Adaptive Bow-Tie Antenna with Increased Bandwidth

The paper describes a conceptual approach to develop an ultra-wideband antenna, which can be adapted to the properties of the environment and to the generator spectrum. Such antennas are of special interest for Ground Pentrating Radars, where the antenna should radiate in a similar way into different types of the ground. The adaptive antenna concept has been verified both numerically and experimentally for a slotted bow-tie antenna. It was shown that by varying the position of the straight slot in the antenna flair it is possible to adapt the antenna to different values of the ground dielectric permittivity. A technical solution for controlling the slot position electrically is proposed.