A novel ultra-wideband (UWB) bandpass filter using MIM CRLH transmission line structure

UWB communication systems demand for ultra-wideband filters of bandwidth of up to 110%, which is challenging to achieve for a compact and low-cost design with conventional materials. This paper presents a novel ultra-wideband (UWB) bandpass filter design using composite right/left-handed transmission line (CRLH TL) structure. In addition, to further simplify the design and reduce the size, metal-insulator-metal (MIM) capacitors and stub inductors are employed. The simulated results demonstrate the negative permittivity and permeability of the composite materials used and show that the filter with an insertion loss of less than 1.0 dB throughout the pass band of 2.8 to 10.2 GHz. The variation of group delay is around 0.20 ns over the most central band which is small enough for the filter to be used in an impulse radio UWB system.