A simple technique for surface-wave power routing and application to power directing circuits

Electromagnetic surface-waves (SWs) on planar dielectric substrates are generally considered an adverse effect that can degrade the performance of printed circuits, antennas, and arrays. However, with appropriate boundary conditions, SWs can be harnessed as an efficient means of power transport achieving bound, guided-wave propagation along a grounded dielectric slab; surface-wave launchers have been shown to be a useful technique to excite such cylindrical-wave field distributions. Recent applications include printed leaky-wave antennas, lensing structures, and planar quasi-optical power combiners. Unfortunately, reduced through powers can be observed in such designs due to the radial propagation of SWs along the slab. But, by the inclusion of a simple parallel-plate waveguide medium to surround such structures, SWs can be confined, further directed, and routed for increased throughput. Concepts are extended to a fixed and tunable three port power divider for SW channeling. Additional applications include other dividing/combining systems and feeding structures for planar antennas and circuits at microwave and millimeter-wave frequencies of operation.