Abstract-In this paper a compact microstrip fed ultra-wideband antenna with a band notch characteristic is presented. The proposed antenna consists of two tridents and two split ring resonators. The overall size of the antenna is 26 mm× 24 mm × 1.53 mm. By adding the uneven split ring resonators to the dual trident ultra-wideband antenna, a band notch of 5.05 GHz to 5.9 GHz is achieved. The band notch is adjusted by the size and the split locations of the resonators. CST microwave studios software was used to simulate the design. The measured |S 11 | (dB) pass band and notch band agree with the simulation within the frequency band from 3.65 GHz to 12.85 GHz.