Preliminary results are presented concerning static properties of a small Josephson junction under the influence of strong microwave radiation. We discuss the correspondence between a Brownian particle moving in a periodic potential and superconducti
ng phase difference in a small Josephson junction. Next, we describe an experimental method of determining the amplitude of microwave current flowing across the junction. Typical examples of static characteristics of the junction are presented, including its dynamical resistance as a function of microwave power. We discuss also the influence of an external magnetic field on the junction dynamics and show that in this case the one-dimensional Stewart-McCumber model becomes insufficient.
