Testing of electrophysical parameters of multilayer dielectric and magnetodielectric coatings: estimation of resolution of the surface electromagnetic wave method

The problem of reconstructing the distribution of permittivity and magnetic permeability over the thickness (profile) of non-metallic coatings is relevant in connection with the increasing role of modern methods of radio wave non-destructive testing for assessing the quality of various types of materials and products. Using radio wave methods, the distribution of permittivity and magnetic permeability over layers of multilayer dielectric and magnetodielectric coatings on a metal substrate was reconstructed. The resolution of the method of surface electromagnetic waves in terms of permittivity and magnetic permeability has been studied – the difference between the values of the permittivity and magnetic permeability of adjacent layers of multilayer dielectric and magnetodielectric coatings, respectively. An original method has been developed for assessing the maximum resolution of the surface electromagnetic wave method depending on the electrophysical parameters of the coating layers, the number and bandwidth of measurements, as well as the standard deviation of noise affecting the result of measuring the field attenuation coefficients of the surface wave. The structure of the measuring complex that implements the developed methodology is given. The results of numerical and full-scale experiments to assess the resolution limits of the permittivity and magnetic permeability of layers of two-layer coatings of various types are presented. Numerical experiments were carried out on a sample of a twolayer radio-absorbing coating, and full-scale experiments were carried out on a sample of a two-layer dielectric coating based on Ro4003C and Arlon25N materials. The results of numerical and natural experiments were found to coincide, which confirms the adequacy of the developed methodology. With a measurement bandwidth of 9.0–12.5 GHz and a standard noise deviation of 0.002, the resolution limit for the permittivity and magnetic permeability of layers is 0.25–0.50 %. The proposed technique can be in demand in various science-intensive fields when assessing the electrical parameters of multilayer coatings during efficiency tests.

1. Lagarkov A. N., Pogosyan M. A. Fundamental and applied problems of stealth technologies. Herald of the Russian Academy of Sciences, 73(9), 779–787 (2003). (In Russ.) https://elibrary.ru/omvijp

2. Vinogradov A. P., Lagarkov A. N., Sarychev A. K., Sterlinga I. G. Multilayer absorbent structures made of composite materials. Journal of Communications Technology and Electronics, 41(2), 158–161 (1996). (In Russ.)

3. Ivanova V. I., Kibets S. G., Krasnolobov I. I. et al. Development of broadband radar absorbing material possessing highlevel operating performance. Zhurnal radioelektroniki, (7), (2016). (In Russ.) http://jre.cplire.ru/jre/jul16/5/text.pdf

4. Baskov K.M., Politiko A.A., Semenenko V.N. et al. Radio wave control of parameters of samples of multi-layer radome walls. Zhurnal radioelektroniki, (11), (2019). (In Russ.) https://doi.org/10.30898/1684-1719.2019.11.12

5. Semenenko V. N., Chistyaev V. A., Politiko A. A. et al. Test Stand for Measuring the Free-Space Electromagnetic Parameters of Materials over an Ultrawide Range of Microwave Frequencies. Measurement Techniques, 62(2), 161–166 (2019). https://doi.org/10.1007/s11018-019-01601-5

6. Antropov O. S., Drobakhin O. O. Increase in the resolution of the reflection coefficient Fourier-transform method by spectrum extrapolation based on the method of the minimum duration principle. Russian Journal of Nondestructive Testing, 45(5), 347–354 (2009). (In Russ.) https://doi.org/10.1134/S1061830909050088

7. Aly O. A. M., Omar A. S. Reconstructing stratified permittivity profiles using super-resolution techniques. IEEE Transactions on Microwave Theory and Techniques, 54(1), 492–498 (2006). https://doi.org/10.1109/TMTT.2005.860491

8. Mirjahanmardi S. H., Albishi A. M., Ramahi O. M. Permittivity Reconstruction of Nondispersive Materials Using Transmitted Power at Microwave Frequencies. IEEE Transactions on Instrumentation and Measurement, 69(10), 8270–8278 (2020). https://doi.org/10.1109/TIM.2020.2988329

9. Omar A. Base bandand Super-Resolution-Passband Reconstructionsin Microwave Imaging. IEEE Transactions on Microwave Theory and Techniques, 67(4), 1327–1335 (2019). https://doi.org/10.1109/TMTT.2019.2894427

10. Li Y., Yang X., Lan T., Liu R., Qu X. Parameter Inversionby a Modified Reflected Signal Reconstruction Method for ThinLayered Media. IEEE Antennas and Wireless Propagation Letters, 21(5), 958–962 (2022). https://doi.org/10.1109/LAWP.2022.3152843

11. Didier Q., Arhab S., Lefeuve-Mesgouez G. Comparative study between different frequency strategies for relative dielectric permittivity and electrical conductivity reconstruction. Application to near subsurface imaging. 2022 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO), Limoges, France, pp. 1–4, 2022. https://doi.org/10.1109/NEMO51452.2022.10038974

12. Mikhnev V. A. Reconstructive microwave structuroscopy of multilayer dielectric media. PChUP “Svetoch” Publ., Minsk (2002). (In Russ.)

13. Grinev A. Yu., Temchenko V. S., Bagno D. V. Subsurface sounding radars. Monitoring and diagnostics of environments and objects. Radiotechnika ” Publ., Moscow (2013). (In Russ.)

14. Kaz’min A. I. Methodological Principles for Determining Electrophysical Parameters of Materials and Coatings with a Complex Internal Structure Using Surface Electromagnetic. Russian Journal of Nondestructive Testing, 58(3), 205–220 (2022). https://doi.org/10.1134/S1061830922030032

15. Felsen L. B., Marcuvitz N. Radiation and Scattering of Waves. Vol. 1, Englewood Cliffs, New Jersey (1973).

16. Brekhovskikh L. M. Waves in layered media. Nauka Publ., Moscow (1973). (In Russ.)

17. Kaz’min, A. I. Multifrequency Optimization Method for Measuring the Frequency Dependences of the Electrical Parameters of Dielectric and Magnetodielectric Coatings. Measurement Techniques, 64(9), 763–771 (2021). https://doi.org/10.1007/s11018-022-02001-y

18. Kaz’min A. I., Fedyunin P. A., Fedyunin D. P. Evaluation of Permittivity and Thickness Gaging for Anisotropic Dielectric Coatings by the Method of Surface Electromagnetic Waves. Russian Journal of Nondestructive Testing, 57(6), 500–516 (2021). https://doi.org/10.1134/S1061830921060085

19. Ufimtsev P. Y., Ling R. T. New results for the properties of TE surface waves in absorbing layers. IEEE Transactions on Antennas and Propagation, 49(10), 1445–1452 (2001). https://doi.org/10.1109/8.954933

20. Kaz’min A. I., Fedyunin P. A., Ryabov D. A. Assessment of the accuracy of reconstruction of the electrical parameters of multi-layer radio-absorbing coatings using the method of surface electromagnetic waves using a simulation model in Matlab. Materials of the XXI International Scientific and Methodological Conference “Informatics: Problems, Methods, Technologies”, Voronezh State University, 11–12 February 2021. (In Russ.)

21. Bogdanov J., Kotchemasov V., Khas’yanova H. Copper clad dielectrics. How to select the optimum version for high frequency and microwave PCBS. Electronics: Science, Technology, Business, (3(125)), 156–168 (2013). (In Russ.)