Ultra-wideband bandpass filters with notched band using slotted linear tapered-line resonators and embedded slot feed

In this paper, ultra-wideband bandpass filters based on slotted linear tapered-line resonators (SLTR) with embedded slot feed structure for notched band are presented. The embedded slot feed at the end of resonators will be comprehensively described. The proposed filters have narrow notches in the passband, resulting from the embedded slot feed. The center frequencies and bandwidths of the notched band can be easily adjusted by tuning the length and width of the embedded slot parameters. The wider upper stopbands caused by resonator characteristics have been also obtained. The simulated and experimental results show narrow notched bands around 250 MHz. High stopband performances with better than 15 dB for a frequency range up to 18 GHz have been obtained.