There is a requirement at CERN for a microwave amplifier to provide pulsed RF power for a sub-harmonic bunching system in the CLIC Test Facility (CTF3). This amplifier is required to have a relatively broad bandwidth, centred at 1.5 GHz, and a peak power level up to 500 kW.

This paper describes the results of a feasibility study into the possibility of meeting this need with a broadband klystron. Previous work has been carried out on a number of different klystron designs which give the same percentage bandwidth as the CERN requirement (approximately 10%) over a range of peak power levels from 50 kW to 2.5 MW.

One design in particular, a 100 kW klystron operating at a band centre of 1.3 GHz, has been chosen as a basis for the design. This tube has been scaled in frequency and power level to meet the CTF3 requirement.