Memristor-Controlled Reconfigurable N-path Filter Structure Design and Comparison
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe article presents the integration of memristors into N-path filter structures to develop a reconfigurable N-path filter with a tunable bandwidth, validating the approach through simulations. Additionally, for one of the proposed architectures, experimental laboratory tests were conducted. The main research question addressed in this study focuses on analyzing the potential of memristor-based N-path filters in achieving reconfigurable and high-Q filtering capabilities for RF applications.
The topic discussed in the manuscript concerns the architectural proposal of a reconfigurable N-path filter with a tunable bandwidth using memristors. For this reason, this study is considered relevant to the field of analog circuit design for radiofrequency applications.
It is mentioned that simulations were performed using the memristor model; however, its characteristics are not presented. Therefore, it is necessary to address the memristor model used in the simulations, including a detailed description and the corresponding schematic.
In the paragraph between lines 54–60, a basic schematic of a single-port, single-ended 4-path filter is mentioned; it is necessary to include a figure that presents the corresponding schematic.
Lines 61–64 reference Equations (1) and (2); however, the literals of the variables used in these equations are not included.
In lines 82–83, it is mentioned that when the frequency is very high, the gain of the filter will tend to become a constant value, which equals the ratio Ro/R. However, it should be Ro/(R+Ro), or alternatively, the corresponding approximation should be explained.
The mathematical exposition for the architecture of Filter 1 is considered sufficient. However, a solid mathematical foundation must be incorporated for the architecture of Filter 2.
In the results section, the noise floor for the analyzed architectures is ambiguously mentioned. It is necessary to clearly and precisely indicate the noise floor values for each presented response.
Line 191 states that the observed differences are caused by the parasitic capacitance Cp of the memristor; this assertion should be further explained.
Lines 191–192 mention, “Referring to equations 3 and 8”; however, Equation (8) does not include capacitance Cp. This discrepancy should be corrected.
Line 214 states “with 10Ω memristor,” but it is considered that this should be 10KΩ.
Line 221: Capitalize “However.”
Section 3.3 discusses the simulation results of the Filter 2 structure and 1 GHz center frequency; however, the Filter 1 structure with a resistor is not considered. This omission should be explained, or the corresponding analysis should be incorporated.
Line 283: Correct the word “memristor.”
Line 398: The term “chapter” should be replaced with “article.”
Figure 4 should be replaced with an image showing the interconnected components with a better presentation (e.g., using a PCB board as mentioned in the conclusions to avoid jumping wires).
A figure should be included to show the complete system tested in the laboratory (including the ArC Two board).
The research methodology is not entirely clear. It is necessary to provide a detailed description of the methodology, outlining each phase or stage required to achieve the stated objectives. The topic should be addressed clearly and comprehensibly, supported by pertinent and up-to-date sources of information.
The discussion presented in the manuscript requires significant strengthening, considering both the obtained results and those reported in other studies related to the topic (supported by recent and relevant sources).
The conclusions and future perspectives are considered coherent concerning the topic discussed throughout the manuscript.
In general, the references are appropriate; however, only 4 out of 23 sources are from the last five years. Strengthening the bibliographic review by incorporating more recent and relevant sources is a priority.
Author Response
Thank you for your review. Please see the attachment to find the reply to the comment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors- The introduction is short. There is room for improvement.
- Which is the lumped element model for all the switches Sx_N in Figure 1. I think the model of the switch should also be included in equation 7.
- Please provide the detailed structure of the memristor. As the author claims, the memristor model used in the simulations of this research has 10kΩ to 17kΩ 149 resistance under 0.5V DC voltage [19], and is assumed to have a parasitic capacitance of 10pF[18]. The reader would like to know more about how to make this type of resistor in the chip.
- What is the advantage of using a memristor to replace a real resistor?
Author Response
Thank you for reviewing this manuscript. Please see the attachment to find the reply to the comment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript presents the integration of memristors into N-path filter structures to develop a reconfigurable N-path filter with a tunable bandwidth, with validation carried out through simulations, and for one of the proposed architectures, experimental laboratory tests were conducted. Furthermore, the potential of memristor-based N-path filters in achieving reconfigurable and high-Q filtering capabilities for RF applications is analyzed. Based on the topic addressed in the manuscript, this study is considered relevant to the field of analog circuit design for radiofrequency applications.
The following details were identified:
- At line 85, the meaning of the letter D should be included.
- At line 99, the meaning of the abbreviation SEM should be placed in parentheses.
In this latest version of the manuscript, the methodology employed for the study is considered appropriate, addressing the topic clearly and comprehensibly. Moreover, the information is supported by reliable and pertinent sources. The conclusions and future perspectives are deemed coherent concerning the theme addressed throughout the manuscript. The references cited throughout the manuscript are considered appropriate and support the information discussed.
Author Response
Thank you for reviewing this manuscript. Please see the attachment to read the response to the comments.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe revised manuscript is recommended for publication in its current form.
Author Response
Thank you for your final confirmation and for considering our manuscript acceptable for publication.
