title: Analysis of the effect of mobile phone base station antenna loading on localized SAR and its consequences for measurements.
abstract: In this work, the effect of antenna element loading on the localized specific absorption rate (SAR) has been analyzed for base station antennas. The analysis was conducted in order to determine whether localized SAR measurements of large multi-element base station antennas can be conducted using standardized procedures and commercially available equipment. More specifically, it was investigated if the antenna shifting measurement procedure, specified in the European base station exposure assessment standard EN 50383, will produce accurate localized SAR results for base station antennas larger than the specified measurement phantom. The obtained results show that SAR accuracy is affected by the presence of lossy material within distances of one wavelength from the tested antennas as a consequence of coupling and redistribution of transmitted power among the antenna elements. It was also found that the existing standardized phantom is not optimal for SAR measurements of large base station antennas. A new methodology is instead proposed based on a larger, box-shaped, whole-body phantom.
authors.affiliation: Ericsson Research, SE-16480 Stockholm, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Hansson
authors.forename: Björn
authors.initials: B
authors.lastname: Thors
authors.forename: Christer
authors.initials: C
authors.lastname: Törnevik
mesh_terms: D000042:Absorption; D040421:Cell Phone; D004574:Electromagnetic Fields / Q000009:adverse effects; D060733:Electromagnetic Radiation; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D017408:Guidelines as Topic; D006801:Humans; D019047:Phantoms, Imaging; D011834:Radiation Monitoring / Q000379:methods* / Q000592:standards; D011835:Radiation Protection / Q000379:methods*; D015203:Reproducibility of Results