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REVIEW 4 major objections 5 minor 34 references

A wireless passive pressure sensor with high sensitivity

T0 review · 4 major / 5 minor · reviewed 2026-08-12 · deepseek-v4-flash

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Pith's one-line read A passive wireless pressure sensor reaches 187 kHz/kPa sensitivity over a 1.5 MPa range.

desk verdict The measured sensor looks plausible and useful, but the paper undercuts itself with inconsistent headline numbers and overclaims the simulation method. read the letter →

arxiv 2411.16759 v1 pith:AT3JGZP5 submitted 2024-11-24 physics.ins-det physics.app-ph

Baiyun Wang , Yijia Cheng , Yujie Hua , Wenxuan Tang , Wei E.I. Sha , Hao Xu , Kang Wang , Jundi Hu
show 3 more authors
Huaqing Fan Huanran Peng Gang Shao
This is my paper · ORCID
classification physics.ins-detphysics.app-ph
keywords wirelesspassivepressuresensorLCresonatorX-bandreadoutdiaphragmdeflectionsphericalconformalmodelhigh-pressuresensingcapacitive
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper reports a wireless, passive pressure sensor built as a three-layer LC resonator with a sealed air cavity, and claims it can measure pressures up to 1.5 MPa with an average sensitivity of 187 kHz/kPa. The measured resonant frequency falls linearly from 10.932 GHz at zero pressure to about 10.64 GHz at 1.5 MPa, giving the calibration $f \approx 10.932 - 0.187P$ (f in GHz, P in MPa). The same paper proposes a simulation method in which the pressure-induced deflection of the edge-fixed diaphragm is modeled as a spherical conformal surface instead of a flat, uniformly thinned cavity, and reports that this improves simulation accuracy by about a factor of three. On the authors' own terms, the paper establishes that passive, wireless X-band readout is sufficient for high-sensitivity pressure monitoring across a wide range, and that a sphere-based deformation model captures the electromagnetic effect of real diaphragm bending.

What carries the argument

The load-bearing element is the LC resonance circuit formed by a circular metallic patch on the upper membrane, the metal ground on the lower membrane, and the air cavity between them; pressure deforms both membranes, reducing the effective gap $d$ and increasing the capacitance $C$, which lowers the resonant frequency $f = 1/(2\pi\sqrt{LC})$. The paper's simulation machinery is a geometric equivalence: the deformation of an edge-fixed circular diaphragm is modeled as part of a sphere of radius 6.5 mm, one millimeter smaller than the cavity radius, with an added bend at the clamped edge. This one-shape substitution lets the full-wave electromagnetic simulation see a curved, conformal cavity instead of a flat reduced-height gap, which is what yields the reported threefold accuracy improvement. Also central are the analytical thin-plate results $d(r) = d_0(1 - r^2/a^2)^2$ for the deflection profile and the flexural-rigidity expression $D = Et^3/(12(1-\nu^2))$, which connect pressure to the geometry fed into the electromagnetic model.

What would settle it

Measure the actual deformed profile of the fabricated diaphragm with an optical profilometer or white-light interferometer at several pressures between 0 and 1.5 MPa, and compare it against the 6.5 mm sphere-plus-bend model; if the measured profile deviates by more than the normalized mean-squared-error difference the paper reports (0.159 vs 0.583), the claimed accuracy gain does not come from faithfully modeling the true deformation.

Watch

Extended reading notes

Core claim

The central claim is that a circular-patch LC resonator built as a sandwich of two dielectric plates with a sealed air cavity acts as a high-sensitivity wireless pressure gauge. Pressure bends the two edge-fixed membranes inward, shrinking the cavity gap, raising the plate capacitance, and lowering the resonant frequency; the measured relation is linear, with an average slope of 187 kHz/kPa and a full-span frequency shift of about 288 MHz over 1.5 MPa. The paper further claims that its new simulation strategy—replacing the deformed diaphragm with a spherical conformal surface of radius 6.5 mm plus an edge bend—reproduces the measured frequency-pressure behavior far better than the conventional uniform-thickness method, reducing the normalized mean-squared error from 0.583 to 0.159 and matching the measured trend after calibration. On the authors' terms, the device provides a passive wireless readout with high sensitivity and wide range, and the simulation method fills a gap in electromagnetic modeling of pressure deformation.

Load-bearing premise

The simulation-accuracy claim rests on the assumption that an edge-fixed diaphragm deformed by pressure is faithfully represented by a spherical conformal surface with a hand-picked radius of 6.5 mm and an added edge bend; if that geometric equivalence is wrong, the novel simulation method's claimed advantage collapses, even though the measured sensor data would remain sound.

Editorial extensions

If this is right

  • With the fitted slope $f \approx 10.932 - 0.187P$, each kilopascal of pressure shifts the resonant frequency by about 187 kHz, so a frequency measurement accurate to 1 MHz corresponds to roughly 5 kPa of pressure.
  • The linear calibration means a single measurement of the S11 minimum gives absolute pressure without any wired connection or internal power source, which is the practical point of a passive wireless sensor.
  • The spherical conformal simulation method lowers the normalized mean-squared error in diaphragm deflection from 0.583 (conventional flat-gap method) to 0.159, so pressure-deformed cavity designs can be simulated directly in a full-wave electromagnetic solver instead of by a series of flat approximations.
  • The sandwich-cavity LC topology, with sensitivity and range both controlled by the plate flexural rigidity $D = Et^3/(12(1-\nu^2))$, gives a concrete design path for adjusting the sensor to other pressure windows.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Because the spherical conformal model is a purely geometric substitution, the same trick could be applied to other diaphragm-based RF pressure sensors; whether the 6.5 mm sphere radius is universal or design-specific is not tested, so a useful next experiment is to vary cavity radius and re-fit the sphere.
  • The residual mismatch between simulated slope ($-0.243$ GHz/MPa) and measured slope ($-0.187$ GHz/MPa) suggests the clamped-edge bend in the model is still an approximation; comparing the sphere model against a finite-element-exact deflection profile would show where the remaining error enters.
  • Since the sensor is fully passive and wireless, the same readout chain could in principle work on rotating or moving machinery, though the paper does not demonstrate such an application.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. This paper reports a wireless passive LC pressure sensor built on Rogers 4003C substrate with a sealed air cavity, operating around 10.9 GHz. The measured resonant frequency decreases approximately linearly with pressure, with the fitting line f = 10.932 - 0.187P (Eq. 16) over 0-1.5 MPa, yielding a claimed average sensitivity of 187 kHz/kPa. The paper also proposes a simulation approach in which the pressure-induced diaphragm deflection is represented by a spherical conformal surface with a selected sphere radius and an added edge bend, and it claims a threefold accuracy improvement over a conventional flat-cavity simulation. The measured sensor data are presented as three experimental sets with error bars; the simulation claim is supported only by MSE on normalized deflection curves and a single S11-based frequency-pressure slope.

Significance. If the measured performance is accepted, the device is a useful passive wireless pressure sensor with a wide range (1.5 MPa) and a calibration slope that could allow roughly 1 kPa pressure resolution with a high-resolution VNA. The inclusion of three repeated measurement sets with error bars is a strength. However, the paper's second advertised contribution, the spherical conformal simulation method, is not quantitatively validated against electromagnetic response, and the advertised 'threefold enhancement' is not consistently defined. The inconsistencies in the reported sensitivity values and pressure range are load-bearing and must be fixed before the paper can be evaluated fairly.

major comments (4)
  1. [Abstract / Conclusion / Comparison] The paper reports three different sensitivity values: 187 kHz/kPa in the abstract and Eq. (16), 192 kHz/kPa in the conclusion, and 288 kHz/kPa in the comparison table, whose pressure range '0-15000 kPa' is ten times larger than the claimed 1.5 MPa operating range. The measured endpoint shift from 10.932 to 10.64 GHz over 1.5 MPa implies approximately 195 kHz/kPa, so the origin of each number must be reconciled and the comparison table corrected.
  2. [Discussion, Simulation] The simulation method is not validated against the measured electromagnetic response. The simulated slope in Eq. (19), -0.243 GHz/MPa, deviates by about 30% from the measured slope in Eq. (16), -0.187 GHz/MPa, and Fig. 12(d) aligns the intercepts before declaring the match 'remarkable' and 'to a certain extent.' No conventional-method S11 frequency sweep is shown; the MSE in Eq. (17) is computed only on normalized one-dimensional deflection curves, so it does not establish the accuracy of the simulated resonant frequency.
  3. [Discussion, Simulation] The sphere radius R=6.5 mm and the added edge bend are free parameters selected to improve agreement, and the text states that reducing the radius brings the curve closer to the theoretical value. If R is chosen by minimizing the deflection MSE, the method is a curve-fit rather than an independent physics-based model; the authors should provide an independent criterion for R or a parameter study showing robustness.
  4. [Discussion, Simulation] The accuracy-enhancement claim is quantified inconsistently: the text reports normalized MSE values of 0.159 (spherical) and 0.583 (conventional), a ratio of 3.67, but later states an improvement 'by a factor of 2.26' for the optimized model. The baseline for the factor of 2.26 is not defined, and the abstract's 'threefold enhancement' cannot be traced to a specific comparison.
minor comments (5)
  1. [Throughout] Two different tables are numbered Table 2 (the vital parameters and the comparison list); renumber to avoid ambiguity.
  2. [Throughout] Typographical errors include 'Yang's modulus' (should be Young's modulus), 'bule' (blue) in the error bar description, and 'memberane' in the Fig. 12 caption.
  3. [Electromagnetic Analysis, Eq. (7)] Eq. (7) uses C0 without a definition; define C0 as the zero-pressure capacitance before use.
  4. [References] The reference list is incomplete or irregular (e.g., [16] lacks a title and [21] lacks full bibliographic data).
  5. [Fig. 2 description] In the Fig. 2 description, the panels are discussed in the order (a), (b), (d), (c); reorder or renumber the panels to match the text.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: measured sensitivity is empirical and the simulation slope is not fitted to it.

full rationale

The paper's central quantitative claim, the pressure-to-frequency calibration f ≈ 10.932 − 0.187P (Eq. 16), is an empirical fit to three sets of measured resonant frequencies (Fig. 11b); it is not obtained from the LC model, so there is no derivation chain that could be circular. The theoretical LC and thin-plate expressions (Eqs. 7–15) are standard results cited to Timoshenko, not to the authors' prior work. The only potentially self-referential element is the 'novel simulation method' in Discussion/Simulation: a spherical conformal shape with hand-chosen radius R=6.5 mm and an added edge bend is used to approximate the theoretical deflection curve Eq. 14, and the sphere radius is selected to make the normalized deflection curve 'closely align with the theoretical value.' This is a modeling fit, but the paper does not fit the final simulated frequency-pressure line (Eq. 19, slope −0.243 GHz/MPa) to the measured line (Eq. 16, slope −0.187 GHz/MPa); the two slopes remain ~30% different, and the intercepts are explicitly calibrated to the same value before comparison. The simulated result therefore is not statistically forced by the measured data. The 'threefold enhancement' claim rests on MSE comparisons of normalized deflection curves (0.159 vs 0.583), which is weak evidence for electromagnetic accuracy and is a correctness/validity concern, not a circularity. No load-bearing self-citation appears anywhere in the manuscript.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The sensor claim relies on standard parallel-plate capacitance, LC resonance, and thin-plate deflection formulas, plus a measured calibration curve. The simulation claim additionally relies on a hand-tuned spherical-conformal shape and a symmetry assumption. No new physical entities such as new particles, forces, or dimensions are introduced.

free parameters (3)
  • Measured frequency-pressure sensitivity slope = 0.187 GHz/MPa (Eq. 16)
    Linear fit to measured average resonant frequencies; reported also as 187 kHz/kPa in abstract, 192 kHz/kPa in conclusion, and 288 kHz/kPa with pressure range 0-15000 kPa in Table 2.
  • Simulated frequency-deformation slope = 3.207 GHz/mm (Eq. 18), combined to f_sim = 10.935 - 0.243P (Eq. 19)
    Linear fit to CST simulated resonant frequencies as a function of center deformation; used to claim the simulation method matches measurement.
  • Conformal sphere radius = 6.5 mm
    Hand-chosen after observing that reducing the sphere radius aligns the deflection curve with the theoretical thin-plate curve (Eq. 14); 1 mm smaller than cavity radius R_c = 7.5 mm.
assumptions (4)
  • standard math Parallel-plate capacitance and LC resonance relation f = 1/(2*pi*sqrt(LC))
    Used throughout the Electromagnetic Analysis (Eqs. 1-10) to map cavity geometry to resonant frequency.
  • domain assumption Clamped thin circular plate deflection formulas of Timoshenko (d(r)=d0(1-r^2/a^2)^2 and d0 = PR^4/(64D)(1+0.488(d0/t_film)^2)^-1)
    Used in the Mechanical Analysis (Eqs. 13-15); assumes linear elastic thin-plate behavior, clamped edges, and uniform pressure.
  • domain assumption Top and bottom membranes deform symmetrically
    Stated in the Mechanical and Electromagnetic Simulation section: given the symmetrical thickness of the structure along its vertical axis, it is reasonable to assume that the deformation observed on the bottom membrane mirrors that of the upper surface.
  • ad hoc to paper Deflected diaphragm can be represented as a spherical conformal shape with a chosen radius and edge bend
    Core of the proposed simulation method (Discussion, Simulation section); the sphere radius 6.5 mm is chosen so the deflection curve aligns with the theoretical thin-plate curve, but no independent physical justification is given.

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Cite this review

Pith. "Pith review of A wireless passive pressure sensor with high sensitivity." pith.science (2026). https://pith.science/paper/AT3JGZP5

@misc{pith2026241116759,
  author       = {Pith},
  title        = {Pith review of: A wireless passive pressure sensor with high sensitivity},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/AT3JGZP5}},
  note         = {Machine review of arXiv:2411.16759}
}
read the original abstract

A high-sensitivity wireless pressure sensor with active processing structure designed on the dielectric substrate has been present and evaluated in this paper. The sensor configuration has been optimized by computer-aided design to achieve highest sensitivity and maximum working range for a given dimension. With the average sensitivity of 187kHz/kPa, the proposed pressure sensor is equipped with the ability to measure pressure loaded up to 1.5MPa under room temperature. Additionally, a novel simulation method applied on pressure related design is proposed in this article, with the accuracy reaching threefold enhancement, filling the blank of electromagnetic simulation of pressure deformation. Other characteristics of the devices have been investigated and are presented.

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

34 extracted references · 34 canonical work pages

  1. [1]

    High Temperature Magnetic Sensors for the Hot Section of Aeroengines

    Edward Rokicki, Radoslaw Przysowa, Jerzy Kotkowski and Paweł Majewski. High Temperature Magnetic Sensors for the Hot Section of Aeroengines. 2021

    work page 2021

  2. [2]

    Prosser S. J. Advances in sensors for aerospace applications. Sensors and Actuators A: Physical, 1993:128-134

    work page 1993

  3. [3]

    To satisfy the condition of resonance, the circuit must be purely resistive

    (9) The resonant frequency is defined as the frequency of a circuit when the values of capacitive impedance and the inductive impedance become equal. To satisfy the condition of resonance, the circuit must be purely resistive. Hence, for a circuit containing resistor, inductor and capacitor, the imaginary part of impedance is zero, which can be expressed ...

    work page

  4. [4]

    Gas pressure measurement using micro-corona-discharging effect in surface acoustic wave resonators

    Hu Baofa. Gas pressure measurement using micro-corona-discharging effect in surface acoustic wave resonators. Results in Physics, 2021:104221

    work page 2021

  5. [5]

    Advances in sensors for aerospace applications

    Javed Yaser. Advances in sensors for aerospace applications. Sensor Review, 2019: 652-664

    work page 2019

  6. [6]

    Miniature Passive Pressure Transensor for Implanting in the Eye

    Collins Carter C. Miniature Passive Pressure Transensor for Implanting in the Eye. IEEE Transactions on Biomedical Engineering. 1967:74-83

    work page 1967

  7. [7]

    Ko, Min Hang Bao and Yeun Ding Hong

    Wen H. Ko, Min Hang Bao and Yeun Ding Hong. A high -sensitivity integrated -circuit capacitive pressure transducer. IEEE Transactions on Electron Devices

    work page

  8. [8]

    A review of principles of MEMS pressure sensing with its aerospace applications

    Yaser Javed, Mohtashim Mansoor and Irtiza Ali Shah. A review of principles of MEMS pressure sensing with its aerospace applications

    work page

Show all 34 references
  1. [9]

    George T. Son K. -A. Harsh environment microtechnology for NASA and terrestrial applications. IEEE Sensors, 2005

    2005

  2. [10]

    Vinoy K. J. Micro and Smart Devices and Systems. Springer, India, 2014

    2014

  3. [11]

    Wafer-Level Self -Packaging Design and Fabrication of MEMS Capacitive Pressure Sensors

    Wan Yuanjie. Wafer-Level Self -Packaging Design and Fabrication of MEMS Capacitive Pressure Sensors. Micromachines, 2022:738

    2022

  4. [12]

    Tactile sensing in dexterous robot hands -Review

    Kappassov Juan -Antonio. Tactile sensing in dexterous robot hands -Review. Robotics and Autonomous Systems. 2015

    2015

  5. [13]

    Review of high sensitivity fibre-optic pressure sensors for low pressure sensing

    V orathin E. Review of high sensitivity fibre-optic pressure sensors for low pressure sensing. Optics & Laser Technology, 2020:105841

    2020

  6. [14]

    Michael A. Fonseca. POLYMER/CERAMIC WIRELESS MEMS PRESSURE SENSORS FOR HARSH ENVIRONMENTS: HIGH TEMPERATURE AND BIOMEDICAL APPLICA TIONS. 2007

    2007

  7. [15]

    MEMS Piezoresistive Pressure Sensor: A Survey

    Meti Shwetha. MEMS Piezoresistive Pressure Sensor: A Survey

  8. [16]

    30-34 2.75 0-100 26 26-27 0.4 0-10000 0.064

  9. [17]

    A wireless passive pressure sensor based on aperture coupled microstrip patch antenna

    Yanjie Guo, Qiulin Tan and Fei Lu. A wireless passive pressure sensor based on aperture coupled microstrip patch antenna

  10. [18]

    70-100 4 70-120 92.98

  11. [19]

    A novel wireless gas sensor based on LTCC technology

    Ma Mingsheng. A novel wireless gas sensor based on LTCC technology. Sensors and Actuators B: Chemical. 2017:711-717

    2017

  12. [20]

    Development of a wireless passive capacitively coupled contactless conductivity detection (WPC4D) for fluidic flow detection utilizing 3D printing and PCB technologies

    Hoang Bao -Anh. Development of a wireless passive capacitively coupled contactless conductivity detection (WPC4D) for fluidic flow detection utilizing 3D printing and PCB technologies. Instrumentation Science & Technology, 2023:591-609

    2023

  13. [21]

    A review on wireless sensors fabricated using the low temperature co-fired ceramic (LTCC) technology

    Yongxiang Li and Xiangyang Guo. A review on wireless sensors fabricated using the low temperature co-fired ceramic (LTCC) technology. 2021:699-711

    2021

  14. [22]

    Jennifer M. E. Wireless Micromachined Ceramic Pressure Sensors. 1999

    1999

  15. [23]

    Polymer/ceramic wireless MEMS pressure sensors for harsh environments: high temperature and biomedical applications

    Fonseca, Michael A. Polymer/ceramic wireless MEMS pressure sensors for harsh environments: high temperature and biomedical applications. Diss. Georgia Institute of Technology, 2007

    2007

  16. [24]

    LC temperature- pressure sensor based on HTCC with temperature compensation algorithm for extreme 1100 ◦C applications

    Qiulin Tan, Fei Lu, Yaohui Ji, Haixing Wang, Wendong Zhang, Jijun Xiong. LC temperature- pressure sensor based on HTCC with temperature compensation algorithm for extreme 1100 ◦C applications

  17. [25]

    Timoshenko, S., & Woinowsky-Krieger, S. (1959). Theory of plates and shells (V ol. 2, pp. 240- 246). New York: McGraw-hill

    1959

  18. [26]

    95-103 8 0-6.7 900.36

  19. [27]

    165-185 1 140-2660(Max) 3.76

  20. [28]

    The conventional method involves simulation by merely adjusting the thickness of the cavity layer to alter the distance between the top and bottom layers

    14900-15000 2.5 0-0.9 2.5 This work 8000-12000 288 0-15000 288 ➢ Simulation To achieve a more precise response curve for enhanced performance understanding and sensor design optimization, a novel approach is proposed for modeling the deflection of the diaphragm in response to ...

  21. [29]

    Benefits of Mixed Dielectrics When Used for High -Frequency PCB Applications

    John Coonrod. Benefits of Mixed Dielectrics When Used for High -Frequency PCB Applications

  22. [30]

    https://www.rogerscorp.com/advanced-electronics-solutions/ro4000-series- laminates/ro4003c-laminates

  23. [31]

    Timoshenko, S

    S.P. Timoshenko, S. Woinowsky-Krieger, Theory of Plates and Shells, McGrawHill, NYC. US, 1959

    1959

  24. [32]

    A wireless batch sealed absolute capacitive pressure sensor

    Orhan Akar. A wireless batch sealed absolute capacitive pressure sensor. Sensors and Actuators A. 2001:29-38

    2001

  25. [33]

    Fabrications and Performance of Wireless LC Pressure Sensors through LTCC Technology

    Lin. Fabrications and Performance of Wireless LC Pressure Sensors through LTCC Technology. Sensors, 2018:340

    2018

  26. [34]

    A Passive Wireless Microelectromechanical Pressure Sensor for Harsh Environments

    Rogers John E. A Passive Wireless Microelectromechanical Pressure Sensor for Harsh Environments. Journal of Microelectromechanical Systems, 2018:73-85

    2018

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