Dielectric Wireless Passive Temperature Sensor

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1.The overall structure of the paper is clear and the sections are well-divided. However, some transitions between sections seem somewhat abrupt; adding transitional explanations could improve the overall logical flow.

2. The paper employs FEM in COMSOL to analyze the dielectric resonator; however, details regarding boundary conditions, mesh discretization, and convergence criteria are insufficient. It is recommended to provide additional specifics to enhance reproducibility and reader comprehension of the simulation process.

3.The material selection in this paper needs to be further demonstrated, and the basis for selecting ZST ceramics (εᵣ=37) is not fully developed (page 3). Data on its temperature stability and dielectric loss properties compared with other candidate materials (such as strontium titanate) should be added, or literature should be cited to support its rationality as a high temperature sensing material.

4. Some of the charts (Figure 4, Figure 15) have fuzzy axis labels and legends are missing (for example, the definition of Zone 1-3 is not illustrated in Figure 4). It is recommended to redraw and add annotations to ensure that the reader does not have to rely on the main text to understand the core information of the chart.

5.The conclusion does not mention potential limitations, such as interference with sensor radiation from the metal environment (sensitivity issues mentioned in Section 2.3) or the effect of changes in the conductivity of the ceramic substrate at high temperatures (experimental Q-factor reduction in Chapter 4). Suggest additional discussions and suggest future improvements (such as encapsulation techniques or multimodal fusion anti-jamming algorithms)

 

Author Response

The authors thank the reviewers for their valuable comments that improve the quality of the manuscript.

Reviewer 1:

1.The overall structure of the paper is clear and the sections are well-divided. However, some transitions between sections seem somewhat abrupt; adding transitional explanations could improve the overall logical flow.

We added some transitional sentences  between some sections.

2. The paper employs FEM in COMSOL to analyze the dielectric resonator; however, details regarding boundary conditions, mesh discretization, and convergence criteria are insufficient. It is recommended to provide additional specifics to enhance reproducibility and reader comprehension of the simulation process.

The authors thank the reviewer for his comments. The details of the FEM simulation in COMSOL remain vague, as the authors have outsourced the detailed description and comparison of the analysis and simulation of the dielectrically isolated resonators to a separate manuscript, which they plan to submit shortly. To address this deficiency, we have added an additional paragraph on the simulation to the manuscript.

3.The material selection in this paper needs to be further demonstrated, and the basis for selecting ZST ceramics (εᵣ=37) is not fully developed (page 3). Data on its temperature stability and dielectric loss properties compared with other candidate materials (such as strontium titanate) should be added, or literature should be cited to support its rationality as a high temperature sensing material.

The authors thank the reviewer for this valid objection. However, the goal of the study presented here was not to optimize the material properties, especially not to develop or manufacture a proprietary ceramic. Rather, samples of unpacked dielectric resonators from the development of base station filters were used. A comparison with other candidate materials (such as strontium titanate) as well as material optimization for higher temperature tolerance and higher epsilon for size reduction must be left to future studies.
Some sentence has been added to this text and the outlook.

4. Some of the charts (Figure 4, Figure 15) have fuzzy axis labels and legends are missing (for example, the definition of Zone 1-3 is not illustrated in Figure 4). It is recommended to redraw and add annotations to ensure that the reader does not have to rely on the main text to understand the core information of the chart.

Figure 4 was redrawn and some explaining text was added in the manuscript.  The label in Figure 15 left was also corrected.

5.The conclusion does not mention potential limitations, such as interference with sensor radiation from the metal environment (sensitivity issues mentioned in Section 2.3) or the effect of changes in the conductivity of the ceramic substrate at high temperatures (experimental Q-factor reduction in Chapter 4). Suggest additional discussions and suggest future improvements (such as encapsulation techniques or multimodal fusion anti-jamming algorithms)

The authors thank the reviewer for this point, which enriches the manuscript. The outlook has been supplemented with two paragraphs on conductive materials in the environment and on changes in conductivity at high temperatures.

The authors thank the reviewers for their valuable comments that improve the quality of the manuscript.

Reviewer 1:

1.The overall structure of the paper is clear and the sections are well-divided. However, some transitions between sections seem somewhat abrupt; adding transitional explanations could improve the overall logical flow.

We added some transitional sentences  between some sections.

2. The paper employs FEM in COMSOL to analyze the dielectric resonator; however, details regarding boundary conditions, mesh discretization, and convergence criteria are insufficient. It is recommended to provide additional specifics to enhance reproducibility and reader comprehension of the simulation process.

The authors thank the reviewer for his comments. The details of the FEM simulation in COMSOL remain vague, as the authors have outsourced the detailed description and comparison of the analysis and simulation of the dielectrically isolated resonators to a separate manuscript, which they plan to submit shortly. To address this deficiency, we have added an additional paragraph on the simulation to the manuscript.

3.The material selection in this paper needs to be further demonstrated, and the basis for selecting ZST ceramics (εᵣ=37) is not fully developed (page 3). Data on its temperature stability and dielectric loss properties compared with other candidate materials (such as strontium titanate) should be added, or literature should be cited to support its rationality as a high temperature sensing material.

The authors thank the reviewer for this valid objection. However, the goal of the study presented here was not to optimize the material properties, especially not to develop or manufacture a proprietary ceramic. Rather, samples of unpacked dielectric resonators from the development of base station filters were used. A comparison with other candidate materials (such as strontium titanate) as well as material optimization for higher temperature tolerance and higher epsilon for size reduction must be left to future studies.
Some sentence has been added to this text and the outlook.

4. Some of the charts (Figure 4, Figure 15) have fuzzy axis labels and legends are missing (for example, the definition of Zone 1-3 is not illustrated in Figure 4). It is recommended to redraw and add annotations to ensure that the reader does not have to rely on the main text to understand the core information of the chart.

Figure 4 was redrawn and some explaining text was added in the manuscript.  The label in Figure 15 left was also corrected.

5.The conclusion does not mention potential limitations, such as interference with sensor radiation from the metal environment (sensitivity issues mentioned in Section 2.3) or the effect of changes in the conductivity of the ceramic substrate at high temperatures (experimental Q-factor reduction in Chapter 4). Suggest additional discussions and suggest future improvements (such as encapsulation techniques or multimodal fusion anti-jamming algorithms)

The authors thank the reviewer for this point, which enriches the manuscript. The outlook has been supplemented with two paragraphs on conductive materials in the environment and on changes in conductivity at high temperatures.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript is written clearly and I did not notice any significant inaccuracies. The introduction does not contain any unnecessary references, but the existing references are well-founded. The manuscript contains quite a few figures that confirm the results of calculations and relevant experiments. It is convincingly shown that such a wireless sensor can measure temperatures up to 700°C with a resolution of 0.5°C at a distance of 1m, which is a very good indicator.
Therefore, the manuscript can be accepted for publication in its original form, unless the authors additionally revise the manuscript and make minor changes.

Author Response

The authors thank the reviewers for their valuable comments that improve the quality of the manuscript.

Reviewer 2:

The manuscript is written clearly and I did not notice any significant inaccuracies. The introduction does not contain any unnecessary references, but the existing references are well-founded. The manuscript contains quite a few figures that confirm the results of calculations and relevant experiments. It is convincingly shown that such a wireless sensor can measure temperatures up to 700°C with a resolution of 0.5°C at a distance of 1m, which is a very good indicator.
Therefore, the manuscript can be accepted for publication in its original form, unless the authors additionally revise the manuscript and make minor changes.

The authors thank the reviewer for his positive review

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents some work on a passive wireless temperature sensor which is potentially interesting for readers and useful for practical applications. My only comment on the experimental work is related with the paragraph below:

 

“Due to the furnace control loop, the distribution of the frequency deviations does not exactly correspond to a Gaussian distribution”

 

The authors should have better had an independent temperature measurement on the sensor surface (e.g. an optical thermometer for example) instead of relaying on the oven thermocouple, which should have been avoiding unnecessary explanations and potential errors, (even if some calibration measurements would have to been probably necessary to be performed ).

 

Below are also some small punctual changes for potentially improving the presentation of the material:

 

Fig. 1

- Explaining the principle is not appropriate as a figure caption in my opinion. Caption should rather describe the content of the figure.

 

RF-ID-based transponder

- Abbreviation should be have been explained

 

“For experimental verification of the simulations, we placed isolated dielectric resonators with high radiation quality on a dielectric substrate, and measured their radiation properties in the far field. The radiation patterns investigated in the laboratory and outdoors agree well with the simulations. The resulting radiation patterns show a directivity of approximately 7.5 dBi at 2.5 GHz. The sensor was then heated in a ceramic furnace. The readout antenna was located outside at room temperature. Wireless temperature measurements up to 700 °C with a resolution of 0.5 °C experimentally prove the outstanding performance of dielectric resonators for practical applications.”

 

- This paragraph is rather a ‘missing part of the abstract” then an introduction. Part of the information should be welcome in the conclusion section as well !

 

“ In order to suppress reflections from the environment, all the measurements have been performed outdoors in a grass field and the high gain antenna suppresses possible ground reflections.”

 

-This is actually an issue which should be at least ‘tangentially’ later addressed for a real sensor case. Consequently, some comments on how the issue should be approached would be required in my opinion.

 

- Fig, 16 b is presenting an asymmetric frequency shift distribution. Could authors comment on that ?

 

 

Author Response

The authors thank the reviewers for their valuable comments that improve the quality of the manuscript.

Reviewer 3
The manuscript presents some work on a passive wireless temperature sensor which is potentially interesting for readers and useful for practical applications. My only comment on the experimental work is related with the paragraph below:
“Due to the furnace control loop, the distribution of the frequency deviations does not exactly correspond to a Gaussian distribution”
The authors should have better had an independent temperature measurement on the sensor surface (e.g. an optical thermometer for example) instead of relaying on the oven thermocouple, which should have been avoiding unnecessary explanations and potential errors, (even if some calibration measurements would have to been probably necessary to be performed ).

The authors fully agree with the reviewer, although measuring with an optical thermometer with the required accuracy (<0.1 °C at 500°C) would have been challenging. The optical thermometer available in the laboratory does not achieve this accuracy. A reliable, non-contact measurement of the actual temperature with the accuracy achievable with a dielectric resonator was actually beyond the laboratory's capabilities. Therefore, quasi-static measurements were performed wherever possible, and the errors due to the furnace control were tolerated. A sentence on this topic was added to the text.

Below are also some small punctual changes for potentially improving the presentation of the material:
Fig. 1
- Explaining the principle is not appropriate as a figure caption in my opinion. Caption should rather describe the content of the figure.

Some sentences on the principle were included in the main text.

RF-ID-based transponder
- Abbreviation should be have been explained

Done

“For experimental verification of the simulations, we placed isolated dielectric resonators with high radiation quality on a dielectric substrate, and measured their radiation properties in the far field. The radiation patterns investigated in the laboratory and outdoors agree well with the simulations. The resulting radiation patterns show a directivity of approximately 7.5 dBi at 2.5 GHz. The sensor was then heated in a ceramic furnace. The readout antenna was located outside at room temperature. Wireless temperature measurements up to 700 °C with a resolution of 0.5 °C experimentally prove the outstanding performance of dielectric resonators for practical applications.”
- This paragraph is rather a ‘missing part of the abstract” then an introduction. Part of the information should be welcome in the conclusion section as well !

The authors integrated this paragraph into the abstract.

“ In order to suppress reflections from the environment, all the measurements have been performed outdoors in a grass field and the high gain antenna suppresses possible ground reflections.”
-This is actually an issue which should be at least ‘tangentially’ later addressed for a real sensor case. Consequently, some comments on how the issue should be approached would be required in my opinion.

The authors added a paragraph on this issue in the outlook and conclusion.

 - Fig, 16 b is presenting an asymmetric frequency shift distribution. Could authors comment on that ?

 

The authors do not know the origin of this asymmetric distribution. We assume it is caused by the furnace control system. A sentence about the asymmetric frequency shift has been added.