Super resolving systems: Toraldo Pupils

(PUTO Project)




Experimental setup

Three coronae pupil




The launcher is a rectangular feedhorn (on the left), while, on the right,  we can see the probe mounted on a vertical plotter moving in the 𝑥y plane perpendicular to the direction of propagation, z. Between the launcher and the receiver is put a screen with a circular composed Toraldo pupil.








Sketch of the three coronae Toraldo-pupil







The three coronae Toraldo-pupil realized with low-loss polyethylene, the refractive index of which is 1.5, which is also the  thickness (cm) of the central ring. For an impinging plane wave, the wavelength of which is 1.5 cm (20 GHz), the circular ring introduces a dephasing of 𝜋 with respect to the wave that propagates in air, thus producing a sign change of the amplitude, as required by the Toraldo model.

(The composed pupil was manufactured at INAF-OAA, Arcetri)