Status of the GLC X-band power source R&D

In this paper, we summarize the R&D status of the X-band power source development for the GLC (Global Linear Collider, previously called JLC) project. Main emphases are on the latest achievements of the PPM klystrons and the development of the IGBT induction modulator. The pulse compression schemes and the optimisation of the tunnel layout for different configuration of the main linac are also discussed.