Project detail
Automated Impedance Matcher
A precision automation tool designed to replace manual tuning in dynamic RF sputtering environments.
Embedded
4 months
CMU Hacker Fab
Overview
In RF sputtering, the chamber acts as a dynamic load with impedance that fluctuates throughout the process. Traditionally in a Hacker Fab, this requires an operator to stay glued to the machine, manually tuning variable capacitors to minimize reflected power (VSWR). This project automates that manual labor using a Teensy 4.1 microcontroller and a custom T-network. The system intercepting forward and reverse power signals to dynamically drive stepper motors, achieving a stabilized performance of ~1.2 VSWR without human intervention.
My Role
Reverse-engineered a COTS SW-112 VSWR meter to automate data acquisition by tapping into internal toroidal sensing lines.
Designed a custom PCB that integrates the Teensy 4.1, active cooling, and dedicated motor drivers to replace manual knob-turning with high-precision digital control.
Developed a buffered sensing pipeline using TLV2372IP op-amps to accurately digitize analog signals from high-impedance lines without causing voltage sag.
Implemented an electro-mechanical interface using 0.9 degree stepper motors, providing the high physical resolution and RF noise resistance required for precise capacitor tuning.
Authored a local GUI for an OLED screen and rotary encoder, allowing the operator to toggle between automated and manual modes while viewing real-time telemetry.
