High-Order Vortex Beams Generation in the Radio-Frequency Domain

A novel technique for generating high-order vortex beams in the radio-frequency domain is reported. Vortex beams with non-null radial index are generated by means of a dielectric mask, mounted upon either a twisted parabolic reflector or a conventional one. The far-field intensity pattern is compared to analytical models and numerical simulations, thus illustrating how diffraction and illumination can affect the generated fields.