5G is the next generation of cellular network to which all of our smartphones and SIM-containing devices connect. It operates at a much higher frequency than past generations which leads to both unique advantages and challenging drawbacks. This high frequency (28-52.6GHz) allows for much wider individual bands, enabling many more devices to occupy a single one or for subdivisions to exist. The shorter wavelength that comes from the higher frequency allows for much lower latency and more flexible packet allocation which, for example, will make face to face communication more seamless and life like. Additionally there is a 10x potential speed improvement over 4G which enables users to download large files in seconds.
The high frequency and shorter wavelength that enables all of these advancements also cause its greatest drawbacks. With such short wavelengths, the range of a 5G signal is greatly diminished. Rather than needing an antenna every couple miles like with 4G, 5G requires one antenna every few city blocks to compensate. The signal also cannot pass through walls or even very thick clothing. To compensate for this, the gain of the signal is boosted from a few hundred milliwatts to 5-10 watts and a technology called MIMO beamforming is implemented. Rather than broadcasting a wide net with the antennas that users can enter to connect, a beamforming enabled antenna locates the device within its range and aims its signal directly at it to cut down on power usage and increase efficiency. Cellular devices will need to have directional antenna arrays positioned around the device as adding MIMO to devices of that size would currently be too expensive and complex. These antennas as they are now add additional heft and power usage to the cellphone. The necessity for these technologies adds complexity and cost to a previously simple system.
While these challenges are daunting, researchers around the world are looking for ways to cut down on power usage and increase efficiency and reliability. This summer, I will be working with Prof. Liu and the manufacturer Jabil to develop faster methods for testing and calibrating 5G antenna arrays to ensure that initial setup and the continued operation of those installations is as fast and efficient as possible.