Experimental verification of frequency multiplication in two-stage tapered gyro-TWT

Summary form only given, as follows. A Ka-band harmonic multiplying two-stage tapered gyroTWT has been developed. The third harmonic interaction of electron cyclotron frequencies is used to multiply X-band signals to Ka-band. A previous similar experimental demonstration at NRL showed a 20 % bandwidth at saturated gain of 25 dB with 16 % efficiency when the predicted velocity spreads of 4 % were assumed at Ka-band with the fundamental harmonic interaction. This work showed the linearly tapered rectangular waveguide at both stages could produce enhanced gain, gain uniformity, and efficiency.