To calculate the length of a helical antenna, multiply the circumference of the helix by the wavelength of the signal. Divide the result by 4 times π. What is a Helical Antenna? This is the vertical spacing between the turns of the helix expressed in wavelengths and millimeters respecitvely. For example, assuming a wavelength of 100 mm and S λ of 0.1, the real turn spacing S would end up being 10 mm. Usually a turn spacing of 0.2 - 0.25 is recommended, though spacings as low as 0.1 are used in practice (for example most of my dish feeds use 0.14, while I have seen commercial Inmarsat antennas use around 0.1). When a lower spacing is used, the number of turns has to be increased accordingly to obtain the same gain and beamwidth. Number of turns (n) Continuing on the topic of polarization, one property of circularly polarized radio waves is that the polarization inverts when reflecting off a surface. This also includes the reflector of a dish antenna. This tells you which diameter to aim for when selecting your conductor to make the helix. As has been proven by many people though, it is not a critical design restriction, especially when using conductor thinner than recommended. Reflector diameter (R min and R max) Helix Length Calculators can be useful in a variety of applications, such as in engineering, architecture, and design. For example, a Helix Length Calculator can be used to determine the length of a spiral staircase or the length of a spring for a particular application.

This is an estimation of how much conductor (wire, tubing, ...) you will need to wind the helix. Once again, this does not consider things like impedance matching or build imperfections, so always leave yourself some extra length if you are cutting it beforehand. Ideal diameter of helix conductor (d) Predicted total height of the helix. This does not include things like the reflector plate or the connector that increase the total height, or impedance matching which can decrease the height. Pitch angle (α) The field of geometry, particularly the study of curves and surfaces, has been shaped by many notable individuals. The Greek mathematician Euclid, known as the father of geometry, laid much of the groundwork. Later, the contributions of mathematicians like Carl Friedrich Gauss in differential geometry and Pierre-Simon Laplace in mathematical physics have significantly influenced our understanding of geometric structures like the helix curve. Interesting Facts The mathematical representation of a helix curve cannot be attributed to a single individual. It is a cumulative effort by many mathematicians and scientists across centuries. However, the concept of parametric equations, which is central to defining a helix curve, was introduced by mathematicians such as Carl Friedrich Gauss and Pierre-Simon Laplace in the 18th and 19th centuries. Real Life Application Self-explanatory; F defines the frequency in MHz that the helix should operate at. At lower frequencies (below ~500 MHz), antennas such as the cross-dipole/cross-yagi are usually preferred for circular polarization due to the large scale of the helical antenna at those wavelengths. At high microwave frequencies (above ~3000 MHz), linear waveguide antennas and dish feeds with depolarizers become more convenient for DIY projects. Of course, when proper thought and care is given to the construction, helical antennas can work even outside of this range just fine, and in fact have been used in practice by amateurs and professionals alike (for example large helicals for the 2m ham band, or tiny ones for 5 GHz WiFi or drone/FPV use). Turn spacing (S λ)

What is a Helix?

This calculator provides the length of a helix with a given pitch, radius, and number of turns. Explanation Same as operating frequency F, except converted to wavelenght. Intermediary value used in other equations mainly for simplicity. For the purposes of this calculator, the wavelength is expressed in millimeters. Helix circumference - real (C) Same as S λ, except calculated for the current wavelength. This value together with diameter D are the two important measurements for constructing your helical antenna. Half power beam width (B hp) The helix is not just a curve in 3-dimensional space, but a fundamental shape in higher dimensions too, with applications in advanced mathematical physics.

Scroll below the calculator to see more information about how to properly build a helix as well as explanations of its individual properties. Length (L). The total length of the wire used to create the coil. Below is the coil length formula: This shows the angle at which the helical conductor is wound. When using a circumference C λ of 1, it essentially expresses the same thing as the turn spacing S λ. Similarly to the height A, this does not consider the pitch angle change in any impedance matching sections of the helix. Length of 1 turn (L t) Helix Length Calculator Radius of Helix (in cm): Pitch of Helix (in cm): Calculate Length of Helix (in cm): Introduction: A helical antenna is a specialized type of antenna that is designed to radiate and receive electromagnetic waves in circular or elliptical polarization. It is constructed by winding a wire in the shape of a helix or spring around a cylindrical or conical form. The key parameters of a helical antenna are the diameter and pitch of the helix, the number of turns, and the overall length of the antenna. These parameters determine the antenna’s operating frequency, gain, and radiation pattern. The helical antenna is widely used in applications such as satellite communication, space probe communication, and radio astronomy due to its ability to produce a directional radiation pattern and to operate over a wide frequency band. How to Calculate Helical Antenna?The Texas Instruments TI-30X IIS Scientific Calculator is versatile and reasonably priced. The two-line display shows both entry and calculated results at the same time. The calculator is capable of performing operations with both fractions and mixed numbers — you can enter fractions exactly as they appear in the textbook, no conversions necessary. Make a mistake? Use the arrow keys to scroll through the original equation to recalculate the answer. Or, use the entry line scrolling feature to review previous entries so you can look for patterns within answers or simply retrieve answers to previous calculations. where HXL is the helix length, R is the rise of the helix in one revolution, and C is the circumference of the helix. Understanding the helix curve is vital not only in the realm of theoretical physics and mathematics but also in numerous practical applications. From the smallest DNA molecules to large mechanical and electromagnetic systems, the helix curve has proven to be a critical element in our understanding of the world. Physics Calculators h: Represents the vertical distance covered by the helix in one complete cycle, also measured in any unit of length.