Propagation of resonance cones in truncated hyperbolic transmission-line grids over ground

Resonance-cone propagation in truncated transmission-line hyperbolic grids over ground, is studied using circuit analysis and verified experimentally in microstrip grids. These structures support the propagation of resonance-cones that propagate within the grids in specific frequency-dependent spatial directions (cone-angles), a property that can be exploited to make spatial filtering and de-multiplexing devices. Analytical and experimental results show that there is no phase variation along a resonance cone. Moreover, a 180/spl deg/ phase variation is observed perpendicular to the cones in lossless grids, which increases in practical grids.