Portable Host Device Simultaneous Transmission Regulatory SAR Evaluation Procedures
Simultaneous transmission SAR evaluation demands spatial ratio summation, proximity sensor backoff calibration, and time-averaged power tracking across radios.
SAR Zoom Scan
Meaning
A high-resolution localized measurement represents a targeted three-dimensional scan performed by a robotic field probe within a specific volume of tissue-simulating liquid. Typically triggered after a wider area scan has located the region of high electromagnetic energy deposition, a sar zoom scan is used to determine the peak spatial-average specific absorption rate. This dense evaluation collects data over a predefined grid to calculate the power absorbed per unit mass.
The process is constrained to a small volume, and it does not scan the entire device surface.
Scan Execution
The robot moves the electric field probe in a series of closely spaced horizontal and vertical steps. For a typical sar zoom scan, the grid spacing is set to a few millimeters to capture the high gradient of the field. The probe records multiple values at each point to minimize noise.
These measurements are synchronized with the transceiver’s output.
Mathematical Interpolation
Because the probe cannot measure all points directly, post-processing algorithms interpolate the collected data to reconstruct the continuous field. The sar zoom scan provides the fine-grained data needed for these mathematical models to calculate the average value over a 1 gram or 10 gram volume of tissue. This step employs advanced cubic spline calculations.
It ensures that the absolute peak is not missed.
Compliance Significance
Regulatory agencies like the Federal Communications Commission require this measurement to approve mobile hardware. By validating the sar zoom scan results against national safety limits, engineers confirm the device will not cause local tissue heating. The generated data forms the core of the final compliance filing.
It is required for market access.