, it may be necessary to list the competing switchable rasorber/absorber for radar systems or make a table of comparison of the proposed work with other published works.

So far, most of the above-mentioned rasorber/absorbers are based on switchable PIN diodes, we firstly present a mechanically-controlled switchable wideband frequency-selective rasorber/absorber with the transmission window inside the absorption band based on frequency selective surface and the rotatable metal plate. Compared on the switchable rasorber/absorber based on PIN diodes[12,17], it has the advantages of simple, reliable and accurate control method with the application values on the communication and radar station.

[12]  Han Y, Che W, Xiu X, Yang W, and Christopoulos C. Switchable low-profile broadband frequency-selective rasorber/absorber based on slot arrays. IEEE Trans. Antennas Propag, 65(12): 6998–7008(2017).

[17]Qian G X, Zhao J M, Ren X M, Chen K, Jiang T, Feng Y J, Liu Y. Switchable broadband dual-polarized frequency-selective rasorber/absorber. IEEE Antennas Wireless Propag. Lett,2019,18(12):2508-2512.

We have added the expression in the revision.

2.Figure 2 and 3 presented the results of the S-parameter, but these results are simulated or measured. The authors are requested to compare simulated and measured results.

I am very sorry. Due to our experimental condition, we cannot carry out fabrication and experiment.

3.In the manuscript, authors presented the relative impedance in the figure 4. So, it is encouraged to mention if the results from the simulation or the measurement.

The relative impedance is calculated from the simulation results. I am very sorry. Due to our experimental condition, we cannot carry out fabrication and experiment.

4.There are numerous grammatical and formatting errors in the manuscript. Not mentioning individually. Please correct all such errors

We have correct the grammatical and formatting errors revision

Author Response File: Author Response.doc

Round 2

Reviewer 1 Report

The author has addressed all my concerns, I do not have any further comments.