A systematic implementation of elliptic low-pass filters using defected ground structures

Abstract

For the past decade, defected ground structures (DGSs) are largely used in the implementation of low-pass filters, without a systematic approach. In this paper, a simple systematic approach for the design of elliptic low-pass filters using DGSs is proposed. An empirical model for a simple rectangular slot DGS is extracted for its equivalent circuit. Using this model, low-pass filters for various orders are designed for critical filter specifications and optimized by reducing the parasitic effects induced by DGSs. This systematic implementation of DGS-based filters achieves more than 90% of the desired filter specifications. Due to the improved slow-wave factor and power handling capacity of DGSs, the filter is more compact and reliable than the conventional filters.

Keywords:

• defected ground structure (DGS)
• elliptic filters
• empirical modeling
• low-pass filter (LPF)

Acknowledgements

The authors would like to thank Dr. Usha Kiran Kommuri and Mr. Anand; VIT Chennai for their assistance in testing; and Mr. Shailendra Shankar, Manager – NPD, Srinar Electronics Pvt. Ltd. for providing the SMA connectors.

Notes

No potential conflict of interest was reported by the authors.