Electromagnetic Analysis of an Inductive Iris in a Rectangular Waveguide via a Hybrid Mode-Matching and Integral Equation Technique
DOI:
https://doi.org/10.64915/RADAP.2026.103.%25pKeywords:
electromagnetic analysis, electromagnetic modeling, mode-matching technique, integral equations, inductive irises, rectangular waveguide, field distribution, basis functions, Gegenbauer polynomials, waveguide componentsAbstract
Inductive irises are applied in modern microwave filters, diplexers, polarizers, and rotators based on waveguides. The article presents an efficient mathematical technique for the analysis of the characteristics of the electromagnetic waves scattered by an inductive iris in a rectangular waveguide. Using the mode-matching technique for the transverse field components, the electromagnetic waves scattering problem was reduced to a set of coupled integral equations, which were then decoupled. Each equation was solved by expanding the electric field in the iris window into a series of basis functions. This procedure was implemented using sets of orthogonal trigonometric basis functions of the aperture field, orthogonal basis functions based on Gegenbauer polynomials with a weighting function of power 1/2, or orthogonal basis functions based on Gegenbauer polynomials with a weighting function of power 2/3. As a result, it became possible to determine the phasors of all modes in each region of the inner volume (before the iris, inside its aperture, and after the iris), along with the complex reflection and transmission coefficients of the fundamental electromagnetic mode TE10.
In order to validate the correctness and accuracy of the developed mathematical model, additional calculations by efficient numerical methods (Finite Element Method and Finite-Difference Time-Domain method) and experimental measurements of reflection characteristics were performed for two inductive irises in a standard rectangular waveguide. Measurement setups included a scalar network analyzer or a vector network analyzer, one of two inductive irises, a matching load, and waveguide channels. The experimentally obtained reflection coefficients were in good agreement with those predicted by the developed mathematical model and numerical methods.
The developed mathematical model can be widely applied to the analysis of electromagnetic wave scattering by inductive irises in waveguides and to the synthesis of various microwave devices based on these irises.
References
1. Cai, H., Liu, H., Su, G., Yang, N., Liu, J. and Sun, L. (2023). A V-band wideband waveguide filters with inductive iris. 2023 16th UK-Europe-China Workshop on Millimetre Waves and Terahertz Technologies (UCMMT), pp. 1-3. DOI: 10.1109/UCMMT58116.2023.10310325.
2. Kireeff Covo, M., Hassan, T., Duran, J. C., Lambert, K., Bloemhard, P. and Benitez, J. (2024). Inductive iris impedance matching network for a compact waveguide DC break. IEEE Transactions on Microwave Theory and Techniques, vol. 72, no. 12, pp. 6793-6798. DOI: 10.1109/TMTT.2024.3409470.
3. Zhao, X., Glubokov, O., Campion, J., Gomez-Torrent, A., Krivovitca, A., Shah, U. and Oberhammer, J. (2020). Silicon micromachined D-band diplexer using releasable filling structure technique. IEEE Transactions on Microwave Theory and Techniques, vol. 68, no. 8, pp. 3448-3460. DOI: 10.1109/TMTT.2020.3004585.
4. Campion, J., Glubokov, O., Gomez-Torrent, A., Krivovitca, A., Shah, U., Bolander, L., Li, Y. and Oberhammer, J. (2018). An ultra low-loss silicon-micromachined waveguide filter for D-band telecommunication applications. 2018 IEEE/MTT-S International Microwave Symposium - IMS, pp. 583-586. DOI: 10.1109/MWSYM.2018.8439601.
5. Mehrabi Gohari, M., Glubokov, O. and Oberhammer, J. (2025). Inline waveguide filters with transmission zeros using frequency-variant couplings. IEEE Transactions on Microwave Theory and Techniques, Vol. 73, Iss. 6, pp. 3310-3318. DOI: 10.1109/TMTT.2025.3541149.
6. Bartlett, C., Glubokov, O., Kamrath, F. and Höft, M. (2023). Highly selective broadband mm-wave diplexer design. IEEE Microwave and Wireless Technology Letters, vol. 33, no. 2, pp. 149-152. DOI: 10.1109/LMWC.2022.3205425.
7. Bulashenko, A. V., Piltyay, S. I., Kalinichenko, Y. I. and Zabegalov, I. V. (2021). Waveguide polarizer for radar and satellite systems. Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, no. 86, pp. 5-13. DOI: 10.20535/RADAP.2021.86.5-13.
8. Piltyay, S. (2021). Square waveguide polarizer with diagonally located irises for Ka-band antenna systems. Advanced Electromagnetics, vol. 10, no. 3, pp. 31-38. DOI: 10.7716/aem.v10i3.1780.
9. Zhang, Y., Wang, Q. and Xin, H. (2014). A compact 3 dB E-plane waveguide directional coupler with full bandwidth. IEEE Microwave and Wireless Components Letters, vol. 24, no. 4, pp. 227-229. DOI: 10.1109/LMWC.2013.2296297.
10. Hao, L., Zhang, B., Niu, Z., Li, D. and Liu, Y. (2025). A waveguide directional coupler with interleaved coupling holes. 2025 IEEE MTT-S International Microwave Workshop Series (IMWS-AMP), pp. 1-3. DOI: 10.1109/IMWS-AMP66175.2025.11136788.
11. Fu, P.-H., Chao, C.-Y. and Huang, D.-W. (2021). Ultracompact silicon waveguide bends designed using a particle swarm optimization algorithm. IEEE Photonics Journal, vol. 13, no. 1, 6600509. DOI: 10.1109/JPHOT.2020.3043828.
12. Prabha, P. U. K. and Raju, G. S. N. (2016). Analysis of L-band waveguide H-plane Tee junction. 2016 International Conference on ElectroMagnetic Interference & Compatibility (INCEMIC), pp. 1-4. DOI: 10.1109/INCEMIC.2016.7921485.
13. Khorsandy, M., Salari, A., Pilevar, A. and Erricolo, D. (2019). An optimized broadband waveguide magic-T for X-band applications. 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring), pp. 207-211. DOI: 10.1109/PIERS-Spring46901.2019.9017712.
14. Piltyay, S., Bulashenko, A. and Shuliak, V. (2022). Development and optimization of microwave guide polarizers using equivalent network method. Journal of Electromagnetic Waves and Applications, vol. 36, no. 5, pp. 682-705. DOI: 10.1080/09205071.2021.1980913.
15. Stutzman, W. L. (2018). Polarization in electromagnetic systems. Artech House, Norwood, 256 p.
16. Virone, G., Tascone, R., Peverini, O. A., Addamo, G. and Orta, R. (2008). Combined-phase-shift waveguide polarizer. IEEE Microwave and Wireless Components Letters, vol. 18, no. 8, pp. 509-511. DOI: 10.1109/LMWC.2008.2001005.
17. Tribak, A., Mediavilla, A., Cano, J. L., Boussouis, M. and Cepero, K. (2009). Ultra-broadband low axial ratio corrugated quad-ridge polarizer. European Microwave Conference (EuMC), pp. 73-76. DOI: 10.23919/EUMC.2009.5295927.
18. Güvenç, M., Şişman, I. and Ergin, A. A. (2023). Design and optimization of a wide-band quad-ridged polarizer for satellite communications. 2023 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (USNC-URSI), pp. 1477-1478. DOI: 10.1109/USNC-URSI52151.2023.10237410.
19. Polo-Lopez, L., Masa-Campos, J. L. and Ruiz-Cruz, J. A. (2017). Design of a reconfigurable rectangular waveguide phase shifter with metallic posts. 2017 47th European Microwave Conference (EuMC). DOI: 10.23919/EuMC.2017.8231036.
20. Deutschmann, B. and Jacob, A. F. (2020). Broadband septum polarizer with triangular common port. IEEE Transactions on Microwave Theory and Techniques, vol. 68, no. 2, pp. 693-700. DOI: 10.1109/TMTT.2019.2951138.
21. Güvenç, M., Şişman, I. and Ergin, A. A. (2023). Design, optimization and fabrication of a X-band septum polarizer for satellite communication. 2023 IEEE International Symposium on Antennas and Propagation (USNC-URSI), pp. 1347-1348. DOI: 10.1109/USNC-URSI52151.2023.10237446.
22. Kirilenko, A., Mospan, L. and Tkachenko, V. (2002). Extracted pole bandpass filters based on the slotted irises. 2002 32nd European Microwave Conference, pp. 1-4. DOI: 10.1109/EUMA.2002.339448.
23. Deng, C., Zhang, R. and Fan, X. (2016). V-band waveguide band-pass filter with tuning screws. 2016 IEEE International Conference on Microwave and Millimeter Wave Technology (ICMMT), pp. 416-418. DOI: 10.1109/ICMMT.2016.7761793.
24. Peverini, O. A., Virone, G., Addamo, G. and Tascone, R. (2011). Development of passive microwave antenna-feed systems for wide-band dual-polarisation receivers. IET Microwaves, Antennas & Propagation, vol. 5, no. 8, pp. 1008-1015. DOI: 10.1049/iet-map.2010.0340.
25. Kirilenko, A., Mospan, L. and Steshenko, S. (2018). A way to realize a multi-frequency polarization plane rotator. 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS), pp. 218-221. DOI: 10.1109/UWBUSIS.2018.8520246.
26. Kirilenko, A. A., Steshenko, S. O., Derkach, V. N. and Ostryzhnyi, Y. M. (2019). A tunable compact polarizer in a circular waveguide. IEEE Transactions on Microwave Theory and Techniques, vol. 67, no. 2, pp. 592-596. DOI: 10.1109/TMTT.2018.2881089.
27. Kirilenko, A., Steshenko, S. and Ostryzhnyi, Y. (2024). Compact filter-rotator of polarization plane with uniform angular response. Radioelectronics and Communications Systems, vol. 67, pp. 258-264. DOI: 10.3103/S0735272724050054.
28. Meixner, J. (1972). The behavior of electromagnetic fields at edges. IEEE Transactions on Antennas and Propagation, vol. 20, no. 4, pp. 442-446. DOI: 10.1109/TAP.1972.1140243.
29. Marchetti, S. and Rozzi, T. (1991). Electric field singularities at sharp edges of planar conductors. IEEE Transactions on Antennas and Propagation, vol. 39, no. 9, pp. 1312-1320. DOI: 10.1109/8.99039.
30. Krähenbühl, L., Buret, F., Perrussel, R., Voyer, D., Nicolas, P. and Nicolas, L. (2011). Numerical treatment of rounded and sharp corners in the modeling of 2D electrostatic fields. Journal of Microwaves, Optoelectronics and Electromagnetic Applications, vol. 10, no. 1, pp. 66-81. DOI: 10.1590/S2179-10742011000100008.
31. Martyniuk, S. Y., Dubrovka, F. F., Zakharchenko, O. S. and Stepanenko, P. Y. (2021). Effective high-precision analysis of thin asymmetric inductive diaphragm in rectangular waveguide using integral equation method. Radioelectronics and Communications Systems, vol. 64, pp. 80-91. DOI: 10.3103/S0735272721020035.
32. Reimer, M. (2003). Gegenbauer polynomials. In Multivariate polynomial approximation (pp. 19-20). Birkhäuser, Basel. DOI: 10.1007/978-3-0348-8095-4_2.
33. Gradshteyn, I. S. and Ryzhik, I. M. (2014). Table of integrals, series, and products (8th ed.). Academic Press, 1133 p. DOI: 10.1016/C2010-0-64839-5.
34. Jin, J.-M. (2014). The finite element method in electromagnetics (3rd ed.). Wiley-IEEE Press, 876 p. DOI: 10.1002/9781119127505.
35. Piltyay, S. I., Bulashenko, A. V. and Herhil, Y. Y. (2021). Numerical performance of FEM and FDTD methods for the simulation of waveguide polarizers. Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, no. 84, pp. 11-21. DOI: 10.20535/RADAP.2021.84.11-21.
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