Design and PIC Simulation of Ka-Band Periodically Loaded High Gain Gyro-Twystron

In this article, the design and multimode analysis of a
Ka
-band, single cavity followed by a periodically dielectric-loaded (PDL) waveguide-based gyro-twystron operating in the fundamental TE
₀₁
mode have been presented. The present amplifier has been studied for its stability against the backward wave oscillations (BWOs) and the beam–wave interaction by using the linear and nonlinear multimode theory, respectively. Furthermore, the design of the present gyro-twystron has been validated by using a commercially available 3-D particle-in-cell (PIC) code. Moreover, a few key subassemblies, including a
${Y}$
-shaped input coupler, triode-type magnetron injection gun (MIG) with
$\sim 4$
% velocity spread, a curved collector, and a double-disk RF window, have been designed and studied for their performance behavior. The 3-D PIC simulation of the present gyro-twystron predicted
$\sim 260$
-kW RF output power in the TE
₀₁
mode at
$\sim 35$
GHz. The gain, efficiency, and bandwidth are calculated as
$\sim 54$
dB, 40%, and 1.3 GHz, respectively.