Arcetri radioastronomy group participates to the ALMA technologic development in three working groups: . Front end: Warm optics for the first 4 bands. In particular Arcetri has designed the feeds for bands 1 (31.4-45 GHz), 2 (69-90 GHz) and 3 (84-116 GHz). ... In particular, a fast sample/hold circuit and a 1:8 demultiplexer have been designed using GaAs technology. Correlator: A digital filter design for the Second Generation Correlator has been studied. ...