Achieving linear phase through geometrically-compensated transformation domains for leaky-wave antenna radiation

A graded dielectric superstrate is designed using transformation optics to couple the radiation from a leaky slot line into free space. Due to coordinate stretching during the transformation process, the phase profile along the air-dielectric interface is not linear, leading to an unsatisfactory radiation pattern. By compensating for phase errors through a modification of the source transformation domain, the phase can be made linear and the radiation pattern improved dramatically.