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Parabolic Dish Antenna Gain & 3dB Beamwidth Calculator

Parabolic dish reflectors collimate RF energy from a focal feed horn into an intensely directional narrow microwave beam.

Calculated Result
47.72 dBi

Antenna Gain

Half-Power Beamwidth (θ_3dB)

0.73°

Linear Power Gain

59205

Wavelength (λ)

2.50 cm

Calculation Breakdown

  1. Calculate RF wavelength λ = c / fλ = 3e8 / (12e9) = 2.50 cm
  2. Compute parabolic aperture gain G = η · (πD / λ)²G = 0.65 * (π * 2.4 / 0.0250)² = 47.72 dBi
  3. Compute half-power beamwidth θ_3dB ≈ 70 · (λ / D)θ_3dB = 70 * (0.0250 / 2.4) = 0.73°

Gain vs Dish Diameter (Ku-Band 12 GHz)

Interactive visualization based on your current inputs

dBi
0.0132740540.6 m1.2 m2.4 m4.8 mDiameter (m)Gain (dBi)

What Is the Parabolic Dish Antenna Gain & 3dB Beamwidth Calculator?

Parabolic dish reflectors collimate RF energy from a focal feed horn into an intensely directional narrow microwave beam.

How Does the Parabolic Dish Antenna Gain & 3dB Beamwidth Calculator Work?

The calculation evaluates user-provided measurements using recognized domain equations, converts between measurement units, and adjusts for real-world efficiency factors.

Parabolic Dish Antenna Gain & 3dB Beamwidth Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

G = \eta \left(\frac{\pi D}{\lambda}\right)^2, \quad \theta_{3\text{dB}} \approx 70^\circ \left(\frac{\lambda}{D}\right)

Gain increases quadratically with diameter-to-wavelength ratio, while 3dB beamwidth narrows inversely with aperture size.

How to Use the Parabolic Dish Antenna Gain & 3dB Beamwidth Calculator

  1. Enter your primary measurements in the input fields above.
  2. Select your preferred units (e.g. metric or imperial) if applicable.
  3. Review or adjust operational assumptions such as field efficiency.
  4. Click Calculate to instantly generate the full results breakdown and visual chart.
  5. Use the Reset button at any time to clear the form and test a new scenario.

Step-by-Step Example Calculation

Ku-Band 2.4m Satellite Dish

Input Values:

dishDiameterM:2.4
frequencyGhz:12
apertureEfficiency:0.65

Understanding Your Result

Your calculated result represents the realistic operational capacity or baseline output under the specified conditions. Comparing theoretical and effective outputs reveals the direct impact of turns, overlap, and practical downtime.

Factors That Affect the Result

Field terrain, operator experience, equipment maintenance, overlap margin, and weather conditions can significantly influence real-world output.

When Should You Use This Calculator?

Use this calculator whenever you need quick, verified estimates for job planning, budgeting, equipment sizing, or project timelines.

Assumptions & Limitations

  • Beamwidth constant 70 is standard for typical parabolic taper illumination.

Frequently Asked Questions

Calculation Accuracy & Reference Note

This calculator implements verified, deterministic mathematical equations based on published standards. Results should be treated as professional engineering estimates; always verify critical operations with local equipment manuals and site inspections.

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