Dual-Band High-Gain Shared-Aperture Antenna Integrating Fabry-Perot and Reflectarray Mechanisms
Round 1
Reviewer 1 Report
The authors present an antenna that combines a Fabry-Perot Cavity (FPC) at 2.45 GHz with a reflectarray operating at 10 GHz. The configuration is original and demonstrates advantages with respect of previous publications on FPC antennas. The authors present satisfactory experimental results to proof the concept. However, I have a few minor comments:
11) In the last sentence of page 4 it is said “The reflection amplitudes of the co-polarization radiation maintain the value of 0 dB at 2.45 GHz …”. The authors should provide the specific values of amplitude, instead of “0dB”, which is not realistic.
22) In the comments of Fig. 7 (last paragraph of page 5), the authors should specify that the amplitude and phase of the curves corresponding to the cross-polar component of the reflected field, and they should provide the range of values for the amplitude. According to the figure, it looks that the amplitude can go up to 2.5dB for 60º incidence and a=27º.
33) In the caption of Fig. 8, it is preferable to say: “Phase-shift distribution on the reflectarray surface”.
44) In the first paragraph of page 6, the sentence: “the antenna can be optimized for better performance”, is not clear enough. Please clarify, whether or not the antenna has been optimized, and provide more details on the optimization procedure.
55) The values of antenna gain provided in Fig. 11 are not consistent with the values of antenna efficiency provided in the text. At 2.45 GHz, the maximum directivity is 18 dBi, and the gain is 16.21 dBi, which means a 20% efficiency. At 10 GHz, the maximum directivity is 31 dBi, and the gain in the paper is 21.6 dBi, which means a 10% efficiency. However, it is said in the paper that radiating efficiencies is 83.2% and 79%, at 2.45 GHz and at 10 GHz, respectively. Probably the authors did not consider the aperture efficiency. A more detailed evaluation of the efficiency should be provided, explaining which kind of losses are taken into account to determine the efficiency.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors presented a Dual-Band High-Gain Shared-Aperture Antenna Integrating Fabry-Perot and Reflectarray Mechanisms. The proposed antenna has a high gain of 16.21 dB at 2.45 GHz, with high isolation of about 30 dB.
I appreciate the work that the authors have done. However, this article missed some of the essential principles that need to be solved before publication, as follows:
1. Introduction:
-The introduction needs to be improved. The authors must study some of the Metasurace reflectors. Frequency selective surfaces (FSSs) are considered one of them [1,2]. Please see these articles, which may add value to the introduction.
[1] Enhancing Gain for UWB Antennas Using FSS: A Systematic Review. Mathematics. 2021; 9(24):3301. https://doi.org/10.3390/math9243301.
[2] Dual-Band Single-Layer Fractal Frequency Selective Surface for 5G Applications. Electronics 2021, 10, 2880. https://doi.org/10.3390/electronics10222880.
2. SHARE-APERTURE ANTENNA DESIGN
2.1. FPCA design
-Why does the reflection phase decrease with frequency? Please clarify?
- What is the gap between the antenna and the Reflector??
-The Gap between the antenna and the Reflector playing a crucial role in the S11 and the Gain parameters?? Please explain!!!
- Please propose the antenna radiation efficiency graph?
That's all for me at this moment! The authors are required to revise the comments above carefully. Thanks
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have revised the given comments successfully, and I believe the article is ready now to be published in a reputational journal like Electronics!
