Planar Microstrip / RF Antenna Array (M × N) Calculator

Computes 2D beamwidths, directivity, grating-lobe conditions and array parameters for a rectangular planar array of M×N isotropic or patch elements.

Inputs

Frequency

Elements along x-direction (M) Elements along y-direction (N) Element spacing dx (along x-axis)

Element spacing dy (along y-axis)

Steering Angles (θ₀, φ₀)

Results will appear here.

Planar Array Diagram & Theory

Rectangular Planar Array (Top View)

Key Equations

Wavelength: λ = c / f

Array Factor (2D):

AF(θ,φ) = AF_x(θ,φ) · AF_y(θ,φ)

AF_x = sin(M·ψ_x/2) / sin(ψ_x/2)

AF_y = sin(N·ψ_y/2) / sin(ψ_y/2)

ψ_x = (2π·dx/λ)[sinθ cosφ − sinθ₀ cosφ₀]

ψ_y = (2π·dy/λ)[sinθ sinφ − sinθ₀ sinφ₀]

HPBW (approx):

HPBW_x ≈ 50.8° / (M·dx/λ)

HPBW_y ≈ 50.8° / (N·dy/λ)

Directivity:

D ≈ M·N (isotropic element assumption)

Grating lobe conditions:

dx ≤ λ / (1 + |sinθ₀ cosφ₀|)

dy ≤ λ / (1 + |sinθ₀ sinφ₀|)

Symbol Glossary