Demonstration of a High-Power and Wide-Bandwidth G-band Traveling Wave Tube with Cascade Amplification

We propose and experimentally demonstrate a high-power and wide-bandwidth terahertz travelling wave tube (TWT), which is with two cascade amplification sections: the output wave of the first TWT is used as the input of the second one. Using a 17 kV, 71 mA electron beam, the measured peak power is over 60 watt and the average output power is over 12 watts with 20% duty cycle at the frequency around 0.22 THz. The gain is about 30 dB and the bandwidth is over 6 GHz. The average power-bandwidth-gain product reaches record high in the designed spectral range. We envisage that this new developed terahertz TWT will have broad application prospects, such as in long-range radar and communication systems.