Bandwidth enhancement of a wearable UWB antenna near a human arm

A dielectric sandwich loading technique is proposed to enhance impedance matching bandwidth of an antenna when it is placed close to the human body. This technique mitigates the body influence by confining the reactive fields in the dielectric loads. This has no side effects on the antenna performance. Unloaded and loaded prototypes of a recently developed UWB antenna have been measured both in free space and near a human arm. Free space results confirm that loading the antenna neither detune |S11| nor decrease efficiency. It was found that in a body proximity scenario, loading the antenna increases the impedance matching by 22% with respect to the unloaded antenna. These results show the suitability of this technique to design antennas for WBAN applications.