Design of the miniaturized Ultra-WideBand(UWB) filter of the shorted open gap ring structure combined with the interdigital line

Abstract

This paper presents the filter of a resonator comprising a shorted open gap ring(SOGR) and interdigital lines. The proposed filter has the ultra wideband characteristic operating from 3 GHz to 10.5 GHz. In order to achieve the remarkable improvement in the size-reduction of the overall filter structure, only one cell of the SOGR with the inter-digital lines is adopted. It is shown that this filter has the size of 18mm X 15mm using a metamaterial, the fractional bandwidth over 100%, the insertion loss much less than ldB, an acceptable return loss performance in the results.