Design of a Novel Broadband Antenna for Photomixer Chips in the Terahertz Frequency Range
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript numerically demonstrates a broadband antenna design in the terahertz frequency range.
The authors first provide a detailed description on the antenna’s design process. In order to improve the radiation performance, they perform an optimization analysis of the design parameters. I think the manuscript can be considered for publication after the authors addressing the following comments:
1. The antenna consists of a pair of bowtie antenna and two pairs of circular patch antennas as the broadband antenna design. Are there any physics intuition about this design? Please comment on the reasons of such designs.
2. They manuscript claims a broadband antenna with little comparison of previous work. Please add some introductions and comparisons of previous work.
Author Response
Dear Reviewer,
Please see the attachment.
Sincerely!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis manuscript presents a broadband antenna comprising bowtie and circular patch antenna for 150 GHz to 500 GHz. Through the antenna parameter analysis, the designed antenna can achieve S11 < 10 dB at the bandwidth of 350 GHz.
I cannot recommend the publishing of this manuscript because of the following reasons. The first one is the lack of originality. There are already many designs of broadband terahertz antennas, e.g., spiral antenna, bowtie antenna, etc. Many of them have exceptional performance and are widely used in many commercial terahertz photomixer devices. The authors fail to demonstrate why we need this new antenna and didn’t showcase why this proposed antenna design can be better than those widely-used antennas. The second reason is that the authors didn’t explain why they choose bowtie and circular patch for the combination. The combination of any two types of antennas (e.g., dipole, bowtie, rectangular patch, circular patch) can be a new antenna design. The authors failed to present scientific arguments to support why this combination can be superior to other combinations. The third reason is that the authors didn’t take the whole device architecture into account. InP substrate cannot absorb 1550nm light, which is widely used for photomixing. Usually InGaAs is grown on InP substrate for light absorption. However, the author only designed the antenna on the InP substrate.
Author Response
Dear Reviewer,
Please see the attachment.
Sincerely!
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsIn this study, the authors introduce a groundbreaking broadband terahertz antenna for a photomixer chip, featuring a novel bowtie-circular patch configuration. Designed for the 150GHz to 500GHz range, the antenna demonstrates impressive performance with a 350GHz impedance bandwidth, satisfying |S11|≤-10dB, and a 107% relative bandwidth. Overall, I believe that this manuscript presents an interesting contribution to the field of the terahertz antenna. With the recommended revisions, the manuscript could be suitable for publication in Photonics. I believe that the manuscript could be improved in several ways as below.
1. It would be beneficial to include a brief comparison of the proposed antenna with existing solutions in the literature. This can highlight the novelty and advantages of the proposed design in the context of current research in the field. It is recommended that the authors add a table to compare the performance of bandwidth, reflection coefficient, etc. with existing solutions.
2. The manuscript lacks information on the simulation methodology used to evaluate the antenna's performance. Providing details on the simulation tools, models, and boundary conditions would enhance the credibility of the results.
3. The manuscript could benefit from a brief discussion of any practical considerations or challenges associated with implementing the proposed antenna in real-world high-speed transmission systems.
4. Please check the parameter symbol and define it the first time it appears. For instance, the t in Table 1. t is also not included in Figure 1.
5. The gap between bowtie antennas was not discussed and optimized. It is recommended that the authors add these discussions.
6. It is recommended that the author add some interesting literature to enhance the introduction, such as Applied Physics Letters 2017, 111, 021101; Electronics 2018, 7, 236; Applied Physics Letters 2019, 2019115, 143507; Applied Sciences 2020, 10, 4688.
Author Response
Dear Reviewer,
Please see the attachment.
Sincerely!
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThis paper presents a novel broadband terahertz antenna designed for the frequency range of 150 GHz to 500 GHz. The authors have performed a detailed optimization analysis. Considering effects of multiple parameters, manufacturing constraints, simulation results demonstrates an optimal design for the proposed antenna.
This paper provides valuable insights into the design of broadband antennas by combining bowtie and circular patch elements. This paper can be accepted in its present form.
Author Response
Dear Reviewer,
Thank you very much for accepting my manuscript for publication. I will continue to strive for excellence in my research and make improvements to meet your expectations and trust. If you have any further questions or suggestions, I welcome your feedback at any time.
Once again, I appreciate your support and assistance.
Sincerely!
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThanks for the revision. My previous points were well addressed, and I recommend publication.
Comments on the Quality of English LanguageThe English writing is good.
