Coupled microstrip slot resonators for bandstop filters: theory and design

Abstract

Bandstop filters with single and dual stop-bands were implemented using coupled mode microstrip slot resonators (MSRs) for the first time. With compact and ease of fabrication, the MSRs provide excellent filter response as desired. It is found that the MSRs can offer narrow bandwidth of less than 20% fractional bandwidth and large isolation of more than 40 dB. The designs of MSRs and filters are systematically demonstrated with the method of coupled mode resonator theory. MSRs may be potential alternative for complicated and arbitrary design of BSFs to achieve desired frequency response.

Keywords:

• Microstrip slot resonator (MSR)
• bandstop filters
• coupled mode resonator filters
• band rejection

Acknowledgments

Authors thank Dr. Yogesh Kumar C, Ms. Shruthi, Ms. P. Sumithra and Mr. Dudekula Shaikshavali of Vellore Institute of Technology, India, for the useful discussions on implementation and fabrication of filters. Authors thank the editor and the anonymous reviewer for the useful comments on the improvement of the paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Lakshmi C. R.

Lakshmi C. R received her Master's degree in Applied Electronics from Anna University Trichy and Bachelors degree in Electronics and Communication Engineering, from Anna University, Chennai. She is currently pursuing her PhD from School of Electronics Engineering, Vellore Institute of Technology, Vellore. Her research interest includes Microwave Filter design, Microwave Meta-surfaces and Meta-materials and Microwave Antennas.

D. Kannadassan

D. Kannadassan received the Ph.D. degree from the School of Electronics Engineering, Vellore Institute of Technology, Vellore, where he is an Associate Professor with the Centre for Nanotechnology Research. He has published 20 articles in reputed journals, a book chapter and five conference papers in microelectronics and microwave resonators. His current research interests are Transparent TFTs, Microwave transistors and Diode, Microwave Filters and Microwave Antennas for future technologies.