A High FoM and Low Phase Noise Edge-Injection-Based Ring Oscillator in 350 nm CMOS for Sub-GHz ADPLL Applications
Round 1
Reviewer 1 Report
The manuscript entitled, "A Low Phase Noise Edge-Injection Based Ring Oscillator in 350 nm CMOS for Sub-GHz ADPLL Applications" is technically sound and well-written. However, there are some important points that need to be addressed:
1. Manuscript Title: The title of the manuscript is still quite long and can be made more concise while conveying the main focus of the research. For example, "Low Phase Noise Edge-Injection Ring Oscillator in 350 nm CMOS for Sub-GHz ADPLL" could be considered.
2. Chip Size: The overall size of the chip is an important parameter and should be mentioned in the manuscript. Please provide the chip's dimensions or any relevant information about its size.
3. 2nd Harmonic Suppression: The measurement of 2nd harmonic suppression is crucial for assessing the oscillator's performance. If you have conducted this measurement, please include the results in the manuscript. This parameter is important as it affects the oscillator's spectral purity and performance in real-world applications.
By addressing these points, the manuscript will be more concise and informative, providing a clearer understanding of the research and its implications.
Author Response
Dear Reviewer,
We would like to thank you for your valuable comments which really enhanced the paper presentation.
We are considering the comments one by one:-
The manuscript entitled, "A Low Phase Noise Edge-Injection Based Ring Oscillator in 350 nm CMOS for Sub-GHz ADPLL Applications" is technically sound and well-written. However, there are some important points that need to be addressed:
1. Manuscript Title: The title of the manuscript is still quite long and can be made more concise while conveying the main focus of the research. For example, "Low Phase Noise Edge-Injection Ring Oscillator in 350 nm CMOS for Sub-GHz ADPLL" could be considered.
Reply: This is a great suggestion and the paper is now retitled to "A High FoM and Low Phase Noise Edge-Injection Based Ring Oscillator in 350nm CMOS for sub-GHz ADPLL Applications"
2. Chip Size: The overall size of the chip is an important parameter and should be mentioned in the manuscript. Please provide the chip's dimensions or any relevant information about its size.
Reply: the overall size is included in the revised version of the paper.
3. 2nd Harmonic Suppression: The measurement of 2nd harmonic suppression is crucial for assessing the oscillator's performance. If you have conducted this measurement, please include the results in the manuscript. This parameter is important as it affects the oscillator's spectral purity and performance in real-world applications.
Reply: This is an important point to consider, from the measurement of THD, the results of 2nd harmonic measurement aree mentioned in the paper revised version.
Reviewer 2 Report
This paper deals with improvements of performances of digitally-controlled CMOS ring oscillators. The paper presents both simulation and experimental results.
1) There are some figures copied (in modified form) from other sources. Did you receive permissions from all copyright holders?
2) Abbreviations RMS, CMOS, RF, VLSI, MOSFET, VCO, DCO should be defined at least once in text.
3) Novelty of the paper should be stated more clearly.
4) Discrepancies between the experimental and simulated results should be explained in details.
5) In order for the paper to be more interesting, it is recommended to show a photo of the experimental prototype with connected measurement equipment.
Minor editing of English language is required.
Author Response
Dear Reviewer,
We would like to express our appreciation of you precious and valuable comments which enhanced the current version of the paper. We are going to reply the comments one by one:-
This paper deals with improvements of performances of digitally-controlled CMOS ring oscillators. The paper presents both simulation and experimental results.
1) There are some figures copied (in modified form) from other sources. Did you receive permissions from all copyright holders?
Reply: thanks for pointing that issue, We have redrawn the figures in a modified form and mentioned (referenced) the original illustration in previous work.
2) Abbreviations RMS, CMOS, RF, VLSI, MOSFET, VCO, DCO should be defined at least once in text.
Reply: you are right, all appreviations are defined one appeared in the revised version of the paper.
3) Novelty of the paper should be stated more clearly.
Reply: a new paragraph is added at the end of section "2. Injection Locking" stating and clarifying the novelty of the paper.
4) Discrepancies between the experimental and simulated results should be explained in details.
Reply: actually, the differences between simulated and measured performance is not so large. These can be implied by the difference between models and real-world implementations.
5) In order for the paper to be more interesting, it is recommended to show a photo of the experimental prototype with connected measurement equipment.
Reply: actually, we do not have a photo of the complete testbench. We have provided the block diagram of the prototype measurement testbench in the revised version of the paper (Figure 6).
Reviewer 3 Report
Page 1, line 26. “attract”, not “possess”.
Page 1, line 32. Not “consumes” but “it consumes”.
Page 4, line 116. Not “pleasant” but “more acceptable” or "improved"
Be more careful in choosing words for a technical paper.
Page 1, line 26. “attract”, not “possess”.
Page 1, line 32. Not “consumes” but “it consumes”.
Page 4, line 116. Not “pleasant” but “more acceptable” or "improved".
Be more careful in choosing words for a technical paper.
Author Response
Dear Reviewer,
We would like to thank you for pointing the following comments in the paper. We are going to reply them one by one:-
Page 1, line 26. “attract”, not “possess”.
Reply: you are right, attract is a more scientist concept.
Page 1, line 32. Not “consumes” but “it consumes”.
Reply: Yes, we have changed to "it consumes"
Page 4, line 116. Not “pleasant” but “more acceptable” or "improved"
Reply: we have replaced pleasant by "improved" which is much better.
Be more careful in choosing words for a technical paper.
Reply: thanks for giving us the opportunity to revise the paper and considering your feedback.
Reviewer 4 Report
The overall organization of this paper is not clear. However, I have some concerns about this manuscript.
1. The introduction is brief, there is room for improvement.
2. What is the advantage of using a double edge-injection scheme in the proposed injection-locked digitally controlled ring oscillator?
3. How does the combinational edge generator help relax the injection timing requirements?
4. In relation to the frequency of the oscillation clock, how large or small should the injection window be?
5. Provide measured the pk-to-pk jitter and rms jitter.
Author Response
Dear Reviewer,
We would like to express our appreciation for providing these comments which helped improving the paper. It is our pleasure to reply your comments one by one :-
The overall organization of this paper is not clear. However, I have some concerns about this manuscript.
Reply: thanks for your comment, the revised version of the paper is much better than its first version.
- The introduction is brief, there is room for improvement.
Reply: we have improved the introduction, please check the paper revised version.
2. What is the advantage of using a double edge-injection scheme in the proposed injection-locked digitally controlled ring oscillator?
Reply: double edge-injection help implementing an adaptive successive edges directions to ensure a periodic clean edges injection and ensured ring oscillator periodic phase error reset.
3. How does the combinational edge generator help relax the injection timing requirements?
Reply: the combinational or free-running edge generator does not need more consideration of the enable or clock insertion moment. It works with no control, it periodically provides clean edges to replace the ILRO noisy edges.
4. In relation to the frequency of the oscillation clock, how large or small should the injection window be?
Reply: the injection window should be wide enough so that clean edges could be injected completely with no defect on ILRO spurs level. So, the reference frequency should be selected small in respect to the oscillation frequency (N>> 10 "100~250").
5. Provide measured the pk-to-pk jitter and rms jitter
Reply: Actually, we have measured the RMS jitter as it is reported in most of recently published work and it is mentioned in the paper.
Round 2
Reviewer 4 Report
The revised manuscript is recommended for publication in its current form.
