mmWave Presence Sensor (24/60GHz, Zigbee / Tuya)

mmWave (millimetre-wave radar) presence sensors detect a stationary person — someone sitting still or sleeping — where a PIR sensor sees nothing. That makes them the upgrade for lighting and occupancy automation in Gulf majlis rooms and offices where people sit motionless. Because the sensor contains a radar transmitter, it needs CST radio type approval for the Saudi market, on top of SASO safety conformity. This page covers 24/60GHz presence sensors sourced from China for KSA.

mmWave vs PIR — why it matters

A PIR sensor detects movement via infrared change; it loses a person who stops moving. mmWave radar detects presence — including micro-motion like breathing — so lights stay on while someone sits still. Two engineering variables decide quality:

• 24GHz vs 60GHz. 60GHz offers finer resolution and smaller zones (good for desk-level presence); 24GHz has longer range and lower cost. Match to the room.
• Zone configuration and false triggers. Radar can trigger on ceiling fans, curtains moving in AC airflow, or an adjacent room through a thin wall. Insist on configurable detection zones and a sensitivity calibration step. Ask for the detection pattern at your mounting height.

The action item: bench-test the exact sensor in a room with AC airflow before committing — radar false-trigger behaviour is environment-specific and not visible on a datasheet.

Power and protocol

mmWave radar draws too much for a coin cell, so these are USB-C / DC powered (continuous), not battery. That removes the UN 38.3 battery requirement but means installation needs power at the mounting point. Zigbee 3.0 binds to a local hub; Tuya Wi-Fi runs through the Tuya app with Arabic support (Tuya reference).

Saudi / GCC market notes

• Wireless approval: the radar radio needs CST type approval — non-negotiable.
• Mains/USB: USB-C 5V; the adapter (if bundled) follows SASO 2203 and the USB-C mandate.
• Safety: IEC 62368; factory supplies the accredited report.
• Documentation: Arabic manual and label.

For the full category walkthrough see sourcing smart home devices for Saudi Arabia. CST documentation and false-trigger behaviour are checked at pre-shipment inspection; for branded programs see private label & OEM management and the smart home overview.