Testing Specific Absorption Rate (SAR) in Mobile Phones

As mobile phones, smartphones and other devices become increasingly integrated into our daily lives, the RF energy emitted from these devices can remain a concern for some people. Specific Absorption Rate (SAR) measures the rate at which the human body absorbs radio frequency (RF) energy emitted by devices used next to the body. This white paper explores the challenges associated with testing SAR in modern devices considering evolving technology, compliance regulations, and the need for consistent regulation.

Why download this white paper?

Our 'Challenges in Testing Specific Absorption Rate (SAR) in Modern Mobile Phones' white paper covers:

• Introduction into SAR testing of modern mobile phones
• Overview of the history of SAR testing 
• Evolution of mobile technology in relation to SAR testing
• SAR testing procedures
• Compliance regulations
• Challenges in modern phone testing

BACKGROUND

SAR testing has been in use for over 20 years and is the primary method for quantifying the RF exposure absorbed into a body from a mobile device. The test methodology has remained largely unchanged throughout this duration with the testing being carried out on one primary test system. This means that that the test methods and definitions are well documented and understood which should lead to a high level of confidence that reported SAR values should be consistent the world over. This is significant to the mobile industry because in the initial years of technology adoption there were legitimate concerns from users of mobile devices that having an RF source so close to the body could cause adverse health effects.

SAR testing allowed the industry to demonstrate that mobile devices emit levels of non-ionizing radiation (RF-energy) far below levels that would cause adverse health effects.

It is also important to note that the limits set in international regulations for consumer technologies fall far below the limits for non-ionizing radiation levels that would be deemed unsafe. This means that although a device might be non-compliant to a regulatory test requirement, it is highly unlikely that that same device would be unsafe. This is particularly true when we factor in how much overall RF output power a small device can transmit, which is very low in terms of actual RF safety. It‘s important to consider this when looking at news stories and social media posts which suggest that smartphones and other such devices might pose safety concerns where none exist.

Modern devices are very complicated and must be fully understood in their capabilities and their operation before testing.

Download our white paper to learn more about the issues you may face when SAR testing modern mobile phones and smartphones.

Author: Jon Kenny, Technical Director, TÜV SÜD, UK

Jon Kenny has over 20 years’ experience in SAR testing. Initially, he worked as a test engineer for the cellular test team at an independent test lab, and later moved to a full-time specialisation in the SAR testing area.

He began his RF-exposure career working to get the UK’s first UKAS-accredited SAR testing facility off the ground. After several years, he made the move from independent test house to mobile device manufacturer, Ericsson, and then Sony Ericsson (SEMC), working on bringing their diverse range of cellular products to market.

At SEMC, he became the SAR technical lead engineer responsible for the company’s SAR testing supporting Sweden, UK, the US, China, and Japan. He also represented the company within the RF-exposure testing community dealing with international groups. Additionally, he provided input to SAR standards groups such as the IEEE and IEC groups.

Jon moved back to his roots at an independent test house and has been with TÜV SÜD for over four years where he’s looking after and growing the RF-exposure testing services and writes blog posts about topics such as when SAR testing is required.