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 a plurality of solid state switches, wherein the driver stage has a stray inductance less than 300 nH, the driver stage generating:
a first input waveform having a first input frequency, a first input voltage, and a first input duration;
a transformer stage coupled with the driver stage that includes one or more transformers;
an output stage coupled with the transformer stage and galvanically isolated from a reference potential, 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 greater than the first input voltage, and a pulse width substantially equal to the first input duration; and
a sink stage that dumps energy stored as capacitance in the output stage.
2. The pulse generator according to claim 1 , wherein the driver stage produces a pulse with a frequency greater than the frequency of the signal pulse output from the output staged, wherein the output signal is not a DC signal.
3. The pulse generator according to claim 1 , wherein the sink stage comprises a switch.
4. The pulse generator according to claim 1 , wherein the sink stage comprises a resistor.
5. The pulse generator according to claim 1 , wherein the output pulse has either or both a variable duty cycle and a variable frequency.
6. The pulse generator according to claim 1 , wherein the transformer includes stray inductance less than 1,000 nH.
7. The pulse generator according to claim 1 , wherein the transformer includes stray capacitance less than 1,000 pF.
8. A pulse generator comprising:
a driver stage that generates:
a first input waveform having a first input frequency, a first input voltage, and a first input duration
a second input waveform having a second input frequency, a second input voltage, and a second input duration, wherein the second input duration is different than the first input duration;
a transformer stage coupled with the driver stage;
an output stage coupled with the rectifier stage galvanically isolated from a reference potential, wherein the output stage outputs:
a first output pulse having a rise time less than 1,000 nanoseconds, a first output voltage greater than the first input voltage, and a pulse width substantially equal to the first input duration; and
a second output pulse having a rise time less than 1,000 nanoseconds, a second output voltage greater than the second input voltage, and a pulse width substantially equal to the second input duration; and
a sink stage that dumps energy stored as capacitance in the output stage.
9. The pulse generator according to claim 8 , wherein the output stage outputs a signal with a frequency greater than 50 kHz.
10. The pulse generator according to claim 8 , wherein the output signal has either or both the variable duty cycle and a variable frequency.
11. The pulse generator according to claim 8 , wherein the driver stage comprises at least one of one or more IGBTs and one or more MOSFETs.
12. The pulse generator according to claim 8 , further comprising a DC bias stage coupled with the output stage configured to provide a DC bias signal to the output stage.
13. The pulse generator according to claim 8 , wherein the driver stage has a stray inductance less than 500 nH.
14. The pulse generator according to claim 8 , 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.
15. The pulse generator according to claim 8 , 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.
16. The pulse generator according to claim 8 , wherein a total inductance in the transformer stage is less than 1,000 nH.
17. The pulse generator according to claim 8 , wherein the output stage outputs a signal with a frequency less than 10 kHz and a rise time less than 1,000 ns.
18. The pulse generator according to claim 8 , wherein a total inductance in the rectifier stage is less than 500 nH.
19. A method comprising:
generating a first input waveform having a first input frequency, a first input voltage, and a first input duration;
outputting a first output pulse having a rise time less than 1,000 nanoseconds, a first output voltage greater than the first input voltage, and a pulse width substantially equal to the first input duration;
turning off the first input waveform for a second input duration;
generating a second input waveform having a second input frequency, a second input voltage, and a second input duration, wherein the second input duration is different than the first input duration;
outputting a second output pulse having a rise time less than 1,000 nanoseconds, a second output voltage greater than the second input voltage, and a pulse width substantially equal to the second input duration; and
sinking energy stored as capacitance in the output stage.
20. The method according to claim 19 , wherein the first output voltage is greater than the first input voltage and the second output voltage is greater than the second input voltage.