Non-Linear Junction Detector

What it is — a handheld or portable counter‑surveillance instrument that detects semiconductor junctions in electronic components by probing with RF and listening for nonlinear harmonic responses.

How it works — it transmits a probe signal (commonly GHz band) and detects 2nd/3rd harmonic returns produced by p‑n junctions, indicating hidden electronics even if the device is powered off.

Key capabilities — can locate concealed circuit boards, transmitters, SIMs or micro‑bugs through non‑metal barriers (walls, furniture, luggage) and during TSCM sweeps.

Important specs — sensitivity (dBm), harmonic coverage (2nd/3rd), probe power control, antenna type (circular/polarised) and optional extension‑pole/visual logging improve effectiveness.

Primary uses — technical surveillance counter‑measures (TSCM), secure facility sweeps, vehicle/parcel inspections, forensic searches, and EOD/IED screening support.

Limits & cautions — subject to false positives (corroded metals, certain alloys), requires skilled operators to interpret results, and emissions/regulatory rules must be checked before use.