Meaning
Electromagnetic radiation evaluations for low-power, high-bandwidth radio devices determine their compliance with localized heating limits. Due to the high frequency and wide bandwidth of these transmitters, ultra wideband exposure must be assessed using specific measurement or simulation methods. This evaluation is required to ensure that the device does not cause excessive heating of the skin or eyes when held close to the body.
Frequency Spectrum
Operational spectrum covers the frequency range from three point one to ten point six gigahertz, using channels wider than five hundred megahertz. This wide spectrum allows for very precise location tracking and high-speed data transfer over short distances. This frequency range requires the use of specialized measurement probes that are calibrated for these higher frequencies.
Exposure Evaluation
Energy deposition profiles are highly localized due to the small wavelength of these signals, meaning that the electromagnetic energy is absorbed primarily in the outer layers of the skin. Measuring the exposure requires a combination of electric field scans and numerical simulations to determine the power density. This process differs from the volumetric absorption measurements used for lower frequency cellular radios.
Compliance Threshold
Regulatory limits specify the maximum allowable power density on the surface of the body to prevent tissue damage. The test results must demonstrate that the device operates well below these limits, even during continuous data transmission. If the limits are exceeded, the device must be redesigned to lower its duty cycle or transmit power, which can impact the precision of the location tracking features.
