Gamma Topology; Table 2-2. Load Capacitor Capacity By Load - Advanced Energy VarioMatch Match Network VM 1000 Platform User Manual

Advanced Energy ®
The major practical problem of the L match network is the need for very large tuning
capacitors when matching low impedances - a
chambers. The following table provides an idea of the load capacitor's capacity. The
load capacitor must provide for different load resistances:
Load capacitor capacity by load
Table 2-2.
R1oad
0.5 Q
l . 0 Q
2.0 Q
3.0 Q
4.0 Q
5.0 Q
6.0 Q
7.0 Q
8.0 Q
At load resistances lower than 3 Q a capacity of larger than 900 pF is required.
The V arioMatch match network uses a load coil to extend the capacitance range of the
load capacitor
information, see

Gamma Topology

In addition to the L match topology, AE produces match networks that use the Gamma
topology. Gamma topology matches allow loads of very low impedances to be
matched. This can be advantageous for ICP loads.
Some VarioMatch match network ICP units can be operated in two different
configurations, which allow two different load impedance ranges. Other VarioMatch
match networks use only Gamma topology. See
2-6
Load capacitor
2335 pF
1640 pF
1150 pF
929 pF
796 pF
704 pF
635 pF
581 pF
537 pF
without the negative side effects described above. For more
"Set Up the Match for Your Load" on page
Product Overview and T heory
typical situation with plasma
5-16.
Chapter 3, "Specifications".
57020080-00D