FieldengRF, Radio & Wireless
Fresnel Zone
First Fresnel-zone radius along a straight-line path. Does not analyse terrain.
RF, Radio & WirelessNetworking & Communications
First Fresnel-zone radius along a straight-line path. Does not analyse terrain.
App id: RF-08. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
r = √(λ d1 d2 / (d1 + d2))Inputs
| Name | Unit |
|---|---|
| Frequency | MHz |
| Total path | km |
| Distance from A | km |
| Clearance (optional) | % |
Outputs
| Name | Unit |
|---|---|
| First-zone radius (hero result) | m |
| Clearance radius | m |
Diagnose
This tool does not attach diagnose observations.
Assumptions
- Straight-line geometry. Leave clearance blank for 100% of the first-zone radius.
- Does not determine whether terrain intersects the zone.
Provenance
- First Fresnel zone. 60% clearance is a common planning rule, not a guarantee.