Helical Antenna Design Calculator

Helical Antenna

Helical antennas are one of the easiest to design in antenna. The conductor width isn’t of great importance in the design. The greater the number of turns the greater the directivity or antenna gain. But make sure to keep the winding on both receiving and transmitting antennas in the same direction, since the wave is polarized.

Understanding Helical Antenna Design:

“A helical antenna, characterized by its conducting wire wound in a spiral shape, finds extensive application in high-frequency operations. The polarization characteristics of this antenna are contingent upon factors including diameter, turns count, excitation, spacing between loops, pitch, and wavelength.”

Design Considerations:

Diameter: The size of the helix influences both the impedance and radiation pattern of the antenna. A greater diameter leads to reduced impedance and a broader radiation pattern.

Number of Turns: The quantity of coils impacts both the frequency spectrum and the emission configuration of the antenna. Increasing the number of coils broadens the frequency spectrum while narrowing the radiation pattern.

Excitation: The stimulation of the helix impacts both the radiation pattern and polarization of the antenna. This stimulation can occur in either an axial or normal manner.

Space between Helical Loops: Varying the distance between the helical loops influences both the radiation pattern and the impedance of the antenna. Reducing this space leads to a more focused radiation pattern and an increased impedance.

Pitch: The helix’s pitch influences both the frequency range and radiation pattern of the antenna. A greater pitch widens the frequency range while narrowing the radiation pattern.

Wavelength: The antenna’s wavelength influences both its radiation pattern and impedance. A greater wavelength leads to a broader radiation pattern and reduced impedance.

Types of Helical Antennas:

Normal Mode Helical Antenna: “This helical antenna configuration is typically excited conventionally and finds application in emitting circularly polarized radiation.”

Axial Mode Helical Antenna: This variant of helical antenna is stimulated axially and serves for emitting linearly polarized waves.

Advantages:

Wide Bandwidth: Helical antennas possess a broad frequency range, rendering them applicable across diverse usage scenarios.

High Gain: Helical antennas possess significant gain, rendering them appropriate for applications necessitating a robust signal-to-noise ratio.

Circular Polarization: Helical antennas have the capability to generate circularly polarized radiation, rendering them apt for applications necessitating circular polarization.

Applications:

Satellite Communications: Helical antennas find application in satellite communications for both signal reception and transmission purposes.

Radar Systems: Helical antennas find application in radar systems to detect and monitor targets.

Wireless Communication Systems: Helical antennas find application in wireless communication setups for both signal transmission and reception purposes.

Conclusion:

“To outline, the design process of helical antennas encompasses several elements including diameter, turn count, excitation, spacing between loops, pitch, and wavelength. These design parameters significantly influence the antenna’s radiation pattern, impedance, and polarization. Helical antennas offer broad bandwidth, high gain, and versatility in producing circularly polarized radiation, rendering them applicable across diverse fields.”

This online calculator helps you calculate Antenna Gain, Impedance, Diameter, Space between coils, Length of wire, Half Power Beam Width, Beam Width First Nulls, and Aperture.

Select M or MHz
Wavelength
M
Frequency
MHz
Number of Turns
Space between coils
wavelength

Formula

\[Antenna\; Gain (G)= 10.8 + 10*log10 \left(\left(\frac{C}{lambda}\right)^2 * N * \left(\frac{S}{lambda}\right)\right)\]
\[Characteristic\; Impedance (Z) = \frac{150}{\sqrt{\frac{C}{lambda}}} \]
\[Diameter (D) = \frac {lambda}{pi}\]
\[Spacing\;Between\;Coils (S) = \frac {C}{4}\]
\[Length\;Of\;Wire (L) =N * \sqrt{lambda^2 + S ^2}\]
\[HPBW = \frac{52}{\left( \left( \frac{C}{lambda}\right) * \sqrt{N * \left( \frac{S}{lambda}\right)} \right)}\]
\[BPFN = \frac{115}{\left( \left( \frac{C}{lambda}\right) * \sqrt{N * \left( \frac{S}{lambda}\right)} \right)}\]
\[Effective\;Aperature\;(Ae) = \frac{D * lambda^2}{4 * pi} \]

where :

  • G = Antenna Gain
  • Z = Characteristic Impedance
  • D = Diameter
  • S = Spacing between coils
  • L = Length of wire
  • HPBW = Half power beam width
  • BWFN = Beam width first nulls
  • Ae = effective Aperture
  • C = Circumference of a turn on the helix antenna 

Any questions? Drop them here!