High rates of data usage from consumers now require that technology evolve to accommodate changes in how mobile technology is used. Mobile devices have gone from being used exclusively for voice communications to focusing first and foremost on data communications. This not only requires high frequency wireless technology, but it also requires that SAR testing for this technology adjust as well. 

Keep reading to learn more about high frequency wireless technology, its uses, and how it affects RF exposure testing.

What is High Frequency Wireless Technology?

There are multiple high frequency bands, all of which are used for different forms of communication. These include the following:

• High Frequency (HF) band: This band makes up frequencies within the range of 3 to 30 MHz. It is optimal for long-distance communication across intercontinental distances and/or mountainous terrains. The HF band is commonly used for international shortwave broadcasting stations, aviation communication, government time stations, weather stations, amateur radio, and RFID.

• Very High Frequency (VHF) band: The VHF band is classified as frequencies within the range of 30 to 300 MHz. Unlike HF, which is ideal for mountainous terrains, VHF transmits largely by line-of-sight, so it’s blocked by hills and mountains. It’s used for Digital Audio Broadcasting (DAB), FM radio broadcasting, television broadcasting, two-way land mobile radio systems, amateur radio, and marine communications.

• Ultra-High Frequency (UHF) band: The UHF band encompasses frequencies between 300 MHz to 3 GHz. It is transmitted largely by line-of-sight and is blocked by hills and large buildings. However, UHF can transmit through building walls for indoor reception. It’s mostly used for television broadcasting, cell phones, satellite communication, Wi-Fi, Bluetooth, walkie-talkies, and cordless phones.

• Super High Frequency (SHF) band: This band is made up of frequencies between 3 to 30 GHz. SHF waves are part of the microwave band, so they are also referred to as microwaves. This band is used for point-to-point communication and data links for radar, radar transmitters, WLANs, satellite communication, industrial microwave heating, medical diathermy, microwave hyperthermy used to treat cancer, and microwave ovens.

• Extremely High Frequency (EHF) band: The EHF band is made of frequencies ranging between 30 to 300 GHz. EHF is known as millimeter wave or millimeter band because its wavelengths range from 10 to 1 millimeter. This band is vulnerable to atmospheric depletion, such as being absorbed by gases in the atmosphere or disrupted by rain. Because of this, EHF can only be used for short-range terrestrial communications of about 1 kilometer. It is used for military fire-control radar, airport security scanners, short-range wireless networks, and 5G cell phone networks.

Consumer wireless devices like Bluetooth devices, cell phones, cordless phones, and Wi-Fi require the use of the UHF band. 5G networks, as well as 5G-enabled devices, use the EHF band. These are the bands we focus on when discussing high frequency wireless technologies.

Benefits of High Frequencies

High frequency bands have provided a variety of benefits for wireless devices. This includes mobile devices shifting to data usage rather than simply voice communication. High frequency wireless technology allows for greater consumption of data without disruption.

Devices that make use of high frequency wireless technology can also be made with smaller antennas due to the short wavelength of these frequencies. 

In addition to this, high frequency bands can be used to improve user experience and network efficiency for mobile devices, especially in the case of smartphones. These spectrums have significant bandwidth that can considerably expand network capacity and provide broad support for multi-Gbps speeds. This makes it possible for devices to meet new and emerging uses for mobile data. 

Challenges of High Frequencies

Although there are many benefits of high frequency bands, utilization of these bands provides challenges as well. One of these challenges is that smaller wavelengths lead to increased atmospheric attenuation. Also, higher frequency wavelengths are less likely to be able to penetrate through walls and windows. 

In addition to this, high frequency technology may also require multiple antennas, which complicates the manufacturing as well as testing of these devices.

RF Exposure Testing for High Frequency Devices

Continuous development of wireless technology means that manufacturers will always have updated RF exposure regulations to keep up with. Fortunately, with help from RF exposure testing experts, manufacturers can focus on developing and producing these devices instead of focusing on testing requirements. So how does RF exposure testing affect high frequency devices?

As mentioned, high path attenuation is a common issue for millimeter wave products as a result of its high frequency. Manufacturers may be able to compensate for this by using antennas that provide multipath suppression and interference mitigation, however, RF exposure requirements need to be taken into account when making these adjustments. 

The Federal Communications Commission (FCC) and IEEE have set RF exposure compliance regulations that must be followed to determine whether or not products are safe for consumer use. Keep in mind that these regulations differ between public and occupational environments. RF exposure compliance testing for millimeter wave products can also be challenging because of the millimeter band’s short wavelength and because these products typically have an increased number of antennas.

In addition to this, millimeter wave devices are capable of operating in far-field as well as near-field, and many MMW wireless devices even support near-field connectivity. This adds yet another layer of complexity for RF exposure testing because near-field power absorption depends on many factors, including frequency of operation, the medium in which the electromagnetic field is transmitted, and the distance between the antenna and the body. All these factors require that thorough RF exposure testing be conducted to prove compliance of these products with FCC standards.

Expert SAR Testing For High Frequency Wireless Devices 

Our team’s expertise comes from RF Exposure Lab’s Owner, Vice President, and Chief Engineer, Jay Moulton. An authority in RF exposure testing with a background in manufacturing and the regulatory side of RF exposure testing, Jay Moulton has more than 25 years of experience. He is unique in his ability, experience, and knowledge of RF exposure. It’s this distinctive expertise and knowledge that allows us to guarantee our clients accurate RF exposure testing results and solutions. 

In addition to this expertise, our team always works hard to go above and beyond, making sure that our clients understand how we are testing their devices and how the standards affect this. We strive to be as communicative and transparent as possible throughout the testing process so our clients are always up to date on the status of their testing.

We offer RF exposure testing services for a variety of wireless devices, such as

• Millimeter wave devices
• Near field charging devices
• Cell phones, laptops, and tablets
• Medical devices
• Modems

As well as many more devices! If you’re looking for RF exposure testing help that is provided with expertise, speed, accuracy, and integrity, contact us to learn more about our services or to get a quote.