Planar Surface-Wave Sources and Metallic Grating Lenses for Controlled Guided-Wave Propagation

Guided surface-waves (SWs) on planar substrates are generally an adverse effect that can degrade the performance of monolithic integrated circuits and antenna arrays. However, with appropriate boundary conditions, such SWs can be harnessed as an efficient means of power transport achieving bound propagation along a dielectric slab. Furthermore, by the addition of planar metallic grating configurations an effective dielectric constant can be achieved, refracting cylindrical SWs transmitted from a central surface-wave launcher (SWL) source. Specifically, two metallic grating lenses are investigated for millimeter-wave frequencies of operation, offering either the convergence or divergence of bound SWs. In addition, design concepts are extended to a novel planar coupler. These metallic grating lenses and directive SWL sources can be useful for new quasi-optical millimeter-wave circuits and planar leaky-wave antennas.