# Aperture Antenna Calculator

Aperture Antenna refers to a receiver of the radio waves. It is the measure of the antenna's efficiency at its transmitting and receiving radio waves. Aperture is defined as the area that is oriented perpendicular to the direction of an incoming radio wave. The aperture would cut off the same amount of power from that wave as is produced by the antenna receiving it. Formula

Eθ = [ ( j*k*a2*E0*e-jkr ) / r ] * Sinφ [ ( J1*k*a*Sinθ) / k*a*Sinθ ]
Eφ = [ ( j*k*a2*E0*e-jkr ) / r ] *(Cosθ*Cosφ) [(J1*k*a*Sinθ) / k*a*Sinθ]

Where,
k = 2π / λ
λ = Wave Length
E0 = 8.8541878176 * 10-12F/m (electric constant)
θ = Coordinate Angle 1
φ = Coordinate Angle 2
a = Radius of Circular Aperture
r = Distance of the observation point from the Origin
j = Electric Current Density
J1 = Electric Current Density for 1st element

The advanced online Aperture Antenna Calculator is used to calculate the electric field radiated by the aperture antennas at two different angles by applying the formula for different angles. 