Half width leaky wave antennas

Leaky travelling wave antennas that use the first microstrip higher-order mode are analysed. The antennas investigated here are only half the width of previous leaky wave designs and utilise a structure that inherently suppresses the fundamental mode. Since mode purity is assured, the need for an elaborate feed structure is eliminated. A means for extracting the complex propagation constant of a leaky wave antenna is presented using the finite difference time domain (FDTD) method. Agreement is shown between the resulting propagation constant and another established theoretical method, the transverse resonance method. Representative measured far-field patterns are included, which are consistent with the computed propagation constants. The properties of curving the leaky wave structure are also studied.