1 GHz Active Oscilloscope Probe

Overview

This project involved designing and building a high-bandwidth active oscilloscope probe capable of measuring signals up to 1 GHz. The probe uses an op-amp based amplifier topology with carefully tuned compensation networks to achieve flat frequency response across the entire bandwidth.

Challenges

• Achieving flat frequency response from DC to 1 GHz required careful compensation network design
• Minimizing input capacitance while maintaining high input impedance
• Controlled impedance PCB routing to prevent reflections and signal degradation
• Managing power supply decoupling at high frequencies

Results

• Achieved -3dB bandwidth of 1.1 GHz
• Input impedance of 1 MΩ || 1 pF
• 10:1 attenuation ratio with < 1% DC accuracy
• Rise time under 350 ps