Advanced Energy Industries, Inc.

Other

Christopher C Mason

Thomas Joel Blackburn

James Alan Edwards

George A Swift

An impedance matching network having a plurality of reactance elements is disclosed. Each of the plurality of switching circuits comprises a first node and a second node; a first diode having an anode coupled to the first node and a cathode coupled to the second node; a second diode having an anode to couple to the second voltage line and a cathode to couple to the first node; and a transistor having a first, second, and control terminals. Each of the plurality of reactance elements is switched into the impedance matching network when the transistor in the respective one of the plurality of switching circuits is on and switched out after the transistor in the respective one of the plurality of switching circuits is off.

Impedance matching network with high frequency switching

In accordance with this invention the above and other problems are solved by a switching apparatus and method that uses a switching circuit having a pair of parallel solid-state diodes (e.g., PN or PIN diodes), one of which is connected to a transistor (e.g., power MOSFET or IGBT), to switch a capacitor (or reactance element) in or out of a variable capacitance element (or variable reactance element) of an impedance matching network. Charging a body capacitance of the transistor reverse biases one of the two diodes so as to isolate the transistor from the RF signal enabling a low-cost high capacitance transistor to be used. Multiple such switching circuits and capacitors (or reactance elements) are connected in parallel to provide variable impedance for the purpose of impedance matching.

High frequency solid state switching for impedance matching

In accordance with this invention the above and other problems are solved by a switching apparatus and method that uses a switching circuit having a pair of parallel solid-state diodes (e.g., PN diodes), one of which is connected to a transistor (e.g., power MOSFET or IGBT), to switch a capacitor in or out of a variable capacitance element of an impedance matching network. Charging a body capacitance of the transistor reverse biases one of the two diodes so as to isolate the transistor from the RF signal enabling a low-cost high capacitance transistor to be used. Multiple such switching circuits and capacitors are connected in parallel to provide variable impedance for the purpose of impedance matching.

There is provided a secondary reactive termination circuit connected between the output of the RF power generator and the input of the plasma chamber to allow the tight regulation or limiting of the voltage and current components of the secondary frequencies within the process plasma. The secondary reactive circuit controls the impedance of the match network designed primarily to operate at the fundamental frequency of the RF power generator as seen by secondary frequencies in the system. Power delivery components are measured at the connection point of the termination circuit and used as feedback signals to control variable values of the termination circuit components.

Termination of secondary frequencies in RF power delivery

There is provided a secondary reactive termination circuit connected between the output of the RF power generator and the input of the plasma chamber to allow the tight regulation or limiting of the voltage and current components of the secondary frequencies within the process plasma. The secondary reactive circuit controls the impedance of the match network designed primarily to operate at the fundamental frequency of the RF power generator as seen by secondary frequencies in the system. A variable capacitor gives the operator the advantage of being able to tightly regulate the voltage, current, and power within a process at discrete frequencies without concern for impedance variability induced by other components in the system.

Impedance matching network with termination of secondary RF frequencies

Emergency deceleration warning devices which may also be manually activated to provide a warning in situations where abnormal deceleration is not involved. The disclosed devices are self-contained units which include: (1) a flasher which is highly visible, even in bright daylight; (2) a circuit for turning the flasher on and off; and (3) a simple, enclosed decelerometer for enabling the flasher-operating circuit when a vehicle equipped with the warning device is decelerated at an abnormal rate.

Growing community of inventors

Fort Collins, CO, United States of America

Christopher C Mason