A high average power lightweight gridded TWT for x-band

The design and performance of a gridded, high power coupled-cavity TWT will be discussed. This x-band tube operates at 50 kW peak power output over a 10% bandwidth with 60 dB gain. Average powers greater than 10 kW have been obtained. The tube uses special construction techniques to achieve a compact configuration of gun and slow wave circuit, suitable for use with a small diameter, separately wound solenoid. The non-intercepting gridded gun utilizes a dimpled cathode. It has a high area convergence ratio and a high mu. A space harmonic coupled cavity circuit is used. It is constructed in rectangular form to achieve accuracy in tolerances and a compact outer diameter. Sever loads are waveguide terminations which use high thermal conductivity lossy tapered ceramics. The gun and circuit, including the sever loads and input waveguide, fit into a two inch I.D. solenoid. Loading of the circuit for band-edge stability will be described.