  This paper presents a non-zoned discrete dielectric lens comprising two or
three matching layers to reduce the 50-110 GHz frequency range reflections.
Based on Chebyshev and binomial multi-section transformers, the designed models
use matching layers at the top and bottom. In addition, the presented designs
use pins instead of the conventional slots for the matching layers, thus easing
the manufacturing process. The results show that the broadband realized gain
obtained using the proposed design is higher for both the two- and three-layer
design than the commonly used quarter-wave transformer. A Binomial lens with
two matchings layers using 38 unit cells is fabricated and illuminated by an
open-ended waveguide to validate the simulation results obtained using CST
Microwave Studio. The fabrication process uses stereolithography additive
manufacturing.
