An open-ended waveguide system for SAR system validation or probe calibration for frequencies above 3 GHz.
Compliance with safety guidelines prescribed in terms of maximum electromagnetic power absorption (specific absorption rate or SAR) for any 1- or 10-g of tissue is required for all newly introduced personal wireless devices such as wireless PCs. The prescribed SAR measuring system is a planar phantom with a relatively thin base of thickness 2.0 mm filled with a lossy fluid to simulate dielectric properties of the tissues. A well-characterized, broadband irradiator is required for SAR system validation or submerged E-field probe calibration for the Wi-Fi frequencies in the 5-6 GHz band. We describe an open-ended waveguide system that may be used for this purpose. Using a fourth-order polynomial least-squares fit to the experimental data gives SAR variations close to the bottom surface of the phantom that are in excellent agreement with those obtained using the finite-difference time-domain (FDTD) numerical method. The experimentally determined peak 1- and 10-g SARs are within 1 to 2% of those obtained using the FDTD both at 5.25 and 5.8 GHz.
Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA.
Qingxiang
Q
Li
Om P
OP
Gandhi
Gang
G
Kang
D000042:Absorption; D002138:Calibration; D003198:Computer Simulation; D004560:Electricity; D004574:Electromagnetic Fields; D006801:Humans; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D012984:Software; D013598:Systems Theory; D013997:Time Factors