Expertise needed to optimise 5G antenna selection
5G technology is bringing a plethora of benefits including improved throughput, decreased latency and increased network capacity, which will in turn enable more devices to access the internet. This will enable faster downloads of movies, other videos and of data of all kinds and will provide an array of business and consumer benefits, says Colin Newman, director of antenna business development, Quectel.
However, for these benefits to be realised, the underlying telecom networks and the wireless products that use them need to be optimised. To assure optimum performance of wireless devices, the entire RF front end design layout needs to be configured to deliver the best 5G performance.
This means using the best antenna types as well as the best design options. Off the shelf antennas can often be used for many types of these designs and there are a variety of antenna types to consider.
Among antennas in common use today are laser direct structuring (LDS) and liquid crystal polymer (LCP) antennas, tuneable antennas and devices that are designed to accommodate multiple antennas, such as for MIMO or beamforming solutions.
Different antennas offer different attributes. Any antenna that is used needs to be paired with the right module for the antenna type to ensure good performance and smooth integration. Multiple antenna arrangements enable greater throughput across different protocols. The typical 5G antenna setup is complex, so wireless device designers should work with module and antenna suppliers that are knowledgeable across all antenna types to ensure that they interact as expected and are backed by engineering support services that can optimise the 5G performance for their customers.
Expert vendors will also help with various antenna array design challenges as well as with the complexities that can arise from newer technologies such as 5G mmWave. Antenna position is critical to optimise performance and is a key consideration that should be addressed at the very early stage of the architecture. Addressing it after the design gets underway can lead to additional costs and delays, hurting revenues and time to market.
Similarly, there are several other design elements that should be addressed when designing devices with antennas for the best 5G performance. Among them are: Whether to use metal or plastic enclosures; the proximity of batteries, LCDs, connectors, shield cans and any other components containing metal; the size, position and orientation of the printed circuit board, any noisy components that can cause interference, other antennas sharing a similar frequency and the location of the device, just to name a few.
Antennas can be broadly categorised into four major types:
External antenna with cable: This type of antenna tends to offer excellent performance with the lowest risk. This type of antenna implementation is well known and tested. The antenna is situated far away from other system electronics, minimising the risk of any proximity issues.
Terminal antenna: Such an antenna also offers known, tested performance as well as low risk. A terminal antenna is usually the best choice for a low signal area, such as a basement.
Embedded Flex/PCB, SMD antenna: This type of antenna is more complex to configure for optimal performance and has higher risk but offers the benefit of low cost. With its surface mount design (SMD), this type of antenna is ideal for high-volume deployments.
Custom antenna: A custom antenna addresses mechanical constraints and performance and can be molded to fit the product, enabling it to be placed where a standard antenna would not be an option.
Customised antenna technologies include LDS, which is the prevailing antenna manufacturing technology on the market and offers high design flexibility with surface mount technology (SMT) component integration possible. Advantages here include the ability to etch an antenna pattern on either a plastic carrier, or the underside of the product housing, but this can be more expensive than flexible printed circuit (FPC) or sheet metal technology and double curved surface designs are not possible. FPC is an alternative option, sometimes using spring contacts for ease of assembly. However, FPC can offer limited layout complexity, with a cost between sheet metal and LDS.
Sheet metal is the most flexible 3D antenna manufacturing technology with antenna volume and RF performance improvements possible. The technology offers lower antenna cost but the tooling charge is greater than for FPC or LDS.
With so many different types of antennas, components and configuration considerations, the technology is not something to buy, plug in, turn on and it’s ready to use. To operate at all, and certainly to operate to its maximum capacity and provide optimal performance, antenna technologies should be selected carefully for their intended uses and locations.
The author is Colin Newman, director of Antenna Business Development, Quectel.