A Novel Harmonic Clocking Scheme for Concurrent N-Path Reception in Wireless and GNSS Applications

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. Figure 5 Caption: Please add some brief description sentences.
2. Can you add a paragraph after Table 2 with additional comments about these parameters?
3. Can you re-organize figure 8 and its captions, to give some information about the signal types?
4. Section 4.3: Please add more discussion about the EVM results
5. Section 5: can the author add novelty discussion? Such as the advantage of the proposed method, compared with the conventional methods.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors, Ibrahim et al., have introduced a novel harmonic-selective clocking scheme, supported by thorough theoretical analysis and experimental validation. The background, rationale, and presentation of the proposed work are clear, and the results and conclusions appear sound. Before publication, I have a few minor suggestions:

1. As illustrated in Figure 1, the non-overlapping of the pulses is crucial, especially when more signal paths are involved. Could the authors elaborate on how the timing or positioning of pulses in each path is adjusted to ensure non-overlap?
2. I recommend that the authors clarify the origin of the discrepancies between the proposed clock harmonics and those of the single clock scheme, as shown in Figure 3. A brief explanation of why and how these differences arise would strengthen the discussion.
3. I am curious about how the authors estimated the value of the switch ON resistance R_SW. Could the authors provide more detail on the estimation method and the rationale behind the chosen value?
4. The inclusion of NMSE and EVM results in Figures 10–12 is commendable and very informative. However, I recommend that the authors include a brief explanation of these two parameters—their physical meaning and significance—and why they are important metrics in evaluating the proposed design.
5. If possible, I suggest the authors compare their results with those of related previous works to better highlight the advantages and innovations of the proposed approach.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This is an interesting paper. While the use of N-Path filter harmonics as the center frequency is a well-documented concept, applying this technique for concurrent reception appears to be a novel approach. I have a few comments and questions:

• Sensitivity Claim: The abstract and conclusion state a receiver sensitivity of -55 dBm. This result is not presented in the main text. Please explain how this value was obtained.

• Clock Generation for N-Path Topologies: It is well-known that typical N-Path topologies require a local oscillator (LO) with twice the switching frequency to generate a 25% duty cycle clock. In your measurement results, the clock was generated externally. For your proposed clock strategy, what would be the required LO frequency? Furthermore, how would these signals be generated from a local oscillator?

• Acceptable Conversion Gain: Some of your results show a conversion gain of -9 dB, which indicates significant insertion loss. What is considered an acceptable conversion gain for this application? A comparison with values reported in the literature would be beneficial here.

• Discrepancy in Frequencies: Why were different frequencies used in the simulations (Test 1) compared to the practical measurements (Test 2, Table 3)? For better validation of the topology, it would be ideal to use the same frequencies for both.

• EVM for GPS Signal: You stated that the EVM for the LTE signal meets the standard. Does the GPS EVM also fall within its standard value?

• Power Consumption Evaluation: The conclusion mentions that "this approach offers power-efficient design," but power consumption was not evaluated in the paper. Please address this claim with supporting data or remove the statement.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Thanks to the authors for their effort in addressing my questions and improving the article's quality. Several issues have been resolved, but some still concern me: 1) Sensitivity: This issue seems critical. I believe it's very difficult to validate sensitivity without knowing the noise figure. 2) Passive Topology: I understand that a passive topology won't provide gain. The problem is that the insertion loss is too high. How to address this issue remains unclear to me. 3)GPS EVM: To me, measuring a metric without a defined target doesn't make sense; it's impossible to determine if the performance is good or bad. 4)Power Efficiency Design: It's very difficult to accept this claim without measurements. Simply stating that the architecture is "inherently power-efficient due to the absence of active amplifiers in the signal path" is not sufficient, especially considering the very high insertion loss.

Author Response

"Please see the attachment"

Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

Comments and Suggestions for Authors

I'm satisfied with the corrections; the final version of the article can be considered for publication.