Design of Coating on Helix for High-Power Traveling Wave Tube

Helix as a key component of traveling wave tube (TWT) for amplifying microwave signal is traditionally made of tungsten, because tungsten has high melting point and good mechanical strength. However, high resistivity and poor thermal conductivity of tungsten limit the further development of high-power TWT. Here, we design and synthesize Cu/Au composite film on the surface of helix based on electromagnetic wave transmission mechanism. The output power of coated helix TWT was obviously improved. The thickness and thermal reliability of Cu/Au composite film having important effects on the output power of TWT were investigated.