Effective Size Reduction Technique for Microstrip Filters

Dhirendra Kumar, Asok De

ECE Department, Maharaja Agrasen Instititute of Technology, Delhi, India.
NIT, Patna, India..

DOI: 10.4236/jemaa.2013.54027                

Abstract

In this paper an effective size reduction technique using fractal structure is suggested. The proposed technique has been applied on a band stop and a low pass filter separately. This technique provides 42% reduction of size for the band stop filter and about 26% for the low pass counterpart. Both the designed structures are fabricated and the measured results are compared with the simulated results. The proposed technique does not require any recalculation or optimization of dimensions of the filter, and is straightforward to implement. The band stop filter is designed for the center frequency of 3 GHz where as the cut-off frequency for low pass filter is 2.5 GHz. A good agreement between the simulated and measured results is observed. A comprehensible explanation of the proposed technique is also provided.

Keywords

Band Stop Filter; Fractal Structures; Kotch Curve; Low Pass Filters; Open Stub; Step Impedance Network

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	M.-Y. Hsieh and S.-M. Wang, “Compact and Wideband Microstrip Bandstop Filter,” IEEE Microwave and Wire less Components Letters, Vol. 15, No. 7, 2005.
[2]	Y.-H. Hsu, C.-H. Tsai and T.-L. Wu, “A New Bandstop Filter Using Artificial Defected Ground Structures with Compact Size and Low Radiation” 2010 IEEE 19th Conference on Electrical Performance of Electronic Packaging and Systems (EPEPS), 25-27 October 2010, pp. 89-92.
[3]	S. U. Rehman, A. F. Sheta and M. Alkanhal, “Compact Bandstop Filter Using Defected Ground Structure (DGS),” 2011 Saudi International Electronics, Communications and Photonics Conference (SIECPC), 24-26 April 2011, pp. 1-4.
[4]	S. Y. Huang and Y. H. Lee, “A Tapered Small-Size EBG Microstrip Bandstop Filter Design with Triple EBG Structures,” Microwave and Optical Technology Letters, Vol. 46, No. 2, 2005, pp. 154-158.
[5]	H. Lim, J.-H. Lee, S.-H. Lim, D.-H. Shin and N.-H. Myung, “A Novel Compact Microstrip Bandstop Filter Based on Spiral Resonators,” Proceedings of Asia-Pacific Microwave Conference 2007, pp. 2221-2224.
[6]	J.-G. Lee and J.-H. Lee, “Parallel Coupled Bandstop Filter Using Double Negative Coupled Transmission Line,” IEEE Microwave and Wireless Components Letters, Vol. 17, No. 4, 2007, pp. 283-285. doi:10.1109/LMWC.2007.892973
[7]	H. W. Liu, R. H. Knoechel and K. F. Schuenemann, “Mi niaturized Bandstop Filter Using Meander Spur Line and Capacititively Loaded Stubs,” ETRI Journal, Vol. 29, No. 5, 2007.
[8]	D. M. Pozar, “Microwave Engineering,” 3rd Edition, Wiley, New York.
[9]	J.-S. Hong and M. J. Lancaster, “Microstrip Filters for RF/Microwave Applications,” John Wiley & Sons, Inc, Lancaster RF/Microwave Filter Design, Lancaster, 2001
[10]	B. M. Schiffman and G. L. Matthaei, “Exact Design of Band-Stop Microwave Filters,” IEEE Transactions on MTT-12, 1964, pp. 6-15.
[11]	M. C. Horton and R. J. Menzel, “General Theory and De sign of Optimum Quarter Wave TEM Filters,” IEEE Transactions on MTT-13, 1965, pp. 316-327.
[12]	M. C. Horton and R. J. Menzel, “The Effectiveness of Component Elements in Commensurate Line Length Filters,” IEEE Transactions on MTT-16, 1968, pp. 555-557.
[13]	http://en.wikipedia.org/wiki/kotch_snowflake
[14]	C. Jianxin, Y. Mengxia, X. Jun and X. Quan, “Compact Microstrip low pass Filter,” Electronics Letters, Vol. 40, No. 11, 2004, pp. 674-675. doi:10.1049/el:20040481
[15]	J.-W. Sheen, “A Compact Semi-Lumped Low-Pass Filter for Harmonics and Spurious Suppression,” IEEE Micro wave and Guided Wave Letter, Vol. 10, No. 3, 2000, pp. 92-93. doi:10.1109/75.845707
[16]	L.-H. Hsieh and K. Chang, “Compact Low Pass Filter Using Stepped Impedance Hairpin Resonator,” Electronics Letters, Vol. 37, No. 14, 2001, pp. 899-900. doi:10.1049/el:20010600
[17]	D. H. Lee, Y. W. Lee, J. S. Park, D. Ahn, H. S. Kim and K. Y. Kang, “A Design of the Novel Coupled Line Low Pass Filter with Attenuation Poles,” IEEE MTT-S International Microwave Symposium Digest, Anaheim, 13-19 June 1999, pp. 1127-1130.
[18]	J.-S. Hong and M. J. Lancaster, “Theory and Experiment of Novel Microstrip Slow-Wave Open-Loop Resonator Filters,” IEEE Transactions on Microwave Theory and Techniques, Vol. 45, 1997, pp. 2358-2365.