TECHNIQUE

Automatic Matching Networks

Introduction to adaptation networks In every plasma treatment system, the adaptation network constitutes a critical component. The adaptation network’s purpose is to transform the complex (*) and variable impedance in keeping with the process conditions, in a purely resistive impedance, with a 50 ohm fixed value necessary for the correct operation of the coaxial transmission line and the RF generator.
GK’s two-decade experience in low-pressure plasma systems has made possible the implementation of a family of flexible and reliable automatic matching networks. Tuners AM1 and AM2 present the same L-circuit configuration, the same general dimensions and the same interfaces, but they are diversified for the different voltage and current ratings. The AM1 model powers loads of up to 15Amp and 2500V AC+DC and deploys variable air-capacitors.

*(in other words, made up by a resistive component, and therefore dissipative, and by a reactive component that must be "cancelled").

Characteristics and advantages

• Preset on variable capacitors.
• Independent management of phase and amplitude channels
• Stability of the adjustment loop on difficult loads
• Reduced matching times, typically <2 sec
• 24Vdc, max 500ma power supply
• Standard interfacing with PLC with 10V analogue levels and 24V commands
• N input connector and 7/16 output (only mod. GGK-AM1)
• Front control panel with diagnostic LEDs and alodyne-treated aluminium case, completely screened.
• Main inductor, pre-set with 4 intermediate plugs for a speedy configuration, and arranged for 3-pad capacitor
• Circuit involved by the high frequency signal, made out of silvered copper
• Possibility of limiting at will the variable capacitors useful excursion

Specifications only for AM1

• Maximum output voltage 2500V AC+DC
• Maximum output current 15Amp RF, N female input connector, 7/16 output
• 1000 Watt end of scale detector, minimum power to tune 25Watt

 

Interface board GGK-CS14

The interface board GGK-CS14 has the task to put in communication the Gambetti's automatic matching network AM1 with the Advanced Energy’s  CESAR ® platforms.
The board provides to the AM1 the necessary tools to interpret the command signals of  the CESAR ® platforms, in a transparently way to the end user.
Thanks to this it is possible to control the AM1 directly from the generator, enabling the operator to manually adjust, directly from the generator panel, the capacitor’s positions of the AM1.
In addition, it becomes possible to use the presets provided by the generators, thereby taking advantage of the automatisms already present in the CESAR ® platforms.
The card is designed to be mounted directly on the body of the AM1, it does not require any kind of maintenance and training costs.

We can realize this kind of interface cards, including other brands of 13.56 MHz RF power supply with power up to 600 W.
For more information, write to sales@gambetti.it, or phone +39 02 90093082