When it comes to specific absorption rate testing, most of the focus is on higher frequency bands. However, many devices use low frequency radio waves, making these just as important to SAR testing as frequencies like the millimeter band. Keep reading to learn more about the low frequency band and why SAR testing is important.
The International Telecommunication Union classifies low frequency radio waves as those within the range of 30-300 kHz. This frequency is also known as the kilometer band or kilometer wave because its wavelengths are between 10-1 km. Radio waves in this frequency range are optimal for long-distance communications due to their low signal attenuation.
Because radio waves in this frequency range have a long wavelength they are able to diffract, which is “the process by which a beam of light or other systems of waves is spread out as a result of passing through a narrow aperture or across an edge,” as defined by Oxford Languages. Due to this ability, LF waves are able to travel over mountain ranges and follow the contour of the Earth. This method of propagation is known as ground wave and is the main method of propagation for this band.
Uses of Low Frequency Radio Waves
LF radio waves have many uses in communication, such as
- Standard time signals: many low-cost consumer devices containing clocks use LF receivers for these time signals.
- Military: many countries use LF radio waves to communicate with submarines due to the fact that signals below 50 kHz are able to reach ocean depths up to about 200 meters. As wavelengths become longer, they can reach further depths, making these radio waves ideal for deep ocean communication.
- Experimental and amateur: as of 2007, amateur radio has been allocated to the LF band.
Other uses include meteorological information broadcasts, radio navigation signals, and radio broadcasting.
Specific Absorption Rate (SAR) Regulations & Compliance
Before October of 2020, the lowest frequency for SAR testing was 30 MHz, but after the IEC updated and combined two standards, this was changed. IEC/IEEE 62209-1528 outlines the procedure for measuring specific absorption rate for human models, now ranging from 4 MHz to 10 GHz. This has increased the number of products that must prove compliance with FCC and other worldwide standards through SAR testing.
For those who are unfamiliar, SAR testing is an assessment method used for a variety of wireless devices, including but not limited to, cellphones, laptops, wireless modems, and medical devices. This is done to determine how these radio frequencies are absorbed by the human body when these devices are in use and prove that wireless devices are safe for humans.
RF Exposure Lab Can Help With Your Specific Absorption Rate Testing Needs
As demand for wireless technologies increases, so does the need for manufacturers to work with SAR testing labs to prove safety and compliance with FCC and other worldwide regulations. This is where RF Exposure Lab can step in to help you. We’re always working to stay up to date on the latest developments in SAR testing and regulations so that you don’t have to.
As part of our dedication to staying up to date, we now have millimeter wave device testing equipment and near field charging device equipment in our lab. Meeting the needs of our clients as technology advances and changes is important to us. In addition to this, we are always communicative and transparent throughout the SAR testing process to keep you updated on your product’s testing.
We offer SAR testing services for a variety of wireless devices including cell phones, laptops and tablets, medical products, survey equipment, wireless modems, and more. If you’re looking for SAR testing help that is provided with expertise, speed, accuracy, and integrity, contact us to get a quote for our services.