A simple and compact printed ultra-wideband antenna with dual-band-notched characteristics is presented. The proposed antenna is composed of a rectangular patch and a modified ground plane. The rectangular patch is etched onto a lossy FR4 substrate. A circular ring strip parasitizes the rectangular patch embedded by a U-shaped slot. Two inverted-L slits and a rectangular slit are embedded onto the ground plane. Some bandwidth enhancement and band-notched techniques are applied in the antenna structure for broadening the bandwidth and generating notches. The simulated and measured results show that the proposed antenna offers a very wider bandwidth ranging from 3.04 to 17.30 GHz, defined by the return loss less than −10 dB, with dual-notched bands of 3.30–4.20 and 5.10–5.85 GHz covering the 3.3/3.7 GHz WiMAX, 3.7/4.2 GHz C-band, and 5.2/5.8 GHz wireless local area network systems. Furthermore, the proposed antenna presents relatively high antenna gain and quasi-omnidirectional radiation patterns.
