Abstract

We will present realisations of MMIC Low Noise amplifiers designed to operate in a cryogenic environment, working from 18 to 26 GHz. These devices have been produced with the intent to be installed in a five beams feed array receiver, realised to improve the single dish survey and VLBI performances of the 32m diameter parabolic dish antenna of the Medicina Radioastronomical Station, near Bologna, in Italy. The entire project named FARADAY has been developed in the FP-5 context supported by EU. Many efforts has been concentrated to produce devices with the best compromise between lowest noise, flat gain, and good input matching. For this device, MMIC 0,1 um gate length InP HEMT process has been used. We will start the work description from the design specification to the on wafer devices measurements. We will also introduce our packaging material investigations in order to have a reliable working device at cryogenic temperature. Packaging device efforts has been devoted also to realise a modular carrier that let the choice between coaxial and waveguide interface.