What GaN innovations will emerge in the next few years?

alan000345

What GaN innovations will emerge in the next few years? [Copy link]

GaN is so popular now that people seem to forget that GaN is still a relatively new technology, still in its early stages of development, with great potential for improvement and room for perfection. This article will introduce several upcoming GaN innovations and predict the impact of these innovations on base station design and development in the next few years.

What GaN innovations will Qorvo have in the next few years? The following conclusions are given.

Power density

We expect to see further improvements to GaN’s already impressive power density over the next three to five years. There are ways to achieve higher power densities with GaN today, but they are too expensive to be commercially viable. For example, putting GaN on a diamond substrate instead of a silicon carbide substrate is successful but too expensive to be used in base stations. Other cost-effective but relatively low-cost processes are being investigated to increase the raw power density of the material in the coming years.

This is very attractive to the 5G infrastructure market, which is looking for lower cost, higher efficiency, and wider bandwidth base stations. Other industries are also showing interest. Radar applications are particularly beneficial as they strive to provide more power and higher efficiency in a given space. As GaN grows rapidly in the market segments, its scale effect will continue to expand and the price point will continue to fall.

Linearity

Without a doubt, the primary consideration for the GaN semiconductor industry in the base station space is to increase linear power, and its R&D efforts are focused on improving linear efficiency in the coming years.

At the same time, we do not expect modulation schemes for base stations to change significantly over the next three to five years. Modulation can be understood as a simple calculation of the number of bits transmitted per hertz. Whether using 256 QAM or 1024 QAM, the system will get a certain number of bits per hertz of bandwidth. If these numbers are not going to change significantly, then the ideal way to get more bits out of the system is to improve linear efficiency.

This does not mean that the problem cannot be solved by increasing the power of the base device. Even if no linearity improvement is achieved, the overall power of the PA can still provide a signal improvement.

Additionally, this approach helps designers reduce system complexity by requiring less system power and fewer antenna arrays. While additional power or two-stage solutions are certainly possible, the goal of GaN suppliers in the industry is to minimize trapping effects to keep the system as simple as possible.

temperature

Base station temperatures will continue to rise over time. Five years ago the standard specified equipment temperatures at 85°C. OEMs have already increased this to 105°C, and base station designs are expected to rise to 125°C.

Most GaAs devices have a maximum operating temperature of 150°C, so there is only a 25°C temperature rise. In the future, GaN suppliers must work closely with system designers to find innovative ways to keep embedded components cool.

The pressure will be even greater for smaller outdoor devices that include massive MIMO arrays. Innovative solutions do exist today, but they are not cost effective. We expect this to change in the next few years.

Total Solution

All GaN suppliers are fine-tuning the physical properties of GaN devices to improve the linear efficiency, power density and reliability of the equipment, while reducing the negative effects caused by trapping effects, current collapse effects and current drift. To a certain extent, the above goals can be achieved at the device level. However, to realize the full potential, the base station RF front-end (RFFE) system should develop in sync with the overall architecture chain, and we see a lot of cutting-edge research in this area.

As the industry moves from LDMOS to GaN solutions, it is especially important to keep pace. The technologies are completely different. You can’t just switch to a GaN PA and get 10 percentage points more efficiency. A base station optimized for LDMOS may not work for a GaN PA, and vice versa, because the system problems and solutions are different. We need to optimize the GaN base station system holistically.

GaN base station systems are already being used today and are expected to become more widely used in the coming years due to performance advantages. Embedded designers who work with suppliers to close the overall design gap will be among the industry leaders. OEMs certainly believe that they are already using a system-level approach, and we do not deny this fact, but as the RF chain becomes smarter and more integrated, we will gain further benefits.

Smart RF and AI

Reducing trapping effects is an issue for all semiconductor materials, and GaN is no exception. High-speed switching applications can create challenging trapping environments for GaN power amplifiers. Addressing these trapping effects can be complex because the PA behavior depends on the signal the PA previously received. Traditional approaches look at the physical layer, all the way down to the substrate, to determine the cause of the problematic behavior. Current technology does not yet fully mitigate trapping effects, but research and development is ongoing.

Another approach is to use software algorithms to predict the changes that lead to a trap effect. With a smart RF controller, it is possible to identify traffic patterns and predict the next peak in activity, given a deep understanding of the given conditions. Or identify a drop in activity and change something at the controller level to reduce power consumption. This approach has been implemented in base stations for many years, but people are still working to improve the technology.

Based on the above, OEMs are beginning to consider applying AI at the radio level. RFFE systems are able to optimize themselves over time. In theory, if a radio output fails in the field, the RFFE system will be able to identify the error and "learn from it". The next time, it can prevent the chain of events that may have caused the failure, or even fix the failure. This eliminates the need to report the failure to the operator, send a truck to the failure site, or send a crew to the cell tower to fix some minor problem. As you can imagine, this can save a lot of downtime and repair costs.

6G

While 5G is still in the early stages of rollout, discussions about 6G have already begun. Early predictions suggest that 6G will be possible at frequencies well above 100GHz. As we all know, this is exactly the frequency band that GaN can support. This solution will most likely not adopt traditional small cell deployment, but no matter what form it takes, we believe that GaN’s efficiency at high frequencies and large bandwidths will make it a key element in achieving 6G.

火辣西米秀

Qorvo's GaN is also powerful

btty038

GaN is now the mainstream trend of solid-state amplifiers, but in the field of communications, gallium arsenide is still needed. After all, it requires IM3 indicators, just like Toshiba's

btty038

When you get high efficiency, you will lose some indicators to compensate. I hope to break through this bottleneck. Except for the institute, it seems that very few other companies in China have GaN bare chips.