Advanced Energy VarioMatch Match Network VM 1000 Platform, Руководство пользователя

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AE VarioMatch
TM
Match Network, VM 1000/1500 P l atform
L Match Topology
Figure 2-1 shows a basic L match network circuit.
50 Ohms
RF-Generator
Shunt (Load)
Capacitor
Series (Tune) Coil
Figure 2-2. L match network circuit
Load
Impedance
r
(Plasma)
3260
The L match network recei v ed its name because of the configuration of the capacitor
and coil used. The L match ne t work is simp l e, and requires only two tuning
e l ements - a series (or tune) coil and a shunt (or l oad) capacitor.
In practice a quality variable coil cannot be economically constructed because a
sliding tap to the coil cannot withstand a high RF current. The typical 5 A RF rating
for a highly variable coil isn't suitab l e for plasma loads with their high associated RF
currents.
As a result of these limitations, the traditional L match network is modified by the
installation of a variable capacitor connected in series with a fixed or tapped coil.
Figure 2-1 shows a t ypical V arioMatch L match network circuit.
50Ohms
RF-Generator
Load
Capacitor
Tune Capacitor
Figure 2-3.
VarioMatch L match network circuit
Load
Impedance
r
(Plasma)
3261
In princip l e, the L match ne t work is a good choice when the load impedance is not
known and must be determined by experimentation. If the ma t ch network uses
inductors and capacitors with very wide tuning range, nearly any impedance can be
properly matched.
The tune coil is connected in series with the wiring to the load. The inductance of the
wire connecting the match ne t work to the load must be considered to be a part of the
tune coil. Because of this, ensure that this wiring is as short as possible and low
inductance. Short connection leads will help to reduce EMI. The V arioMatch match
network must be well grounded to the load.
57020080-00D Product Overv i ew and Theory
2-5