S.G. Vesnin1, V.V. Nizhnev2, M.K. Sedankin3, R.A. Mishkhodev4, N.S. Maksimov5, S.V. Chizhikov6

1,3,6 Bauman Moscow State Technical University (National Research University) (Moscow, Russia)
1,2 RTM Diagnostics LLC (Moscow, Russia)
4 LLC "Firm" RES "(Moscow, Russia)
5 NIA "Moscow Power Engineering Institute" (Moscow, Russia)
5 Institute of Radio Engineering and Electronics named after V.A. Kotelnikov (IRE RAS) (Moscow, Russia)
 

Microwave radiothermographs are widely used in medicine, industry and other fields to detect and measure thermal radiation. However, existing filters do not always effectively suppress unwanted signals, which can lead to distortion of the results and deterioration of image quality.

The aim of the work is to develop miniature band–pass filters capable of providing effective suppression of unwanted signals in microwave radiothermographs. To achieve this goal, research was conducted based on mathematical modeling and optimization of filter parameters.

Within the framework of the article, a study was conducted that showed that a miniature microstrip filter with attenuation bands at finite frequencies, built on the basis of parallel cascade switching of resonators, and implemented on a substrate with a high permittivity value has a high frequency selectivity (Kp 40 = 2,4), which corresponds to the parameters of a six-part microstrip filter on half-wave resonators. The developed filters have a high efficiency of suppression of unwanted signals in a wide frequency range. They also have a compact size, which makes them convenient to use in microwave radiothermographs.

The practical significance of this work lies in the possibility of improving the image quality and more accurate measurement of thermal radiation in microwave radiothermographs. This may lead to the development of more effective diagnostic and control methods in medicine, industry and other areas where microwave radiothermographs are used. It is very important to note that the dimensions of the miniature filter are comparable to the dimensions of other SMD components of the printed circuit board and it can be integrated into surface mounting technology.

The research was carried out with the financial support of the Russian science Foundation in the framework of agreement No. 19-19-00349-П in the theme: «A method and a multichannel multifrequency microwave radiothermography on the basis of monolithic integrated circuits for finding the 3D distribution and dynamics of brightness temperature in the depths of the human body».

Vesnin S.G., Nizhnev V.V., Sedankin M.K., Mishkhodev R.A., Maksimov N.S., Chizhikov S.V. Miniature band-pass filters for microwave radiothermographs. Nanotechnology: development and applications – XXI century. 2023. V. 15. № 3. P. 5–10. DOI: https://doi.org/10.18127/ j22250980-202303-01 (in Russian)

1. Chizhikov S.V., Solov'ev YU.V. Elementnaya baza MIS SVCh dlya mikrovolnovoj radiotermometrii. Nanotekhnologii: razrabotka, primenenie – XXI vek. 2020. T. 12. № 2. S. 48–57. DOI: https://doi.org/10.18127/j22250980-202002-06 (in Russian).
2. Fel'dshtejn A.L. i dr. Spravochnik po elementam poloskovoj tekhniki. M.: Svyaz'. 1979. S. 4–71 (in Russian).
3. Belyaev B.A. i dr. Selektivnye svojstva mikropoloskovyh fil'trov na chetvert'volnovyh sonapravlennyh shpil'kovyh rezonatorah. Radiotekhnika i elektronika. 2006. T. 51. № 1. S. 24–36 (in Russian).
4. Aristarhov G.M., Zvezdinov N.V., CHernyshev V.P. Mikropoloskovye fil'try na sonapravlennyh shpilechnyh rezonatorah s povyshennoj chastotnoj izbiratel'nost'yu. Radiotekhnika. 2014. № 10. S. 22–28 (in Russian).
5. Osipenkov V., Vesnin S.G. Microwave filters of parallel-cascade structure. IEEE transactions on microwave theory and techniques. 1994. V. 42. № 7. P. 1360–1367.
6. Vesnin S.G. et al. Portable microwave radiometer for wearable devices. Sensors and Actuators A: Physical. 2021. V. 318. P. 112506.
7. Katalog keramicheskih materialov. Rezhim dostupa: https://ramics.ru/ (data obrashcheniya: 20.06.2023) (in Russian).
8. Zelyah E.V. i dr. Miniatyurnye ustrojstva UVCH i OVCH diapazonov na otrezkah linij. М.: Radio i svyaz'. 1989. S. 110 (in Russian).