Design of W-band coupled-cavity TWT by LIGA fabrication

The ladder-core structure of coupled-cavity TWTs with dual in-line coupling has attracted interest in a high-power mm-wave amplifier. The limit of practical power is 10kW using a solenoid-focused electron beam. The main goal of this paper is to design a circuit capable of producing up to 20kW with a moderate bandwidth and a PPM focusing system. Two-step LIGA is employed for this CCTWT design in order to eliminate the machining required for the beam tunnel and coupling slots and eliminate almost all post-LIGA machining steps.