Design and experimental study of a broadband U-band TE01 gyrotron traveling wave tube

Design and experimental study of a wide-band U-band gyrotron travelling wave tube (gyro-TWT) amplifier are presented. The interaction circuit is constructed by periodic loaded dielectric, which provided required loss for stable operation. Potential oscillations are effectively suppressed. The U-band gyro-TWT is zerodriven stable at the operating points. A saturated peak power of 158 kW was measured at 48GHz by hot test, corresponding to a saturated gain of 47.4dB and an efficiency of 22.6%. Measured bandwidth over 100kW is in the range of 46.2-49.4GHz. Large-signal prediction shows excellent agreement with the hot test results.