It takes more than just the 5G mobile phone and network to enable the entire 5G revolution. This article highlights some examples that enables 5G, the updates and associated challenges.
5G development and deployment are accelerating, especially in Asia. Field trials are underway, components are coming, and testing covers the spectrum in more ways than one. What are the challenges and how is the ecosystem shaping up? Find out more in this month’s In Focus series.
For a while now, we keep hearing about 5G deployment and devices in the news. In our mind, we usually think about the next 5G mobile phone from your favorite brand. A few of us would know that it takes more than just the 5G mobile phone and mobile network to enable to entire 5G revolution.
In this article, we will highlight some examples that enables 5G, the updates and associated challenges.
Powering the 5G Revolution
All electronics starts operating from a power source. As the devices evolve in 5G, the very power source that runs 5G needs to be upgraded as well. The latest buzzwords in power semiconductors are the wide bandgap devices, powered by silicon carbide (SiC) and gallium nitride (GaN).
While we take so much for granted, many engineers and scientists are working every day with materials like SiC and GaN to develop power electronic systems that will drive the new 5G revolution, components and modules for hybrid and electric vehicles, military and aerospace systems, and power systems for computing and consumer products. But what is the significance of SiC and GaN, and how do you handle the testing challenges we are facing with these materials?
After years of research and design, SiC and GaN power devices are becoming more viable. The shift to SiC and GaN is driving new designs from the ground up. SiC, with its capability of driving high power at high voltages for high power applications, and GaN, with its super high-power density for medium to low power applications, are pushing the limits of what is possible with silicon-based designs in efficiency and power density. For example, SiC is finding applications in higher power, higher voltage designs such as motor drives in automobiles, locomotives, and PV inverters. GaN technology is also shaking up the world of RF power amplifiers, thanks to many of the same attributes that make it well-suited for power conversion. GaN is carving its niche in data-center power, wireless power, consumer power supplies, and automotive and military/government power electronics.
Experts from Qualcomm, Rohde & Schwarz, Keysight Technologies, Movandi, EdgeQ, Infineon, and SPIL will share their insights and strategies—from the testing challenges, to semiconductor design and packaging, all the way to deployment and new applications and services—to stay ahead of this rapidly growing mobile technology.
These devices, though high-performance, come with challenges for designers. Setting cost and reliability aside, these power devices are not drop-in replacements for their silicon counterparts. Semiconductor R&D engineers are working to validate and characterize new components. Driver manufacturers are developing new gate drivers to withstand the demands of faster switching, EMI management, and more sophisticated topologies. Manufacturing engineers in these companies are dealing with wafer testing challenges – having to thoroughly test smaller devices over wider voltage and current ranges than ever.
Manually characterizing wafer and package-part level devices for electrical performance requires learning new techniques, equipment, and probing infrastructure for low level measurement (e.g., pA of leakage current measurement in the presence of high breakdown voltage).
Some of the biggest challenges working with SiC and GaN devices are the gate drive requirements. SiC requires much higher gate voltage (Vgs) with a negative bias for turn off. GaN, on the other hand, has much lower threshold voltage (Vth), requiring tight gate drive designs. Wide band gap (WBG) devices, by the nature of their physics, also have a higher body diode voltage drop that requires much tighter control of dead-time and turn-on/turn-off transitions.
Solving these challenges may be tough for us. It is critical that we have accurate electrical source and measure testing when characterizing these high voltage devices so that the right design decisions can be made in a timely fashion. Increasing design margins and overdesigning will only drive costs up and bring performance down. And, due to the high voltages involved—usually >200 V—keeping the scientist and engineer safe from harmful voltage is very important.
Increasing the performance of data processing, transfer, and storage
From augmented reality to artificial intelligence, cloud computing to IoT, 5G is fueling growth in new technologies—and the data they create. Besides new CPU, GPU, ASICs and FPGA that drives the data processing, other parts of the system evolve along too.
With more and more data comes the need for storage and fast access, which means that technology like DDR5 has never been more important. The need for data centers to continuously store, transfer and process this data pushes the limits of high-speed signaling and ushers in testing challenges not seen in memory to date.
DDR5 is very different from DDR4 and is more like LPDDR4. Check out these nine changes that DDR5 brings to the table:
High Speed Serial Buses
Next generation innovations are bringing with them next generation challenges. High-speed communication between subsystems within the hardware is often based on the well trusted PCI Express bus. As the PCI Express standards progress from Gen 4 (16.0 GT/s) to Gen 5 (32.0 GT/s), engineers face a variety of new validation challenges from the doubling of data rates:
With 5G, the amount of data transacted is grow over 50% by 2025. The drives rapid worldwide growth and demand for high-performance datacenter infrastructure and cloud computing. To keep pace with this relentless demand, developers are transitioning to 400G technologies enabling smaller, faster, lower cost-per-bit solutions.
There are several core technologies that are enabling 400G or even 800G, including the use of higher order modulation and higher data rates up to 56 GBaud. This new modulation scheme provides four-level pulse amplitude modulation (PAM4), which transmits two bits per symbol, doubling the data rate compared to conventional NRZ.
PAM4 signals, having a lower signal-to-noise ratio and one-third of the amplitude of equivalent NRZ, require more advanced tools and features for successful validation.
One of the greatest challenges is keeping test cost per device as low as possible while meeting required specifications. With PAM4 signals increasing the number of tests needed to conduct versus NRZ signals by a factor greater than 10, solutions providing measurements quickly for optimized tuning, with the lowest noise to maximize production yields are required.
Evolution at the consumer end of 5G
The consumer computing industry also demands a new form of IO’s that can deliver on a vision of future needs. These needs include improved video and audio quality, such as 2K, 4K, and 8K displays, shrinking of the system form factor so that we can design thinner, lightweight laptops, and flexible performance. Thunderbolt technology meets the competing demands of a convenient standards-based, multifunctional small form factor, and of course, faster data rates.
Fundamentally, Thunderbolt is a tunneling architecture designed to take a few underlying protocols and combine them into a single interface so that the total speed and performance of the connection can be shared between the underlying usages of these protocols. Whether they are data, display or something else, Thunderbolt 1 and 2 built on a mini-DisplayPort connector and deliver the physical data rate of 10Gbps. By aggregating two lanes Thunderbolt 2 doubles the data to 20Gbps. Now, Thunderbolt 3 builds on a USB Type-C connector and doubles the data rate again to 40Gbps in each direction by aggregating two lanes of 20Gbps. Thunderbolt 3 supports the basic USB 2.0 and USB 3.1 power delivery modes. In short, Thunderbolt 3 offers the best single cable docking solution.
The Thunderbolt 3 specification was released to USB-IF for royalty-free use in the development of USB4 specification. Now, Thunderbolt 4 and USB4 products will use the same underlying protocol specification. Thunderbolt 4 offers the maximum data rate of 40Gbps bi-directional and offers the same 15W to devices or 100W of charging power.
The Thunderbolt 4 system requirement is 32Gbps of data using four lanes of PCIe Gen-3. If you talk about the electrical verification of Thunderbolt 4, then it’s the same as Thunderbolt 3. From an end-user perspective, Thunderbolt 4 peripherals will have four ports—one up-facing-port (UFP) and three down-facing-ports (DFP). The Thunderbolt 4 cable can work with any of the USB-C ports and can support Thunderbolt 3, USB 2.0 or USB 3.1/3.2 and DisplayPort Type-C devices.
Next Generation applications
5G is also expected to drive several new applications that requires smart communication between end nodes and the wider smart environment. Smart estates will have next generation of IoT enabling predictive maintenance, smart monitoring, waste, and energy management.
Manufacturing will be even more connected with artificial intelligence and smarter robotics to increase both efficiency and effectiveness. Mobility in both land and maritime can expect to get smarter with more data sharing for more advanced tasks to be automated and better managed.
Putting next generation technologies together
5G is a buzzword we hear these days, but the underlying technologies that enables 5G is often under-estimated. With the myriad of new technologies assuring that the entire ecosystem works starts with understanding the changes in the complexity. The complexity to enable them gives rise to new test challenges.
Measurement need not be a necessary evil. With a good set of measurement, characterization tool and knowledge, engineers now know why the device fails and what made it went well. We can now double down on our strength and learn from the mistakes with knowledge and data provided by good measurement plans and tools. At the same time, measurement tools have also evolved to be more automated via software and cloud. This has made life of engineers so much easier.
These evolution in tools enable engineers to have data on hand in a quicker and systematic way to analyze and collaborate. These learnings and data then become the foundation of our key to build and engineer a better future.