A new design of compact Super Wideband (SWB) antenna for performance comparison between in free space and in plain water is presented in this paper. The proposed antenna consists of basic circular patch as radiating element associated with partial ground and a zinc reflector to realize high gain and wide bandwidth. Dimension of 20 mm × 30 mm made the proposed antenna as a compact antenna. The significant feature of this design is the cautious manufacturing of the feed line with additional of two microstrip lines between the patch and the feed line known as stepped transmission line that altering the capacitance between the radiating element and the ground plane. The patch is directly connected with SMA connector using 50 Ohm mirostrip feed line through side feeding and deploy the air gap stacked. The antenna exhibit high performance in free space indicated by operated frequency ranged from 4.3 GHz until more than 15 GHz (<-10dB) with maximum gain of 9.79 dB. On the other hand, plain water medium degraded the antenna performance yet still within acceptance limit associated with resonant frequency ranged from 4.7 GHz until more than 15 GHz (<-6dB) and 2.2 dB for the maximum gain. The results reflect the reliability of the SWB antenna operated within liquid medium for various related applications especially for biomedical related applications such as microwave imaging for cancer detection.
