Sharp Roll-Off Microstrip Low-Pass Filter with Transmission Zero Using SIR Stub T-Shaped for C-Band Synthetic Aperture Radar Transceivers UAV Payload
DOI:
https://doi.org/10.55981/ijoa.2026.16098Keywords:
low-pass filter, transmission zero, synthetic aperture radar, t-shaped, SIRAbstract
This paper presents the design and experimental realization of a 5th-order Chebyshev microstrip low-pass filter (LPF) based on a Stepped Impedance Resonator (SIR) integrating T-shaped stub topology at center frequency (fc) 5.575 GHz for synthetic aperture radar (SAR) system applications. Two topologies are systematically compared: conventional SIR and SIR T-shaped stub (SIRS T-Shaped), and both are fabricated on Rogers 5880 substrate. The simulation was conducted using two electromagnetic simulations as perform cross-validation. The measurement results show that the SIRS-T topology achieves insertion loss (IL) S21 of -4.67 dB at the center frequency with a transmission zero (Tz) depth of -61.46 dB at 12.24 GHz, while the conventional SIR yields IL S21 of -8.2 dB, well beyond the acceptable degradation threshold. The deviation may be attributed to practical factors such as fabrication tolerances, conductor and dielectric losses, soldering effects of SMA connectors, and parasitic discontinuities introduced by the embedded T-shaped structure. The SIRS-T structure demonstrates clear superiority in harmonic suppression and roll-off sharpness, establishing it as the preferred LPF architecture for C-band SAR for UAV payload applications.
References
Appleby, T., Studley, M., Moorhouse, B., Brown, J., Staddon, C., & Bean, E. (2021). Sea of possibilities: Old and new uses of remote sensing data for the enforcement of the Ascension Island marine protected area. Marine Policy, 127, 103184. https://doi.org/10.1016/j.marpol.2018.06.012
Bignami, C., Ruch, J., Chini, M., Neri, M., Buongiorno, M. F., Hidayati, S., … Surono. (2013). Pyroclastic density current volume estimation after the 2010 Merapi volcano eruption using X-band SAR. Journal of Volcanology and Geothermal Research, 261, 236–243. https://doi.org/10.1016/j.jvolgeores.2013.03.023
Cao, S., Zhao, C., Dong, J., & Fu, X. (2024). Ship Detection in Synthetic Aperture Radar Images under Complex Geographical Environments, Based on Deep Learning and Morphological Networks. Sensors, 24(13), 4290. https://doi.org/10.3390/s24134290
Collin, R. E. (1992). Foundations for Microwave Engineering (2nd ed.). New York, NY, USA: McGraw-Hill.
Cope, S., Tougher, B., Morten, J., Pukini, C., & Zetterlind, V. (2022). Coastal radar as a tool for continuous and fine-scale monitoring of vessel activities of interest in the vicinity of marine protected areas. PLOS ONE, 17(7), e0269490. https://doi.org/10.1371/journal.pone.0269490
Geng, J., Ma, X., Fan, J., & Wang, H. (2018). Semisupervised Classification of Polarimetric SAR Image via Superpixel Restrained Deep Neural Network. IEEE Geoscience and Remote Sensing Letters, 15(1), 122–126. https://doi.org/10.1109/LGRS.2017.2777450
Hayati, M., Salahi, R., Akbari, M., Zargari, S., & Abbott, D. (2023). Low Complexity Compact Lowpass Filter Using T-Shaped Resonator Loaded With a Stub. IEEE Access, 11, 35763–35769. https://doi.org/10.1109/ACCESS.2023.3263794
Hong, J. S., & Lancaster, M. J. (2011). Microstrip Filters for RF/Microwave Applications (2nd ed.). Hoboken, NJ, USA: Wiley.
Liu, S., Yu, C., & Liu, Y. (2019). Optimized design of the flexible stepped impedance lowpass filter based on defected ground structure. 2019 IEEE 6th International Symposium on Electromagnetic Compatibility (ISEMC), 1–3. IEEE. https://doi.org/10.1109/ISEMC48616.2019.8986105
Majidifar, S., Makki, S. V. A.-D., Ahmadi, A., & Alirezaee, S. (2012). Compact Microstrip Lowpass Filter Using Stepped Impedance Spiral Resonator. 2012 4th International Conference on Computational Intelligence and Communication Networks (CICN), 23–26. IEEE. https://doi.org/10.1109/CICN.2012.64
Micallef, T., Gu, X., & Wu, K. (2024). Resolution Enhancement of Radar Systems through Super Fusion of Non-Contiguous Frequency Bands. 2024 21st European Radar Conference, EuRAD 2024, 356–359. IEEE. https://doi.org/10.23919/EuRAD61604.2024.10734957
Ouf, E. G., El-Hameed, A. S. A., & Abdallah, E. A. F. (2024). Compact lowpass filter with vast out-of-band rejection utilizing DGS. AEU - International Journal of Electronics and Communications, 177, 155207. https://doi.org/10.1016/j.aeue.2024.155207
Pozar, D. M. (2012). Microwave Engineering (4th ed.). Hoboken, NJ, USA: Wiley.
Sri Sumantyo, J. T., Shimada, M., Mathieu, P.-P., & Abidin, H. Z. (2012). Long-Term Consecutive DInSAR for Volume Change Estimation of Land Deformation. IEEE Transactions on Geoscience and Remote Sensing, 50(1), 259–270. https://doi.org/10.1109/TGRS.2011.2160455
Tomiyama, N., Koike, K., & Omura, M. (2004). Detection of topographic changes associated with volcanic activities of Mt. Hossho using D-InSAR. Advances in Space Research, 33(3), 279–283. https://doi.org/10.1016/S0273-1177(03)00483-6
Vali, S. K. S., & Rao, K. S. (2024). Design of wide stopband lowpass filter using defected ground structure. Microsystem Technologies, 30(6), 721–728. https://doi.org/10.1007/s00542-024-05651-w
Wang, N., Shi, G., Liu, L., Zhao, L., & Kuang, G. (2012). Polarimetric SAR Target Detection Using the Reflection Symmetry. IEEE Geoscience and Remote Sensing Letters, 9(6), 1104–1108. https://doi.org/10.1109/LGRS.2012.2189548
Zhang, F., Gao, Y., Liu, B., & Xu, J. (2020). A Compact Sharp Roll-Off Microstrip Lowpass Filter With Ultra-Wide Stopband. 2020 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 1–3. IEEE. https://doi.org/10.1109/ICMMT49418.2020.9386826
Zhang, J., Yang, R., & Zhang, C. (2019). High-Performance Low-Pass Filter Using Stepped Impedance Resonator and Defected Ground Structure. Electronics, 8(4), 403. https://doi.org/10.3390/electronics8040403
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Abdul Rohman, Catur Apriono, Farohaji Kurniawan, satria arief aditya
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
