S-band 300kW T.W.T.

This paper describes the development of a high power, grid pulsed T.W.T. being developed for a mobile radar system requiring high efficiency, minimum size and weight. The T.W.T. uses a single section cloverleaf r.f. structure giving good pushing and linearity performance for pulse compression systems and is novel in having a compact P.P.M. focussing system incorporated in the structure. It will be capable of a minimum peak power of 300kW and saturated gain of 20dB in a 9% 1 dB bandwidth. Efficiency should be at least 45% mid-band using collector depression and a frequency dependent velocity taper. The first tubes produced over 300kW with 90% beam transmission when 40% collector depression was used.