Gallium Nitride (GaN) was discovered in 1875 by French scientist Paul-Émile Lecoq de Boisbaudran. Research into GaN continued culminating with the growth of single-crystal films of GaN in 1960. However, it was not until 2010 when GaN products first became widely available for sale.
The properties of GaN have made it a leading candidate to replace SiC-based (silicon carbide) transistors, especially concerning power conversion. Compared to SiC, GaN-based devices can deliver increased energy efficiency, higher temperature operation, and produce less heat. ”The ability of a GaN to operate at a high switching frequency can reduce the size of energy storage components in the power circuit thereby scaling down the system form-factor (see Pushpakaran, Bejoy, et al, “Commercial GaN-Based Power Electronic Systems: A Review” in Journal of Electronic Materials, Vol. 49, No. 11, 2020, p.6260). These characteristics help contribute to GaN devices that require less space resulting in more compact devices and faster-charging cycles.
Most of the challenges associated with the early implementations of GaN devices, such as reliability, supplier diversity, and production capacity have been solved. However, the cost of GaN devices has become an oft-cited impediment when looking to understand the future of GaN as a replacement for SiC-based products. For example, in 2012 a 2” inch GaN substrate was priced at $1,900 (see Anzaldua, Antonio, “GaN Transistors for a Dollar? GaN Overcomes One Major Setback” All About Circuits, 16 August,, 2021”). Some of the pricing disadvantages of GaN are due to its lower volumes shipped, given GaN’s status as a challenger to the mature SiC technology. This disadvantage is rapidly declining as improvements in Chip-scale packaging technology will help reduce the price of low-voltage to GaN $1.00, making it less costly when compared to a similar SiC device. Also, many next-generation devices used in 5G and 6G networks do not have a SiC equivalent and will require GaN components to operate, driving production and demand and lowering costs.
In the smartphone market, the bill of materials dictates pricing, which is a significant driver for purchasing decisions in the mass market. At the same time, poor battery performance and long lengthy recharge cycles have been consistently cited as an area in need of significant improvement throughout the portable device market. The combination of power efficiency, size, and heat reduction coupled with pricing will help push GaN past SiC.
Official UnWired Contributor
Mobile Device Technology and Trends
As we approach the mid-point of 2021, the evolution and reach of the wireless power industry continues to grow. The following trends provide new challenges and opportunities for forward-thinking companies:
Focus Shifts Beyond Mobile
The wireless power market continues to expand beyond smartphones, to wider applications across computing, wearables, hearables, small appliances, smart home, medical, industrial, robotics, automotive, 5G telecom, and retail sectors.
New applications with unique form factors, design challenges, charging needs, and the strong desire for interoperability are adopting next-generation wireless power solutions that include – low-frequency induction and resonance, high-frequency resonance, new emerging high-frequency NFC Charging, ultra-high frequency ‘distance’ wireless charging based on radio frequency (RF), infrared (IR), or ultrasonic (US) technology.
Note: Applications in each bubble (above figure) are segmented based on the industry sectors they belong, irrespective of which wireless power technology they are/may adopt and their interoperability status.
Market Needs Further Technology Advancement
Wireless power technology is on the brink of becoming mainstream and being offered as a standard feature, but it needs further technological advancement. Each wireless power solution type – low-frequency, high-frequency, and distance wireless charging – is at a different development stage.
While low-frequency induction-based solutions continue to dominate the wireless power market, mainly driven by its adoption across mobile ecosystem devices (primarily smartphones), other sector OEMs continue to assess the credibility, commercial viability, and appropriateness of integrating other wireless power solutions for their devices. Considering the product needs, some companies are also using high-frequency resonance, NFC charging, or uncoupled distance charging based on RF or IR solutions, while some are developing customized, multi-frequency ‘hybrid’ systems.
Low Frequency Inductive Solutions Continue to Dominate
Based on WAWT’s recently published ‘Wireless Power Market Tracker’ report, the low-frequency wireless power technology segment driven by WPC’s induction-based (Qi-) standard, will continue to have a majority share of unit shipments through the five-year forecast period. However, its share is expected to drop from almost 100% to around 75% in the next five years. This decline in market share is a result of growth in wider applications adopting wireless power solutions (magnetic resonance, NFC charging, and distance charging), that are better aligned to their needs.
WPC (Wireless Power Consortium) with its low-frequency inductive solution is developing standards beyond low-power (PC0- 5W-15W) to medium-power (PC1- 30W-65W) and to high-power profile (200W-2200W) with its Ki-Cordless Kitchen Standard. However, one still finds gaps between power groups which could be relevant for other emerging applications. However, there is lack of interoperability across its power classes within low-frequency solutions.
Other Technology Solutions Continue to Develop Further
WEVC solution gradually moves to the fast track
The standard for low-frequency magnetic resonance-based solution, backed by SAE (Society for Automotive Engineers) continues to develop at a faster pace, with regulatory bodies across other regions providing additional approvals. The low-frequency resonance standard primarily focuses on the wireless charging of electric vehicles (WEVC) with its 3kW-11kW solutions, possibly extending to 21kW power levels.
AirFuel Alliance facilitates wider applications to benefit from its resonance and RF standard
AirFuel Alliance is releasing enhanced standard specifications for its high-frequency, resonance-based wireless charging solution for a wide range of applications such as laptops, personal e-mobility devices like e-bikes/e-scooters, service robots, 5G repeaters. Innovation-driven Chinese mobile manufacturer, Oppo had recently demonstrated wireless power solution for its mobiles using Airfuel Alliance Resonance. AirFuel is also providing hands-on training and development kits to companies and developers. AirFuel Alliance on the other hand is also working on its AirFuel RF wireless charging standard.
While NFC Charging is carving out its niche, ‘distance-charging’ solutions gains more traction
Devices with smaller form-factors, design constraints, and low power needs are seeking NFC charging or distance charging solutions using either RF or IR.
The market for such wireless power solutions is expected to show robust growth, driven by wearables, IoT sensors, ESLs (Electronic Shelf Labels), and others. However, the opportunity is restricted to applications needing less than 1W (max 2W) power levels.
WAWT expects 2021 to be the ‘make-or-break’ year for companies developing ‘distance-charging’ solutions, as this segment gains traction, with few new players entering this segment.
Are We Losing Interoperability?
There is a trend towards use of proprietary solutions, using either low-frequency induction or high-frequency resonance solutions.
Apple’s iPhone 12 launch, where the company introduced a 15W wireless charging solution using its proprietary MagSafe technology instead of WPC’s EPP solution, confirms the trend towards use of proprietary solutions. While Apple may have created a relatively better user experience (key innovation driver for Apple) with it MagSafe technology (addressing the alignment issues), one could argue whether this approach is a step forward from a wireless power technology perspective – or a few steps back.
Apple’s cancellation of its AirPower technology in 2018, followed by introduction of MagSafe in 2020, have created some disruption in the wireless power market, possibly triggering renewed interest amongst OEMs and developers to re-assess existing low-frequency induction and possibly exploring new wireless power transfer solutions including high-frequency magnetic resonance solutions and/or working on a new wireless power transfer solution.
WAWT speculates about the possible emergence of another wireless power solution/specification in the next 12 months, with the aim of becoming an industry standard.
Opportunity Is Huge, with 8 Billion Devices Expected to Ship in the Next 5 Years
Based on WAWT’s recently released Wireless Power Market Tracker report, the following trends will drive industry growth and innovation in the coming years:
The total wireless power receiver and transmitter market, in terms of unit shipments, is forecast to grow at a five-year CAGR of 30%.
While smartphones, personal appliances and smartwatches are currently the top three applications adopting wireless power, other applications across wearables, industrial (IoT sensors and AGVs), and retail sectors are expected to see a lot of traction in the next 2-3 years.
WAWT expects the ‘distance’ wireless charging market (using RF and IR-based solutions) to witness a lot of activity during 2021. Several new players such as Xiaomi, Motorola, Huawei have already announced development of RF-based solutions, with more such announcements expected during the year.
The total addressable wireless power receiver (Rx) and transmitter (Tx) market is expected to be around 8 billion units in the next five years.
WAWT Covers It All
Wired and Wireless Technologies (WAWT) is a strategic technology analyst and consultancy firm providing reliable data, knowledge, insights and market intelligence on the latest technology trends and developments. WAWT offers the industry’s most comprehensive research on the wireless power technology, consisting of critical market data (estimates and forecast), trends, insights, and market intelligence. Its wireless power research covers all key wireless power technology types, power classes, and wide range of 30+ applications. If you are interested to gain further knowledge and insights on the market, and access to its valued and insightful reports please visit www.wawt.tech and submit your enquiry.
Dinesh Kithany, Founder and Chief Analyst at WAWT, is an established wireless power industry expert with over 26 years of experience providing high-level insights and strategic advice to companies across technology sectors. Former Lead Analyst at Informa/Omdia and IHS Markit, with deep expertise in wireless power, power supplies, wired interface and connectivity technology, smart home and home appliances, service robots and drones, connectivity, semiconductors, and wider consumer electronics markets. Dinesh is a frequent and most sought-after speaker at key industry conferences, trade shows and events worldwide including CES, IFA, CABA, ITRI, WPC Conferences, NFC Forum and AirFuel Alliance. To contact Dinesh, please visit www.wawt.tech or email him at firstname.lastname@example.org
In February 2020, due to concerns about the COVID-19 pandemic, the GSMA canceled its annual Mobile World Congress (MWC) trade show and conference. With the advent of vaccines and declining infection rates, on February 23rd, GSMA launched MWC Shanghai 2021, heralding the return of large in-person events. The event featured the expected announcements regarding the latest mobile technology, including 5G, IoT, new smartphones, and regulatory initiatives. Surprisingly, there were also several product announcements focused upon wireless charging.
Chengdu Sprouting and Oppo Debut “Wireless Air Charging” at MWC Shanghai 2021
In partnership with Oppo, Chengdu Sprouting announced at MWC Shanghai 2021 the upcoming release of a smartphone powered by AirFuel Resonant. AirFuel Resonant is a mature technology with mature technical specifications, a proven testing and certification process, and early products have already proven in-market, making it an ideal solution for multiple applications, including smartphones.
Oppo demonstrated its “Wireless Air Charging” functionality in the company’s booth and through an official video featuring an Oppo X 2021 rollable concept phone (announced in November 2020) placed on a wireless charging pad. Even when lifted or tilted in various directions, the device charges successfully as long as it is within 10cm of its charging pad. The critical feature drawing industry and media attention is an experience that is truly wireless – freeing users from the requirement to place devices with a millimeter level of precision or using magnets to align devices with coils. Using Magnetic Resonance, Oppo claims that its Wireless Air Charging Solution can deliver 7.5 watts of charging power. The debut of this wireless charging solution indicates we have reached a stage where the technology is ready for integration into mainstream consumer products.
The debut of Oppo’s wireless charging solution suggests that the industry has reached a stage where the technology is ready for integration into mainstream consumer products. However, it is important to place the product within the context of the announcement. First, Oppo has made it clear that the phone and its charging technology are conceptual, and the company has not announced a release date for either product. Second, the ability to charge the phone while hovering within 10 cm of the charging pad is laudable but is not the endgame but rather a stop along the technology adoption curve.
Readers in China can view a recap of the announcement HERE. English language readers can reference a comprehensive Yahoo! Finance article HERE or International Business Times’ perspective HERE.
RF Charging Announcements
Both Motorola and Xiaomi also demonstrated air charging solutions using RF-based wireless power at MWC Shanghai 2021. RF technology is governed by safety regulations that limit the amount of power that can be delivered. RF technology is maturing rapidly and a number of products based on RF wireless power have hit the market and have passed all appropriate regulatory requirements.
Xiaomi’s solution, known as the Mi Air Charge, is a 5W charging system that uses 144 antennas in the base station known as the pile sending millimeter waves to a phone, which receives them on a 14-antenna array inside the device. The device antenna array converts millimeter-wave into electrical power via a rectifier circuit. Xiaomi has yet to announce a released date, a phone that is compatible with the charging system or specifications.
Answering the challenge from Xiaomi, Motorola announced an RF wireless charging system that it claims could charge phones from as far as 100cm away and charge multiple phones simultaneously. Known as the One Hyper, Motorola demonstrated its solution on Weibo, charging two Motorola Edge phones placed at 80cm and one at 100cm. During the demonstration, someone’s hand was placed in front of the charging One Hyper hub, which caused the immediate cessation of charging. Similar to Xiaomi, Motorola did not provide a release date or specifications.
In 2021 and beyond, we look forward to seeing many more products come to market utilizing next-generation wireless power solutions. The solutions demonstrated at MWC Shanghai 2021 clearly hint at an exciting future for wireless power. However, the wireless power industry should realize that announcements that provide demos that elicit oohs and aahs from the audience need to deliver working products to market. This is no easy task given the technical challenges but every product that goes nowhere or is vaporware makes it difficult for the industry to move forward.
Official UnWired Contributor
Program Director, Mobile Device Technology and Trends, International Data Corporation (IDC)