Short Josephson junction with a current concentration (for example, a variable thickness bridge or a point contact) is considered. Phase-current relation obtained differs significantly from sinusoidal one. In particular, it allows to explain the appearance of rf-induced subharmonic steps on the I-V curve (CVC). One-dimensional bridge (for example, a proximity effect bridge) and series arrays of such bridges are considered also. Properties of such bridges are determined by the penetration of the electric field into a superconductor over a large depth.