Helical antenna calculator
This calculator allows you to determine the main parameters of a helical antenna from the wavelength, the number of turns (N) and the spacing between the turns (S, in wavelengths). It provides essential results such as gain, diameter, half-power beamwidth (HPBW), first zero lobe width and effective antenna aperture.
Formulas
D = λ / 3.14
Circumference (m) = π × D
Cλ = (π × D) / λ
HPBW = 52 / ( Cλ × √(N × S) )
First zero lobe = 115 / ( Cλ × √(N × S) )
Gain (dB) = 10.8 + 10 × log10(N × S)
Effective aperture Ae = ( linear G × λ²) / (4 × π)
Explanation of formulas
The equations use the wavelength and geometry of the antenna to determine its directional behavior and efficiency. The diameter sets the circumference, which directly affects beam width and gain. A higher number of turns or wider spacing improves gain and reduces beamwidth, making the antenna more directional.
Uses of the calculator
- Design of helical antennas for satellite or amateur radio applications.
- Optimization of gain and radiation pattern.
- Useful for RF engineers, antenna designers and telecommunications students.
- Allows you to quickly check the dimensions of an antenna before manufacturing.