Spiral Microstrip Bandpass Filters


  • Ghaith Mansour Sirte University
  • Mohammed Elmahdi Sirte University
  • Ekasit Nugoolcharoenlap Rajamangala University of Technology Rattankosin


Microstrip Filters, Bandpass Filters, Spiral Resonators, Small Filters


Microstrip bandpass filters based on spiral resonators are designed at 700MHz for 5G applications. In order to achieve size reduction, spiral resonators are used. The proposed filters are of third and fifth orders. The filters are printed on FR4 substrate with thickness of 1.6mm and dielectric constant of 4.5. The filters are simulated using CST electromagnetic simulator. The simulated results show that the presented filters exhibit good return losses, low insertion losses within the passband. Furthermore, a good selectivity is obtained. The simulated reflection coefficients are -15 dB and -12 dB for the 3rd and 5th order filters respectively. The fifth order bandpass filter provides higher selectivity but higher insertion loss as expected.


Y. I. A. Al-Yasir, N. O. Parchin, A. Alabdallah, A. M. Abdulkhaleq, R. A. Abd-Alhameed and J. M. Noras, "Design of Bandpass Tunable Filter for Green Flexible RF for 5G," 2019 IEEE 2nd 5G World Forum (5GWF), Dresden, Germany, 2019, pp. 194-198, doi: 10.1109/5GWF.2019.8911719.

J. Nieto and R. Sauleau, "Miniature coplanar waveguide and microstrip stop-band filters using spiral resonators," in 2006 First European Conference on Antennas and Propagation, 2006, pp. 1-5.

M. K. T. Al-Nuaimi and W. G. Whittow, "Compact microstrip band stop filter using SRR and CSSR: Design, simulation and results," in Proceedings of the Fourth European Conference on Antennas and Propagation, 2010, pp. 1-5.

A. R. Mallahzadeh, B. Rahmati, M. Alamolhoda, R. Sharifzadeh, and A. H. Ghasemi, "Ultra-wide stop band LPF with using defected microstrip structures," in 2012 6th European Conference on Antennas and Propagation (EUCAP), 2012, pp. 1-3.

W. Tang and J. Hong, "Varactor-Tuned Dual-Mode Bandpass Filters," IEEE Transactions on Microwave Theory and Techniques, vol. 58, no. 8, pp. 2213-2219, 2010.

J. Long, C. Li, W. Cui, J. Huangfu, and L. Ran, "A Tunable Microstrip Bandpass Filter with Two Independently Adjustable Transmission Zeros," IEEE Microwave and Wireless Components Letters, vol. 21, no. 2, pp. 74-76, 2011.

H. Tsai, T. Huang, and R. Wu, "Varactor-Tuned Compact Dual-Mode Tunable Filter With Constant Passband Characteristics," IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 6, no. 9, pp. 1399-1407, 2016.

J-S Hong and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, 2nd edition, John-Wiley & Sons, 2011.

G. Mansour, M. K. A. Rahim and H. A. Aldeeb, "Cross-Coupled Microstrip Bandpass Filters With Finite Frequency Transmission Zeros," 2021 IEEE 1st International Maghreb Meeting of the Conference on Sciences and Techniques of Automatic Control and Computer Engineering MI-STA, Tripoli, Libya, 2021, pp. 684-688.




How to Cite

Mansour, G., Elmahdi, M., & Nugoolcharoenlap, E. (2024). Spiral Microstrip Bandpass Filters. International Journal of Engineering Research, 3(1), 68–76. Retrieved from https://journal.su.edu.ly/index.php/ijer/article/view/2693