Scan performance of low index lens reflector

A compact 26dBi gimballed lens reflector antenna was developed for aeronautical Q-band application. The design has a stationary feed and consequently does not require rotary joints. A 4λ₀ radius hemispherical homogeneous low relative permittivity lens was shown through both simulation and experiment to meet the required gain specification across ±48° scan range, obviating the need for a Luneburg Lens as stated in most prior work. Consequently, the final antenna design had a minimum number of parts and could be conveniently manufactured using a numerically controlled milling machine. The measured scan performance of the different scalar feed - lens combinations agreed well with simulations of a spherical lens fed by those same feeds. The full wave spherical lens simulations were in general agreement with equivalent prior work done using empirical equations, despite some ripple in the focal length-gain curves.