A Novel Application of the Active Surface of the Shaped Sardinia Radio Telescope for Primary-Focus Operations

The 64-m Sardinia Radio Telescope (SRT) is a shaped dual-reflector antenna designed to optimize secondary-focus operations. A novel application of the SRT active primary reflector aimed at achieving efficient operations also at the primary focus is presented. To this purpose, we show how the panels of the shaped primary mirror can be moved to best fit a parabolic surface. The modified primary reflector permits increasing the maximum frequency for primary-focus operation and also improves low-frequency multifeed capabilities. In fact, our numerical simulations show that at 80 GHz, the aperture efficiency from the primary focus drops only 10% with respect to 300 MHz.