Inputs
Example data table
| Scenario | N | f (GHz) | d (λ) | Weighting | SNR₀ (dB) | Gain (dB) | SNR₁ (dB) | BW (MHz) | Throughput (Mbps) |
|---|---|---|---|---|---|---|---|---|---|
| Urban rooftop | 64 | 3.5 | 0.50 | Uniform | 5 | ≈ 16–18 | ≈ 21–23 | 100 | ≈ 700–900 |
| Indoor arena | 128 | 28 | 0.50 | Hamming | 0 | ≈ 19–21 | ≈ 19–21 | 200 | ≈ 1200–1600 |
| Industrial yard | 32 | 6.0 | 0.55 | Taylor | 8 | ≈ 13–15 | ≈ 21–23 | 80 | ≈ 550–750 |
Formula used
How to use this calculator
- Enter frequency, element count, and spacing to set the array geometry.
- Set steering and user angles to check alignment and relative attenuation.
- Pick a weighting taper to trade sidelobes against beamwidth.
- Add realistic losses: efficiency, coupling, and pointing error.
- Choose a power model, then enter transmit power and site losses.
- Press Calculate to see results above the form, then export CSV or PDF.
Project brief
Array size and coverage intent
In dense construction environments, array size directly drives spatial selectivity. A 64‑element array typically targets roughly 18 dB of combining gain before practical losses, while 128 elements can move the planning gain above 21 dB. Larger arrays support narrower beams, improved interference rejection, and higher reuse in compact sectors. Use this calculator to compare N versus achievable capacity under the same baseline link conditions.
Spacing, scan range, and physical build
Element spacing is entered in wavelengths and converted to meters from frequency. Values near 0.50λ are common for wide scan without severe grating lobes, especially when steering beyond ±30°. Increasing spacing can reduce count for a fixed aperture, but can introduce extra lobes at large scan angles. The tool reports physical spacing and aperture length to align with mounting rails and enclosure dimensions.
Weighting choices and sidelobe control
Uniform weighting yields the narrowest main lobe but higher sidelobes. Windowed tapers reduce sidelobes and help manage spillover toward adjacent work zones, but widen HPBW and reduce coherent sum. The calculator applies typical sidelobe targets and a practical gain penalty so you can see the trade between sidelobe management and peak gain.
Hardware realism: quantization and losses
Phase shifter resolution limits beam quality. The model uses a standard quantization loss factor that improves rapidly as bits increase; moving from 4 to 6 bits typically reduces the penalty to a small fraction of a decibel. Efficiency, coupling loss, and pointing error further reduce realized gain. Include conservative values to avoid overestimating field performance on first deployment.
Capacity and EIRP checks for compliance
The calculator converts post-beamforming SNR into a Shannon capacity estimate using selected bandwidth. Treat the result as a planning upper bound, then apply scheduler, overhead, and modulation limits separately. EIRP is also estimated from transmit power, element gain, array directivity, and losses. This helps construction teams validate RF exposure zones, equipment placement, and regulatory power limits early.
FAQs
What does “beamforming gain” represent here?
It is the approximate coherent combining gain from N elements after applying efficiency, taper, phase quantization, coupling, and pointing losses. It is relative to a single element, so it complements your baseline single‑element SNR.
Why does spacing above 0.50λ matter?
Wider spacing can create grating lobes when steering away from broadside, which wastes power and increases interference. The results note flags this risk, but final validation should use full array simulations for your exact geometry.
How should I choose a weighting taper?
Use Uniform for maximum peak gain and narrow beams. Use windowed tapers when sidelobe reduction is more important than peak gain, such as near sensitive zones. Compare HPBW and estimated sidelobe level to support an informed trade study.
Does the array factor value replace a full radiation pattern?
No. The tool reports a normalized ULA array‑factor estimate at one angle to show steering alignment and attenuation trends. Real patterns depend on element patterns, coupling, housing, and mounting effects, so lab or field validation remains necessary.
What is the difference between the two power models?
Fixed total power holds total transmit power constant as N changes. Fixed per‑element power keeps each element constant, so total power increases with N. The choice affects EIRP and may change whether your design stays within site constraints.
Is the throughput result a guaranteed user rate?
No. The throughput is a Shannon-based planning estimate from bandwidth and post‑beamforming SNR. Real networks include overhead, coding gaps, scheduling, and interference variability. Use it for comparisons, then refine with detailed link budgets.