Impact of Temperature on Turn-On Characteristics of Avalanche Transistors and Output Pulses of Their Marx Circuits

Avalanche bipolar junction transistors (ABJTs) can be conducted in the time scale of nanosecond-level or subnanosecond level. Marx bank circuits (MBCs) based on ABJTs can generate pulses with high amplitude, fast rising edge, and high repetition frequency. In order to meet the demand for the stability of the output pulses of MBCs under different operating temperatures and frequencies, the impact of temperature on the turn-on characteristics of ABJTs and their MBC is investigated. Through analyzing the principles of the turn-on characteristics of ABJTs, the variations in the turn-on characteristics of ABJTs and the output pulses of MBCs under different temperatures and operating conditions are experimentally investigated. The results indicate that an increase in temperature affects the carrier avalanche multiplication process, leading to slower turn-on speeds and reduced voltage drop in base-triggered ABJTs, while the overvoltage amplitude and duration increase under voltage ramp triggering. The impact of temperature on the turn-on characteristics of a single ABJT accumulates in the MBC. As the temperature rises from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$25~^{\circ }$ </tex-math></inline-formula>C to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$125~^{\circ }$ </tex-math></inline-formula>C, the output pulse amplitude of the ten-stage MBC decreases from 976 to 540 V, the rise time increases from 0.28 to 1.44 ns, and the full-width at half-maximum (FWHM) increases from 1.57 to 2.95 ns. The theoretical analysis is consistent with the experimental observations, validating the effectiveness of the theoretical explanation and providing a reference for the design and reliability improvement of MBCs under high repetition frequency or high temperatures.