Beam-Scanning Lens Antenna Based on Corrugated Parallel-Plate Waveguides

A lens antenna based on dispersion characteristics of corrugated waveguide is presented for one-dimensional (1-D) beam scanning at Ka-band. The dispersion characteristics of the corrugated waveguide can be controlled by adjusting the parameters of the corrugations. Thus, the effective index of refraction of the corrugated waveguide can be designed to realize the required phase delay to transform cylindrical waves into plane waves. A five-element linear array of waveguide slot antennas is used to feed the corrugation lens for multiple beam scanning. The measured aperture efficiency of the lens antenna is above 60% for the on-axis beam from 30 to 32 GHz. The resulting -3 dB coverage of the designed lens antenna is +/- 14.1 degrees at 30 GHz.