Compact high voltage RF generator using a self-resonant inductor
RF generators including active devices driving series resonant circuits are described. The series resonant circuits include a self-resonant dual inductor. The RF generators can be used to drive capacitive loads.
1. An RF circuit for providing a radio frequency signal, the circuit comprising:
a dual inductor including one winding including an input and an output, and another winding including an input and an output;
wherein the one winding and the another winding are arranged to provide, between the one winding and the another winding, a parasitic capacitance selected to determine the frequency of the radio frequency signal; and
wherein the outputs of the windings are configured to electrically couple to a capacitive load.
2. The RF circuit of claim 1 in which the one winding and the another winding are spatially arranged so the selected parasitic capacitance and the inductance of the dual inductor provide a resonant circuit having an RF resonant frequency.
3. The RF circuit of claim 2 further comprising the capacitive load, and in which the selected parasitic capacitance, and the capacitive load, and the inductance of the dual inductor provide a resonant circuit having an RF resonant frequency.
4. The RF circuit of claim 1 in which the dual inductor comprises a ferrite or iron powder core.
5. The RF circuit of claim 4 in which the core is a closed loop shape, and the one winding and the another winding are wound onto the core.
6. The RF circuit of claim 1 in which the one winding and the another winding are arranged so that an alternating current in the one winding induces an alternating current having opposing phase in the another winding.
7. The RF circuit of claim 2 in which the dual inductor comprises a ferrite or iron powder core.
8. The RF circuit of claim 3 in which the dual inductor comprises a ferrite or iron powder core.
9. The RF circuit of claim 2 in which the one winding and the another winding are arranged so that an alternating current in the one winding induces an alternating current having opposing phase in the another winding.
10. The RF circuit of claim 3 in which the one winding and the another winding are arranged so that an alternating current in the one winding induces an alternating current having opposing phase in the another winding.
11. The RF circuit of claim 4 in which the one winding and the another winding are arranged so that an alternating current in the one winding induces an alternating current having opposing phase in the another winding.
12. The RF circuit of claim 5 in which the one winding and the another winding are arranged so that an alternating current in the one winding induces an alternating current having opposing phase in the another winding.