Millimeter-wave diagnostics at JET, mainly reflectometry, are employing state of art electronics but are limited in performance by the existing waveguides and antenna system that are inadequate and obsolete. The use of long runs of waveguides with high losses and non optimized antennas lead to difficult measurement conditions for reflectometry. The new access system presented in this article has been designed to improve the performance of reflectometry measurements and enable the installation of antennas for oblique viewing ECE. These two new antennae will allow the ECE radiation to be collected at different angles with respect to the magnetic field. This oblique ECE set-up is expected to be extremely useful in improving the interpretation of ECE temperature measurements in fusion experiments with significant additional heating. For reflectometry there is an urgent need to improve the edge density measurements as both the lithium beam and Thomson scattering exhibit resolution limitations at lower densities. The project proposal states that the expected improvement in reflectometry S/N ratio is 30dB. If realized, this will allow broad band reflectometry, for the measurement of the electron density profile, for the first time in JET.