Non-Linear Junction Detector (NLJD)

Purpose & Function — NLJDs detect electronic components (semiconductors) hidden in devices, furniture, or vehicles by identifying nonlinear junctions, even if the target device is powered off.

How It Works — emits a high‑frequency RF signal and measures harmonics (2nd and 3rd) generated by semiconductor junctions, indicating the presence of electronic circuits.

Key Features — adjustable probe power, dual‑harmonic detection, circularly‑polarized antennas, telescopic poles for ceilings/walls, and visual/audio indicators for precise localization.

Applications — technical surveillance countermeasures (TSCM), corporate and government facility sweeps, vehicle inspections, forensic analysis, and detection of hidden transmitters or bugs.

Advantages — can detect electronics through non-metal barriers, works passively on powered‑off devices, and allows covert inspections without alerting targets.

Considerations — operator training is critical, false positives may occur from metallic objects, and local regulations regarding RF emissions must be followed.