It studies of linear modulator s average-voltage circuit and spring circuit when linear modulator adopts series-wound SCR(Silicon Controlled Rectifier) as switch tube, and linear modulator adopts flyback charging technic for satisfying radar transmitter technic guideline.

This paper introduces the composition and principle of fly-back charging modulator.

Emphasis is put on the broadband klystron,the technology of flyback power,and the solid-state modulator,solving the problems of output power fluctuation and heat dissipation of the klystron under the condition of the equal excitation.

This paper first analyzes the charging process of uniform distributed parameter circuits charged by DC voltage supply, then analyzes rectifying voltage supply to charge the charging circuit, and calculates the ununiformity of the charging voltage of stage capacitors.

Then through the establishment of the EMTP simulation model of impulse voltage generator,the impact of component parameters of charging circuit,charging methods and the charging time on the ununiformity is investigated.