Characteristics of a Low-Voltage Gyrotron Backward-Wave Oscillator

Gyrotrons are usually operated on high voltages to generate high power coherent radiation in the millimeter to terahertz band. Recently, some high frequency applications do not require high power sources. For such applications, lowering the voltage of a gyrotron becomes an important issue. This study analyzes linear and nonlinear characteristics of a gyrotron backward-wave oscillator (gyro-BWO) operating in low voltage regime. Simulation results predict that the start-oscillation current of a gyro-BWO increases rapidly when the voltage decreases to a lower limit. Moreover, the efficiency and the tuning bandwidth of a low-voltage gyro-BWO are investigated.