Study of an Attenuator Supporting Meander-Line Slow Wave Structure for Ka-Band TWT

An attenuator supporting meander-line (ASML) slow wave structure (SWS) is proposed for a Ka-band traveling tube (TWT) and studied by simulations experiments. The ASML SWS simplifies the fabrication assembly process of traditional planar metal meander-lines (MLs) structures, employing an to support ML on bottom enclosure rather than welding them together sides. To reduce surface roughness molybdenum caused laser cutting, coated thin copper film magnetron sputtering. measured S11 below −20 dB S21 varies around −8 −12 without attenuator, while −40 with attenuator. Particle-in-cell (PIC) simulation results show that 4.4-kV, 200-mA sheet electron beam, maximum output power 126 W obtained at 38 GHz, corresponding gain 24.1 electronic efficiency 14.3%, respectively.