A Specific Absorption Rate Measurement Method Using Fiber Optic Thermal Sensors

Prospects for Millimeter-Wave Compliance Measurement Technologies [Measurements Corner]

“…Average SAR is evaluated within a 1- or 10-g mass, covered by multiple optical fiber thermal sensors, by measuring the temperature rise Δ T due to field exposure in each sensor location and using $$\text{SAR}=C_{ph}\mathrm{\Delta }T/\mathrm{\Delta }t,$$ where C ph is the specific heat of the semisolid phantom material and Δ t is the exposure duration. Thermal SAR evaluation systems show a good agreement with E-field probe measurements for frequencies <6 GHz [22]. Additionally, they are used for validating the standard based on E-field probes and for evaluating the uncertainty of the measurement system [9], [22].…”

“…Thermal SAR evaluation systems show a good agreement with E-field probe measurements for frequencies <6 GHz [22]. Additionally, they are used for validating the standard based on E-field probes and for evaluating the uncertainty of the measurement system [9], [22]. Figure 8 illustrates an optical fiber thermal sensor and its features.…”

Electric Field Sensing with a Modified SRR for Wireless Telecommunications Dosimetry

“…We understand that this has not been fully investigated for electric field sensing. Moreover, there are few sensors for specific absorption rate (SAR), which are principally based on optical systems; data acquired with optical fibers have been previously reported in [6], but the power levels sent to the phantom are higher than those reported for wireless devices, and the physical measurement of interest is only temperature. On the other hand, the miniaturization of flexible antenna sensors, based on the microstrip patch antenna, has been used in the medical field for monitoring physiological variables [7], but they have not been tested as electric field sensors for dosimetry applications.…”