SUNRAY-2.5 D code for multi-signal large-signal analysis of a complete helix TWT

Accurate and fast SUNRAY-2.5D code has been developed for multi-signal large signal analysis of a complete helix TWT. Ring model of electron beam was used and relativistic equations of motion were solved with variable focusing field, circuit loss and pitch profiles. Improved expressions of the circuit field and induced voltages were developed. Complete RF output and beam performance including higher harmonics, inter-modulation components, beam interception were simulated. It is fast and accurate and has been validated with experimental results of several broadband and high efficiency TWTs. Agreement for saturated output power is achieved within 0.5 dB and for saturated gain within 2 dB. High efficiency TWTs at different frequency bands have been designed using this code. Spent beam data generated by the code has been used for the design of multi-stage collectors, accurately for space TWTs.