volume | PIER Journals

Abstract

A novel capacitive loaded U-slot defected ground structure (DGS) is presented in this letter to provide narrowband rejection property. The principles for the selective rejection and the strategies for size-reduction and external Q-factor improvement are detailed based on transmission line equivalent model and the lumped parallel RLC model developed from transmission line model at resonance frequency. The design concept is well validated by the design and measurement of an exemplary high Q BSF.

1. Wang, C. J. and C. S. Lin, "Compact DGS resonator with improvement of Q-factor," IET Electron. Lett., Vol. 44, 908-909, 2008.
doi:10.1049/el:20081417

2. Wang, X. H., B. Z. Wang, H. Zhang, et al. "A tunable bandstop resonator based on a compact slotted ground structure," IEEE Trans. Microw. Theory Tech., Vol. 55, 1912-1918, 2007.
doi:10.1109/TMTT.2007.904045

3. Woo, D. J., T. K. Lee, J. W. Lee, et al. "Novel U-slot and V-slot DGSs for bandstop filter with improved Q factor," IEEE Trans. Microw. Theory Tech., Vol. 54, 2840-2847, 2006.
doi:10.1109/TMTT.2006.875450

4. Huang, S. Y. and Y. H. Lee, "A compact E-shaped patterned ground structure and its applications to tunable bandstop resonator," IEEE Trans. Microw. Theory Tech., Vol. 55, 657-666, 2009.
doi:10.1109/TMTT.2009.2013313

5. Yang, M., J. Xu, Y. Dong, et al. "A novel open-loop DGS for compact bandstop filter with improved Q factor," International Symposium on Antennas, Propagation and EM Theory, 649-652, 2008.

6. Kakhki, M. A. and M. H. Neshati, "Numerical investigation and experimental study of two novel band-reject DGS filters with a very high Q-factor," IEEE Electrical Engineering, 1-4, 2011.

7. Lee, S., S. Oh, W. S. Yoon, et al. "A CPW bandstop filter using double hairpin-shaped defected ground structures with a high Q factor," Microwave & Optical Technology Lett., Vol. 58, 1265-1268, 2016.
doi:10.1002/mop.29791

8. Caloz, C., H. Okabe, T. Iwai, et al. "A simple and accurate model for microstrip structures with slotted ground plane," IEEE Microw. Wireless Compon. Lett., Vol. 14, 133-135, 2004.
doi:10.1109/LMWC.2004.828725

9. Wong, J. S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, Sec. 8.4, Wiley, New York, 2001.

Dr. Gang Liu

Dr. Zhuo-Ying Wang

Dr. Jia-Jia Wu

Dr. Lin Li