EHT Inductive Adder for Nanosecond-Scale High Voltage Pulses into Low-Impedance Loads
EHT inductive adders allow high voltage pulses into 50 Ohm loads with rise times on the nanosecond-scale. This topology has the following benefits:
All drive components are ground-referenced. This eliminates switching jitter problems, and floating gate drive complexities.
Agility of pw (pulse width) and prf (pulse repetition frequency). The output pulses are defined by input pulses to gates.
Identical modules all switch same voltage and current are triggered simultaneously, i.e. a modular design.
More modules allows scaling to higher voltages.
A wide range of loads can be driven.
Load and load voltage are almost completely independent.
Case study, Office of Naval Research (ONR): the intent is to drive non-linear transmission lines (NLTLs) producing high power microwaves. 35 kV pulses were produced with adjustable pulse widths (40-100 ns) and fast rise times (11 ns). Short bursts were demonstrated at prf up to 1 Mhz.
A next-generation unit will achieve the following specs:
Input power: 15 kW DC supply
Energy per pulse: 1.8 J at 30 kV
Adjustable output pulse width: 25-100 ns
Output voltage: At least 30 kV into a 50 Ω load
Output rise time: 12 ns or less
PRF at 12 kW and 100 ns PW: 6 kHz
PRF at 12 kW at 25 ns PW: 25 kHz
Duty cycle: pulser will operate at least 2 seconds continuously, once every 2 minutes