Design of Compact Ultra-Wideband Microstrip Bandstop Filter using Split Ring Resonator

This article presents the design of microstrip bandstop filter for ultra-wideband applications using split ring resonator. The emerging interest and ease of design for split ring resonator using microstrip transmission line technology has lead to this research. In this paper, a compact bandstop filter is designed with single and double ring split ring resonator and is simulated using HFSS, the full wave electromagnetic simulator. This structure gives a wide stopband response. The increase in the number of rings in the split ring resonator gives a sharp cut off improving the stopband performance. Simulation results show that for the bandstop filter using double ring split ring resonator, the sharp cut off is increased to -38.5dB compared to the single ring of -34.8dB and to -23dB from -18.5dB. The microstrip bandstop filter designed using single and double ring split ring resonator with ultra-wideband of 6GHz can be used for short range ultra-high speed communications in the frequency range of 4.3 to 10.4GHz. The compact filter size is 6x6mm excluding the feed.