Sensor downsizing, as well as advancements in wearable technology, embedded software, digital signal processing, and biomedical technologies, have caused the emergence of user-centric networks, in which devices may be carried in the user’s pockets and connected to the user’s body. Ultra-Wideband (UWB) technology has a lot of potential in wireless body sensor networks (WBSNs).Due to its small size, low transmission power, and high data rate UWB technology will be very good for WBSNs. Ultra-wideband antenna is one of the crucial components for WBSNs and it will be integrated with the wearable sensor system. The UWB antennas’ parameters change when attached to the human body, which needs to be investigated before developing the wearable system. Another unlisencedband according to FCC is Ultra Wideband frequency range which covers from 3.1 GHz to 10.6 GHz. However, there are other frequencies between 5 GHz to 6 GHz for some other applications within this range. As a result, a band notch in the UWB frequency range is necessary to avoid conflict with these frequencies.A good approach is to design an efficient UWB antenna using band-notch technology. The antenna design and performance investigation of an Ultra Wideband band-notch antenna for WBSNs is presented in this research. FR4 substrate material has been used in the proposed design. The Antenna’s free space and on-body behavior are both researched and assessed. To examine the on-body performance, the antenna is placed on a human torso phantom. This antenna’s free space and on-body simulation results were compared. The performance characteristics of the antenna are also tested by moving the antenna away from the human body at different distances. Key antenna characteristics such as return loss response, gain, impedance bandwidth, efficiency, and radiation pattern are extensively examined for better comparisons.Its small size, unique form, perfect band-notch feature, and excellent on-body behavior make it ideal for wireless body sensor networks in healthcare division applications.