Design of an all-metal broadband Rotman lens for satellite communications at K/Ka-Band

In this work an all-metal Rotman lens antenna design is presented. Ridge waveguides are used for the input and output ports of the lens to achieve broadband behavior in the K/KA bands of the new generation of satellite communications (17.3 GHz to 31 GHz). The Rotman lens is composed by 5 input and 5 output ports, with a maximum beam scanning of 20 degrees. The connection between the input and output ports is done through a parallel plate waveguide (PPW) in the TEM regime. This simple configuration allows to have an initial assessment of the antenna port isolation and return losses, for the designed ridge to parallel plate waveguide transitions. This preliminary work shows promising results which pave the way for future improvements in terms of bandwidth and scanning performance.