Helical (Helix) Antenna
Frequency, f= Hz
Length, L= m
D= m
S= m
Turns=
Wire Length= m
Bandwidth= Hz
Gain= dB
Beamwidth= °

The (axial mode) helical antenna is an antenna for circular polarized radio waves. The antenna in the picture is left hand polarized and radiates to the right. Enter frequency and length and press Compute to calculate all other values. The feedpoint impedance is 140 ohms. Ideally the groundplane diameter should be slightly larger than half the wavelength.

© 2011 Tom Ahola