Round 1

Reviewer 1 Report

The authors described that  a Ku-band Transmit/Receive IC in 0.13 µm CMOS technology for mobile satellite communication systems. 

The authors must pay effort to finish these experiments; however, many published papers demonstrated these characteristics earlier. Please tell and compare with these papers to emphasize the advantage of this research . (The first one showed same one author in this manuscript)  

SUCH AS: 

1: An X/Ku-band bi-directional true time delay T/R chipset in 0.13 µm CMOS technology

• June 2014

DOI:10.1109/MWSYM.2014.6848608

• Conference: 2014 IEEE/MTT-S International Microwave Symposium - MTT 2014

  2: Nguyen, V.-V.; Nam, H.; Choe, Y.J.; Lee, B.-H.; Park, J.-D. An X-band Bi-Directional Transmit/Receive Module for a Phased Array System in 65-nm CMOS. Sensors 2018, 18, 2569. https://doi.org/10.3390/s18082569  

 

 

Author Response

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Reviewer 2 Report

applsci-1740900 -Peer-Review-V1

A Ku-band Bi-Directional Transmit/Receive IC in 0.13mm CMOS Technology

By Jeong-Geun Kim and Donghyun Baek

 

This paper proposed a design of a new type of Ku-band Transmit/Receive IC in CMOS technology for mobile satellite communication beamforming systems. It is mainly composed of bi-directional amplifier, a 6-bit phase shifter, and a 6-bit digital step attenuator. Experimental tests are performed to verify the performance of the design. The whole structure of the paper is fine. Besides, I have the following comments for your consideration.

 

1. The Introduction part should be further extended and explained. According to the authors’ description, the switchless bi-directional amplifier is used to reduce the losses by two SPDT switches. The switched filter phase shifter is used to provide good linearity with nearly zero DC power consumption. What about the third component in the proposed Ku-band IC? What is the function or advantage of the step attenuator?

 

2. Following the first comment, there should be a more detailed description about the advantages and disadvantages of existing Transmit/Receive ICs. More emphasis should be put to the merits of the proposed design compared to existing structures.

 

3. Page 1, Line 39. Part 2. Why did the authors used a 6-bit phase shifter and a 6-bit digital step attenuation? Why not other bit?

 

4. In section 2.1, the authors claimed that “… four parallel- and cross-connected series transistors of 16-fingers 64 mm (T1-T4) and four shunt transistors of 8-fingers 40 mm (T5-T8). The series inductors (L1) of 260 pH…”. How did the authors decide the values of 64 mm, 40 mm and 260 pH? Can we use other values?

 

5. In section 3 the experiment part, did the authors consider the background noise? What is the SNR of your received signals?

 

6. In page 5 line 120. How did the authors manufacture the 0.13mm CMOS IC? Can you give a figure illustrating your experiment condition or test environment?

 

7. Page 8. The conclusion should be labelled as section 4. Moreover, please list your conclusions as 1)… 2)… 3)… Each of your conclusion should be simple but precise about the conclusion you have achieved. Your conclusion should not be a repeat of your abstract.

 

Author Response

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Reviewer 3 Report

The authors designed and measured a Ku-band Transmit/Receive IC used for the satellite communication beam-forming system. Several questions are as follows:

1, The paper presents lots of designed schemes and measured results, do you have some simulated results using the commercial software or from the theory?

2, Please give some more details about the bi-directional transmit/receive IC, including its advantages.

Author Response

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Reviewer 4 Report

Comments of applsci-1740900

 

The main weaknesses of the manuscript:

 

1.     About the introduction: the significance of the article need to be increased and the highlight is prominent.

2.     In the conclusion section, it is restating what is already in the abstract and not a discussion of the results.

3.     Your reference list is quite outdated, all papers more than 10 years old.

Comments for author File: Comments.pdf

Author Response

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Round 2

Reviewer 1 Report

The authors have well modified the manuscript compared to previous version. I suggested to consider this manuscript to publish in this journal after minor revision. The English grammar  should be checked carefully again. 

Author Response

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