Born in Helsinki in 1946, Leppänen is a Professor of Radio Communication Techniques at the University of Oulu and a pioneer in the research and development of new wide-band radio communication techniques.

The Finnish Air Force initiated Prof. Leppänen almost 20 years ago into starting the university-level basic research into the spread spectrum technique; the first research of its kind in Finland. As a result, spread spectrum techniques are now successfully used both in mobile communication systems and modern military communication systems. The technique means that a radio signal can be spread across a wider bandwidth which means that communications are less likely to be detected or jammed.
 
Prof. Leppänen has founded solid research cooperation across the globe with key partners in Europe, USA and Japan. The basic research results of Prof. Leppänen’s group have been employed by the Finnish defence industry for 15 years. His group is also a leading Finnish team in the research and development of new software defined radio communication techniques.