Transmission characteristics of 0.3 THz wave using FUCW-I Gyrotron

The transmission characteristics of 0.3 THz wave through a circular waveguide whose diameter charged from 90 mm to 5 mm by two taper waveguides was investigated. As a power source, FUCW-I gyrotron ( GYCOM, Russia) was used. The gyrotron is operated in CW regime at weak power (20~ 100 W) Gaussian mode with the frequency of 0.3THz. The usual beam current is 130 mA at the accellated voltage 15 KV. The used antenna consists of a Teflon rod dielectric antenna and an insert rod antenna set at 2.4~5.0 mm waveguide. Under the various conditions, the output power from the antenna was measured by water load.