Popis: |
Specific absorption rate (SAR) assessment plays a crucial role in the development of small antennas for wireless systems. Indeed, such antennas are generally in close interaction with human body, resulting in exposure safety issues. While the standard procedure remains the reference to ensure compliance with existing norms, various needs for faster SAR measurement have been pushing for the development of new approaches. The attempt of this paper is to provide an overview of these approaches and to outline their respective advantages and limitations. More particularly, accuracy limitations may result from assumptions made to simplify the measurement process. Cost is also an issue of practical relevance especially for those of fast SAR assessment systems, which are based on the use of probe arrays to avoid time consuming mechanical scanning. |