Design of Series-Fed Circularly Polarized Beam-Tilted Antenna for Microwave Power Transmission in UAV Application
, Wonseob Lim 2, Youngoo Yang 1 and Keum Cheol Hwang 1,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper presents a very good application of the series-fed circularly polarized beam-tilted antenna, which is the microwave power transmission for UAV. The design is simple and easy installation. However, there is barely any new design for a circularly polarized antenna. Patch with truncated corners is a quite traditional design of a circularly polarized antenna. Also, there is nothing special for the series fed of the antenna array. There also lacks a comparison of the proposed antenna with other antennas for microwave power transmission.
Author Response
Dear reviewer,
I would like to thank you very much for your disposition on my paper (applsci-2852428, title: "Design of Series-fed Circularly Polarized Beam-Tilted Antenna for Microwave Power Transmission in UAV Application"). Based on the reviewer’s comments, the paper has been revised. The revised sections are notated in highlighted text in the PDF file. The detailed responses for the review comments are attached in a separated file. We greatly value this chance to revise our manuscript.
Your consideration is very much appreciated.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsReview of the paper entitled "Design of Series-fed Circularly Polarized Beam-Tilted Antenna for Microwave Power Transmission in UAV Application" submitted by the authors for publication in the journal "Applied Sciences".
The context of the study is well established and clear: it involves using MPT technology to recharge, using antennas designated for this purpose, the batteries of a UAV in flight. This is how the context of this work is described in the introduction.
As such, it is a shame that only the "antenna" element is presented in the paper, the measurement with the rectifier circuits (to go up to the rectenna array as a complete system) is not presented here but announced as a perspective in the conclusion.
Apart from this pitfall, the work is well written and referenced. Some points to take into account before publication:
- The acronym CP is well defined in the abstract but not in the article. Please do it on line 55.
- A particular reason for the frequency of 5.84 GHz? If this is the carrier frequency of a modulated signal, what is the width of the modulation?
- Line 80: for what frequency are the supplied dielectric parameters given?
- Line 101: what software is used for the simulations? Given the presentation of the surface current maps in Figure 3, I assume that this is Ansys HFSS.
- Equation 1: what is the term "ae" immediately after the exponential? If "a" is related to the chamfer of the patch antenna, then what does "e" correspond to? Please clarify.
- Line 125: specify "Array Factor (AF)" as you did for "Element Pattern (EP)". Perhaps even specify the “Linear” index to understand that there is a link with equation 1? Because this is not obvious...
Figure 5(a): the term "transmission coefficient (deg)" for the ordinate axis is questionable... Specify something like "Transmission coefficient phase (deg)".
After taking these few remarks into account, the paper can be published.
Author Response
Dear reviewer,
I would like to thank you very much for your disposition on my paper (applsci-2852428, title: "Design of Series-fed Circularly Polarized Beam-Tilted Antenna for Microwave Power Transmission in UAV Application"). Based on the reviewer’s comments, the paper has been revised. The revised sections are notated in highlighted text in the PDF file. The detailed responses for the review comments are attached in a separated file. We greatly value this chance to revise our manuscript.
Your consideration is very much appreciated.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper proposes a new design for patch array antennas, providing circularly-polarized and beam tilt operation.
The state of the art is comprehensively presented, evidencing that beam-tilting operation is a critical functionality for reducing beam misalignment losses.
All figures and tables are fully informative.
Prototypes of these innovative designs are fabricated and convincing measurements are reported.
I recommend that the paper should be published after additional information has been added, according to the detailed comments listed below.
C1 something has to be changed in the sentence on lie 96
C2 can authors indicate the simulation tool which is used to perform the simulation presented?
C3: Could authors comment how far it is straightforward to adapt the design for a different frequency range ? Also authors could comment about how far such a concept can be scaled down for a even more minimized dimension? The simulation is performed for a 12-element antenna. What about reducing the number of elements to 6? What is/are the main performances that are impacted/degraded? This could be discussed after table 2 including all the measured performances.
C4: do the colours of fig. 7 are right? Red versus blue?
C5 in the caption of Fig. 8 add: photographs (with s) of the fabricated ? aren’t they?
Author Response
Dear reviewer,
I would like to thank you very much for your disposition on my paper (applsci-2852428, title: "Design of Series-fed Circularly Polarized Beam-Tilted Antenna for Microwave Power Transmission in UAV Application"). Based on the reviewer’s comments, the paper has been revised. The revised sections are notated in highlighted text in the PDF file. The detailed responses for the review comments are attached in a separated file. We greatly value this chance to revise our manuscript.
Your consideration is very much appreciated.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThis paper proposes series-fed CP and passively beam tilted patch array antennas for microwave power transmission. Some issues need to be addressed as follows.
1. In the abstract, the motivation and background needs to be introduced. Besides, the format of abbreviations should be revised. For example, “circularly polarized(CP)” should be revised as “circularly polarized (CP)”.
2. Authors are suggested to update the references by recent works on prestigious journals and conferences.
3. For the issue of wireless power transmission efficiency, the recent works and their contributions should also be introduced, such as Throughput maximization of wireless-powered communication network with mobile access points, IEEE TWC, 2023.
4. In the introduction, the contributions and novelties should be better summarized point-by-point.
5. The reasonability analysis of specific values should be provided for the proposed antennas, i.e., “The proposed antennas are designed on a Taconic RF-35 dielectric substrate with a relative permittivity of 3.5, a loss tangent of 0.0018, and a thickness of 0.76 mm”.
6. Similarly, the reasonability analysis of parameters in Table I should be provided.
7. More details and explanations should be provided for the configuration of the proposed series-fed antennas in figure 1.
8. Why figure 5 and figure 7 are provided in Section II antenna design?
9. How do the proposed antennas advance in the research field compared with existing ones? The main idea should be presented in detail.
10. Important results and findings should be better summarized in conclusion.
11. Please describe how the conclusions are or are not consistent with the evidence and arguments presented. Please also indicate if all main questions posed were addressed and by which specific experiments.
Comments on the Quality of English Language
Minor editing of English language is required for this manuscript.
Author Response
Dear reviewer,
I would like to thank you very much for your disposition on my paper (applsci-2852428, title: "Design of Series-fed Circularly Polarized Beam-Tilted Antenna for Microwave Power Transmission in UAV Application"). Based on the reviewer’s comments, the paper has been revised. The revised sections are notated in highlighted text in the PDF file. The detailed responses for the review comments are attached in a separated file. We greatly value this chance to revise our manuscript.
Your consideration is very much appreciated.
Author Response File: Author Response.pdf
Round 2
Reviewer 4 Report
Comments and Suggestions for AuthorsAuthors have well addressed my previous comments.
