The problem of maintenance of stability of the parallel multiplier of frequency (MF) with the help of of directed filters on connected smooth inhomogeneous transmission lines (CSITL,) is decided. For want of it parasitic peak modulation on an input of the multiplier completely is eliminated. Problems of the coordination of the diode with the generator and load also are considered. As a broadband agreeing circuit the sequential single irregular transmission line (ITL) with the smooth law of a modification of a wave drag is used. The topology of the doubler in microstrip performance is designed.