Multijurisdictional Co Location SAR Evaluation Limits for Portable Host Devices
Multijurisdictional co-location SAR evaluation requires host-level total exposure ratio analysis and spatial decoupling to ensure global market clearance.
Electric Field Probes
Meaning
Specialized sensors measure the intensity of high-frequency electromagnetic radiation in close proximity to a transmitting device. Using electric field probes allows lab technicians to determine how much energy a human body would absorb from a smart mobile device or wearable. These tools contain miniaturized diode detectors mounted on non-conductive mechanical arms that sweep through an area inside a phantom container.
Every capture provides a localized value that contributes to a three-dimensional field map.
Sensing Component
The tip of the probe houses three mutually orthogonal dipoles to provide isotropic detection of the signal. Because electric field probes are designed to be minimally invasive, they utilize materials that do not distort the radio waves they are measuring. Precise calibration ensures that the conversion from diode voltage to field strength remains accurate across varying temperatures.
High spatial resolution allows for the identification of small local hotspots on the surface of the hardware.
Calibration Accuracy
Annual maintenance of the sensor ensures that aging components do not introduce sensitivity drift into the results. Electric field probes must be referenced against a standard wave source in a shielded anechoic environment to verify linear response. The dynamic range of the sensor must cover levels from a few milliwatts to several watts to capture various device types.
Errors in alignment result in a failure to pass the strict measurement repeatability tests.
Data Collection
Automated arms guide the sensors along a pre-programmed path to ensure every millimeter of the integration area is checked. Electric field probes transmit data back to the central console via fiber optic links to avoid interference from metallic signal wires. If probes identify a value above specific exposure limits, the integration team must redesign the antenna housing.
Final test reports contain the model and serial number of every sensor utilized during the evaluation.