Novel Compact Eye-Shaped UWB Antennas

This letter proposes a novel shrinking technology of ultrawideband (UWB) antennas among the conventional various ultrawideband antenna structures. An eye-shaped UWB antenna was designed to extend the lower frequency band under a limited antenna size. The operating band (1.2 ~ 4.5 GHz) can reach a fractional bandwidth of as high as 142%. The overall dimension, including the ground area, can be shrunk to 0.027λ
₀
²
. The group delay is nearly constant to ensure minimal distortion and dispersion. From the measurement, the antenna radiation pattern is close to omnidirectional and is suitable for general applications.