An ultra-wideband antenna with controllable band-notched is presented. Two semi-ellipses with different radiuses are subtracted to result in the main patch. By varying inner and outer radiuses, much more enhancement in bandwidth occurred. A U-shaped slot is used to make band-stop performance. Measured S11 is ≤-10 dB over 2.3 - 5 GHz and 6.1 - 15.1 GHz.