Parabolic Antenna Gain Calculator

Enter your Antenna Diameter, Operating Frequency, and Antenna Efficiency into the Parabolic Antenna Gain Calculator to find your dish's Antenna Gain, along with 3dB Beamwidth, Wavelength, and Half Power Beamwidth — everything you need to understand how well your parabolic antenna focuses and delivers signal.

m

Physical diameter of the parabolic dish in meters

GHz

Operating frequency in GHz (e.g., 14-14.5 GHz for VSAT)

%

Typical efficiency ranges from 50-80%

Results

Antenna Gain

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3dB Beamwidth

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Wavelength

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Half Power Beamwidth

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Antenna Performance Metrics

Frequently Asked Questions

What is parabolic antenna gain and how is it calculated?

Parabolic antenna gain is the measure of how much the antenna boosts signal strength compared to an isotropic antenna. It's calculated using the antenna diameter, operating frequency, and efficiency factor, typically expressed in dBi (decibels relative to isotropic).

What efficiency value should I use for my parabolic dish?

Typical parabolic antenna efficiency ranges from 50-80%. For professional VSAT dishes, use 65-75%. For consumer satellite dishes, use 55-65%. Higher quality dishes with better surface accuracy achieve higher efficiency.

How does frequency affect parabolic antenna gain?

Higher frequencies result in higher antenna gain for the same dish size. This is because the antenna becomes electrically larger relative to the wavelength. However, higher frequencies also suffer more from atmospheric attenuation and require more precise pointing.

What is the 3dB beamwidth and why is it important?

The 3dB beamwidth is the angular width of the antenna beam where the signal strength drops to half power (-3dB). It determines the antenna's directivity and pointing accuracy requirements. Smaller dishes have wider beamwidths.

Can I use this calculator for satellite TV dishes?

Yes, this calculator works for any parabolic reflector antenna including satellite TV dishes, VSAT antennas, and radio astronomy dishes. Just enter the dish diameter and operating frequency for your specific application.

What diameter should I choose for VSAT applications?

Common VSAT dish sizes are 0.75m, 1.2m, 1.8m, and 2.4m. Larger dishes provide higher gain and better performance but cost more and require sturdier mounting. 1.2m is most common for Ku-band VSAT systems.

How accurate does my dish surface need to be?

Surface accuracy affects efficiency. For good performance, surface deviations should be less than λ/16 (wavelength divided by 16). At 14 GHz, this means surface accuracy better than ±1.3mm for optimal efficiency.

What's the difference between dBi and dBd gain measurements?

dBi measures gain relative to an ideal isotropic antenna, while dBd measures gain relative to a dipole antenna. dBi is 2.15 dB higher than dBd for the same antenna. This calculator uses dBi which is the standard for satellite applications.

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