Metering
Mobile application
Propagation of radio waves
Radio waves (RF stands for Radio Frequency) propagate in straight lines in several directions. The propagation speed of waves in a vacuum is 3.108 m/s.
In any other medium, the signal is weakened by
– reflection
– refraction
– diffraction
– absorption
Absorption of radio waves
When a radio wave encounters an obstacle, part of its energy is absorbed and transformed into energy, part continues to propagate in an attenuated manner and part may eventually be reflected.
Reflection of radio waves
When a radio wave encounters an obstacle, all or part of the wave is reflected, with a loss of power.
The reflection is such that the angle of incidence is equal to the angle of reflection.
Properties of media
| MATERIAL | ATTENUATION | EXAMPLES |
|---|---|---|
| Air | None | Open space, courtyard |
| Wood | Low | Door, floor, partition |
| Plastic | Low | Partition |
| Glass | Low | Non tinted glass |
| Verre teinté | Medium | Vitres teintées |
| Water | Medium | Aquarium, fountain |
| Living beings | Medium | Crowd, animals, humans, vegetation |
| Bricks | Medium | Walls |
| Plaster | Medium | Partitions |
| Ceramic | High | Tiles |
| Paper | High | Paper rolls |
| Concrete | High | Load-bearing walls, floors, pillars |
| Armoured glass | High | Bulletproof glass |
| Metal | Very high | Reinforced concrete, mirrors, metal cabinet, lift shaft |