Multibeam SIW Leaky-Wave Antenna with Beam Scanning Capability in Two Dimensions

Round 1

Reviewer 1 Report

Authors have presented 2D Multibeam Antenna (2D-MBA) for two-dimensional scanning of space with fully passive elements using the Substrate Integrated Waveguide (SIW) Leaky Wave Antenna (LWA) and Rotman lens for telecommunication applications. The antenna exhibits wideband characteristics with high gain up to 20.3 dBi. The work is good and is supported with results. Following comments would be helpful to improve the manuscript.

·       Add missing dimensions in Fig. 1 for array configuration and unit cell.

·       Add sub figure to Fig.1 with dimensions of the matching ends.

·       Provide the dimensions for the designed Rotman lens shown in Fig. 5.

·      Similarly provide the missing dimensions for the overall system shown in Fig. 7, and for the joining section between the array and Rotman lens.

·    Some of the figure have smaller font size for text on axis and legends. That should be increased for better readability, such as Fig. 6 and 8. Please check for other figures as well.

·    For consistency use same units. Such as, at some places degree sign is used and at some place “degrees” is used.

·       It is suggested to check the manuscript for typos and grammatical errors.

Author Response

Dear Reviewer,

Thank you very much for taking your time and considering our manuscript. We appreciate your valuable suggestions on our manuscript, which are very helpful to improve the overall quality of the paper. We have revised the manuscript based on your valuable comments, and would like to re-submit it for your consideration.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper introduces 2D LWA with beam-scanning, the paper is good and some points need to be cleared:

1. The design of the unit-cell

how the authors select the structure and its dimensions.

what is the setup used for calculating the unit-cell characteristics? please give more details.

2. what is the number of unit-cells used for the final LWA

3. more details about the rotman lens should be added

4. the input impedance of the LWA and the design of tapered microstrip line should be added.

5.the gain variation over frequency and radiation efficiency should be added.

6. the E-field distribution at different frequencies should be added

more update references should be added

Author Response

Dear Reviewer,

Thank you very much for taking your time and considering our manuscript. We appreciate your valuable suggestions on our manuscript, which are very helpful to improve the overall quality of the paper. We have revised the manuscript based on your valuable comments, and would like to re-submit it for your consideration.

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript reports a SIW leaky-wave array antenna for 2-D beam scanning applications. Both full-wave simulated and measured results are provided to show the performance of the proposed scheme. As for the configuration of the SIW leaky-wave antenna, it has already been studied in the previous studies in [15]. Therefore, I mainly concern the contribution of this work. Here I have some comments, given as follows.

(1) Since the LWA is not new, and the Lens used in this work is also a common configuration, what’s the novelty of this work? The contribution should be clarified at the beginning of this manuscript.

(2) In Fig. 1(a), it seems that the SIW LWA has two ports. When one port is excited for, is another port opened, shorted, or terminated with 50-Ohm load?

(3) In Fig. 2, the magnitude of S21 is around -5 dB, which implies that the total efficiency of the antenna would be less than 75%. If the reflection is considered, the efficiency would be lower. Am I correct? I suggest to give some discussion about the efficiency.

(4) In Fig. 8, the S parameters between different beam ports are provided. How about the transmission coefficient between a beam port and the loaded ports of the antenna array? I believe it is important to provide this key information for evaluating the radiation performance.

(5) It is better to give the full name of the abbreviation when it appears for the first time in the manuscript, such as “OSB”, which should represent “open stopband”.

(6) Some figures need to be readjusted, where curves are not easily distinguished, such as Fig. 6, Fig. 8.

Author Response

Dear Reviewer,

Thank you very much for taking your time and considering our manuscript. We appreciate your valuable suggestions on our manuscript, which are very helpful to improve the overall quality of the paper. We have revised the manuscript based on your valuable comments, and would like to re-submit it for your consideration.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Authors have addressed the comments and manuscript has been improved.

Reviewer 3 Report

Thanks for revising the manuscript. All my comments have been addressed.