Question

A hypothetical isotropic antenna is radiating in free space. In the antenna's far-zone at a 100m distance, the measured total electric field (Eθ) is 5 V/m. find:

a)Power density, Savg(Pavg in the textbook)

Answer 1

The power density (or average power per unit area) can be found using the equation Savg = (E²) / (120π), where Eθ is the electric field strength. Plugging in the given value, we find that the power density is approximately 0.0666 W/m².

Step-by-step explanation:

To find the power density (or average power per unit area), we can use the equation:

Savg = (Eθ²) / (120π)

Here, Eθ is the electric field strength measured in the far-zone at a 100m distance, which is given as 5 V/m. Plugging in this value, we get:

Savg = (5²) / (120π) = 25 / (120π)

Using a calculator to approximate this value, we find that the power density is approximately 0.0666 W/m².