Dipole Designer
Mount elements 180° apart for a 73Ω match.
The half-wave dipole is the “gold standard” reference antenna. It consists of two poles of equal length, totaling approximately half the wavelength (λ/2) of the target frequency.
The Calculation Formula:
Velocity Factor (k): This calculator assumes a standard value of 0.95. If you are using very thick wire or if the antenna is inside a plastic enclosure, the antenna might need to be slightly shorter (k=0.92).
Mounting: A dipole is balanced. If you are connecting it to an unbalanced coaxial cable, you should ideally use a 1:1 Balun at the feed point to prevent the cable shield from becoming part of the antenna.
Tuning: Always cut your wire a few centimeters longer than the calculation. It is much easier to trim a wire to find the perfect SWR (Standing Wave Ratio) than it is to add length back!
The physical length of an antenna in a vacuum is L=fc. However, because radio waves travel slower in wire than in a vacuum, we use a “velocity factor” (k≈0.95).