A co‐planar waveguide fed printed ultra‐wideband antenna with dual frequency notch band is proposed in this letter. Small antenna size of 27.5 × 16.5 × 0.8 mm3 is achieved by considering the intersection of three conventional circular disks of equal diameter. Two frequency notch bands of 2.2–3.9 and 5.1–6 GHz are achieved by introducing a curved U‐shaped slot at balloon‐shaped radiator and an inverted patch‐shaped parasitic resonator at the back side of feed respectively. These notch bands prevent the possible interference from coexisting ISM, WiMAX, WLAN, HIPERLAN/2, IEEE 802.11y, and DSRC bands. An inverted U shape slot is added on radiating patch to improve antenna impedance band, gain and efficiency profile. The proposed antenna provides wide bandwidth from 1.75 to 10.3 GHz, with a gain variation between 2 and 4.5 dBi, average radiation efficiency of >80%, linear transfer function and non‐varying group delay in the pass band of operation.