Abstract
The operation of a high harmonic gyro-traveling-wave-tube amplifier which is based on the synchronous interaction of a rotating beam of large orbit, axis-encircling electrons with a TEn1 cylindrical waveguide mode is described. Principal results include amplification of the TE81 mode at the eighth harmonic of the cyclotron frequency mode with a small signal gain of 10 dB, an instantaneous interaction bandwidth of 4.3%, and a saturated power transfer of 0.5 kW. © 1989 The American Physical Society.