The main research activities of prof. Riva are in the fields of tropospheric propagation of millimeter-waves, propagation impairment mitigation techniques, and satellite communication adaptive systems.

In 1999, he joined the Electronics and Information Science Department, Politecnico di Milano, where, since 2006, he has been an Associate Professor of electromagnetic fields.

Since 1992, he participated in the Olympus, Italsat and Alphasat ‘Aldo Paraboni’ propagation measurement campaigns, in the COST255, COST280 and COSTIC0802 international projects on propagation and telecommunications and in the Satellite Communications Network of Excellence (SatNEx).

In 2011 he is has been nominated to the Steering Committee of ESA’s Network of Experts as Italian Representative.

In 2012 he has been appointed Principal Investigator by the Italian Space Agency for the Alphasat Aldo Paraboni propagation experiment

He supports the ITU-R Study Groups activities as a delegate of SG3 and focal point for related propagation studies.

He is the author of more than 260 papers published in international journals or international conference proceedings (January 2021).