High-power reflex klystrons for millimetre wavelengths

Describes the design and construction of a series of high-power reflex klystron tubes for the band 18 to 100 Gc/s. The design aims were a high level of reliability and life and least number of adjustments; accordingly, the tubes covering this band differ only in respect of resonator cavity, output waveguide and window dimensions. The development work was carried out largely at 35 Gc/s for which data is presented; tubes covering the whole of the band have also been made to establish the suitability of design. At 35 Gc/s the power output was 2.5 W, corresponding to an efficiency of over 3%; maximum tuning range was 8%.