volume | PIER Journals

Abstract

A highly miniaturized low-pass filter using microstrip open-loop and semi-hairpin resonators is designed and analyzed to enhance the bandwidth and further size reduction of this kind of elements. Initially, two microstrip open ring resonators and separately, two semi-hairpin resonators are arranged and attached back-to-back to each other respectively. A compact LPF is designed and simulated using these modified resonators. The size reduction of this proposed filter is reported about 65% with 190% enhancement of bandwidth in analogy with the conventional low-pass filters.

1. Giannini, F., M. Salerno, and R. Sorrentino, "Design of low-pass elliptic filters by means of cascaded microstrip rectangular elements," IEEE Trans. Microwave Theory Tech., Vol. 30, Sep. 1982. Google Scholar

2. Hsieh, L.-H. and K. Chang, "Compact elliptic-function low-pass filter using microstrip stepped-impedance hairpin resonators," IEEE Trans. Microwave Theory Tech., Vol. 51, No. 1, Jan. 2003. Google Scholar

3. Hsieh, L.-H. and K. Chang, "Compact low-pass filter using stepped-impedance hairpin resonator," Electron. Lett., Vol. 37, No. 14, Jul. 2001. Google Scholar

4. Arnedo, I., I. Arregui, F. J. Falcone, M. A. G. Laso, and T. Lopetegi, "Low pass filter with wide rejection band in microstrip technolog," International Symposium ISSSE'07, 13-16, Jul. 2007. Google Scholar

5. Dahlon, S. H. and M. Esa, "Miniaturized low-pass filter using modified unifolded single hairpin-line resonator for microwave communication systems," International RF and Microwave Conference, 16-20, Sep. 2006.
doi:10.1109/RFM.2006.331028 Google Scholar

6. Nosrati, M. and A. Najafi, "Bandwidth enhancement and further size reduction of a class of elliptic-function low-pass filter using modified hairpin resonators," Progress In Electromagnetics Research C, Vol. 5, 187-194, 2008. Google Scholar

7. Nosrati, M., T. Faraji, and Z. Atlasbaf, "A compact composite broad stop-band elliptic-function low-pass filter for ultra wide-band applications using interdigital capacitor," Progress In Electromagnetics Research Letters, Vol. 7, 87-95, 2009.
doi:10.2528/PIERL09011707 Google Scholar

8. Hong, J.-S. and M.-J. Lancaster, "Coupling of microstrip square open-loop resonators for cross-coupled planar microwave filters," IEEE Trans. Microwave Theory Tech., Vol. 44, No. 9, 2099-2109, Nov. 1996. Google Scholar

9. Pozar, D. M., Microwave Engineering, Wiley, 1998.

Dr. Mohsen Hayati

Mr. Hamdolah Kakaee

Dr. Azim Fard

Dr. M. Nosrati