PULSED MODULATOR FOR C-BAND KLYSTRON

Hardware R&D on C-band (5712 MHz) RF-system for an electron/positron linear collider started in 1996 at KEK [1,2]. One of the most important R&D items is to develop a compact, reliable and low-cost modulator (pulsed klystron power-supply), called the “Smart Modulator”. As the first step toward the smart modulator, we have developed a prototype modulator. An inverter-type power supply was used to charge a high-voltage into the PFN capacitors, which eliminated the massive chargingtransformer and also the de’Q-ing circuit from the traditional design. The developed modulator has a simple configuration and compact size. It shows excellent performances, and it is currently used for testing new Cband klystrons.