Planar lens using embedded quasi-lumped-element stripline filters

Lenses are an alternative antenna type for narrow beam antennas. Dielectric lenses, however, typically are relatively thick, heavy, and complicated to fabricate due to their specific contour. A possible solution for this problem are planar printed antennas which are thin, lightweight, and can be fabricated easily. This paper describes the design of a planar lens based on an array of slot-coupled planar filter structures; the required phase delay is adjusted by different center frequencies of the respective filters. An example lens at 35 GHz has been designed, fabricated, and tested.