High-Power Semiconductor-Based Nano and Subnanosecond Pulse Generator With a Low Delay Time

One of the promising designs of high-power nanosecond and subnanosecond pulse generators is based on the fast ionization dynistor (FID) stack triggered with nanosecond pulse of overvoltage. This pulse is usually formed by semiconductor opening switches. Delay time of these switches equals the sum of forward and reverse current pulse duration, i.e., several hundreds of nanoseconds. The novel opening switch, inverse recovery diode (IRD), is capable of forming a nanosecond pulse of voltage with the delay time equal to the reverse current pulse duration (15–20 ns) due to the special diode structure. High-voltage nanosecond pulse formed with IRD is used for fast triggering of the first FID from high-voltage dc-biased FID stack. The resulting fast overvoltage pulse is applied to the second FID, etc. As a result, the high-voltage FID-stack is switched for units of nanosecond. Total delay time of IRD-FID-based pulse generators is less than 30 ns.