Enter Array Values
Formula
ψ = 2π(d/λ)cosθ + β
|AF| = |sin(Nψ/2) / [N sin(ψ/2)]|
The normalized result is 1 at perfect coherent reinforcement and approaches 0 near an ideal array null.
Worked Example
A four-element broadside array with 0.5λ spacing and β = 0 has maximum reinforcement at θ = 90° from the array axis.
Grating Lobes and Model Limits
This is an ideal uniform array factor. It excludes each element's own radiation pattern, mutual coupling, feed errors, amplitude taper, mounting effects, and finite ground structures.
Spacing above 0.5λ can create grating lobes for some scan angles. Even at smaller spacing, wide electronic scanning needs a scan-specific grating-lobe check.