The measurement of the plasma parameters close to the ICRF antennas is important to understand the wave propagation and improve modelling. For this purpose one of the 3-strap ICRF antennas in ASDEX Upgrade, that were installed in 2014, is equipped with 10 horn antenna pairs; three of these antenna pairs are used for reflectometry in the extended U-Band at frequencies from 40-68 GHz. One of the unused horn antenna pairs close to the ICRF antenna limiter was removed; with some additional waveguide sections and new supports for the horn antennas we could set up a new microwave diagnostic that allows density measurements in the limiter shadow. The diagnostic, called Microwave Intensity refractometer in the Limiter Shadow (MILS), operates with 47 GHz amateur radio transmitter and receiver units and allows phase and amplitude measurements at an intermediate frequency of 145 MHz. After the successful installation and commissioning of MILS in 2019 and some modifications in 2020, we plan to upgrade the system to three receiver horn antennas, as the microwave beam from the transmitter horn antenna, which is tangential to the plasma, is refracted by the large density gradient at the plasma edge. The amplitude and phase information from the addition receiver antennas will improve our knowledge about the plasma properties.