RF GaN, where to go from here?

RF GaN technology has evolved over the past two decades.

From its initial roots in defense applications, to now exploring new areas to meet the needs of telecommunications infrastructure and satellite communications. As Gallium Nitride on Silicon Carbide (GaN-on-SiC) technology matures, GaN is becoming the standard for a variety of applications, steadily gaining market share over competing technologies such as Si LDMOS and GaAs. With a focus on power efficiency, reliability, and space optimization, GaN technology has become indispensable.

The telecom infrastructure market is witnessing a significant shift in power amplifier (PA) requirements, paving the way for Infineon's GaN-on-Si technology to be launched on an 8-inch platform in 2023. This strategic move not only intensifies competition with GaN-on-SiC, but also opens up new prospects, especially in the mobile phone market.

According to Yole Group's RF GaN Compound Semiconductor Monitoring Report, the overall market value of GaN RF devices is expected to soar from $1.4 billion to over $2.2 billion, at a compound annual growth rate (CAGR) of 8.7% during 2022-2028, driven by demand for 5G telecom infrastructure and defense radar applications.

While the RF GaN market may not evolve at exactly the same rate as the wide bandgap (SiC and GaN) market for power conversion applications during 2022-2028, it is still dynamic and is transforming its supply chain. A major player in the industry, MACOM USA, completed two major acquisitions in 2023: GaN-on-Si technology from OMMIC SAS in France and RF GaN-on-SiC business at Wolfspeed in the US, a leader in RF GaN. These strategic initiatives make it possible for MACOM to become one of the leaders in the RF GaN space. At the same time, vendors such as SEDI, Qorvo and NXP maintain strong leadership positions in the RF GaN industry.

In China, companies such as SICC, Sanan Integrated Circuit, Dynax, and CETC continue to develop and develop the local RF GaN market. At the beginning of 2023, Infineon introduced the first commercial GaN-on-Si PA technology with 8-inch wafers to the telecom infrastructure market. Other vendors such as ST MicroElectronics, UMC, and GlobalFoundries are likely to follow suit in the coming years.

RF GaN has been successful in a variety of applications

Since the 90s of the 20th century, the U.S. Department of Defense has recognized the superior output power and efficiency of RF GaN-on-SiC compared to materials such as InP, GaAs HBT, GaAs HEMT, and Si LDMOS. Not only does RF GaN offer wider bandwidth, but it also helps reduce system size – two attributes that are highly sought after as telecom infrastructures expand their frequency and base station models.

The superior power and efficiency characteristics of RF GaN have led to widespread adoption in defense applications, especially in solving thermal challenges in high-power scenarios such as airborne radar systems. Defense continues to stand out as one of the largest segments of the RF GaN market. Airborne systems, which are characterized by a large number of devices, are expected to dominate the market, and the number of devices for shipborne systems is also expected to increase in the coming years.

Outside of the U.S., both Europe and China are actively nurturing their GaN ecosystems, with a particular focus on expanding deployments in radar applications, where ongoing demonstrations and GaN projects guarantee continued growth. Due to its wideband operation and enhanced reliability, GaN is preferred by the industry over alternative technologies. Satellite communications are expected to witness significant growth between 2022 and 2028. GaN devices will be the preferred choice for deploying Ka-band block upconverter systems, exhibiting a combination of high power output and lightweight. In the C- and X-band segments, the selection of GaN systems is guided by the key criterion of power added efficiency (PAE).

At the same time, RF GaN has begun to enter the credit satellite communications market, taking advantage of its high efficiency compared to other materials to achieve smaller device sizes, thereby saving valuable space at the system level. Satellite communications is the third largest RF GaN market after telecom infrastructure and defense markets, and is expected to reach $270 million by 2028, growing at a CAGR of 18% during 2022-2028.

RF GaN power amplifiers offer higher data throughput, smaller antennas, wider bandwidth, and higher efficiency. The transition from the L/C/X band to the Ku/Ka band enables higher data rates for mobile satellite communications. While traveling wave tube (TWT) technology has historically been dominant, it also has limitations, such as bulkiness and reliability issues. GaAs-based solid-state power amplifiers (SSPAs) are attracting interest in low-power and lightweight satellite systems, but their efficiency and bandwidth are limited compared to GaN.

GaN PA also offers numerous advantages over GaAs SSPA, making it attractive for a variety of applications such as GEO HTS, "New Space", LEO, and higher-frequency Earth observations. We are witnessing a growing interest in satellite communications, especially due to the growing interest in the "New Space" trend.

In addition, there is a growing focus on satellite communications in the telecom infrastructure industry, especially Space X's plan to provide 5G coverage through satellite technology. This approach raises the likelihood that there is no region of the world that lacks reliable telephone network coverage. RF GaN technology can take this opportunity to expand its market share.

GaN-on-SiC for telecom infrastructure was first introduced by Huawei in 2015 and began mass production in 2020 for 4G base stations. Since then, RF GaN technology has benefited from the rollout of 5G by meeting new base station requirements and replacing LDMOS technology. Companies around the world, such as SEDI, Wolfspeed (whose RF business is now part of MACOM), NXP, and Qorvo, have also made significant investments to ensure that GaN-on-SiC dominates and replaces its Si LDMOS counterpart in their target applications.

4G micro and macro base stations are mainly based on RRH (remote radio heads), which integrate the RF chain and analog-to-digital conversion components of the base station with up to 8 multi-stream PAs with an output power of up to 100W.

As the 4G era comes to an end, the reliance on LDMOS-based PAs for 3GHz base stations is expected to decrease. Emerging sub-6GHz 5G base stations are moving from 2x2 MIMO models to 64x64 massive MIMO (mMIMO) and replacing RRH with active antenna systems (AAS).

While increasing the number of PAs, each PA is expected to operate at a lower output power (from 100W to 5W). PAs also need to handle increasing data traffic while reducing power consumption.

GaN can meet all of these requirements. As GaN-on-SiC solves the problem of 5G frequencies up to 7GHz, the LDMOS market share is expected to decline. For 5G mmWave and 6G, RF GaN technology is expected to face stiffer competition with other materials such as SiGe and InP technologies due to higher requirements for high frequency and lower power consumption.

How is RF GaN evolving?

Since 5G telecom base stations at sub-6GHz require lower power PAs, GaN-on-Si will have a place in the 32T32R / 64T64R mMIMO base stations operating below 10W. Over the past two years, STMicroelectronics has partnered with major players such as MACOM, OMMIC (now part of MACOM), GCS, Infineon Technologies, and foundries such as Global Foundries and UMC to introduce gallium nitride on silicon on RF (GaN-on-Si) technology.

The move to mmWave small cells (2-stream and 4-stream) running at 28 – 60GHz with reduced output power opens up additional opportunities for GaN-on-Si. As telecom infrastructure increasingly adopts lower output power systems, the demand for antenna array systems (AAS) and small cells is driving the adoption of GaN-on-Si to meet the demands for multi-stream, small cell, and millimeter wave beamformer performance.

Looking ahead to the next generation of 6G, which will have higher frequencies, GaN-on-Si is expected to coexist with the existing technology GaN-on-SiC.

A significant development this year was the introduction of GaN-on-Si PA with 8-inch technology to meet the needs of the telecom infrastructure market. Anticipating this trend, other major players such as Global Foundries, UMC, MACOM, and STMicroElectronics expect to follow suit in the coming years. Notably, many vendors choose to enter the market directly with GaN-on-Si, bypassing GaN-on-SiC technology.

GaN is expected to account for more than 87% of telecom infrastructure PA device shipments by 2028. Of these, more than 77% will be gallium nitride on silicon carbide (GaN-on-SiC) and 10% will be gallium nitride on silicon (GaN-on-Silicon), while LDMOS is expected to lose market share.

The promise of GaN-on-Si technology extends to power amplifiers for 5G mobile phones in the FR3 band. While GaN-on-Si has potential in mobile phone PAs at sub-7GHz and 5G mmWave frequencies, the existing dominance of mature GaAs solutions in sub-7GHz and the traction that silicon-based solutions are gaining in mmWave must be acknowledged. These technologies have matured in both technology and supply chain, making them significant competitors. GaN-on-Si is promising in the open race for FR3, but complex design changes are required to integrate into mobile phone systems, making its adoption in the FR3 band a long-term goal.

The decisive impact on the fate of GaN-on-Si technology ultimately depends on smartphone OEMs (OEMs) such as Apple, Samsung, and Xiaomi, which could be a turning point for the GaN-on-Si industry.

In the mobile ecosystem,

RF GaN 仍然引起关注

Today, GaN-on-SiC has a well-established supply chain as the main platform. GaN-on-SiC technology is available from equipment suppliers such as SEDI, Qorvo, Wolfspeed and NXP, as well as defense-related companies such as Raytheon, BAE Systems and Northrop Grumman.

In 2022, SEDI, Qorvo and Wolfspeed were the leaders in RF GaN. As a newcomer to the GaN space, NXP entered the telecom supply chain with significant growth by opening a 6-inch GaN-on-SiC fab in the U.S. in 2020. LDMOS products have become a leader in GaN-based telecom infrastructure. In addition, GaN-on-SiC has welcomed innovators such as Altum RF, mmTron, and GaN Semiconductors over the past few years. Now, this expanding industry offers more room for GaN-on-Si technology, with low-power GaN solutions expected for 32T32R / 64T64R mMIMO base stations below 10W, with more coming to market this year.

The S.I.SiC wafer market is still divided between the three major suppliers, Wolfspeed, Coherent and SICC. In the defense sector, companies such as Raytheon and Northrop Grumman are leading the way in the adoption of GaN. Wolfspeed and Qorvo are also GaN foundries. Ericsson and Nokia are expanding the supply of RF GaN devices from multiple equipment vendors around the telecom market, while Samsung is working closely with Korean equipment manufacturers. Since U.S. sanctions, Huawei and ZTE have turned to Chinese supply chains to develop autonomous capabilities.

To overcome U.S. sanctions, China continues to develop its domestic RF GaN technology and Chinese supply chain. In the GaN-on-SiC ecosystem, leading players are world-class at both the wafer and end system levels, and since 2020, China has been accelerating the development of epitaxial wafers, front-end, back-end processes and designs. There is more than one active participant at each level, which shows the progress of the Chinese ecosystem over the past two years.

Yole Intelligence's RF GaN 2023 report accurately predicts Wolfspeed's decision to divest its RF business, marking a strategic shift to SiC power technology. Following its initial acquisition of $345 million in 2018, Wolfspeed was acquired by Infineon Technologies for $125 million, a move that makes Wolfspeed a major player in the power SiC industry. The decision to stop supplying competitors after the sale enhanced their expansion potential.

At the same time, MACOM's early exploration of GaN-on-Si since 2018 and its collaboration with STMicroelectronics have made it a pioneer. The successful production of RF GaN-on-Si prototypes in 2022 reflects their commitment to introducing GaN-on-Si technology, with an emphasis on applications in the telecom and consumer sectors. MACOM's strategic acquisition of OMMIC SAS in 2023 demonstrates their focus on mmWave technology, enhancing their product portfolio in the defense and aerospace sectors in the U.S. and Europe.

In the early 2020s, MACOM strategically shifted its focus to GaN on SiC technology, specializing in high-power devices up to 7kW. In collaboration with the Air Force Research Laboratory and with the U.S. Department of Defense, they have made significant advances in GaN-on-SiC technology, which operates at high frequencies in the K to Ka band.

MACOM recently acquired Wolfspeed's RF business, solidifying its position in the defense, aerospace, and telecommunications markets. With Wolfspeed's position in the RF GaN market, MACOM strengthens its strategic position, emphasizing its commitment to expanding its share of the RF GaN market with a comprehensive portfolio of GaN-on-Si and GaN-on-SiC technologies covering a wide frequency range.

Companies such as STMicroelectronics, MACOM, and Infineon Technologies, as well as foundries such as GF and UMC, have been actively involved in the development and adoption of RF GaN-on-Si technology in the GaN-on-Si ecosystem over the past few years. Earlier this year, Infineon Technologies introduced GaN-on-Si PA technology on 8-inch wafers to meet the needs of the telecom infrastructure market. We hope other players will follow suit.

Companies such as GlobalFoundries, STMicroelectronics, and Infineon are already active in the power GaN industry. Despite challenges such as technology nodes and epitaxial control, these players are still exploring synergies between RF and power GaN, leveraging similar GaN-on-Si technologies to meet different market needs.

In addition, innovative companies are entering the ecosystem, such as Finwave, which is focused on developing 3DGaN FinFET technology on 8-inch GaN-on-Si wafers. They use standard silicon manufacturing tools in the development process. In addition to these innovative companies, established companies such as GCS, UMC, Sony, and Global Foundries also have the potential to adapt and enter the market quickly.

Participants are preparing for these killer applications to run their technology and usher in a new era of high-volume GaN-on-Si manufacturing in the RF industry.

What's next for the RF GaN industry?

In summary, the RF GaN industry has shifted over the past two decades, from dominance in defense applications to coexistence in multiple markets such as telecommunications and satellite communications. GaN-on-SiC technology has become a mainstream technology for power amplifiers in defense and telecom infrastructure and has gained market share. The introduction of GaN-on-Si in telecom infrastructure bodes well for growth and opens up new opportunities. Yole Group's RF GaN Compound Semiconductor Monitoring predicts strong growth in the market, driven by 5G and defense applications, and expects the RF GaN device market to exceed $2.2 billion by 2028.

2023 has been a significant year to date, as MACOM has made two high-profile strategic acquisitions that can help them gain more market share in the current landscape, while Infineon has introduced the first GaN-on-Si Pa technology based on an 8-inch platform.

Globally, GaN is becoming increasingly important in the defense sector, especially in airborne systems. The advent of 5G presents an opportunity for GaN in mMIMO base stations and extends into the expected 6G era. GaN-on-Si shows promise in mobile phone technology trends, but faces stiff competition from established platforms. The RF GaN-on-Si supply chain is diversifying with the addition of new players, thereby contributing to the sustainable growth of the market in the future.

At the end of the day, the RF GaN industry is at a critical juncture as GaN-on-Si technology matures. This begs the question: is now a good time to explore new growth prospects in an untapped market, or can GaN-on-Si gain a larger market share than GaN-on-Si?