A new undulator scheme was investigated which appeared to be perspective for the short period designs. A high current coil is used to provide the strong longitudinal magnetic field over the total undulator volume. A set of steel blocks inserted into the core area causes redistribution of this magnetic flux providing periodically alternating transverse field components. A new element of the scheme is an additional set of permanent magnet blocks placed between the steel undulator pole blocks. Magnetic field measurements made with an undulator prototype model have shown that the transverse field component can be enhanced up to a level comparable with the primary longitudinal magnetic field.