Electromagnetic analysis of the Petzval surface for Medicina Radio Telescope

Multi-feed represent one of the new frontiers in the field of radio astronomy. The technology is now quite mature to allow the fabrication of receivers with high performance at relatively low cost. Hence, one can get numerous benefits by simultaneously using many feeds, placed in the focal plane of the reflector antenna. However the array dimension is set by the maximum loss acceptable in the antenna gain due to off-axis feed aberrations. These effects can be limited by adjusting the position along the reflector axis according to the Petzval surface. Nowadays, the very powerful electromagnetic software makes the optimization of such a best-focus position easier. In this contribution we show several numerical results of the electromagnetic performance exploiting the Petzval surface. The numerical analysis has been conducted for the Italian radio telescope of Medicina (Bologna) at 43 GHz.