Variable-Gain Plasma Diagnostic Circuit for Wide Ion Current Ranges

The patent implements a variable amplification unit with multiple gain stages (first gain stage with gain1, second gain stage with gain2) that can dynamically adjust the amplification factor based on plasma conditions. The selection controller switches between different gain combinations (e.g., gain1 only, gain2 only, or gain1+gain2) to match the measurable ion current range to the actual plasma state, thereby maintaining diagnostic accuracy across varying plasma conditions without requiring physical circuit reconfiguration.

The patent changes the electrical parameter (amplification factor) of the diagnostic circuit by selecting different gain stages in the variable amplification unit. Instead of changing physical circuit configuration, the system adjusts the amplification parameter software-controlled, allowing the same hardware to accurately measure ion current across a wide range of plasma states by simply changing the gain parameter.

The patent makes the single plasma diagnostic circuit universal by equipping it with a variable amplification unit that can handle multiple plasma states. The selection controller automatically selects appropriate gain stages based on real-time plasma conditions, allowing one circuit to perform the function of multiple specialized circuits would otherwise be needed, thereby eliminating the need for physical probe or circuit changes and improving operational efficiency.

The system employs feedback control where the selection controller monitors plasma conditions and automatically adjusts the amplification factor by selecting appropriate gain stages. This closed-loop approach ensures diagnostic accuracy is maintained across varying plasma states without manual intervention or physical reconfiguration, significantly improving operational efficiency compared to existing circuits that require manual probe or circuit changes.

The patent segments the amplification function into multiple independent gain stages (first gain stage with gain1, second gain stage with gain2). Each stage can be independently controlled and switched, allowing flexible combination of gains to match different plasma conditions. This segmentation enables the amplification unit to adapt to various plasma states while keeping each individual gain stage relatively simple in design.

The patent transforms the static amplification factor into a dynamic parameter through the variable amplification unit with multiple switchable gain stages. The selection controller dynamically adjusts which gain stages are active based on real-time plasma conditions, enabling the circuit to adapt to various plasma states without requiring complex reconfiguration of the underlying amplifier architecture.