Ultra-wideband band pass filter with built-in notch filter configured by multi-layered CRLH unit cells

An ultra-wideband (UWB) band pass filter with a built-in notch filter is newly proposed. The filter is composed of a conventional multi-layered (ML) composite right-/left-handed (CRLH) transmission line and a super-compact notch filter configured by a ML CRLH unit cell. Two notches created by the notch filter are applied to improve a skirt characteristic of the UWB passband and to reduce interference from other existing wireless communication systems. Due to the structural compatibility of the notch filter, it can be fabricated just in the original CRLH UWB filter without any dimensional increase. In addition, flexible and wide-range tunability of the notches is also demonstrated.