Microwave Common-Frequency Absorption/Transmission Mode Conversion Based on Active Components

Round 1

Reviewer 1 Report

The author introduces a new active frequency selective surface (AFSS) that can convert between absorption and transmission modes within the same frequency range. The simulation, fabrication, and measurement are clearly demonstrated in this work. However, the simulation and measurement of the work are not clearly discussed. Therefore, I recommend that the manuscript be accepted after major revision. My comments are listed as follows:     

 

1.      In Figure 3, the ON-/OFF states are applied in the bottom layer to switch the proposed AFSS into absorption and transmission modes. How much is the bias voltage applied on the AFSS? Moreover, what mode will the AFSS generate in ON or OFF states? The author did not mention those in detail in this manuscript.

 

2.      What analysis software does the author use to get the Equivalent circuit of AFSS?

 

3.      The author describes the reflectivity and transmissivity as S11 and S21, respectively, in Eq. (6) and Eq. (7). Why did the author not put the AFFS absorptivity in Figure 4?

 

4.      Simulated results in Figure 6 reveal that the proposed AFSS is not independent polarization. However, the circular independent polarization antennas offer versatile reception, reliable performance, wide-coverage, reduced interference, and stronger signals, making them suitable for various applications in wireless communication, satellite communication, RFID systems, and radio broadcasting.

 

5.      The inset of Figure 7 is a 90-degree rotation of Figure 2(a). Why did the author rotate the top layer in the fabrication?

 

6.      Figure 8(a) presents that the reflectivity and transmissivity scattering parameters have absorption peaks at 11.5 GHz and 12 GHz. Why did those peaks not appear in measurement absorptivity in Figure 8(c)?

 

7.      Figure 8 (b) presents the scattering parameters of measurement transmission states. However, the transmit transmissivity (S21) showed no transmission peak at 11.5.

 

 

8.      To help the readers have a more comprehensive understanding of the new research on metasurfaces, I suggest supplementing some latest works about biosensors with large refractive-index sensitivities [Photonics Research 10(9),2215-2222, 2022]; fano resonance base on multi-layer metamaterial [Optics Letters 47(22), pp 5781-5784, 2022], terahertz liquid crystal programmable metasurface [Optics Letters 47, no. 7 (2022): 1891-1894], Dual-band multifunctional coding metasurface [Photonics Research 10, no. 2 (2022): 416-425], electrically controllable terahertz metamaterials with large tunabilities and low operating electric fields using electrowetting-on-dielectric cells [Optics Letters 46, no. 23 (2021): 5962-5965] and metalens [Photonics Research 10, no. 4 (2022): 886-895].

Comments for author File: Comments.pdf

Author Response

List of Responses

Dear Editor and Reviewer:

Thank you for your letter and for the reviewer’s comments concerning our manuscript entitled “Microwave Common-Frequency Absorption/Transmission Mode Conversion Based on Active Components” (ID: electronics-2435749). The comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied the comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and responds to the reviewer’s comments are as follows:

 

Comment 1:

In Figure 3, the ON-/OFF states are applied in the bottom layer to switch the proposed AFSS into absorption and transmission modes. How much is the bias voltage applied on the AFSS? Moreover, what mode will the AFSS generate in ON or OFF states? The author did not mention those in detail in this manuscript.

Response:

Thanks for the helpful comment. It is true that we should clarify all the details in the paper. Actually, when the PIN diodes are in the OFF-state, the varactors are loaded with 5 V bias voltage, the AFSS functions as a bandpass filter at around 11.5 GHz, while when the bottom layer’s diodes are in the ON-state, the top layer’s varactors are loaded with a bias voltage of 16 V, the AFSS acts as an absorber at around 11.5 GHz. We have made explanations and modifications in the paper as follows.

Revision in the paper:

We have clarified in the main text to include this issue:

“when the PIN diodes are in the OFF-state, the varactors are loaded with 5 V bias voltage, the AFSS functions as a bandpass filter at around 11.5 GHz, while when the bottom layer’s diodes are in the ON-state, the top layer’s varactors are loaded with a bias voltage of 16 V, the AFSS acts as an absorber at around 11.5 GHz.”

 

Comment 2:

What analysis software does the author use to get the Equivalent circuit of AFSS？

Response:

Thanks for the helpful comment. It is true that we should include the relevant information to help the readers know how we get Equivalent circuit of AFSS.

We used the analysis software “AWR Microwave Office software” in this work and have made explanations in the main text.

Revision in the paper:

We have made explanations in the main text as follows:

“Figs. 3(a) and 3(b) illustrate the equivalent circuit model of the proposed AFSS under PIN diodes’ ON- and OFF-states, respectively. The Equivalent circuits of AFSS are obtained using AWR Microwave Office software.”

 

Comment 3:

The author describes the reflectivity and transmissivity as S11 and S21, respectively, in Eq. (6) and Eq. (7). Why did the author not put the AFFS absorptivity in Figure 4?

Response:

Many thanks for the helpful comment. The purpose of Figure 4 is to verify the accuracy of equivalent circuit, and therefore only the original S₁₁ and S₁₂ data are needed. By fitting the S parameters data from the HFSS and AWR software, we are able to determine the accuracy of the Equivalent circuit model.

Since the purpose of this figure in the part is not to acquire its reflection and absorption effects, therefore Figure 4 does not provide calculated results of absorption rate by Eq. (6) and Eq. (7). Calculated results of absorption rate is provided in Figure 8.

Revision in the paper:

We have made revisions in the main text to explain to the reader why we didn’t put AFFS absorptivity in Figure 4 as follows:

“Figs. 4(a) and 4(b) illustrate the scattering parameters’ comparison results between the full-wave simulation and the equivalent circuit model simulation in the transmission and absorption states. To clarify, we described the reflectivity and transmissivity as S₁₁ and S₂₁, respectively, because it is sufficient to verify the validity of the AWR software.”

 

Comment 4:

Simulated results in Figure 6 reveal that the proposed AFSS is not independent polarization. However, the circular independent polarization antennas offer versatile reception, reliable performance, wide-coverage, reduced interference, and stronger signals, making them suitable for various applications in wireless communication, satellite communication, RFID systems, and radio broadcasting.

Response:

Thanks for the helpful comment. Indeed, the circular independent polarization antennas offer versatile reception and is more suitable for various applications. However, this work is intended to develop AFSS for scenarios such as antenna dome.

Revision in the paper:

We added explanations in the abstract and introduction as follows:

“The developed AFSS structure is highly valuable to be used in scenarios such as antenna dome etc.”

 

Comment 5:

The inset of Figure 7 is a 90-degree rotation of Figure 2(a). Why did the author rotate the top layer in the fabrication?

Response:

Thanks for the helpful comment. It is our mistake to cause ambiguous to the readers, and we have revised the Figure to make it consistent in configuration with Figure 2.

Revision in the paper:

We made revisions in Figure 7:

Figure 7 Photograph of the fabricated prototype. (a) Top side. (b) Bottom side.

 

Comment 6:

Figure 8(a) presents that the reflectivity and transmissivity scattering parameters have absorption peaks at 11.5 GHz and 12 GHz. Why did those peaks not appear in measurement absorptivity in Figure 8(c).

Response:

Thanks for the helpful comment. Both the reflectivity and transmissivity scattering parameters have absorption peaks at 11.5 GHz, as is shown in Figure 8a and Figure 8b. Actually, The peak in measurement absorptivity also appears at 11.5 GHz in Figure 8c. Please refer to Figure 8c.

 

Comment 7:

Figure 8 (b) presents the scattering parameters of measurement transmission states. However, the transmit transmissivity (S21) showed no transmission peak at 11.5.

Response:

Thanks for the comment. Since Figure 8b and Figure 8d together demonstrate the transmission states, we suggest analyzing this mode combing these two figures. Referring to Figure 8d, it is clear that transmission peak appears at 11.5 GHz for calculated transmissivity, verifying the validity of the design.

 

Comment 8:

To help the readers have a more comprehensive understanding of the new research on metasurfaces, I suggest supplementing some latest works about biosensors with large refractive-index sensitivities [Photonics Research 10(9),2215-2222, 2022]; fano resonance base on multi-layer metamaterial [Optics Letters 47(22), pp 5781-5784, 2022], terahertz liquid crystal programmable metasurface [Optics Letters 47, no. 7 (2022): 1891-1894], Dual-band multifunctional coding metasurface [Photonics Research 10, no. 2 (2022): 416-425], electrically controllable terahertz metamaterials with large tunabilities and low operating electric fields using electrowetting-on-dielectric cells [Optics Letters 46, no. 23 (2021): 5962-5965] and metalens [Photonics Research 10, no. 4 (2022): 886-895].

Response:

Thanks for the helpful suggestions, we have carefully checked all the recommended papers and cited them in the paper. We have added supplement in the paper to analyze the above mentioned work on biosensors, metamaterial et al. as follows.

Revision in the paper:

We have cited and analyzed new references as follows:

“On the other hand, propagation mode control via metasurfaces are also well documented in recent years, which is capable of converting a linearly polarized (LP) incident wave into a circularly polarized (CP) wave or its cross-polarized LP wave at different frequencies [26]. Various types of metamaterials with strong electromagnetic resonance have been reported [27-32], for instance, Pan et al. proposed dual-band multifunctional coding metasurface in compact 5G/6G communication systems [27]. These researches covered from K band to THz.”

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is original and very interesting for the readers. I have one only comment and ask the authors to address it in the final version.

In the description it seems that the simulations of the AWR model do not include any I/O port/connector that, given the high frequencies, could affect the entire behaviour of the system. Also, powering the miniPCB using cables could afftect the antennas transmitting and receiving performance. I guess that the author have powered the card and soldered or connected it using some type or connector or cables for measuring its behavior and making comparisons with the expected simulated performance.

Please comment

Author Response

List of Responses

 

Dear Editor and Reviewer:

Thank you for your letter and for the reviewer’s comment concerning our manuscript entitled “Microwave Common-Frequency Absorption/Transmission Mode Conversion Based on Active Components” (ID: electronics-2435749). The comment is indeed valuable and very helpful for revising and improving our paper. We have made correction which we hope meet with approval. The main corrections in the paper and responds to the reviewer’s comment are as follows:

 

Comment 1:

In the description it seems that the simulations of the AWR model do not include any I/O port/connector that, given the high frequencies, could affect the entire behaviour of the system. Also, powering the miniPCB using cables could affects the antennas transmitting and receiving performance. I guess that the author have powered the card and soldered or connected it using some type or connector or cables for measuring its behavior and making comparisons with the expected simulated performance.

Response:

Thanks for the comment. Since the Figure 4 shows the simulation results in HFSS and AWR, the deviations caused by connector soldering can be omitted during the comparison process. As for the antennas transmitting and receiving performance, the I/O ports/connectors during the measured process are not connected to the AFSS. The AFSS just acts as a filter screen when S parameters are measured, and the ports/connectors are connected to the vector network analyzer.

In experiment, measurements are carried out in an anechoic chamber. Two X-band standard gain horns antennas are used as transmitting and receiving antennas. The prototype is surrounded by pyramid absorbers to reduce the diffraction effect. Before the measurement, the horn antennas and the prototype are normalized to eliminate the environmental impact. For transmission measurements, the two horn antennas are calibrated in free space, and then for reflection tests, a metal plate of the same size as the prototype is used for calibration. Then the horn antennas are used to transmit the normal incident quasi-plane wave, which is fixed 1 meter away from the prototype. The reflection coefficient is measured by placing the transmitting and receiving horn antennas on the same side of the prototype.

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript entitled “Microwave Common-Frequency Absorption/Transmission Mode Conversion Based on Active Components” has been submitted by the authors. The paper presents an interesting approach to microwave common-frequency absorption/transmission mode conversion using active components. The concept is novel and has the potential for practical applications in microwave systems. Some issues to be addressed will improve the quality of the manuscript. Therefore, I recommend this work could be published after the major revision

1.      The author needs to highlight the novel of this work in the abstract section.

2.      The author needs to add a comparative study based on the present finding in the introduction section.

3.      The paper lacks sufficient detail regarding the active components, their specifications, and the experimental setup configuration. Incorporating these specifics would enhance the reproducibility of the results.

4.      Comparing current methods would improve the paper. The experimental results are promising, however, the proposed method must be compared to other methods on efficiency, bandwidth, and cost.

5.       The English composition requires many improvements. The authors should proofread the manuscript carefully to minimize grammatical errors.

 

6.       All the references mentioned in the paper should be cited in the text or vice-versa.

Comments for author File: Comments.pdf

Author Response

List of Responses

 

Dear Editor and Reviewer:

Thank you for your letter and for the reviewer’s comments concerning our manuscript entitled “Microwave Common-Frequency Absorption/Transmission Mode Conversion Based on Active Components” (ID: electronics-2435749). The comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. We have studied the comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and responds to the reviewer’s comments are as follows:

 

Comment 1:

The author needs to highlight the novel of this work in the abstract section.

Response:

Thanks for the helpful comments.

We would like to highlight that traditional AFSS mostly use a monolithic metal as the bottom layer, which limits the transmission of electromagnetic waves, the conversion between absorption mode and transmission mode cannot be realized. At the same time, the existing new AFSS with absorption and transmission switching proposed for the above problem, the absorption frequency and transmission frequency are usually not at the same frequency, which not only wastes the spectrum resources but also fails to meet the switch between stealth and communication states.

To overcome these limitations, in this paper, we propose a compact AFSS that can switch between absorption and transmission modes in the same frequency by controlling the lumped components on the AFSS. Its geometry is comprised of two tunable electric resonators spaced by a dielectric substrate, with varactor and PIN diodes embedded on the top and bottom metallic layers, respectively. Due to the underlying structure is also designed as an electrical resonant structure instead of a monolithic metal ground, the proposed AFSS can achieve functional switching between transmission and absorption. In the common-frequency switch between absorption and transmission modes, the impedance matching of the AFSS is attained by altering the capacitance value of the varactors embedded on the top structure of the AFSS. The proposed AFSS is fabricated and demonstrated. The numerical and experimental results show that the presented structure has the capability to achieve transmission/absorption conversion in the same frequency of around 11.4 GHz under normal incidence. The absorption and transmission modes are angularly stable up to 35°by changing the capacitance of the varactors, which compensates the asymmetry of the structure.

Revision in the paper:

We have revised the abstract as follow:

“To overcome the limitations of traditional frequency selective surfaces in flexible state switching at the same frequency, this paper proposes a novel active frequency selective surface (AFSS) that simultaneously exhibits conversion between absorption and transmission modes at the same frequency band. By welding PIN diodes on the bottom structure of the AFSS, the conversion between band-pass (transmission) and band-stop (absorption) filter can be controlled electronically. In the common-frequency switch between absorption and transmission modes, the impedance matching of the AFSS is attained by altering the capacitance value of the varactors embedded on the top structure of the AFSS. The functionalities of the proposed AFSS design are investigated by full-wave simulations (in HFSS software) at 11.4 GHz. Furthermore, the operating principle is analyzed using an equivalent circuit model (in AWR software). To verify the concept, a prototype is manufactured and the responses of mode switching are measured by adjusting the bias voltage. The measurement result is consistent with the simulation analysis. Owing to the tunability of the varactors, the structural asymmetry is compensated to achieve 80% absorptivity and transmissivity within a field-of-view of +/-35°. The developed AFSS structure is highly valuable to be used in scenarios such as antenna dome etc.”

 

Comment 2:

The author needs to add a comparative study based on the present finding in the introduction section.

Response:

Thanks for the helpful comment. We have further studied the literature and added 7 more papers in the introduction section. It may help the readers have a more comprehensive understanding of the new research.

Revision in the paper:

We have provided more information in the introduction as follows:

“On the other hand, propagation mode control via metasurfaces are also well documented in recent years, which is capable of converting a linearly polarized (LP) incident wave into a circularly polarized (CP) wave or its cross-polarized LP wave at different frequencies [26]. Various types of metamaterials with strong electromagnetic resonance have been reported [27-32], for instance, Pan et al. proposed dual-band multifunctional coding metasurface in compact 5G/6G communication systems [27]. These researches covered from K band to THz.”

 

Comment 3:

The paper lacks sufficient detail regarding the active components, their specifications, and the experimental setup configuration. Incorporating these specifics would enhance the reproducibility of the results.

Response:

Many thanks for the helpful comment. It is indeed necessary to supplement more detail concerning the active components and experimental setup configuration etc to make it clear, as follows.

Revision in the paper:

“For experimental verification, measurements are carried out in an anechoic chamber. The varactors used in this paper are SMP1321-079LF PIN diodes and SMV1231-011LF varactors. A dual DC regulating power supply is used to provide voltage to the active components. Two X-band standard gain horns antennas are used as transmitting and receiving antennas. The prototype is surrounded by pyramid absorbers to reduce the diffraction effect. Before the measurement, the horn antennas and the prototype should be normalized to eliminate the environmental impact. For transmission measurements, the two horn antennas are calibrated in free space, and then for reflection tests, a metal plate of the same size as the prototype is used for calibration. Then the horn antennas are used to transmit the normal incident quasi-plane wave, which is fixed 1 meter away from the prototype. The reflection coefficient is measured by placing the transmitting and receiving horn antennas on the same side of the prototype.”

 

Comment 4:

Comparing current methods would improve the paper. The experimental results are promising, however, the proposed method must be compared to other methods on efficiency, bandwidth, and cost.

Response:

Thanks for the helpful comment. Since the significance of this paper lies in the capability of the proposed AFSS in mode conversion at the same frequency, we compared the results with existing work at working mode, biasing network, and polarization etc.

Revision in the paper:

Comparison of this work with related existing articles are listed in Table 3.

“With independent control of the biasing conditions (ON-/OFF- states) of the diodes, the AFSS realizes same frequency conversion between transmission and absorption modes unlike the existing articles, as shown in Table 3.”

 

Comment 5:

The English composition requires many improvements. The authors should proofread the manuscript carefully to minimize grammatical errors.

Response:

Thanks for the helpful comment. We have proofread the manuscript carefully and minimized grammatical errors.

 

Comment 6:

All the references mentioned in the paper should be cited in the text or vice-versa.

Response:

Thanks for the helpful comment. We have proofread the manuscript carefully and guaranteed that All the references mentioned in the paper have been cited in the text.

Author Response File: Author Response.pdf

Reviewer 4 Report

Microwave Common-Frequency Absorption/Transmission Mode Conversion Based on Active Components

 

- The abstract communicates the main aspects of the proposed research. However, there are a few areas where further information could enhance the abstract:

1. Motivation: It would be beneficial to include a brief statement regarding the motivation behind developing this novel AFSS. What are the practical applications or problems that this research aims to address? Providing context can help readers understand the significance of the work.

2. Methodology: While the abstract mentions full-wave simulations and an equivalent circuit model, it would be helpful to provide a concise description of the simulation tools and software used for the simulations. Additionally, if any specific numerical or computational techniques were employed, such as finite element method (FEM) or finite-difference time-domain (FDTD) method, it would be useful to mention them.

3. Future Directions or Potential Applications: Consider adding a sentence at the end of the abstract mentioning potential future directions of research or practical applications enabled by this novel AFSS design. This can help readers understand the broader impact and potential avenues for further exploration.

 

- The provided introduction gives an overview of the importance and application of frequency selective surfaces (FSSs) in various fields. However, it can be improved in the following ways:

1. The introduction should clearly identify the research gap or limitation in existing AFSS designs. It could mention the need for achieving dynamic switching between absorption and transmission modes in the same frequency band and the challenges faced by previous designs. This would provide a stronger motivation for the proposed work.

2. The introduction briefly mentions a few references but lacks a comprehensive literature review. It should provide a more detailed review of the state-of-the-art AFSS designs, discussing their limitations, achievements, and relevance to the proposed work. This would help position the proposed AFSS within the existing knowledge and highlight its novelty.

3. The introduction briefly mentions the proposed AFSS structure but lacks a clear and concise explanation of its key features and working principles. Providing a brief overview of the geometry, the role of varactors and PIN diodes, and how they enable the mode conversion between absorption and transmission would enhance the reader's understanding.

4. The introduction should explicitly state the significance and contributions of the proposed AFSS design. What are the unique features and advantages offered by this design? How does it address the limitations of previous designs? Clearly outlining these points would help readers understand the potential impact of the research.

 

 

 

- The authors could consider explaining some of the technical terms and acronyms used in the manuscript for the benefit of readers who may not be familiar with the field.

 

- The methodology section could be more detailed, particularly regarding the data collection and analysis methods used in the study.

 

- The provided conclusion gives a brief summary of the proposed reconfigurable AFSS structure, its capabilities, and the experimental results. However, it could be improved in the following ways:

1. Begin the conclusion by restating the main contributions of the research. What are the key achievements or advancements of the proposed AFSS design? This will reinforce the significance of the work and remind the reader of its main contributions.

2. Instead of simply stating that the experimental results are consistent with the simulation ones, provide a concise discussion of the results. Highlight any notable findings or observations from the experimental measurements. Were there any challenges encountered during the measurements or any unexpected results? This will add depth to the conclusion and provide a more comprehensive summary of the research outcomes.

3. Discuss the potential practical implications and applications of the proposed AFSS design. How can it be utilized in real-world scenarios or industries? Are there any specific areas or fields that could benefit from this research? Providing a brief discussion on the practical significance of the findings will help readers understand the broader impact of the research.

4. Acknowledge any limitations or potential areas for improvement in the proposed AFSS design. Are there any challenges or drawbacks that should be addressed in future research? Additionally, briefly mention potential avenues for future research that can build upon the current work. This will demonstrate a forward-looking perspective and encourage further exploration in the field.

 

- This article can be accepted after these corrections.

Extensive editing of English language required

Author Response

List of Responses

 

Dear Editor and Reviewer:

Thank you for your letter and for the reviewer’s comments concerning our manuscript entitled “Microwave Common-Frequency Absorption/Transmission Mode Conversion Based on Active Components” (ID: electronics-2435749). The comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied the comments carefully and have made correction which we hope meet with approval. The main corrections in the paper and responds to the reviewer’s comments are as follows:

 

Comment 1:

The abstract communicates the main aspects of the proposed research. However, there are a few areas where further information could enhance the abstract:

Motivation: It would be beneficial to include a brief statement regarding the motivation behind developing this novel AFSS. What are the practical applications or problems that this research aims to address? Providing context can help readers understand the significance of the work.

Methodology: While the abstract mentions full-wave simulations and an equivalent circuit model, it would be helpful to provide a concise description of the simulation tools and software used for the simulations. Additionally, if any specific numerical or computational techniques were employed, such as finite element method (FEM) or finite-difference time-domain (FDTD) method, it would be useful to mention them.

Future Directions or Potential Applications: Consider adding a sentence at the end of the abstract mentioning potential future directions of research or practical applications enabled by this novel AFSS design. This can help readers understand the broader impact and potential avenues for further exploration.

Response:

Thanks for the help comments, we carefully revised the abstract according to the reviewer’s suggestions. We firstly introduce the motivation of developing this novel AFSS, which is to overcome the limitations of traditional AFSS such as wasting the spectrum resources. It then indicates the software used for simulations in the “methodology” part. For the future directions or potential applications, we highlighted at the end of the abstract that the developed AFSS structure is highly valuable to be used in scenarios such as antenna dome etc. The revised version of abstract is shown as follows.

Revision in the paper:

We have revised the abstract as follows:

“To overcome the limitations of traditional frequency selective surfaces in flexible state switching at the same frequency, this paper proposes a novel active frequency selective surface (AFSS) that simultaneously exhibits conversion between absorption and transmission modes at the same frequency band. By welding PIN diodes on the bottom structure of the AFSS, the conversion between band-pass (transmission) and band-stop (absorption) filter can be controlled electronically. In the common-frequency switch between absorption and transmission modes, the impedance matching of the AFSS is attained by altering the capacitance value of the varactors embedded on the top structure of the AFSS. The functionalities of the proposed AFSS design are investigated by full-wave simulations (in HFSS software) at 11.4 GHz. Furthermore, the operating principle is analyzed using an equivalent circuit model (in AWR software). To verify the concept, a prototype is manufactured and the responses of mode switching are measured by adjusting the bias voltage. The measurement result is consistent with the simulation analysis. Owing to the tunability of the varactors, the structural asymmetry is compensated to achieve 80% absorptivity and transmissivity within a field-of-view of +/-35°. The developed AFSS structure is highly valuable to be used in scenarios such as antenna dome etc.”

 

Comment 2:

The provided introduction gives an overview of the importance and application of frequency selective surfaces (FSSs) in various fields. However, it can be improved in the following ways:

The introduction should clearly identify the research gap or limitation in existing AFSS designs. It could mention the need for achieving dynamic switching between absorption and transmission modes in the same frequency band and the challenges faced by previous designs. This would provide a stronger motivation for the proposed work.

The introduction briefly mentions a few references but lacks a comprehensive literature review. It should provide a more detailed review of the state-of-the-art AFSS designs, discussing their limitations, achievements, and relevance to the proposed work. This would help position the proposed AFSS within the existing knowledge and highlight its novelty.

The introduction briefly mentions the proposed AFSS structure but lacks a clear and concise explanation of its key features and working principles. Providing a brief overview of the geometry, the role of varactors and PIN diodes, and how they enable the mode conversion between absorption and transmission would enhance the reader's understanding.

The introduction should explicitly state the significance and contributions of the proposed AFSS design. What are the unique features and advantages offered by this design? How does it address the limitations of previous designs? Clearly outlining these points would help readers understand the potential impact of the research.

Response:

Thanks for the helpful comment. We have made some revisions according to the suggestions on introduction. Six more references are cited and reviewed to elaborate the existing knowledge. The role of varactors and diodes are also highlighted. Advances offered by this design are estimated to enhance the significance of the research. Please refer to the introduction.

 

Comment 3:

The authors could consider explaining some of the technical terms and acronyms used in the manuscript for the benefit of readers who may not be familiar with the field.

Response:

Thanks for the helpful comments, we carefully checked all the technical terms and acronyms that appeared in the paper and explained them, which is indeed more friendly to readers who may not be familiar with the filed.

 

Comment 4:

The methodology section could be more detailed, particularly regarding the data collection and analysis methods used in the study.

Response:

Thanks for the helpful comment. We have added more detailed information to describe the methodology including analysis method and data collection.

Revision in the paper:

We have provided information regarding analysis method and data collection such as in Line 110 and Line 120 “To better under the working principle from the equivalent circuit models, the impedance of the top and bottom layers can be written as…… The scattering results of the equivalent circuit model have been acquired by ANSYS HFSS software and the AWR Microwave Office software.”

 

Comment 5:

The provided conclusion gives a brief summary of the proposed reconfigurable AFSS structure, its capabilities, and the experimental results. However, it could be improved in the following ways:

1. Begin the conclusion by restating the main contributions of the research. What are the key achievements or advancements of the proposed AFSS design? This will reinforce the significance of the work and remind the reader of its main contributions.
2. Instead of simply stating that the experimental results are consistent with the simulation ones, provide a concise discussion of the results. Highlight any notable findings or observations from the experimental measurements. Were there any challenges encountered during the measurements or any unexpected results? This will add depth to the conclusion and provide a more comprehensive summary of the research outcomes.
3. Discuss the potential practical implications and applications of the proposed AFSS design. How can it be utilized in real-world scenarios or industries? Are there any specific areas or fields that could benefit from this research? Providing a brief discussion on the practical significance of the findings will help readers understand the broader impact of the research.
4. Acknowledge any limitations or potential areas for improvement in the proposed AFSS design. Are there any challenges or drawbacks that should be addressed in future research? Additionally, briefly mention potential avenues for future research that can build upon the current work. This will demonstrate a forward-looking perspective and encourage further exploration in the field.

Response:

Thanks for the helpful comment. We have revised the conclusion according to the help suggestions.

Revision in the paper:

We have revised the conclusion as follows.

“A compact AFSS that can switch between absorption and transmission modes in the same frequency by controlling the lumped components on the AFSS is proposed in this paper. The reconfigurable AFSS structure is designed, analyzed, and measured, whereas it not only realizes the dual-functional conversion between transmission and absorption modes at the same frequency, but also compensates the angular sensitivity of the asymmetric structures by independently controlling the bias conditions (ON-/OFF-state) of the PIN diodes and the tuning capacitance value of the varactors. Both equivalent circuit modeling and surface current analysis are used to further analyze the absorption and transmission mechanism of the designed structure, which outstands the functionality of the active components in mode conversion. The designed AFSS was manufactured by the PCB technology and measured in an anechoic chamber. Both simulated and measured results demonstrated that the presented structure has the capability to achieve transmission/absorption conversion in the same frequency of around 11.4 GHz under normal incidence. The absorption and transmission modes are angularly stable up to 35° by changing the capacitance of the varactors, which compensates the asymmetry of the structure. The proposed AFSS is of high value in applications scenarios that is not sensitive to polarization such as antenna dome etc.”

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I thank the authors for their replies, and the replies satisfy me. I would like to recommend the publication of the current manuscript in the journal.

Reviewer 3 Report

Author solve all comments carefully,  I recommended to accept in present form.

Accept in present form.

Reviewer 4 Report

Dear Editor/Author,

              The revised version of manuscript looks very fine. The authors have addressed all the comments suggested by the reviewers. Hereby i give my recommendation to accept it for Publication

 

Best Regards