The 5th generation of mobile communications is designed to employ both FR1 and FR2 bands throughout the world. The higher frequency bands (i.e., FR2 n257 26.50 - 29.50 GHz) are posing several challenges to operators and national telecom agencies for performing electromagnetic fields (EMF) measurements. In this work we present the design and preliminary evaluation of an FR2 sensor node to measure EMF radiations in urban environments. The design is carried out in an RF circuit design software, i.e., Keysight ADS, where the various nonidealities (i.e., nonlinearities, noise behavior and electromagnetic response) of the various sub blocks of the systems are accounted for. The sensor
concept is then implemented in a prototype board technology (i.e., X-microwave) and its response is experimentally verified in the FR2 band.