Dual synchro-resonant electrosurgical apparatus with bi-directional magnetic coupling

1. An electrosurgical generator comprising:

a power supply operable to generate a DC voltage;

a first parallel inductor-capacitor circuit configured to be driven by a first signal at a first predetermined frequency;

a second parallel inductor-capacitor circuit configured to be driven by a second signal at the first predetermined frequency phase-shifted 180 degrees; and

a series inductor-capacitor resonant circuit operably connected in series with a primary winding of a transformer, the first and second parallel inductor-capacitor circuits operably connected to the transformer, the first parallel inductor-capacitor circuit being configured to generate a positive half sine wave from the DC voltage and the second parallel inductor-capacitor circuit being configured to generate a 180 degrees phase-shifted positive half sine wave from the DC voltage to generate a full sine wave in a secondary winding of the transformer.

2. An electrosurgical generator as in claim 1 , wherein the first parallel inductor-capacitor resonant circuit is tuned to a first self-resonant frequency that is substantially equivalent to the first predetermined frequency.

3. An electrosurgical generator as in claim 2 , wherein the first parallel inductor-capacitor resonant circuit includes a first inductor having a first inductance value and a first capacitor having a first capacitance value, wherein the first inductance value and the first capacitance correspond to the first self-resonant frequency.

4. An electrosurgical generator as in claim 1 , wherein the second parallel inductor-capacitor resonant circuit is tuned to a second self-resonant frequency that is substantially equivalent to the first predetermined frequency.

5. An electrosurgical generator as in claim 4 , wherein the second parallel inductor-capacitor resonant circuit includes a second inductor having a second inductance value and a second capacitor having a second capacitance value, wherein the second inductance value and the second capacitance correspond to the second self-resonant frequency.

6. An electrosurgical generator as in claim 1 , wherein the first and second parallel inductor-capacitor circuit are driven by switching on and off first and second switching components respectively.

7. An electrosurgical generator as in claim 6 , wherein the first and second switching components are selected from the group consisting of transistors, relays, metal-oxide semiconductor field-effect transistors and insulated gate bipolar transistors.

8. An electrosurgical generator as in claim 1 , wherein the series inductor-capacitor resonant circuit is tuned to a third self-resonant frequency that is substantially equivalent to the first predetermined frequency.

9. An electrosurgical generator as in claim 8 , wherein the series inductor-capacitor resonant circuit includes a third inductor having a third inductance value and a third capacitor having a third capacitance value, wherein the third inductance value and the third capacitance correspond to the third self-resonant frequency.

10. A method for generating high frequency electrosurgical current comprising the steps of:

providing a power supply operable to generate a DC voltage, a first parallel inductor-capacitor circuit, a second parallel inductor-capacitor circuit, a series inductor-capacitor resonant circuit, wherein the first parallel inductor-capacitor circuit, the second parallel inductor-capacitor circuit, and the series inductor-capacitor resonant circuit are operably connected in series with a primary winding of a transformer;

driving the first parallel inductor-capacitor circuit by a first signal at a first predetermined frequency;

driving the second parallel inductor-capacitor circuit by a second signal at the first predetermined frequency phase-shifted 180 degrees; and

generating a positive half sine wave at the first inductor-capacitor parallel circuit;

generating a 180 degrees phase-shifted positive half sine wave at the second parallel inductor-capacitor circuit; and

combining the positive half sine wave and the 180 degrees phase-shifted positive half sine wave at a secondary winding of the transformer to generate a full sine wave.

11. A method as in claim 10 , wherein the first parallel inductor-capacitor resonant circuit of the providing step is tuned to a first self-resonant frequency that is substantially equivalent to the first predetermined frequency.

12. A method as in claim 11 , wherein the first parallel inductor-capacitor resonant circuit of the providing step includes a first inductor having a first inductance value and a first capacitor having a first capacitance value, wherein the first inductance value and the first capacitance correspond to the first self-resonant frequency.

13. A method as in claim 10 , wherein the second parallel inductor-capacitor resonant circuit of the providing step is tuned to a second self-resonant frequency that is substantially equivalent to the first predetermined frequency.

14. A method as in claim 13 , wherein the second parallel inductor-capacitor resonant circuit includes a second inductor having a second inductance value and a second capacitor having a second capacitance value, wherein the second inductance value and the second capacitance correspond to the second self-resonant frequency.

15. A method as in claim 10 , wherein the first and second parallel inductor-capacitor circuits of the providing step are each driven in the respective driving steps by switching on and off first and second switching components respectively.

16. A method as in claim 15 , wherein the first and second switching components are selected from the group consisting of transistors, relays, metal-oxide semiconductor field-effect transistors and insulated gate bipolar transistors.

17. A method as in claim 10 , wherein the series inductor-capacitor resonant circuit of the providing step is tuned to a third self-resonant frequency that is substantially equivalent to the predetermined frequency.

18. A method as in claim 17 , wherein the series inductor-capacitor resonant circuit of the providing step includes a third inductor having a third inductance value and a third capacitor having a third capacitance value, wherein the third inductance value and the third capacitance correspond to the third self-resonant frequency.

19. A radio frequency output stage circuit, comprising:

a first parallel inductor-capacitor circuit configured to generate a positive half sine wave driven by a first signal at a first predetermined frequency, the first parallel inductor-capacitor circuit being operably connected to a transformer which includes a first winding and a series inductor-capacitor resonant circuit connected in series to a second winding;

a second parallel inductor-capacitor circuit configured to generate a 180 degrees phase-shifted positive half sine wave driven by a second signal at the first predetermined frequency phase-shifted 180 degrees, the second parallel inductor-capacitor circuit being operably connected to the transformer such that the positive half sine wave and the 180 degrees phase-shifted positive half sine wave are combined at the secondary winding of the transformer to generate a full sine wave.