This document describes a baseband digital correlator implemented using two commercial synchronized FPGAs. The correlator is part of a broadband radioastronomy radiometer demonstrator aimed to obtain polarization data of Cosmic Microwave Background (CMB) radiation from the sky in the W band. Using correlation techniques, it is possible to obtain the Stokes parameters (I, Q, U) of the CMB correcting the phase differences produced by the different subsystems between the receivers’ branches on real time. Ought to the input frequency limitation of the digitizers, it is necessary to down convert all the signals from IF to baseband using commercial mixers and filters. Other digital implementations could be applied to large antenna arrays like the Square Kilometre Array (SKA) using specific electronics or supercomputing networks designed to work with lots of real time data
