Development of a single switch cell for modular nanosecond pulse generation systems

The development of a single switch cell for a modular nanosecond pulse generation system is described with the proposed use in plasma-assisted ignition for scramjets. Using the inductive voltage adder topology and high voltage MOSFETs, the proposed system can generate nanosecond pulses with variable duration from 20 ns to 50 ns, fast rise time (< 6 ns), fast fall time (< 6 ns) and variable amplitude. The minimum pulse width (17 ns) is achieved. A simulation model for the modular system with single switch cell is developed. The outputs from the simulation model agree with the experimental results. The model predicts the characteristics of the single switch configuration accurately, such as the propagation delay of V_out compared with V_ds and the load time constant. It is also concluded that the ratio of leakage inductance and the load resistance is mainly responsible for the rise time and fall time of output pulse; the propagation delay of V_out mainly depends on the inductive elements, L_leakage, L _parasitic and L_load.