Assessment of discretised Sochacki lenses

Machined plastic lens antennas have the advantage of lower cost small volume production compared to traditional Luneburg lenses which require high cost overhead moulding. Prior work has concentrated on 2-layer lenses individually machined from common low loss plastics. However, the aperture efficiency of these lenses has proven to fall off for large radii beyond about 20 wavelengths, and must be increased if this type of lens is to be used for applications such as satellite terminal antennas where upwards of 36 dBi gain is required. Novel 3-layer lens designs are presented which have higher gain and aperture efficiency in simulation compared to the earlier 2-layer lenses, potentially justifying the expense of machining the additional plastic layer.