A fast and slow wave combined-mode metamaterial ridged waveguide for array antenna applications

A new structure for a `metamaterial' ridged waveguide with the ability to control wavelength is proposed. The structure has the remarkable features of a wide control-range in wavelength from the fast-wave to slow-wave regions across the TEM wavelength in free space, and a waveguide impedance-control function that is independent of wavelength. This feature can improve the performance of array antennas in the reduction of grating lobes and side lobes.