Dipole Antenna

Electronics Engineering

How It Works

A half-wave dipole antenna consists of two collinear conducting rods of total length L = λ/2 fed by a balanced transmission line at the center. Alternating radio-frequency current standing waves establish an oscillating electric dipole moment, generating transverse electromagnetic (TEM) waves in free space. The resulting far-field electric radiation pattern forms an omnidirectional toroidal (donut) geometry with null radiation along the dipole axis and maximum radiation broadside.

Governing Equation
E_θ = j · ((η · I₀) / (2π r)) · e^{-j k r} · [cos((π/2) cos θ) / sin θ]   |   R_{rad} ≈ 73.13 Ω