H.N. Nguyen1, A.A. Sochava2, K.V. Greshnevikov3, S.V. Bogachev4, A.S. Cherepanov5, M. V. Sochava6

1-6 Peter the Great St. Petersburg Polytechnic University (St. Petersburg, Russia)

1 nguyenhanama1@gmail.com; 2 sochava@spbstu.ru; 3 bogachev_sv@spbstu.ru; 4 greshnev_kv@spbstu.ru; 5 cherepanov@spbstu.ru; 6 sochava_mv@spbstu.ru

In a T-junction of rectangular waveguides with a longitudinal slot diaphragm, efficient control over the transmitted power and phase characteristics of the electromagnetic wave is required. An important factor is considering the influence of resistance and the placement of additional resistors at the slot on the amplitude and phase characteristics of the S-parameters. By conducting a detailed analysis of the influence of resistors on wave propagation in the T-junction of rectangular waveguides, an equivalent circuit is constructed to identify optimal conditions for effective control of electromagnetic waves in waveguide systems. Through numerical modeling, the influence of resistors, their resistances, quantity, and placement along the longitudinal slot on the S-parameters was studied. A simple equivalent circuit with lumped elements is proposed, which yields similar results. It was found that correct selection of resistor values and positioning allows for the regulation of power and phase of the transmitted signal. The obtained results enable targeted adjustment of transmitted power and signal phase in waveguide systems. The equivalent circuits of the slot diaphragm provide an opportunity for optimization to precisely tune the characteristics of antennas and other radio-frequency devices, enhancing their efficiency and expanding their functional capabilities.

Nguyen H.N., Sochava A.A., Greshnevikov K.V., Bogachev S.V., Cherepanov A.S., Sochava M.V. Wave propagation characteris-tics through a longitudinal slot with the possibility of installing additional resistors. Radiotekhnika. 2025. V. 89. № 3. P. 44−56.
DOI: https://doi.org/10.18127/j00338486-202503-05 (In Russian)

1. Stevenson A.F. Theory of slots in rectangular waveguides. Journal of Applied Physics. 1948. № 19(1). Р. 24–38.
2. Josefsson L.G. Analysis of longitudinal slots in rectangular waveguides. IEEE Trans. Antennas Propagat. 1987. № AP-35.
   Р. 1351-1357.
3. Bethe H.A. Theory of diffraction by small holes. Physical Review. 1944. № 66. Р. 163-182.
4. Oliner A.A. The impedance properties of narrow radiating slots in the broad face of rectangular waveguide. Pt. 1. Theory. Pt. 2. Comparison with measurements. IRE Trans. 1957. № AP-5(1). Р. 4-11, 12-20.
5. Dikij D.V., Akimov V.P., Sochava A.A., Cherepanov A.S. Upravlenie fazovym sdvigom s pomoshh'ju volnovodno-shhelevogo fazovrashhatelja. Nauchno-tehnicheskie vedomosti SPbGPU. Fiziko-matematicheskie nauki. 2018. T. 11. № 2. S. 130–138. DOI: 10.18721/JPM.11212 (in Russian).
6. Nguen H.N., Sochava A.A., Nguen D.K. Model' jelektricheski upravljaemogo volnovodno-shhelevogo fazovrashhatelja. Sb. materialov Vseross. konf. «Nedelja nauki IJeiT». SPb. 2022. S. 56-58  (in Russian).
7. Nguen H.N. Issledovanie volnovodno-shhelevogo fazovrashhatelja v programmnom komplekse ANSYS. Tezisy dokladov Dvadcat' devjatoj mezhdunar. nauch.-tehnich. konf. studentov i aspirantov «Radiojelektronika, jelektrotehnika i jenergetika». M. 2023. 57 s. (in Russian).
8. Nguyen H.N., Sochava A., Bogachev S., Cherepanov A., Dikii D. Waveguide-slot phase shifter controlled by p-i-n-diodes system. 2023 International Conference on Electrical Engineering and Photonics (EExPolytech). 2023. Р. 84-86. DOI: 10.1109/EExPoly-tech58658.2023.10318588.
9. Seo D., Choi J., Ryu J., Jung K.-Y. Simple SLL reduction method for an SIW longitudinal slot array antenna. IEEE Access. 2024. № 12. Р. 146359-146365. DOI: 10.1109/ACCESS.2024.3473910.
10. Wang T., Tomura T., Hirokawa J., Pyne B., Akbar P.R., Saito H. A Feeding network with collinearly centered longitudinal coup-ling slots for a rectangular parallel-plate slot array antenna. IEEE Transactions on Antennas and Propagation. 2023. № 71(7).
    Р. 5838-5849. DOI: 10.1109/TAP.2023.3270458.
11. Boxer A.S., Hershenov S., Landry E.F. A high-power coaxial ferrite phase shifter (correspondence). Transactions on Microwave Theory and Techniques. 1961. № 9(6). S. 577-577. DOI: 10.1109/TMTT.1961.1125401.
12. Dragoman M. Low-voltage phase shifters based on HfxZr1-xO2 ferroelectrics integrated with phased antenna arrays. 2018 48th European Microwave Conference. 2018. Р. 950-953. DOI: 10.23919/EuMC.2018.8541592.
13. Chan E.H.W., Minasian R.A. Photonic RF phase shifter and tunable photonic RF notch filter. Journal of Lightwave Technology. 2006. № 24(7). Р. 2676-2682. DOI: 10.1109/JLT.2006.875211.
14. Nguen Ha Nam, Sochava A.A., Greshnevikov K.V., Bogachev S.V., Cherepanov A.S., Dikij D.V. Optimizacija volnovodno-shhelevogo fazovrashhatelja, upravljaemogo sistemoj p-i-n-diodov ili MJeMS-kommutatorov. Radiotehnika. 2024. T. 88. № 3. S. 127−137. DOI: https://doi.org/10.18127/j00338486-202403-12 (in Russian).