Reconfigurable ultra-wide band monopole antenna with a continuously tunable band notch

In this study, the authors introduce a reconfigurable ultra-wide band (UWB) antenna, which exhibits novel behaviour and could potentially be used in future cognitive radio or software defined radio systems. It is based on an UWB monopole antenna and features a narrow-band rejection, which can be tuned over the whole matched bandwidth. Reconfigurability is achieved through the use of active semiconductor-based components. Biasing circuits and components have been taken into account, for simulations as well as measurements, both antennas being prototyped with the embedded active components.