Paul Dixon describes how collaboration can help overcome heat issues and electromagnetic interference in high-performance 5G devices: https://www.linkedin.com/pulse/two-biggest-challenges-making-5g-hype-reality-paul-dixon
Read below:
The two biggest challenges to making 5G hype a reality
5G hype is everywhere you look. From electronics manufacturers to the military to consumers, it seems like everyone is itching to capitalize on the ability to transmit more data, more precisely and faster than ever before.
The impact of 5G promises to be huge. IHS Markit estimates that 5G will enable $12.3 trillion of global economic output in 2035. Potential applications for 5G are nearly endless. Technologies like virtual reality gaming will thrive on 5G. 5G will likely also play a key role in the high-volume data exchange that will be part of autonomous driving advancements. More immediately, 5G will facilitate the advent of fixed wireless access, which untethers homes and businesses from fiber optic lines, delivering hyper-fast internet speeds through wireless beams.
For all its promise, however, 5G also poses some vexing challenges for the design engineers who build the hardware that will make all this potential a reality. The challenges emanate from the fact that 5G operates at higher frequencies and requires putting more high-powered electronics in tinier and more compact spaces. As a result, 5G produces overlapping challenges related to electromagnetic interference (EMI) and heat. If design engineers don’t address these issues effectively, they risk producing unreliable hardware and even running afoul of FCC regulations.
The advent of 5G is great news for all consumers of data. But the stakes are high for design engineers to innovate and devise solutions to the complex, multifaceted challenges that accompany 5G.
The Catch-22 of EMI and heat
The most immediate application of 5G technology is in the base stations that will send signals for fixed wireless access. 5G base stations utilize the millimeter wave range, where large amounts of bandwidth are available. This higher frequency spectrum enables the transfer of large amounts of data. And with low latency, the delay between issuing a command and execution of a command becomes short enough to enable real-time operation in fast-moving systems.
Further, 5G base stations use multiple in-multiple out (MIMO) antennas to facilitate spatial multiplexing. In layman’s terms, this means that antennas send signals directly to users, which prevents the familiar problem of overloaded cell networks. However, all of this requires a large number of antennas – MIMO arrays at mmWave typically use 64 or 128 elements. Each element requires its own power amplifiers and analog-digital converters – all within a very tight space (we’re talking as small as eight centimeters on a side). These tightly packed electronics produce significant amounts of heat that design engineers must dissipate to ensure reliable operability.
Traditionally, engineers would use a metal heat sink to manage heat (a thermal interface material is often used between the heat source and heat sink to enhance the thermal coupling between these two components). However, putting metal heat sinks next to antennas can create an electromagnetic interference problem. Thus, by fixing the heat problem using traditional methods, design engineers may create an EMI problem.
Things don’t get any easier when we turn to EMI. The effectiveness of typical EMI mitigation tools such as board-level shields decreases with higher frequencies, because smaller wavelengths make it easier for energy to leak through gaps in shields. This of course poses a problem at mmWave. Further, cavity resonance, which occurs when a conductive enclosure is larger than half a wavelength, can cause trouble at higher frequencies.
Within any piece of 5G technology, there’s an internal battle taking place between electromagnetic interference and heat. It seems like a Catch-22. But design engineers can tackle the problem. Here’s how:
1. Remove silos in the design process
Too often, design engineers address electromagnetic interference and heat during separate stages of the design engineering process. These two issues are sometimes even dealt with by different teams. This siloed approach is inefficient no matter if the project is 5G-related or not. But it is increasingly untenable with 5G, given the interrelated EMI and heat challenges.
It’s crucial that design engineers break down barriers between teams and work together to address EMI and heat challenges. A streamlined approach will enable them to shorten the design cycle and move products to market quicker.
2. Include protective components in your blueprint
There’s a misconception among some design engineers that if they use protective components like absorbers, they are tacitly admitting that their designs are somehow fundamentally flawed. That couldn’t be further from the truth – especially when it comes to 5G devices. In fact, with 5G, I’d argue it’s impossible to design around protective components like absorbers, which increase in effectiveness at higher frequencies and can help address heat sink-generated EMI issues at mmWave. Of course, there are many different absorber materials (everything from polyurethane foams to silicone or urethane elastomers) and a variety of product-specific considerations that go into determining the precise absorber solution for a particular piece of hardware.
But the fact remains that these protective components are essential elements of 5G devices. As pressures on design engineers mount – and design cycle times shrink as companies seek to meet market demand – they can’t afford a setback, especially one that could be traced back to a reluctance to incorporate protective components. So, make protective components such as absorbers a fixed piece of the bill of materials at the beginning of the design process. Design engineers that don’t account for these protective components run the risk of having to go back to the drawing board – which delays production and wastes time and money.
3. Think multifunctional
While there’s no one-size-fits-all solution to EMI and heat challenges in 5G technology, multifunctional products are coming on the market that enable design engineers to address EMI and heat issues simultaneously and save space within devices. These products essentially act as heat-mitigating gap fillers and EMI-reducing absorbers. Innovation is constantly happening in this emerging area. So, as design engineers develop 5G devices, they must stay on top of industry developments to ensure they’re using the most advanced solutions.
The future of 5G is in the hands of design engineers. They can speed its accessibility and impact by thinking strategically and in a unified way about EMI and heat.
Follow Laird Performance Materials on LinkedIn for comprehensive coverage of how to enable and protect 5G devices.