The Helical Antenna Design conversion calculator helps determine the main design parameters of a helical antenna, including gain, diameter, beamwidth, and effective aperture, based on the wavelength, number of turns, and spacing between turns. It provides key values for engineers working on antennas used in satellite, space communication, and RF systems that need circular polarization and wide bandwidth.
Formulas
Diameter (D) = λ / 3.14
Circumference (meters) = π * D
Cλ = (π * D) / λ
HPBW = 52 / ( Cλ * √(N * S) )
First Null = 115 / ( Cλ * √(N * S) )
Gain (dB) = 10.8 + 10 * log10(N * S)
Effective Aperture (Ae) = (G_linear * λ²) / (4 * π)
Formula Explanation
- λ is the operating wavelength of the antenna.
- N is the number of turns of the helix.
- S is the spacing between turns, measured in wavelengths.
- Cλ represents the normalized circumference, which affects beamwidth and radiation pattern.
- HPBW and First Null define the antenna’s directional characteristics.
- Gain measures antenna directivity and efficiency, while the effective aperture represents its receiving area.
Uses of this calculator
- Designing helical antennas for satellite and space communication.
- Estimating gain and beamwidth for given antenna parameters.
- Optimizing number of turns and spacing to achieve desired performance.
- Calculating aperture and effective area for power reception analysis.
What is the gain and beamwidth of a 10-turn helical antenna with 0.25λ spacing?
Input: N = 10 turns, S = 0.25λ, λ = 0.1 m
Output:
- D = 0.1 / 3.14 = 0.0318 m (3.18 cm)
- Cλ = (π * 0.0318) / 0.1 = 1
- HPBW = 52 / (1 * √(10 * 0.25)) = 52 / 1.58 = 32.9°
- First Null = 115 / 1.58 = 72.8°
- Gain = 10.8 + 10 * log10(10 * 0.25) = 10.8 + 10 * log10(2.5) = 10.8 + 3.98 = 14.78 dB
- Effective Aperture (Ae) = (10^(14.78/10) * 0.1²) / (4 * π) = (30.1 * 0.01) / 12.57 = 0.0239 m²