On the reduction of phase-aberrations in three-dimensional Rotman lens design

In this paper, several design procedures for three-dimensional lens antennas to be used in multiple beam antenna applications are discussed and compared based on phase-only analyses with an attempt to reduce phase-aberrations over a wide angular scanning range. In particular, focused designs and non-focused designs are described and parametric analyses are presented to identify some guidelines in the design of such structures. Our investigations confirm that designs with multiple foci are not necessarily better than non-focused designs, but different dependency on the lens´ main parameters are found which may be considered to select the more suitable lens design for a given set of constraints.