FieldengRF, Radio & Wireless
Antenna Electrical Length
Starting length for a quarter-wave or half-wave element. Not a final cut length.
RF, Radio & WirelessNetworking & Communications
Starting length for a quarter-wave or half-wave element. Not a final cut length.
App id: RF-15. 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
L = VF × (c / f) × fractionInputs
| Name | Unit |
|---|---|
| Frequency | MHz |
| Element fraction (0.25 = λ/4, 0.5 = λ/2) | fraction |
| Velocity factor (optional) | fraction |
Outputs
| Name | Unit |
|---|---|
| Estimated physical length (hero result) | m |
| Free-space electrical length | m |
Diagnose
This tool does not attach diagnose observations.
Assumptions
- Starting dimensions only. Diameter, end effect, ground, loading, and nearby objects change resonance.
- Leave velocity factor blank for 1.0 (free space).
Provenance
- Wavelength from FUND-01. Physical length ≈ VF × electrical length.