Compact High-Directivity Contra-Directional Coupler

Round 1

Reviewer 1 Report

This paper presents a compact high-directivity contra-directional coupler, which is designed well. The presentation of this paper is also OK. This paper provided a lot of equations such as (1) and (2), but they include a lot of equations. It is better to make them clearly one by one.

The design process is suggested to list details for a table to show a framework.

There are some format problems. Please correct all of the format problems in this paper and also in reference.

 

Author Response

Dear Sir,

We appreciate you and the reviewers for your precious time in reviewing our paper and providing valuable comments. They were valuable and insightful comments that led to possible improvements in the current version. The authors have carefully considered the comments and tried our best to address every one of them. We hope the manuscript, after careful revisions, meets your high standards.

We attached the point-by-point responses. Below we provide the point-by-point responses. English edited changes are marked up using the ‘Track Changes’ function, and all the modified or inserted sentences in the manuscript have been highlighted in green.

Sincerely,

Won Il Chang

Author Response File: Author Response.pdf

Reviewer 2 Report

This work outlines the development of a compact, high-power, high frequency directional coupler.  The work is interesting but presentation and especially the English requires improvement to make it easier for a reader to understand the work.  A few other technical comments are also added below:

- The design layout of the cross is listed as 'optimized in 3D simulation' but details of this optimization process are lacking.  Can further explanation of the design method be explained?

- Simulation figures and results are difficult to compare with experiment because the lines often overlap, maybe consider dotted lines so that both responses can be clearly seen.

Author Response

Dear Sir,

We appreciate you and the reviewers for your precious time in reviewing our paper and providing valuable comments. They were valuable and insightful comments that led to possible improvements in the current version. The authors have carefully considered the comments and tried our best to address every one of them. We hope the manuscript, after careful revisions, meets your high standards.

We attached the point-by-point responses. Below we provide the point-by-point responses. English edited changes are marked up using the ‘Track Changes’ function, and all the modified or inserted sentences in the manuscript have been highlighted in green.

Sincerely,

Won Il Chang

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper presents a ring-type high-directivity (low coupling -20dB) coupler for higher power application at Ku-band 12.8 GHz to 14.8 GHz.  Below are some comments to the author:

1. Please keep the same sign (+ or -) for coupling and directivity in the paper, for example:

 

Page1 Line 15, it should be -20dB coupling?

Page10 line 206, the coupling is -20dB?

Page10 line 222 to 234, 20 dB directivity?

and other places in the paper. 

2. Fig9, did you include the SMA connectors in the simulation? If not, how do you de-embed the connectors?

3. The results in Figure10, especially the return loss S11 from measurement, seem to be disturbed. Maybe the connectors are in poor contact with the metal traces on the PCB and there is some reflection from mismatching. This result needs to be improved.

4. How do you validate the high power application? What is the power level?

5. In table 2, the comparisons are all working much lower frequency compared with this work. With lower frequency and larger wavelength, they would normally come with larger size. The author needs to compare with design in similar frequency range ~14GHz.

 

 

Author Response

Dear Sir,

We appreciate you and the reviewers for your precious time in reviewing our paper and providing valuable comments. They were valuable and insightful comments that led to possible improvements in the current version. The authors have carefully considered the comments and tried our best to address every one of them. We hope the manuscript, after careful revisions, meets your high standards.

We attached the point-by-point responses. Below we provide the point-by-point responses. English edited changes are marked up using the ‘Track Changes’ function, and all the modified or inserted sentences in the manuscript have been highlighted in green.

Sincerely,

Won Il Chang

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Thank you for making suggested changes, I have no further comments at this point