Use our Helical Antenna Calculator to quickly determine key design parameters such as wavelength, circumference, pitch angle, total wire length, axial length, and gain in dBi. Essential for RF engineers, radio amateurs, and students designing axial-mode helical antennas for satellite communications, WiFi, or other directional applications. Input your desired frequency, helix dimensions, and number of turns to get instant results for efficient antenna optimization.
Formula:
The calculator uses the following formulas for axial-mode helical antennas, based on the input parameters:
- Wavelength (λ):
λ = c / f - Circumference (C):
C = π × D - Pitch Angle (α):
α = arctan(S / C) - Wire Length per Turn (Lturn):
Lturn = √(C2 + S2) - Total Wire Length (Lwire):
Lwire = N × Lturn - Total Axial Length (Laxial):
Laxial = N × S - Gain (GdBi):
GdBi = 11.8 + 10 × log10(C2 × N × S / λ3)(This formula is an approximation for well-designed axial mode helical antennas with C ≈ λ and S ≈ 0.25λ)
Where:
f: Operating Frequency (in Hz)D: Helix Diameter (in meters)S: Spacing between turns (in meters)N: Number of Turns (dimensionless)c: Speed of light (approx. 3 × 108 m/s)λ: Wavelength (in meters)C: Circumference of one turn (in meters)α: Pitch Angle (in degrees)Lturn: Wire Length per Turn (in meters)Lwire: Total Wire Length (in meters)Laxial: Total Axial Length (in meters)GdBi: Gain in dBi (decibels relative to an isotropic radiator)