Calculator Inputs
Plotly Radiation Trend
This graph uses a normalized main-lobe approximation.
Example Data Table
| Scenario | Frequency (MHz) | X Width (m) | Y Height (m) | Efficiency (%) | Net Gain (dBi) | X Beamwidth (°) | Far Field (m) |
|---|---|---|---|---|---|---|---|
| Case 1 | 2,400 | 0.80 | 0.60 | 58 | 20.57 | 10.93 | 10.25 |
| Case 2 | 5,800 | 1.20 | 0.90 | 62 | 31.74 | 3.02 | 55.72 |
| Case 3 | 10,000 | 1.60 | 1.10 | 68 | 38.70 | 1.31 | 170.78 |
Formula Used
λ = c / f
BWx ≈ 70 × (λ / Dx)
BWy ≈ 70 × (λ / Dy)
D ≈ 41253 / (BWx × BWy)
Glinear = η × D
GdBi = 10 log10(Glinear) − losses
Ae = η × Dx × Dy
Rff = 2Dmax2 / λ
Footprint = 2R tan(BW / 2)
These are first-pass engineering equations. Detailed designs still benefit from full-wave simulation and measured pattern data.
How to Use This Calculator
- Enter the operating frequency in megahertz.
- Provide the X and Y antenna aperture dimensions.
- Set the expected aperture efficiency percentage.
- Enter feed power, distance, and total system loss.
- Define a target gain for quick margin checking.
- Press the calculate button to view results.
- Review gain, beamwidth, aperture, and far-field distance.
- Use CSV or PDF export for documentation.
Frequently Asked Questions
1. What does this calculator estimate?
It estimates wavelength, X and Y beamwidth, directivity, net gain, effective aperture, far-field distance, EIRP, and beam footprint from basic antenna design inputs.
2. Why are X and Y dimensions separate?
Separate dimensions help estimate asymmetric beams. Many practical antennas have different horizontal and vertical apertures, so each plane needs its own beamwidth estimate.
3. Does higher frequency always narrow beamwidth?
For the same physical aperture, higher frequency means shorter wavelength. That usually narrows beamwidth and raises directivity.
4. What does efficiency change?
Efficiency affects usable gain and effective aperture. Lower efficiency means more losses from illumination, spillover, surface quality, or feed mismatch.
5. Why is far-field distance important?
Far-field distance marks where angular pattern behavior becomes stable. Measurements taken before that region can misrepresent true beam shape and gain.
6. Can this replace full electromagnetic simulation?
No. It gives rapid design estimates. Final validation still needs simulation, measurement, tolerance review, and application-specific constraints.
7. How accurate are the beamwidth formulas?
They are practical approximations for early design work. Actual performance changes with taper, edge effects, reflector shape, and construction quality.
8. Why export results as CSV or PDF?
Exports help with reporting, comparison, handoff, and record keeping across design reviews, procurement checks, and installation planning.