Liu, L.L.LiuGrainge, K.K.GraingeNAVARRINI, AlessandroAlessandroNAVARRINI2020-11-092020-11-092018978-90-82598-73-5978-1-5386-3764-7http://hdl.handle.net/20.500.12386/28244This paper describes the main features of the PHased Arrays for Reflector Observing Systems project, called PHAROS, and of its upgraded version PHAROS2. PHAROS is a cryogenically cooled phased array feed designed for radio astronomy observation across the 4-8 GHz band. The PHAROS project started around the year 2004, thus some of its technology is old with regards to current standards. PHAROS2 will replace most of the key components of PHAROS in order to reduce the system noise temperature, enhance aperture efficiency, and digitize the signals from the antenna elements. This paper will focus on the front end description, while the signal down-conversion and back end section will be described in more detail in a paper titled "Design of PHAROS2 Phased Array feed" [1] which is presented at this conference.ELETTRONICOenConference paper10.23919/URSI-AT-RASC.2018.84715422-s2.0-85055830233https://ieeexplore.ieee.org/document/8471542FIS/05 - ASTRONOMIA E ASTROFISICA