Microwave motion sensor (doppler radar module)
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|---|---|
| Frequencies | 5820 MHz,5840 MHz |
| Frequency Range | 5820 MHz - 5840 MHz |
| Mode | CW, RAW |
| Modulation | CW doppler |
| ACF | — |
| Emission Designator | — |
| Bandwidth | 100 Hz |
| Location | Worldwide |
| Short Description | Microwave motion sensor uses a small Doppler radar module to detect movement. The sensor emits microwave signals and monitors the reflected waves. |
| I/Q Raw Recording | Download file |
| Audio Sample | |
A e.g. luminaire equipped with a microwave motion sensor uses a small Doppler radar module to detect movement. The sensor emits low‑power microwave signals and monitors the reflected waves. When motion causes a Doppler shift, the sensor triggers the light to switch on or adjust brightness. This makes the fixture highly sensitive, capable of detecting motion even through thin materials like glass or plastic.
Most commercial microwave motion sensors use Continuous‑Wave Doppler Modulation. The sensor transmits a continuous unmodulated carrier at around 5.8 GHzGigaHertz (GHz) 10^9 Hz. Motion is detected by analyzing the frequency shift in the reflected signal. The output is a low‑frequency Doppler signal proportional to movement speed.
Some modules use FMCW or FSKFrequency-Shift Keying variants, but only in more advanced presence‑detection sensors. Standard lighting sensors are almost always CWContinuous Wave.
The RFRadio Frequency bandwidth of the transmitted signal is very narrow, usually a few MHzMegaHertz (MHz) 10^6 Hz or less. Many modules specify 1–20 MHzMegaHertz (MHz) 10^6 Hz occupied bandwidth. The Doppler output (baseband) is only tens to hundreds of HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., depending on motion speed.
