Design Antenna Geometry
1 hourCalculate dipole or vertical element lengths for target frequency and environment.
Field context
This workflow is part of 4 niche fields
Complete guide for antenna building — step-by-step workflow, tools, checklist, and expert tips to get started.
Calculate dipole or vertical element lengths for target frequency and environment.
Model feedpoint impedance and select matching network or balun approach.
Assemble elements, install insulators, and raise antenna with safe clearance.
Trim or adjust matching until SWR meets target across operating bandwidth.
Compare predicted gain and take field strength notes on first contacts.
Calculate dipole and quarter-wave element lengths for target band.
Verify SWR after trimming and matching adjustments.
Cross-check element lengths for multiple band designs.
Design L-network or stub match for feedpoint mismatch.
Compare predicted antenna gain vs reference dipole.
Common approximations for wire dipoles in free space vs with ground effects.
| Design | Formula (ft) | Notes |
|---|---|---|
| Half-wave dipole | 468 / f(MHz) | Trim 2–5% for ground |
| Quarter-wave vertical | 234 / f(MHz) | Add radials for low angle |
| 5/8 vertical | 585 / f(MHz) | Needs matching coil |
Duplicate a proven dipole — field swaps are faster than on-site tuning.
Stronger than pure copper for tree-mounted dipoles.
Antenna work is a leading cause of amateur radio fatalities — stay far from energized lines.