Balancing RF circuit and control for a cross-coupled SIMO distribution network
A single input multiple output plasma control system includes a splitter that receives a single input and generates multiple outputs. Each output from the splitter is provided to a load. The splitter includes branch circuits connected between selected splitter outputs. The branch circuits control voltage, current, power, frequency, or phase between each branch to enable controlling a predetermined relationship between the voltage, current, power, impedance, frequency, or phase measured at each load.
1. An electrical splitter receiving a RF output signal and generating a first RF output and a second RF output to respective a first load and a second load, comprising:
a first leg providing the first RF output to the first load;
a second leg providing the second RF output to the second load; and
a balancing circuit connected between the first leg and the second leg, the balancing circuit controlling a first value of an electrical parameter associated with one of the first leg or the second leg and a second value of the electrical parameter associated with an other of the first leg or the second leg,
wherein the first value and the second value are controlled to a predefined relationship.
2. The electrical splitter of claim 1 wherein the electrical parameter is one of voltage, current, power, impedance, frequency, or phase.
3. The electrical splitter of claim 1 wherein the balancing circuit is shunted between the first leg and the second leg and further comprises at least one of an inductor and a capacitor.
4. The electrical splitter of claim 3 wherein the inductor and capacitor are arranged in parallel.
5. The electrical splitter of claim 4 wherein at least one of the capacitor or inductor are variable and are controlled to vary the relationship between the first value and the second value.
6. The electrical splitter of claim 5 further comprising a controller configured to vary the at least one of the capacitor or inductor in order to vary the relationship between the first value and the second value.
7. The electrical splitter of claim 1 wherein the balancing circuit includes at least one component that is varied in order to adjust the relationship between the first value and the second value.
8. The electrical splitter of claim 1 further comprising a controller configured to vary the relationship in accordance with sense signals that vary in accordance with the first value and the second value, respectively.
9. The electrical splitter of claim 1 wherein the predefined relationship is determined in accordance with minimizing a difference between the first value and the second value in accordance with one of:
min
(
Δχ
j
)
=
ξ
-
(
α
1
χ
1
+
α
2
χ
2
+
⋯
a
K
χ
K
)
or
min
(
Δχ
j
)
=
∑
∀
i
≠
j
(
α
i
χ
i
-
α
j
χ
j
)
where:
i and j refer to one of K legs of the electrical splitter;
ξ is the electrical parameter;
α n is a coefficient corresponding to an i th leg; and
χ n is a sensed value of the electrical parameter corresponding to an n th leg.
10. The electrical splitter of claim 9 wherein a setpoint for the electrical parameter for a j th leg is determined in accordance with:
χ j ( n+ 1)=α j χ j ( n )
where:
α 1 is the coefficient corresponding to the j th leg, and
X j (n) is a sensed value of the electrical parameter corresponding to the j th leg during a n th iteration for a current setpoint.
11. The electrical splitter of claim 1 wherein at least one of the first leg and the second leg includes an isolation circuit to isolate the at least one of the first leg and the second leg from the other of the first leg and the second leg, and the isolation circuit includes at least one of an inductor and a capacitor.
12. The electrical splitter of claim 1 wherein the electrical splitter generates a third RF output to a third load, further comprising:
a third leg providing the third RF output to the third load; and
a second balancing circuit connected between a selected one of the first leg or the second leg and the third leg,
wherein the second balancing circuit varies a third value of the electrical parameter and the first value or the second value corresponding to the selected one of the first leg or the second leg, and
wherein the third value and the first value or the second value corresponding to the selected one of the first leg or the second leg are controlled to a second predefined relationship.
13. The electrical splitter of claim 12 further comprising:
a third balancing circuit connected between the other of the selected one of the first leg or the second leg and the third leg,
wherein the third balancing circuit varies the third value and an other of the first value or the second value corresponding to the other of the first leg or the second leg, and
wherein the third value and the other of the first value or the second value corresponding to the other of the selected one of the first leg or the second leg are controlled to a third predefined relationship.
14. The electrical splitter of claim 13 wherein the first, the second, and the third values are controlled to one of equal or different predefined relationships.
15. A RF system comprising:
a RF power source generating a RF signal;
a splitter receiving the RF signal and generating a first RF output and a second RF output to respective a first load and a second load, including:
a first leg providing the first RF output to the first load;
a second leg providing the second RF output to the second load;
a balancing circuit connected between the first leg and the second leg, the balancing circuit including at least one component, wherein the at least one component is variable to control a first value of an electrical parameter associated with one of the first leg or the second leg and a second value of the electrical parameter associated with an other of the first leg or the second leg; and
a controller configured to vary the least one component,
wherein the controller controls the at least one component so that the first value and the second value are controlled to a predefined relationship.
16. The RF system of claim 15 wherein the electrical parameter is one of voltage, current, power, impedance, frequency, or phase.
17. The RF system of claim 15 wherein the balancing circuit further comprises at least one of an inductor and a capacitor, and the controller is configured to vary the at least one of the inductor or capacitor to vary a relationship between the first value and the second value.
18. The RF system of claim 17 wherein the inductor and capacitor are arranged in one of a parallel connection or a series connection.
19. The RF system of claim 15 wherein the controller is configured to vary the predefined relationship in accordance with sense signals that vary in accordance with the first value and the second value, respectively.
20. The RF system of claim 15 wherein the predefined relationship is determined in accordance with minimizing a difference between the first value and the second value in accordance with one of:
min
(
Δχ
j
)
=
ξ
-
(
α
1
χ
1
+
α
2
χ
2
+
⋯
a
K
χ
K
)
or
min
(
Δχ
j
)
=
∑
∀
i
≠
j
(
α
i
χ
i
-
α
j
χ
j
)
where:
i and j refer to one of K legs of the splitter;
ξ is the electrical parameter;
α n is a coefficient corresponding to an i th leg; and
χ n is a sensed value of the electrical parameter corresponding to an n th leg.
21. The RF system of claim 20 wherein a setpoint for the electrical parameter for a j th leg is determined in accordance with:
χ j ( n+ 1)=α j χ j ( n )
where:
α 1 is the coefficient corresponding to the j th leg, and
X j (n) is a sensed value of the electrical parameter corresponding to the j th leg during a n th iteration for a current setpoint.
22. The RF system of claim 15 wherein at least one of the first leg and the second leg includes an isolation circuit to isolate the at least one of the first leg and the second leg from the other of the first leg and the second leg, and the isolation circuit includes at least one of an inductor and a capacitor.
23. The RF system of claim 15 wherein the splitter generates a third RF output to a third load, further comprising:
a third leg providing the third RF output to the third load; and
a second balancing circuit connected between a selected one of the first leg or the second leg and the third leg,
wherein the second balancing circuit varies a third value of the electrical parameter and the first value or the second value corresponding to the selected one of the first leg or the second leg, and
wherein the third value and the first value or the second value corresponding to the selected one of the first leg or the second leg are controlled to a second predefined relationship.
24. The RF system of claim 23 further comprising:
a third balancing circuit connected between the other of the selected one of the first leg or the second leg and the third leg,
wherein the third balancing circuit varies the third value and an other of the first value or the second value corresponding to the other of the first leg or the second leg, and
wherein the third value and the other of the first value or the second value corresponding to the other of the selected one of the first leg or the second leg are controlled to a third predefined relationship.
25. The RF system of claim 24 wherein the first, the second, and the third values are controlled to one of equal or different predefined relationships.
26. A balancing circuit of an electrical splitter receiving a RF output signal and generating a first RF output and a second RF output to respective a first load and a second load, wherein a first leg provides the first RF output to the first load and a second leg provides the second RF output to the second load, comprising at least one component connected between the first leg and the second leg, wherein the at least one component is variable to control a first value of an electrical parameter associated with one of the first leg or the second leg and a second value of the electrical parameter associated with an other of the first leg or the second, wherein the first value and the second value are controlled to a predefined relationship.
27. The balancing circuit of claim 26 wherein the electrical parameter is one of voltage, current, power, impedance, frequency, or phase.
28. The balancing circuit of claim 26 wherein the balancing circuit further comprises at least one of an inductor and a capacitor, and a respective least one of a inductance or a capacitance is controlled to vary a relationship between the first value and the second value.
29. The balancing circuit of claim 28 wherein the inductor and capacitor are arranged in one of a parallel connection or a series connection.
30. The balancing circuit of claim 26 wherein the at least inductance or capacitance varies the predefined relationship in accordance with sense signals that vary in accordance with the first value and the second value, respectively.
31. The balancing circuit of claim 26 wherein the predefined relationship is determined in accordance with minimizing a difference between the first value and the second value in accordance with one of:
min
(
Δχ
j
)
=
ξ
-
(
α
1
χ
1
+
α
2
χ
2
+
⋯
a
K
χ
K
)
or
min
(
Δχ
j
)
=
∑
∀
i
≠
j
(
α
i
χ
i
-
α
j
χ
j
)
where:
i and j refer to one of K legs of the splitter;
ξ is the electrical parameter;
α n is a coefficient corresponding to an i th leg; and
χ n is a sensed value of the electrical parameter corresponding to an n th leg.
32. The balancing circuit of claim 31 wherein a setpoint for the electrical parameter for a j th leg is determined in accordance with:
χ j ( n+ 1)=α j χ j ( n )
where:
α 1 is the coefficient corresponding to the j th leg, and
X j (n) is a sensed value of the electrical parameter corresponding to the j th leg during a n th iteration for a current setpoint.