A Tunable Frequency Selective Rasorber with Broad Passband and Low Transmission Loss at X-Band
Round 1
Reviewer 1 Report
The authors have presented an article entitled "A Tunable Frequency Selective Rasorber with broad passband 2 and low transmission loss at X-band"
Few suggestions are listed below:
1. Introduction needs to improved.
2. In comparison table, try to include recent articles (2022-2023) and compare with outcomes.
3. The equations are not properly arranged.
Good
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The submitted paper “A tunable frequency selective rasorber with broad passband and low transmission loss at X-band” by S. Shi, Z. Chai, S. Zhang, Y. Shi and Y. Zhang is devoted to simulations of electromagnetic response of a newly designed frequency selective rasorber. This kind of devices is currently intensively investigated because of possible applications in stealth technologies and for solving electromagnetic compatibility problem. The main advantage (compared to FSS) is that the filtered frequencies are mainly absorbed and not reflected. A commonly used combing of lossy and lossless FSS to get both transmissive and adsorbing properties is employed. The unit elements containing chip-resistors and varactors are designed and the frequency tuning is realized by changing the capacity of varactors. The simulation was done employing HFSS software and equivalent circuit model. The S-parameters of the structure (as a two-port device) were obtained for different angles of incidence. The main advantage of the designed structure (compared to many others previously published) is probably associated with low insertion loss.
The main demerit of the study is that there is no experiential realization. Also there is a big discrepancy in the spectra modeled using ECM and HFSS. Nevertheless, the comprehensive simulation and modeling are provided. The text is well written. In my opinion the paper could be accepted for publication in Materials in its present form.
The misprint found: Line 267, “transverse and transverse polarizations”, probably transverse electric and transverse magnetic were meant.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors present studies on a frequency-selective rasorber (FSR) in the 4-16 GHz band. I can recommend publication after these observations are addressed:
1. The purpose of the study, together with the comparison between the FSR and other reported results, should be reported upfront, rather than in a table somewhere on page 10.
2. It is unclear how the authors establish the link between the geometric & material properties and the lumped circuit parameters. Lines 199-203 only declare these values, without any link
3. The work presented here is completely based on simulations, which is not specifically stated in the abstract or the introduction.
4. No study on the tolerance of the response vs variations in the geometric parameters is shown. This is usually covered by experimental results, but here there isn't any. The Authors should include such a study.
5. The authors may want to include recent studies on dielectric-semiconductor and all-dielectric FSRs in the THz and MIR as part of their reference list: https://doi.org/10.3390/polym13111860 , and https://doi.org/10.3390/s21165600
There are minor English corrections that need to be done, authors should re-read and correct mistakes.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
This manuscript A Tunable Frequency Selective Rasorber with broad passband and low transmission loss at X-band) describes a dual-mode frequency selective rasorber aimed at X-band. And dedicated modeling is provided. Below are the small issues to be considered before publication.
1. Capitalization is mix-used in the title. Please give it consistency.
2. The order of Figure 6 could be better, if 6, 11, and 14 Ghz, respectively.
3. In Figure 7, it is hard to recognize the S21_TE parameter. Is it the same or omitted?
4. For better understanding of the readers, I would be better to combine the contents of Figures 1 and 2 into one Figure to show its connectivity.
5. I cannot find an experimental approach in the manuscript. I suggest comparing the simulation with the real structure. If the author wants to argue about performances.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
