A Frequency-Agile Relativistic Magnetron With Axial Tuning

A frequency-agile relativistic magnetron with axial tuning is presented. To achieve axial tuning, reentrant cavity which has two radial parts connected by a coupling hole had been introduced. Resonant frequency of this cavity configuration can be tuned by adjusting the axial length of each coupling hole without any variation of other parameters. Multi-antenna output technique had been integrated with the reentrant cavity chain to obtain high conversion efficiency in the whole tuning range. Simulation results showed that this tube had a tuning range between 1.23 GHz to 1.70 GHz, corresponding to relative bandwidth of 32% about a center frequency of 1.465 GHz. In this tuning range, the maximum output power is 1.81 GW at 1.605 GHz, corresponding to an efficiency of 54.5%. This axial tuning RM is a promising compact high power microwave source with wide tuning range.