volume | PIER Journals

Abstract

A compact elliptic-function low pass filter using microstrip stepped-impedance modified-hairpin resonators is developed and a multiple cascaded filter using semi-hairpin resonators is designed, analyzed and tested. Sharpness of cut off frequency, low insertion-loss, enhancement of bandwidth and very compact size are features of the proposed low-pass filter. Size reduction of this filter is reported about 62% with 13% enhancement of bandwidth respects to the conventional filter with comparable performance. The measurement results are in good agreement with the theoretical ones.

1. Kuo, J. T., M. J. Maa, and P. H. Lu, "A microstrip ellipticfunction filter withcompact miniatorized hairpin resonator," Phil.Trans. Roy. Soc. London, Vol. A247, 529-551, IEEE Microwave Guided Wave Lett., Vol. 10, 94–95, Mar. 2000.

2. Lee, S. Y. and C. M. Tsai, "New cross-coupled filter design using improved hairpin resonator," IEEE Trans. Microwave Theory Tech., Vol. 48, 2482-2490, Dec. 2000.

3. Hsieh, L.-H. and K. Chang, "Compact low-pass filter using stepped impedance hairpin resonator," Electron. Lett., Vol. 37, 899-900, Jul. 2001.
doi:10.1049/el:20010600

4. Ahn, D., J. S. Park, C. S. Kim, J. Kim, Y. Qian, and T. Itoh, "A design of the low-pass filter using the novel microstrip defected ground structure," IEEE Trans. Microwave Theory Tech., Vol. 49, 86-92, Jan. 2001.
doi:10.1109/22.899965

5. Giannini, F., M. Salerno, and R. Sorrentino, "Design of lowpass elliptic filters by mean of cascaded microstrip rectangular elements," IEEE Trans. Microwave Theory Tech., Vol. 30, 1348-1353, Sep. 1992.
doi:10.1109/TMTT.1982.1131259

6. Amedol, I., L. Arregui, F. J. Falcone, M. A. G. Laso, and T. Lopetegi, "Low pass filter with wide rejection band in microstrip technology," International Symposium ISSSE' 07, 13-16, Jul. 2007.

7. Dahlon, S. H. and M. Esa, "Miniaturized low-pass filter using modified unifolded single hairpinline resonators systems," International RF and Microwave Conference, 16-20, Sep. 2006.
doi:10.1109/RFM.2006.331028

8. Hsieh, L.-H. and K. Chang, "Compact elliptic-function low-pass filters using microstrip stepped-impedance hairpin resonators," IEEE Trans. Microwave Theory Tech., Vol. 51, 193-199, Jan. 2003.
doi:10.1109/TMTT.2002.806901

Mr. Mehdi Nosrati

Dr. Ayat Najafi