Yagi-Uda Antenna Designer

Design Yagi-Uda antennas using the DL6WU method. Generates element lengths and spacings.

What is a Yagi antenna?

A Yagi antenna is a directional flashlight for RF — it focuses energy in one direction using a row of metal rods. One rod transmits or receives (the driven element), one reflects energy forward (the reflector), and the rest (directors) focus the beam. More rods = narrower, more focused beam.

Why it matters: Those old rooftop TV antennas are Yagis. Ham radio operators still build them to reach distant stations, and they're used in point-to-point WiFi links between buildings.

Design Parameters
Enter operating frequency and physical constraints.

The frequency you want the antenna to work at. 144 MHz = 2-meter ham band.

Includes 1 reflector + 1 driven element + directors. More elements = higher gain but longer antenna.

The metal tube the elements are mounted on. Wider boom slightly shortens the effective element lengths.

Performance Summary
Estimated Gain
12.1 dBi
Est. F/B Ratio
≥ 18 dB
Boom Length
2.917 m
Boom Length
114.83 in
Wavelength (λ)
2083.3 mm
Total Elements
7

Element Table
7-element Yagi at 144 MHz — lengths and positions from reflector.
#ElementLength (mm)Length (in)Position (mm)Position (in)
1
Reflectorrefl.
1018.840.1080.00.000
2
Drivendriven
984.238.748416.716.404
3
Director 1
935.236.821833.332.808
4
Director 2
929.036.5751302.151.263
5
Director 3
922.736.3291812.571.358
6
Director 4
916.536.0832354.292.684
7
Director 5
912.335.9192916.7114.829

DL6WU method gives good starting dimensions. Final optimization with NEC2 or similar electromagnetic simulation software is recommended for best performance. Element lengths assume round conductor diameter ≈ 0.01λ. Adjust as needed.