In recent years wireless technology has dramatically improved to meet the need of the digital era. Users are now usually continuously connected to some form of wireless device and data consumption has increased (and is increasing!) which is creating the need for more frequency bands and higher bandwidth to accommodate the data needs of the average consumer.

Wireless technology can be found in most if not all mobile devices such as smartphones, tablet PC’s, USB dongles and wearable devices and most often several types of technology! It has been said that mobile devices are also becoming an “extension of the user “with apps for almost everything imaginable.

Most mobile devices will be used within 20cm of the body, head, ankle or wrist. At this proximity the user is exposed to electromagnetic fields (EMF – the wireless technology – a form of non-ionising radiation). This is how wireless devices communicate.

Exposure to these EM Fields is often a concern for the consumer; so the question asked is “is the end-user protected from electromagnetic radiation?”

Many countries globally have mandated requirements to address the Radio Frequency (RF) health and safety aspects for mobile devices.  Manufacturers placing products on the market must ensure their mobile device complies with recommended guidelines such is International Commission on Non‐Ionizing Radiation Protection (ICNIRP) limits for limiting exposure or their own national limits which are derived from these guidelines. But many questions still remain such as:

• How are these devices assessed
• Where do mobile device and wireless products get tested?
• How well are products evaluated and how can you tell if it has been certified?
• Who reviews the compliance work?
• Are all regulators opinions aligned and are there ongoing surveillance on these products?

For example Europe and North America mobile devices with wireless capability that are operated within close proximity to the user are tested using a test method known as Specific Absorption Rate (or SAR). This method is documented in FCC KDB procedures, IEEE and IEC standards.

SAR testing involves the use of a “phantom” which simulates the human head. A liquid which is designed to be the electromagnetic equivalent of human tissue (brain) is placed in this phantom. The device under test is put into a “call” at maximum power and a robotic arm then moves a measurement antenna through the liquids and makes Electric field measurements.

SAR Testing

If you would like to see a demonstration – contact us and we will be happy to arrange it.

Due to product design and user configuration there may be instances where the evaluation methods could deviate from the specified configuration. In such cases for example with FCC testing, they provide well documented guidance, so all configurations could be accommodated.

However there is no such detailed alternative process; in this case a Notified Body may be used to define a test suite.

Find out more about SAR assessment of mobile devices and new technologies.

Source: http://europe-ul.com/sar-testing-what-is-it/