Radiometers based on SIS mixers to measure SZ effect from galaxy clusters

We present a project to realize radiometers devoted to the observation of the Sunyaev-Zeldovich effect towards galaxy clusters. Radiometers are based on SIS mixers and are working at three frequency bands (around 94, 240 and 345 GHz) covering both the positive and negative part of the spectral displacement. The radiometers have been developed to be used at a telescope of 3 m class, like MITO. The observation program would be completed performing low frequency measurements first at the Noto radiotelescope (at 43 GHz) and then at SRT (at 40 and 90 GHz).