Plasma generating device
According to one embodiment of the present disclosure, there can be provided a plasma generating device for performing plasma discharge, the plasma generating device having multiple operation modes including a first mode and a second mode, and including: a first power supply capable of changing a frequency within a first frequency range; a second power supply capable of changing a frequency within a second frequency range that is at least partially different from the first frequency range; a dielectric tube; and an antenna module including a first unit coil wound around the dielectric tube at least one time, a second unit coil wound around the dielectric tube at least one time, and a first capacitor connected in series between the first unit coil and the second unit coil.
1. An antenna module coupled to a dielectric tube and receiving a power from a power supply, the antenna module comprising:
a multi-layer coil structure including a first end, a second end, and a first coil structure to an Nth coil structure electrically interposed between the first end and the second end, wherein:
N is a natural number greater than or equal to 2,
each of the first coil structure to the Nth coil structure includes two or more turns, the two or more turns comprise an innermost turn and an outermost turn,
the first coil structure to the Nth coil structure are on respective first to Nth planes, and the first to Nth planes are parallel to but different from each other, and
the multi-layer coil structure further includes a first inter-layer capacitor to an Mth inter-layer capacitor, wherein the first coil structure to the Nth coil structure and the first inter-layer capacitor to the Mth inter-layer capacitor alternate in series such that the first inter-layer capacitor is electrically connected between the first coil structure and the second coil structure, and so on until the Mth inter-layer capacitor is electrically connected between the N−1th coil structure and the Nth coil structure, and M is equal to N−1;
a first terminal capacitor electrically connected between the first end and a first terminal of the power supply, wherein the innermost turn of the first coil structure is at the first end; and
a second terminal capacitor electrically connected between the second end and a second terminal of the power supply, wherein the outermost turn of the Nth coil structure is at the second end; wherein
the first terminal capacitor has a first capacitance and the second terminal capacitor has a second capacitance, and
the first capacitance is greater than the second capacitance,
each of the first inter-layer capacitor to the Mth inter-layer capacitor has a third capacitance, and
a sum of (i) a reciprocal of the first capacitance and (ii) a reciprocal of the second capacitance has a same value as a reciprocal of the third capacitance, such that, when the antenna module receives the power, an absolute value of an electric potential with respect to ground is minimal on the innermost turn of the two or more turns in each of the first coil structure to the Nth coil structure.
2. The antenna module of claim 1 , wherein the electric potential is a voltage.
3. The antenna module of claim 2 , wherein when the antenna module receives the power, the voltage becomes maximum on the outermost turn of each of the first coil structure to the Nth coil structure.
4. The antenna module of claim 1 , wherein:
the first terminal capacitor is directly connected to the innermost turn of the first coil structure, and
the second terminal capacitor is directly connected to the outermost turn of the Nth coil structure.
5. The antenna module of claim 1 , wherein the first capacitance is greater than or equal to two times of the second capacitance.
6. The antenna module of claim 2 , wherein when the antenna module receives the power, the innermost turn of each of the first coil structure to the Nth coil structure includes a point where the voltage is zero.
7. The antenna module of claim 1 , wherein the first capacitance is greater than the third capacitance.
8. The antenna module of claim 7 , wherein the second capacitance is smaller than the third capacitance.
9. The antenna module of claim 1 , wherein the minimal absolute value of the electric potential on the innermost turn minimizes production of a by-product caused by collision with the dielectric tube of a plasma produced in the dielectric tube when the antenna module receives the power.
10. The antenna module of claim 1 , wherein each of the first coil structure to the Nth coil structure includes three or more turns.
11. The antenna module of claim 1 , wherein Nis four or more.
12. A plasma generating system, comprising:
a dielectric tube providing a space for inducing a plasma;
a power supply configured to provide a power; and
an antenna module coupled to the dielectric tube and configured to induce the plasma by receiving the power from the power supply; wherein
the antenna module includes:
a multi-layer coil structure including a first end, a second end, and a first coil structure to an Nth coil structure electrically interposed between the first end and the second end, wherein Nis a natural number greater than or equal to 2,
at least one first terminal capacitor electrically connected between the first end and a first terminal of the power supply, and
at least one second terminal capacitor electrically connected between the second end and a second terminal of the power supply,
each of the first coil structure to the Nth coil structure includes two or more turns, the two or more turns comprise an innermost turn and an outermost turn, the innermost turn of the first coil structure is at the first end, and the outermost turn of the Nth coil structure is at the second end,
the first coil structure to the Nth coil structure are on respective first to Nth planes, and the first to Nth planes are parallel to but different from each other,
the multi-layer coil structure further includes a first inter-layer capacitor to a Mth inter-layer capacitor, wherein the first coil structure to the Nth coil structure and the first inter-layer capacitor to the Mth inter-layer capacitor alternate in series such that the first inter-layer capacitor is electrically connected between the first coil structure and the second coil structure, and so on until the Mth inter-layer capacitor is electrically connected between the N−1th coil structure and the Nth coil structure, and M is equal to N−1;
the first terminal capacitor has a first capacitance and the second terminal capacitor has a second capacitance,
the first capacitance is greater than the second capacitance,
each of the first inter-layer capacitor to the Mth inter-layer capacitor have a third capacitance, and
a sum of (i) a reciprocal of the first capacitance and (ii) a reciprocal of the second capacitance has a same value as a reciprocal of the third capacitance, such that, when the antenna module receives the power, an absolute value of an electric potential with respect to ground minimal on the innermost turn of the two or more turns in each of the first coil structure to the Nth coil structure.
13. The plasma generating system of claim 12 , wherein the electric potential is a voltage.
14. The plasma generating system of claim 11 , wherein:
the first terminal capacitor is directly connected to the innermost turn of the first coil structure, and
the second terminal capacitor is directly connected to the outermost turn of the Nth coil structure.
15. The plasma generating system of claim 12 , wherein the first capacitance is greater than or equal to two times of the second capacitance.
16. The plasma generating system of claim 13 , wherein when the antenna module receives the power, the innermost turn of each of the first coil structure to the Nth coil structure includes a point where the voltage is zero, and the voltage becomes maximum on the outermost turn of each of the first coil structure to the Nth coil structure.
17. The plasma generating system of claim 12 , wherein the first capacitance is greater than the third capacitance, and the second capacitance is smaller than the third capacitance.
18. The plasma generating system of claim 12 , wherein the minimal absolute value of the electric potential on the innermost turn minimizes production of a by-product caused by collision with the dielectric tube of the plasma.
19. The plasma generating system of claim 12 , wherein each of the first coil structure to the Nth coil structure includes three or more turns, and N is four or more.
20. The plasma generating system of claim 12 , wherein the power supply comprises a variable-frequency RF power source, and the variable-frequency RF power source comprises a rectifier converting commercial AC power into DC power; a controller controlling a driving frequency and the power by providing a switching signal; and an inverter converting the DC power into RF power based on the switching signal.