Yagi-Uda Antenna Calculator

A Yagi-Uda antenna is a directional antenna used in radio communications, TV reception, and amateur radio — built from a driven dipole, a reflector, and one or more director elements on a boom. Enter your center frequency, number of elements, element diameter, and boom diameter into the Yagi-Uda Antenna Calculator, then select your unit system, element shape, dipole type, and whether elements are insulated. You'll get the total boom length, along with reflector length, driven element length, first director length, and estimated gain in dBi.

MHz

Operating frequency of the antenna

Total number of antenna elements (minimum 3 for Yagi)

mm

Diameter of antenna elements

mm

Diameter of the boom (supporting structure)

Check if elements are insulated (PVC/Wood boom)

Results

Total Boom Length

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Reflector Length

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Driven Element Length

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First Director Length

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Estimated Gain

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Results Table

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Frequently Asked Questions

What is the minimum number of elements for a Yagi antenna?

A Yagi antenna requires at least 3 elements: one reflector, one driven element (dipole), and one director. However, for optimal performance and accuracy of calculations, at least 5 elements are recommended.

How does boom diameter affect antenna performance?

Boom diameter affects the antenna's electrical characteristics by influencing the coupling between elements. A larger boom diameter can shift resonant frequencies and require compensation in element dimensions for optimal performance.

What's the difference between straight and folded dipole elements?

A folded dipole has higher input impedance (around 300 ohms) compared to a straight dipole (75 ohms), making it easier to match to transmission lines. Folded dipoles also have broader bandwidth but are more complex to construct.

Should I use insulated or non-insulated elements?

Insulated elements (mounted on PVC or wood booms) reduce interaction with the boom material, maintaining more predictable performance. Non-insulated metal-to-metal mounting may require slight adjustments to compensate for boom effects.

How accurate are these calculated dimensions?

These calculations provide a good starting point, typically within 2-5% of optimal dimensions. Final tuning may be required based on actual construction methods, materials, and environmental factors.

What frequency range works best for Yagi antennas?

Yagi antennas work well from HF through microwave frequencies. They're most commonly used in VHF/UHF applications (30 MHz to 3 GHz) where their directional properties and manageable size make them ideal.

How do I convert between metric and imperial units?

The calculator handles unit conversion automatically. For reference: 1 inch = 25.4mm, 1 foot = 304.8mm. Most antenna literature uses metric units for precision in element dimensions.