Antennas for 5G: How to guarantee the best performance
5G offers a wealth of benefits to wireless devices – high speeds, low latency and reliable connectivity, to name a few. To enjoy these benefits, antennas play a vital role. As the transmitter and receiver, a wireless device can only operate as well as an antenna allows it to. And, with cellular carriers scrutinising a device’s performance, choosing the right antenna is critical.
What are the best antennas for 5G?
5G uses more frequency bands than 4G, meaning that mobile devices need different, multiple or multiband antennas to perform properly. The right high performing antenna type in the correct position improves transmission distance and signal quality, and allows it to better exploit the benefits of 5G.
The frequency bands used depend on the geographical location and network carrier. If the antenna is to perform well across a wide variety of bands and international markets, this must be included in the specification from the outset.
5G networks, and some 4G networks, use frequencies as low as 617MHz. Ideally, the antenna ground plane should be a quarter length of the wavelength of operation. To achieve performance levels that meet network carrier requirements on this frequency band, the ground plane must be a minimum of 115mm. Many small devices cannot support such a large ground plane if the antenna sits within it.
Another option is choosing flexible printed circuit (FPC) antennas that allow tiny Internet of Things (IoT) devices to pass network carrier certification. This enables the application to still enjoy 5G’s performance improvements.
Many IoT applications do not need the performance improvements that come with 5G. For example, the data volume from sensors in a plant or on a pipeline is usually low. Optimising the antenna for 5G may be overengineering the solution.
How to optimise PCB design for 5G
Optimised PCB design is required for devices that exploit 5G technology. The antenna location affects system performance. It impacts on communication range, power consumption and battery life.
Many antennas are designed to be placed on the edge or corner of the PCB. This requires a clearance area that is typically detailed in manufacturer datasheets, although care should be taken when comparing datasheets. The proximity of other components can also affect antenna performance. For example, if metal components or casings are too close to the antenna.
To optimise circuit efficiency, impedance matching and RF transmission lines must be considered. Impedance matching is always carried out at 50ohm. Correct matching ensures that most of the power from the RF source is delivered to the antenna, and vice versa for receiving data.
Transmission lines carry radiofrequency power from the source to the load via a structured path. These are PCB traces that should also match the impedance of the antenna and remaining circuitry.
Optimising 5G mobile device performance by prototyping
Prototyping new mobile devices helps designers optimise for 5G benefits. A prototype can be tested according to the application and network carrier specifications. Before operating on their network, carriers require devices to achieve minimum performance levels. In the US, this is PTCRB certification. A similar specification is required in other regions, such as Asia and Europe.
The Global Certification Forum (GCF) certification is available to all device manufacturers. It covers cellular functionality as well as quality assurance criteria. Having minimum performance requirements for mobile devices used over operator networks guarantees service continuity and quality.
The testing and certification process examine various parameters that affect the performance of a cellular device. These include voltage standing wave ratio (VSWR), total radiated power (TRP), total isotropic sensitivity (TIS) and radiated spurious emissions (RSE). Each device is tested in the cellular brands that will be used in an anechoic chamber. The results show how well the device will transmit and receive data on a cellular network.
Devices used across international markets need testing and certification across all target frequency bands. Depending on the device application, further certification according to industry standards may be required. For example, IoT devices or products used by the medical, aerospace, energy and automotive industries have specific certification requirements.
5G mobile device manufacturing scale-up
Design for manufacture is a core element of new product design and prototyping. This is important for high volume 5G mobile devices for IoT applications, and for consumer electronics devices aimed at mass markets.
Some antennas work best for a first generation product. This is when developers release an early model with limited performance capabilities. For example, a product suitable for use on certain frequency bands is released first. Later iterations that will work internationally follow in the development pipeline.
Selecting antennas that optimise 5G performance
We recommend starting the mobile device design optimisation process with antenna selection. Factors such as ground plane length, efficiency requirements, device size and frequency bands will narrow down antenna choice. This helps you decide which type of antenna would work best for your 5G application.
Antenova manufactures a wide range of antenna products to suit different devices and their applications. Browse our full range of 5G and 4G antennas or download our antenna comparison guide.