A Broad Dual-Band Bandpass Filter Design Based on Double-Layered Spoof Surface Plasmon Polaritons

Round 1

Reviewer 1 Report

Dears.

The paper address, double-layered SSPPs with comb-shaped units are used for the main transmission line to realize broad dual-band bandpass filters. The circuits for efficient mode conversion and impedance matching from microstrip line to SSPPs are designed by applying gradient double-layered metal gratings with sector structures at two sides.

My opinion, this paper is well written, and the idea is well presented, and good comparison between the presented work and previous work.

So, my decision the manuscript is accepted with some minor corrections:

 

• 11 should be increasing its size to allow the reader to visualize the result clearly.
• If it is possible to state, the fabrication steps and the used devices to get the fig. 12 results.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The authors have presented a dual-band bandpass filter design based on Double Layered Spoof Surface Plasmon Polaritons (DLSSPPs). Some major modifications are needed in this manuscript as follows:

 

• The manuscript should be revised very carefully to correct all the typos and grammatical errors. There are several typos in the manuscript. For examples: 1) the captions of Fig. 4 and Fig. 11 are written incorrectly. 2) don’t use square bracket in Fig. 1[a]. 3) The references in the text are not in the numerical order and etc.  
• The S-parameters between 0-12 GHz is not acceptable. The filter cannot properly attenuate the higher frequencies. It is better to remove this figure or explain it clearly.
• What is the main advantages of the proposed filter compared to the other similar filter? it should be clearly described in the abstract. Also explain the advantages of the proposed filter performance according to the comparison table.
• All of the abbreviations are not explained in the text. For example, RBW%, Mea. IL and etc.
• It would be better to write the "operating frequency" instead of "No. of passbands" in the Table 1 third column.
• Explain in the results that how did you calculate the bandwidth%.
• It seems that the measured insertion losses are higher than 3 dB in some frequencies, which is not acceptable. Also if the the reported values in the table are measured values, it should be clarified.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

1. The proposed filter is compact with high isolation between the passbands. However, the quality of the manuscript needs to be improved. Just point out a few as follows.
2. In the first Section, the term “SSPP” can be found in Line 38. Later on, the term is defined over Line 40. Please define the abbreviation at first mention.
3. The meaning of “17” shown in Line 46 is not clear. Please clarify it.
4. Please clarify “F4B” shown in Line 81.
5. If Fig. 1 (b) is directly taken from ref. [35], it is recommended to add this reference number over the end of the figure caption.
6. The length ratio (Line 156) and the impedance ratio (Lin 157) need to be specified.
7. There are 5 subfigures in Fig. 11. However, the corresponding figure captions are problematic. Please correct it.
8. In most of journey papers, only cited articles will be included in a reference list. In this manuscript, many non-cited references are found in the reference section.
9. In Table 1, the term “RBW” should be “FBW”. Please correct it.

Author Response

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Reviewer 4 Report

In this paper, authors present a dual-band bandpass filter using double-layered spoof surface plasmon polaritons (SSPP). To induce the transmission zeros of SSPP, open and short stubs are employed. A parametric study for the proposed structure is conducted to examine the design parameter effect. The proposed structure is validated through the electromagnetic simulation and measurements. The paper is well written and organized. The reviewer suggests a few comments.

- It would be better if the effect of the stub position were examined.

- Please check the Fig. 12 (b). Its orientation is confusing.

- It would better if abbreviations in Table 1 were carefully checked.

- Please check the captions of Figs. 4 and 11

- Please check some typo and grammatical errors. (e.g., line 303)

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have addressed all of my comments and the paper can now be accepted in the present form.

Author Response

Thanks

Reviewer 4 Report

Thank you for considering the comments. Authors claim that the stub position effect will be studied in the future. However, I recommend that authors include the analysis in the revised manuscript. The key idea of this study is behind combining the stub with the SSPP. The concept of double layered SSPP is equivalent to the transmission line having sub-wavelength corrugations that is already introduced. So, the further analysis of the stub is needed to improve the quality and novelty of this study.  

Author Response

Point 1: Thank you for considering the comments. Authors claim that the stub position effect will be studied in the future. However, I recommend that authors include the analysis in the revised manuscript. The key idea of this study is behind combining the stub with the SSPP. The concept of double layered SSPP is equivalent to the transmission line having sub-wavelength corrugations that is already introduced. So, the further analysis of the stub is needed to improve the quality and novelty of this study. 

 

 

Response 1: Our deepest gratitude goes to you for your careful work and thoughtful suggestions, as shown in Fig. 7(d), the effect of the position of stubs on the performance of our designed SSPP filter structure was anylysised in the revised manuscript. (Line 205-219)

Author Response File: Author Response.pdf

Round 3

Reviewer 4 Report

Thank you for considering the comment.