Radio environment
How radio waves travel between the boards in the World: free space (Friis), a ground reflection (two rays, the far-away loss grows with the 4th power of distance) or indoors (log-distance exponent). Optional fading and shadowing, seeded so a run can be repeated. Applies to every far-field radio of the document (SX1280, Wi-Fi). Without this part the World is free space.
Key data
- Category
- Radio
- Simulation model
- Behavioural mixed-signal model
- Reference prefix
- ENV
- Pins
- 0
Simulation model
A behavioural model implements the interface of the chip (registers, protocol, timing) at its pins. The pins are connected to the analog circuit like CMOS pins.
- Model
- rf_environment
- Supply pins
- /
Pins 0
| Pin | Name | Use |
|---|
Parameters 9
modeln2 = free space, 3 = office (ITU-R P.1238), 4–6 = through walls
floorTwo-ray model: the ground that reflects lies this far below the World floor (e.g. 1 m for a table). Low antennas lose a lot of range.
epsMedium dry ground ≈ 15, wet ground ≈ 30, sea water ≈ 70
sigmafadingKPower of the direct path over the scattered paths. Open field 10 dB or more, indoors 0–6 dB.
shadowSlow, log-normal variation from obstacles; indoors 3–6 dB
seedPCB
No land pattern: the part is not placed on the board.