In this era of technology, EMC application have become more important because the increase of electronic devices due to the demand from users. Every electronic appliance is a source of radiated electromagnetic fields called radiated emission. Hence, it is important to make sure the radiation is in a safe level where an antenna will be used to detect the radiated electromagnetic fields. The existing antenna used for EMC testing such as log-periodic antenna, fractal antenna and biconical antenna have a large dimension that make it hard to set up for the testing and majority can only operate starting from 3 GHz and above. In order to overcome that problem, an ultra-wideband monopole patch antenna is proposed which aimed to be operated from 0.7 to 6.8 GHz for EMC testing. The UWB antenna can be achieved by having a truncated ground plane and notches at the ground structure. The edges of the rectangular patch antenna have been cut to improve the return loss and a tapered feed is implemented to increase the gain. To design and simulate the proposed antenna, CST Microwave Studio software has been used in this project to get the desired result which is the return loss and gain. The design for this antenna is very simple to ease the fabrication process. Overall, the structure consists of an antenna patch with a rounded rectangular shape, tapered feed line, and a truncated ground plane with notches at both corners. The simulation result of reflection coefficient of the antenna is at 0.7 GHz up to 6.8 GHz which has a high bandwidth efficiency at 162%, and have a good gain which is in around 2 to 5.6 dB if compared to the previous study by [1], as the bandwidth efficiency was 109% and gain values varies between 1 to 3.83 dB only.
