A millimeter-wave cylindrical modified Luneberg lens antenna

A new cylindrical modified Luneberg lens antenna at millimeter-wave frequencies is designed using parallel plate techniques. The cylindrical modified Luneberg lens consists of two parallel plates which are filled with air. The plates spacing is continuously varied with the normalized radius to achieve a general Luneberg´s variation of the effective index of refraction. A planar antipodal linearly-tapered slot antenna (ALTSA) is placed between the parallel plates at the focal position of the lens as a feed antenna. A ray-tracing method and CST-MWS are used to analyze and design this cylindrical lens antenna at 30 GHz. Measurements show good agreement with the simulations.