UWB
Understanding UWB
UWB takes the opposite approach from narrowband communications: instead of concentrating power in a narrow channel, UWB spreads a very small amount of power over a very wide bandwidth. This makes UWB signals appear as noise to narrowband receivers, enabling spectrum overlay with existing services.
| Version | Data Rate | Range | Key Feature |
|---|---|---|---|
| BT 4.0 (BLE) | 1 Mbps | 50 m | Low Energy intro |
| BT 5.0 | 2 Mbps | 200 m | 4x range, 2x speed |
| BT 5.2 | 2 Mbps | 200 m | LE Audio, LC3 codec |
| BT 5.4 | 2 Mbps | 200 m | PAwR, ESL support |
UWB Characteristics
- Bandwidth: > 500 MHz (typically 500 MHz channels within 3.1-10.6 GHz).
- Power: Very low (-41.3 dBm/MHz, FCC limit). Total power below noise floor of many receivers.
- Range: Typically 10-30 meters indoors.
- Positioning accuracy: 10 cm or better using time-of-flight ranging.
UWB Applications
- Precise ranging: Time-of-flight between UWB devices measures distance to ~10 cm. Apple AirTag, digital car keys.
- Indoor positioning: Triangulate position from multiple UWB anchors. Warehouse, factory, hospital tracking.
- Radar imaging: Through-wall radar, ground-penetrating radar using UWB pulses.
Frequently Asked Questions
What is UWB?
UWB uses very wide bandwidth (>500 MHz) at very low power for precise ranging (10 cm accuracy), indoor positioning, and short-range communications. It operates at 3.1-10.6 GHz and is integrated into modern smartphones for spatial awareness.
How does UWB positioning work?
UWB measures the time-of-flight of very short pulses between devices. With 500 MHz bandwidth, time resolution is 2 ns = 60 cm path difference. Advanced processing achieves 10 cm accuracy. Multiple anchors triangulate 3D position.
How is UWB different from Bluetooth?
UWB provides centimeter-level ranging accuracy (vs meters for Bluetooth RSSI). UWB uses much wider bandwidth (500 MHz vs 2 MHz), much lower power per MHz, and direct time-of-flight measurement. UWB is for precision location; Bluetooth is for connectivity.