An UWB bandpass filter with dual-notched band and improved stopband performance

This paper proposes an ultra-wideband bandpass filter based on slotted linear tapered-line resonator (SLTR) with embedded fold-slot feed structure which can create dual-notched band. The embedded fold-slot feed at both ends of resonator will be comprehensively described. The proposed filter has two notches in the passband, resulting from the embedded fold-slot feed. The center frequencies and bandwidths of both notched bands can be controlled by adjusting dimensions of the embedded fold-slot. The wider upper stopbands caused by resonator characteristics have been also obtained. The simulated and experimental results show dual-notched band around 300 MHz and 400 MHz, respectively. High stopband performances with better than 15 dB for a frequency range up to 18 GHz have also been obtained.