Near-Field Probe with Integrated LNA (MAX2611)

This project implements an active near-field probe with an integrated Low Noise Amplifier (LNA) for electromagnetic compatibility (EMC) diagnostics.
It is designed to improve sensitivity when measuring low-level emissions from circuits under test, enabling effective near-field scanning in the DC to 1.1 GHz range.

The active probe is based on the MAX2611 LNA, powered directly via USB Micro connector, and outputs through standard SMA connectors for seamless integration with spectrum analyzers.

🔑 Features

• Near-field probe optimized for EMC pre-compliance measurements.

• Integrated MAX2611 LNA:

  • Frequency range: DC – 1.1 GHz

  • Low noise figure for enhanced sensitivity

  • Broadband linear gain suitable for EMC diagnostics

• USB-powered:

  • Micro-USB input for easy powering from spectrum analyzers or USB power sources

  • Eliminates the need for external bias-T or dedicated LNA supply

• SMA connectors for robust and standard RF interface.

• Transmission line and impedance simulation performed with uSimmics EM software for probe geometry optimization.

📂 Repository structure

• /schematic/ → Circuit schematic files.

• /pcb/ → PCB layout and Gerber files for manufacturing.

• /doc/ → Simulation results, EMC measurement notes, and technical references.

• /img/ → PCB renders, probe photos, and measurement setups.

🔧 Typical applications

• EMC debugging and diagnostics.

• PCB and IC near-field emission scanning.

• Pre-compliance testing in the lab environment.

• RF design verification and troubleshooting.

📑 References

• MAX2611 Datasheet (Analog Devices)

• uSimmics EM Simulation Software

• Practical Guide to Near-Field Probing for EMC

📸 Project preview

(Insert here PCB renders, photos of the probe, and simulation plots of the transmission line and impedance)

⚖️ License

This project is released under the MIT License.
You are free to use, modify, and distribute it, provided that proper credit is given.