Circularly-polarized discrete lens antennas in the 60-GHz band

This paper presents the design and demonstration of circularly-polarized transmit-arrays operating in the 60-GHz band. These arrays have a fairly simple structure with three metal layers and are fabricated with a standard printed-circuit board technology. The simulation method is based on an electromagnetic model of the focal source and the unit-cells, associated to an analytical modeling of the full structure. The experimental results in V-band are in very good agreement with the simulations and demonstrate very satisfactory characteristics. Power efficiencies up to 60% are reached with a -1 dB gain-bandwidth up to 7%, and low cross-polarization level.