A New Kind of Planar Waveguide Luneburg Antenna for the MM-Wave Region

For the purpose of short- and medium-range high resolution imaging in darkness or low visibility conditions, e.g. for airfield surveillance use, narrow beamwidth millimeter wave antennas for fast and wide-angle scanning are required. Based on the principle of the Luneburg lens, a planar waveguide lens antenna is described which is appropriate for this purpose and stands out for compactness and simple construction. Theory, technical details and performance data of a prototype designed for use at 70 GHz are presented. Further, a modification of this lens is shown which makes easy high-speed mechanical scanning feasible.