New transmission lines and antennas recently installed at JET under the EFDA enhancement project "Millimeter Wave Access (MWA)" meet the performance requirements of broadband reflectometry for density profile measurements. Using the new access a fast swept Frequency Modulation Continuous Wave (FMCW) using coherent detection of the reflected signal, was developed to probe the mid-plane plasma in the X-mode polarization in the 50-75GHz frequency range, aiming at measuring the edge density profile in the JET advanced scenarios with axis magnetic field of 2.4T. This paper describes the operating principles of the new system and presents some preliminary results obtained with it. Special attention is given to the fact that this swept reflectometer is capable of operating on bi-static antenna arrangements over long waveguides, by using a local generated reference, as these will be the operating conditions considered adequate for ITER reflectometer.