A folded lens antenna with triple use of the lens

A novel type of folded lens antenna is presented in this contribution. In addition to known concepts of folding reflector or lens antennas, the lens of the antenna described here is used threefold, resulting in a further reduction of antenna depth. Furthermore, a novel type of twist reflector printed on a planar dielectric substrate of given thickness is included. As an example, a test antenna in the 20 GHz range was designed, fabricated and tested, showing good results and giving the basis for compact antennas, especially in the mm-wave frequency range.