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Antenna Array Pattern Visualiser

Interactive beam pattern for Uniform Linear Arrays (ULA) and Uniform Rectangular Arrays (URA). Adjust element count, spacing, phase steering and amplitude taper in real time.

// Array Type
// ULA Parameters
16
0.50λ
0°
// Amplitude Taper
// Display
40 dB
// Element Pattern
ULA Orientation
Array Factor + Element Pattern
HPBW
—°
First SLL
—dBc
Directivity
—dBi
Scan Angle
—
Grating Lobes
—
Aperture
—λ
Element Weights — Amplitude Taper
Array orientation: Array along x-axis. θ = elevation from broadside (y-axis = 0°, x-axis = ±90° endfire).
Array Factor: AF(θ) = Σₙ wₙ·e^(jn·ψ)   ψ = 2πd·sinθ + β   β = −2πd·sinθ₀
URA: AF(θ,φ) = AFx·AFy (separable). Plot shows elevation cut at φ=φ₀.
Dipole ⊥ array = dipole along z (vertical), pattern = cos(π/2·cosθ_z)/sinθ_z, uniform in azimuth, null at zenith/nadir.
Dipole ∥ array = dipole along x (horizontal), pattern has null along array endfire direction.
Grating lobes appear when d > λ/(1+|sinθ₀|).

About the Antenna Array Pattern Visualiser

An antenna array combines multiple individual elements to achieve a beam pattern that a single element cannot provide — narrow beamwidth, high directivity, beam scanning or shaped coverage. Arrays are fundamental to radar, 5G base stations, satellite communications, electronic warfare and modern wireless access points.

Uniform Linear Array (ULA)

A ULA consists of N identical antenna elements equally spaced along a line. The array factor is the product of element pattern and the array factor AF = sum of w_n * exp(j*n*psi), where psi = 2*pi*d*sin(theta) + beta. The phase shift beta between elements steers the beam: setting beta = -2*pi*d*sin(theta_0) points the beam to angle theta_0. The half-power beamwidth narrows with increasing N*d (aperture), approximately as HPBW = 0.886 * lambda / (N*d*cos(theta_0)).

Amplitude Tapering and Sidelobes

A uniform array (all elements at equal amplitude) has the narrowest main beam for a given aperture, but the first sidelobe is only 13.2 dB below the main lobe. Amplitude tapering — reducing the amplitude of outer elements — trades beamwidth for sidelobe suppression. Chebyshev tapering achieves the narrowest beamwidth for a given sidelobe level. Taylor tapering provides a practical approximation with monotonically decreasing sidelobes.

Grating Lobes

When the element spacing exceeds half a wavelength, additional main lobes called grating lobes appear at angles where the array factor repeats. For a scanned array, grating lobes appear when d/lambda > 1/(1 + |sin(theta_0)|). In phased arrays for base stations and radar, element spacing is kept at or below lambda/2 to avoid grating lobes at any scan angle.