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) |