A novel ultra-wideband (UWB) bandpass filter with dual band-notched characteristics at 5. 21 GHz and 7.95 GHz is proposed in this paper according to that UWB system is easy to be interfered with the narrow-band signals. Dual band-notched characteristics of the UWB filter is realized by the method of introducing complementary split-ring resonator (CSRR), CSRR has simple structure, easy to be fabricated and integrated with microstrip plane circuit. Relations between the physical size of CSRR single structure and the filter's transmission characteristic is discussed in detail using simulation software. The proposed UWB filter is fabricated, it is in good agreement between simulations and measurements, which verify the effectiveness and correction of the design.
