On The Radiation Characteristics of Planar Printed UWB Antennas

Transmission and reception of narrow pulses is often impaired by the radiation characteristics of the antenna. Designing RF front ends for UWB systems pose challenges compared to their narrow and wide band counterparts because in addition to having electrically small size, high efficiency and band width, the antenna has to have excellent transient response. The present work investigates the suitability of four novel antenna designs- Square Monopole, Semi-Elliptic Slot, Step and Linear Tapered slot - proposed for UWB systems. In these antennas, multiple resonances in the geometry are matched to UWB by redesigning the ground-patch interfaces. The thesis also proposes a technique to avoid narrow band interference by designing slot resonators in the antenna and its effect on a base band pulse has been studied. Performances of these designs are studied in the frequency and time domains by simulation and experiments. Accounting the resonances in each structure, design guidelines are deduced, allowing their implementation in laminates of any permittivity.