volume | PIER Journals

Abstract

In this paper, a compact band-stop filter with a wideband and high-selectivity performance is proposed and analyzed. This band-stop filter includes two parallel-coupled lines of different electrical lengths and two open-circuit stubs. A lossless transmission line model is used to obtain the filter design parameters. In order to verify this new filter circuit structure and its corresponding design theory, five groups of numerical examples are demonstrated. Finally, a practical band-stop filter with a 3-dB cutoff frequency bandwidth of 58.2% centered at 0.94 GHz has been designed, simulated and measured. The measured results show a good agreement with the simulated responses.

1. Hong, J.-S. and M. J. Lancaster, Micro-strip Filters for RF/Microwave Applications, Chapters 2, Wiley, 2001.
doi:10.1002/0471221619

2. Fallahzadeh, S. and M. Tayarani, "A compact microstrip bandstop filter," Progress In Electromagnetics Research Letters, Vol. 11, 167-172, 2009.
doi:10.2528/PIERL09082407

3. Wang, J., H. Ning, Q. Xiong, M. Li, and L. Mao, "A novel miniaturized dual-band bandstop filter using dual-plane defected structures," Progress In Electromagnetics Research, Vol. 134, 397-417, 2013.
doi:10.2528/PIER12102313

4. Velidi, V. K., A. B. Guntupalli, and S. Sanyal, "Sharp-rejection ultra-wide bandstop filters," IEEE Microwave and Wireless Components Letters, Vol. 19, No. 8, 503-505, 2009.
doi:10.1109/LMWC.2009.2024834

5. Wu, Y. and Y. Liu, "A coupled-line band-stop filter with three-section transmission-line stubs and wide upper pass-band performance," Progress In Electromagnetics Research, Vol. 119, 407-421, 2011.
doi:10.2528/PIER11072003

6. Wu, Y., Y. Liu, S. Li, and C. Yu, "A simple microstrip bandpass filter with analytical design theory and sharp skirt selectivity," Journal of Electromagnetic Waves and Applications, Vol. 25, No. 8-9, 1253-1263, 2011.
doi:10.1163/156939311795762060

7. Mrinal, K., K. Vamsi, S. Sanyal, and A. Bhattacharya, "Design of ultra-wideband band-stop filter with three transmission zeros," Microwave and Optical Technology Letters, Vol. 50, No. 11, 2955-2957, 2008.
doi:10.1002/mop.23819

8. Wang, W., M. Liao, Y. Wu, and Y. Liu, "Small-size high-selectivity bandstop filter with coupled-line stubs for dual-band applications," Electronics Letters, Vol. 50, No. 4, 286-288, 2014.
doi:10.1049/el.2013.3704

9. Cui, D., Y. Liu, Y. Wu, S. Li, and C. Yu, "A compact bandstop filter based on two meandered parallel-coupled lines," Progress In Electromagnetics Research, Vol. 121, 271-279, 2011.
doi:10.2528/PIER11061902

Dr. Menglou Rao

Prof. Yongle Wu

Dr. Weimin Wang

Dr. Yuan'an Liu