About Simultaneous Hotspot SAR: Understanding SAR Testing for Mobile Devices
Mobile devices have become an integral part of our daily lives, and it’s hard to imagine a world without them. However, concerns have been raised about the potential health risks associated with long-term exposure to radiofrequency radiation emitted by these devices. This is where Specific Absorption Rate (SAR) testing comes in, which measures the amount of radiation absorbed by the body when using a mobile device. In this article, we will be discussing SAR testing, specifically the simultaneous hotspot SAR value, which is a measure of the amount of radiation absorbed by the body when using a mobile device with multiple antennas transmitting at the same time.
History of SAR Testing
SAR testing is a technique that measures the amount of electromagnetic energy absorbed by the human body when using a wireless device. The practice dates back to the 1980s when researchers began investigating the potential health effects of cell phone radiation. At the time, there was a lot of uncertainty about the long-term effects of exposure to electromagnetic radiation. Some researchers were concerned that the radiation emitted by cell phones could cause cancer, while others argued that the radiation levels were too low to have any significant impact on human health.
To settle the debate, researchers developed a standard method for measuring SAR, which involved using a phantom head that simulated the absorption characteristics of human tissue. The phantom head became known as the Specific Anthropomorphic Mannequin (SAM), and it’s still used today for SAR testing.
Understanding SAR Testing
The SAR value is a measure of the rate at which RF energy is absorbed by the body tissue closest to the phone’s antenna. It is measured in watts per kilogram (W/kg). SAR testing involves placing a mobile phone in different positions on the SAM phantom, including the cheek and tilt positions. The mobile phone is then exposed to an RF signal at its highest power level, and the SAR value is measured.
The SAR measurement is done using a specific test protocol that involves a reference measurement, an area scan, a zoom scan, and a drift measurement. During the area scan, the SAR value is measured in a grid pattern across the entire body region covered by the mobile phone. The zoom scan is a more precise measurement that measures a small cube around the maximum SAR measured during the area scan. The reference measurement and drift measurement are done to ensure that the power from the device does not drift during the measurement.
Simultaneous Hotspot SAR Values
The simultaneous hotspot SAR value is a measure of the amount of radiation absorbed by the body when using a mobile device with multiple antennas transmitting at the same time. This is particularly important because multiple antennas can produce a higher level of radiation than a single antenna.
To measure the simultaneous hotspot SAR value, SAR testing is performed on each antenna separately, and the highest reported SAR result is selected for each test position. These results are then summed together, assuming that the hotspots are co-located, to determine if the simultaneous SAR is within the safety limit. In the USA, the safety limit for simultaneous hotspot SAR is 1.6 W/kg.
If the simultaneous hotspot SAR value is over the limit, the two results are summed again using the Combined Fast SAR feature of ComSEMCAD X software. This is because the hotspots of the two summed measurements may not be exactly on top of each other, so using the software can produce a more accurate result. If the final value is within the safety limit, the phone is considered safe for use.
FAQs
- How can I find out the SAR value of my mobile phone?
You can usually find the SAR value of your mobile phone in the phone’s user manual or on the manufacturer’s website. Alternatively, you can search for your phone’s make and model on the FCC’s database of SAR values.
- What is the difference between SAR and simultaneous SAR values?
SAR values measure the amount of RF energy absorbed by the body from a single transmitter, while simultaneous SAR values measure the amount of RF energy absorbed by the body from multiple transmitters operating simultaneously.
- What is the safety limit for SAR values in the USA?
The safety limit for SAR values in the USA is 1.6 W/kg.
- Are low SAR values always better?
While lower SAR values generally indicate lower levels of RF energy absorbed by the body, it is important to also consider other factors such as duration of use, distance from the body, and specific absorption rates of different tissues when assessing the potential health effects of mobile phone use.
Understanding Simultaneous Hotspot SAR: A Comprehensive Guide
Simultaneous Hotspot SAR and Its Effects on Human Health: What You Need to Know
The Importance of Simultaneous Hotspot SAR Testing for Wireless Devices
Navigating the World of Simultaneous Hotspot SAR: A User’s Guide
Simultaneous Hotspot SAR and Wireless Technologies: What You Should Consider
