Analysis and Design of a Non-Magnetic Bulk CMOS Passive Circulator Using 25% Duty-Cycle Clock

Round 1

Reviewer 1 Report

This article presents a non-magnetic CMOS circulator based on switched transmission line architecture with 25% duty cycle clocks:

·        Line 38: Did the authors mean the transistors biased in the active region suffer from noise? Most circulators implemented on CMOS use transistors even the implementation presented in this article.

·        Line 54: As shown in the analysis section, this architecture with 25% duty cycle clocks has not resulted in better insertion loss. So, the authors should correct this statement.  

·        Line 95: The proposed architecture is loss-free just like the one proposed with 50% duty cycle clocks. However, in this architecture with 25% duty cycle clocks, a total of 16 switches are clocked which is a factor of 2x higher than the 50% duty cycle clock architecture. This translates to 2x higher power consumption and also 2x higher parasitics. In a real implementation, I believe this architecture performs poorly and require a larger PDC compared to prior implementations.

o   So, why should one use this new proposed architecture?  Authors should clearly demonstrate the advantage of this proposed architecture over prior proposed architecture.  

·        Table 3: Contains errors in references. Add the 60GHz circulators as well to the comparison table.

·        Measurements: a) Noise figure, and b) P1dB measurements should be added. c) The overall spectral performance has to be shown to show that spurious harmonics are not generated.

 

·        The insertion losses of this implementation seem to be higher than in prior works. Authors should elaborate on the sources of insertion losses and how to mitigate them. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Paper is well written and formulated clearly but technically it needs some major revisions.

Abstract:

Follow the basic pattern of template of abstract formation….as:

We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: Describe briefly the main methods or treatments applied; (3) Results: Summarize the article's main findings; and (4) Conclusions: Indicate the main conclusions or interpretations. (5) Add something about the benefits results of the research.  ……also give quantitative results in the abstract. 

[Please revise-according to point 2,3,4 and 5 Conclusion and benefits]

Introduction:

-Can you please establish the research gap [Please add]

-Please add a data table along with citation in the manuscript considering following points:

(a) Previously used method/leaves of other trees for same purpose (b) New ideeas/leaves of other trees for same purpose to be studied (c) Previously asked Questions (d) Previously used techniques for similar type of research.

-Establish your research questions in this section.

-Update your literature review with more additional references of published work in recent years.

-So, establish a research gap and connect your research methodology, data analysis, results with that research gap and produce a discussion on future directions.

Methods

-A Comprehensive research framework is missing (flowchart). This portion should be written in step wise pattern so that readers can understand the procedure for implementation purpose. [Please add]

-Also add references(citations) related to applied methodology.

Limitations of the study:

-Please add heading about the limitations of the study.

-Suggestion/recommendation to the policy makers must be there and it is responsibility of scientist to device such solution which are practically applicable.

Best regards, 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I don't think the switched transmission line gyrator with 25% clocks has a higher gain. Ideally, this architecture just like the 50% duty cycle architecture, just exhibits a gain of unity. 

Please explain the advantages of this proposed architecture over prior work clearly.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf