The Antenna Power Density conversion calculator determines the power density at a given distance from an antenna based on transmitted power, antenna gain, and distance. It helps engineers evaluate electromagnetic exposure, link budget, and radiation safety levels for RF systems.
Formula
S = (P * G) / (4 * π * R²)
Formula Explanation
- S is the power density, typically expressed in mW/cm² or W/m².
- P is the input power applied to the antenna, in watts or milliwatts.
- G is the antenna gain, which can be entered in linear scale or converted from dB using 10^(GdB/10).
- R is the distance from the antenna’s center of radiation, usually in centimeters or meters.
- The formula assumes free-space conditions where the power radiates uniformly in all directions.
Uses of this calculator
- Estimating RF exposure levels around transmitting antennas.
- Calculating effective radiated power density for compliance testing.
- Evaluating link budgets for microwave and satellite systems.
- Planning safe distance for high-power transmission sites.
What is the power density 10 meters from a 100 W antenna with 15 dB gain?
Input: P = 100 W, G = 15 dB, R = 10 m
Output:
- G (linear) = 10^(15/10) = 31.62
- S = (100 * 31.62) / (4 * π * 10²) = 3162 / (1256.6) = 2.52 W/m²
- Power Density = 2.52 W/m² (or 0.252 mW/cm²)