Meaning
Anthropomorphic containers filled with dielectric fluid simulate the energy absorption characteristics of human tissue during radio frequency exposure testing. A sar phantom provides a repeatable environment for measuring how much power the human body absorbs from a wireless device. These models follow standardized shapes, such as the Specific Anthropomorphic Mannequin, to ensure results are comparable across different laboratories.
Tissue Simulation
Liquids used in testing must match the permittivity and conductivity of human muscle or brain matter. The fluid inside a sar phantom mimics these electrical properties at specific frequencies, such as 1900 megahertz or 2.4 gigahertz. Regular calibration of the liquid is required to maintain accuracy.
Shell Morphology
Outer surfaces of the model are constructed from low-loss materials to minimize interference with the measurement probe. The geometry of a sar phantom shell represents the average dimensions of the human head or torso. Manufacturers must ensure the shell thickness remains uniform to avoid measuring errors.
Measurement Repeatability
Fixed positions for the device under test allow for consistent data collection across multiple units. Using a sar phantom removes the variability inherent in testing with human subjects. Automated probes map the electric field strength inside the liquid to calculate the energy distribution.
This data confirms that the device operates within safe exposure limits.
