Total views : 315

Design of Narrowband Band Pass Filter using Open-loop Square Resonators with Loading Element


  • National Instruments, Bannerghatta Road, Bangalore - 560029, Karnataka, India
  • Manipal Institute of Technology, Manipal – 576104, Karnataka, India


Objectives: In this paper we propose to design a compact, sharp-rejection narrowband BandPass Filter (BPF). Methods/Statistical Analysis: The behavior of the microstrip open-loop resonator is observed using full-wave electromagnetic simulations. By adding a loading element at the center of the open loop square resonator we are achieving two operating modes (even and odd modes) exist within a single resonator. Variation of parameters of the loading element leads to asymmetric frequency response used for filter design. The simulated results met all the design specifications of the given band pass filter. Findings: In the dual-mode open loop resonator the even and odd modes (currents are mutually exclusive in nature) do not couple each other and leads to a rejection point in the frequency, which is associated with the even mode. Multiple sections of resonator give the sharp rejection (high dynamic range) after the passband. Application/Improvements: The proposed band pass filter can be widely used in communication system and space technology, especially mobile and satellite communication due to its better performance and compactness.


BandPass Filter, Dual-mode Resonator, Electromagnetic Coupling, Micro Strip Antennas, Strip Lines.

Full Text:

 |  (PDF views: 213)


  • Mansour RR. Filter technologies for wireless base stations.IEEE Microwave Magazine. 2004; 5(1):68–74.
  • Hong J. Reconfigurable planar filters. IEEE Microwave Magazine. 2009;10(6):73–83.
  • Nisenoff M, Pond JM. Superconductors and microwaves.IEEE Microwave Magazine. 2009; 10(3):84–95.
  • Khanna S, Majumder D, Kumar V, Prasad S, Islam A. Impact of temperature variation on resonant frequency of active grounded inductor-based bandpass filter. Indian Journal of Science and Technology. 2016 Aug; 9(33).DOI:10.17485/ ijst/2016/v9i33/99505.
  • Ansari MS, Ravindranath SVG, Bhatia MS, Patidar RK, Navathe CP. Application of wavelet transform for analysis of radiated electromagnetic interference in a high power terawatt laser setup. Indian Journal of Science and Technology. 2012 Nov; 5(11).DOI:10.17485/ijst/2012/v5i11/30655.
  • Plesca AT. Mechanical analysis of power electromagnetic contactors. Indian Journal of Science and Technology. 2013 Aug; 6(8).DOI:10.17485/ijst/2013/v6i8/36353.
  • Jegan G, Juliet AV, Silvia MF, Krishna GBVS. Novel design and performance analysis of rectangular frequency reconfigurable micro strip patch antenna using line feed technique for wireless applications. Indian Journal of Science and Technology. 2016 Aug; 9(29).DOI:10.17485/ijst/2016/ v9i29/98582.
  • Srikanth S, Jeyalakshmi V. Compact UWB micro strip band pass filter with open circuited stubs. Indian Journal of Science and Technology. 2015 Jul; 8(13).DOI:10.17485/ ijst/2015/v8i13/58531.
  • Hong J, Lancaster M. Canonical microstrip filter using square open-loop resonators. Electronics Letters. 1995; 31(23):2020–2.
  • LancasterMJ. Couplings of microstrip square open-loop resonators for cross-coupled planar microwave filters. IEEE Transactions on Microwave Theory and Techniques. 1996; 44(12):2099–109.
  • Kong JS.Microstrip cross-coupled trisection bandpass filters with asymmetric frequency characteristics. IEEE Proceedings on Microwaves, Antennas and Propagation. 1999; 146(1):84–90.
  • Hong JS. Design of highly selective microstrip bandpass filters with a single pair of attenuation poles at finite frequencies. IEEE Transactions on Microwave Theory and Techniques. 2000; 48(7):1098–107.
  • Sagawa M, Takahashi K, Makimoto M. Miniaturized hairpin resonator filters and their application to receiver frontend MIC’s. IEEE Transactions on Microwave Theory and Techniques. 1989; 37(12):1991–97.
  • Lee S, Tsai C. New cross-coupled filter design using improved hairpin resonators. IEEE Transactions on Microwave Theory and Techniques. 2000; 48(12):2482–90.
  • IE3D Version 14.10. Zeland Software Inc., Fremont, CA; 2008.


  • There are currently no refbacks.

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.