DESIGN OF A WIDEBAND BANDPASS FILTER WITH NOTCH-BAND USING SPURLINES
In this paper, a simple structure bandpass filter with an ultra-wideband range from 4.73 GHz to 10 GHz and a notched band at 7.18 GHz has been introduced. Spurlines and coupled lines are used for the UWB response. The bandwidth and the notched band can be set at the desired frequency by the lengths and the width of spurlines. By adding L-shaped open stubs to the multi-mode resonator, the stopband rejection has been improved. Finally, one prototype is designed, manufactured, and measured, with results of 72.19% fractional bandwidth at the central frequency of 7.3 GHz, 0.5 dB insertion loss (IL), and return loss (RL) of -27 dB; this proves the feasibility and reliability of this filter.
Bandpass filter; Notched band; Parallel-couple line; Ultra-wideband