Nanosecond pulser
A pulse generator is disclosed that includes at least the following stages a driver stage, a transformer stage, a rectifier stage, and an output stage. The driver stage may include at least one solid state switch such as, for example, of one or more IGBTs and/or one or more MOSFETs. The driver stage may also have a stray inductance less than 1,000 nH. The transformer stage may be coupled with the driver stage and/or with a balance stage and may include one or more transformers. The rectifier stage may be coupled with the transformer stage and may have a stray inductance less than 1,000 nH. The output stage may be coupled with the rectifier stage. The output stage may output a signal pulse with a voltage greater than 2 kilovolts and a frequency greater than 5 kHz. In some embodiments, the output stage may be galvanically isolated from a reference potential.
1. A pulse generator comprising:
a driver stage comprising at least one of one or more IGBTs and one or more MOSFETs, the driver stage generates a first input waveform;
a transformer stage coupled with the driver stage, the transformer stage including one or more transformers;
a rectifier stage coupled with the transformer stage having stray inductance less than 1,000 nH;
an output stage coupled with the rectifier stage, the output stage having a storage capacitor, the output stage outputting a first output pulse having a rise time less than 1,000 nanoseconds, a first output voltage greater than 2 kilovolts; and
a sink stage coupled with the output stage, the sink stage comprising a fast switch, wherein energy stored in the storage capacitor is dumped when the fast switch is closed.
2. The pulse generator according to claim 1 , wherein the driver stage has a stray inductance less than 300 nH.
3. The pulse generator according to claim 1 , wherein the fast switch opens and closes within 1 μs or faster.
4. The pulse generator according to claim 1 , wherein the fast switch comprises at least one of one or more IGBTs and one or more MOSFETs.
5. The pulse generator according to claim 1 , wherein the fast switch comprises one or more fast switches arranged in parallel and/or arranged in series.
6. The pulse generator according to claim 1 , wherein the first input waveform has a voltage less than 1 kV.
7. The pulse generator according to claim 1 , wherein a total inductance in the rectifier stage is less than 500 nH.
8. The pulse generator according to claim 1 , further comprising a balance stage coupled with the driver stage and the transformer stage that includes one or more blocking capacitors.
9. The pulse generator according to claim 1 , wherein the fast switch comprises a plurality of switches.
10. A high voltage pulser comprising:
a driver stage comprising at least one of one or more IGBTs and one or more MOSFETs, the driver stage generates a first input waveform;
a transformer stage coupled with the driver stage, the transformer stage including one or more transformers;
an output stage coupled with the transformer stage, the output stage having a storage capacitor, the output stage outputting a first output pulse, the first output pulse having a rise time less than 1,000 nanoseconds and a first output voltage greater than 2 kilovolts; and
a sink stage coupled with the output stage, the sink stage comprising a fast switch, wherein energy stored in the storage capacitor is dumped when the fast switch is closed.
11. The high voltage pulser according to claim 10 , further comprising a rectifier stage coupled with the transformer stage and the output stage, the rectifier stage having stray inductance less than 1,000 nH.
12. The high voltage pulser according to claim 10 , wherein the first output pulse has a rise time less than 1,000 nanoseconds.
13. The high voltage pulser according to claim 10 , wherein the output stage outputs a signal with a frequency greater than 50 kHz.
14. The high voltage pulser according to claim 10 , wherein the driver stage has a stray inductance less than 500 nH.
15. The high voltage pulser according to claim 10 , further comprising a filter stage coupled with the rectifier stage and the output stage, wherein the filter stage comprises an inductor with an inductance of less than 50 nH.
16. The high voltage pulser according to claim 10 , further comprising a filter stage coupled with the rectifier stage and the output stage, wherein the filter stage comprises a capacitor with a capacitance of less than 50 nF.
17. The high voltage pulser according to claim 10 , wherein a total inductance in the transformer stage is less than 1,000 nH.
18. The high voltage pulser according to claim 1 , wherein the fast switch comprises a plurality of switches.
19. A method comprising:
closing at least a first switch to provide a first input waveform to a transformer, the first switch coupled with a source and disposed on a primary side of the transformer;
charging a storage capacitor disposed on the secondary side of the transformer with the first input waveform after passing through the transformer;
opening the first switch after a first duration;
opening a second switch, the second switch disposed on a secondary side of the transformer;
outputting a first output pulse having a rise time less than 1,000 nanoseconds and a first output voltage, the first output pulse being provided by energy in the storage capacitor;
closing the second switch causing energy stored in the storage capacitor to be dumped.
20. The method according to claim 19 , further comprising stepping up a voltage of the first input waveform to the voltage of the first output pulse with the first output voltage of greater than 2 kV.