When dozens of people speak into your ear at the same time, it is undoubtedly difficult to distinguish what each of them is saying. Smartphones face a similar challenge. The difference is that a smartphone can accurately filter out the signals it wants to "hear" through its built-in RF filters. Although this small component, the RF filter, may seem inconspicuous, it is one of the most critical devices in the RF front-end of a smartphone. As 5G smartphones support an increasing number of frequency bands, the wireless signals a single device needs to process become increasingly complex, posing higher requirements for both the quantity and quality of RF filters.
Smartphone RF Filters In 2025, the global RF front-end IC market was valued at approximately USD 44 billion, equivalent to about RMB 314.3 billion; the Chinese market was valued at approximately RMB 115 billion, accounting for about 36% of the global market. However, the actual share belonging to Chinese manufacturers was only about 10%—the combined revenue of the six major domestic RF front-end companies in 2025 was approximately RMB 12 billion, accounting for merely 10.5% of the Chinese market. A massive share of the market was captured by companies from the United States, Japan, and South Korea.
Within the RF front-end, filters represent a highly lucrative yet tough segment.
According to data from Yole, the global RF filter market for mobile terminals was approximately USD 7.35 billion in 2022 and is projected to grow to about USD 9.2 billion by 2025, with a compound annual growth rate of nearly 8%. Among them, the market size for BAW (Bulk Acoustic Wave) filters has reached approximately USD 3.2 billion, accounting for over 30% of the entire filter market, and is expected to maintain double-digit growth in the coming years.
However, a lucrative prize is still a tough bone to chew. The entry barriers for BAW filters are particularly high, imposing stringent requirements on materials, wafer fabrication, thin-film processes, packaging, and yield rates. More troublingly, global leading companies have established deep patent barriers around these technologies. This means it is extremely difficult for latecomers to bypass patents to develop products, and even harder to truly reach mass production and commercialization.
Microgate Technology is a typical example. This domestic company, which has been manufacturing RF filters for many years, disclosed at this year's earnings briefing that, due to continuous losses in its RF business, it has currently halted investments in BAW products.
On one side is a filter market approaching USD 10 billion and still growing rapidly; on the other side are domestic manufacturers that have been making filters for years, choosing to pause their investments in BAW.
This may seem contradictory, but it precisely exposes the true harshness of the BAW market: the market is huge, but the barriers are extremely high. Developing a product is merely the starting point; the ability to achieve mass production and maintain competitiveness is the real survival challenge for the future industry.
Over the past few years, domestic BAW development was more focused on solving the "whether it exists or not" problem; now, an increasing number of companies have begun to enter the stages of mass production, shipment, and customer competition. Even among domestic companies, disputes over patents and products are increasingly being taken to court.
From "Almost Zero" to Domestic Companies Having "Something to Compete For" In June this year, a patent lawsuit between domestic BAW companies brought the ongoing changes in this domestic industry to light.
On June 12, Nosontek announced that the BAW filters produced by Wuhan Minsound were suspected of infringing its invention patent No. ZL201010267632.6, and a lawsuit had been filed with the Shenzhen Intermediate People's Court. Wuhan Minsound subsequently responded that it had not yet received the relevant judicial documents, and also believed that its products did not cover all the technical features of the patent in question, thus not constituting infringement.
Nosontek Sues Wuhan Minsound Nosontek is one of the earliest domestic companies to deploy BAW technology, having long focused on the R&D and industrialization of bulk acoustic wave filters. Patent No. ZL201010267632.6 is one of its representative patents. This patent primarily involves the core component of BAW filters—the piezoelectric resonator—which can relatively simply and effectively enhance device performance. Its structure is typical and clear; once peers adopt this structure in their products, it is easily identifiable, leaving almost no room for rebuttal.
This is not the first time Nosontek has used this patent to file a lawsuit. Earlier this year, it sued another domestic BAW company, Fotone, specifically naming its C3f-type bulk acoustic wave resonator chips and a series of filter products as suspected infringements. Even earlier, this patent was involved in a years-long patent dispute between Nosontek, Apple, and Avago, which ultimately ended in a settlement in 2024, including a cross-license for some Chinese patents.
Founded in 2019, Wuhan Minsound, despite its later establishment, has already achieved mass production of BAW filters. It possesses an 8-inch production line, has mass-produced over 20 products, and supplies more than 40 customers. As of April 2026, Wuhan Minsound has cumulatively shipped over 800 million RF filter chips, which are widely used in smartphones, tablets, IoT (Internet of Things), network communication base stations, satellite and aerospace, and other fields. Notably, it only collaborated with Silex to build an 8-inch BAW production line around 2022, achieved mass production in July 2023, and reached shipments of 100 million units by the end of 2024—in less than two years, the shipment volume has increased eightfold.
Whether Wuhan Minsound has actually infringed the patent cannot be concluded at this moment. However, as domestic BAW products enter mass production on a large scale, BAW is no longer just a story of "domestic substitution," but has truly evolved into an industrial competition.
Shifts in Technology Routes and the High Patent Wall Behind this competition lies the ongoing shift in the technology routes of RF filters themselves.
Currently, the two most widely used acoustic filters in smartphone RF front-ends are SAW (Surface Acoustic Wave) and BAW. Simply put, SAW propagates acoustic waves along the surface of a material, while BAW propagates acoustic waves within a thin-film structure. They utilize resonance characteristics at different frequencies to filter out desired signals and suppress unwanted ones.
In the past, relying on mature processes and lower costs, SAW was always the mainstay of smartphone filters. However, with the advent of 4G, 5G, and even 6G, smartphones need to support more and more frequency bands at increasingly higher frequencies, making the signals more congested. Traditional SAW is beginning to struggle to simultaneously meet the requirements of high frequency, high bandwidth, and low loss. At this point, the importance of BAW filters begins to emerge.
Filters However, the BAW filter industry has always been a "small but beautiful" and highly concentrated sector. For a long time, the global BAW filter market was essentially dominated by two U.S. companies: Broadcom and Qorvo. Data from QYResearch shows that in 2024, the combined revenue share of just Broadcom and Qorvo in the global BAW filter market reached 91%; and 2025 data even indicates that Broadcom alone accounts for approximately 84% of the global BAW market.
One of the most critical reasons driving this highly monopolized industry status is undoubtedly the patent barriers.
In 2021, Qorvo taught latecomers a lesson through a lawsuit.
In October 2021, Qorvo sued Akoustis, a U.S. BAW filter company, accusing it of infringing BAW-related patents and stealing trade secrets. In May 2024, a U.S. jury overwhelmingly sided with Qorvo, ruling that Akoustis had infringed patents and engaged in willful and malicious trade secret misappropriation, ordering it to pay Qorvo approximately USD 38.59 million.
Qorvo This was not the end. The court subsequently added attorney fees and interest, bringing the final amount to over USD 57 million, and issued a permanent injunction against the products involved, prohibiting the manufacture, sale, or importation of the infringing products in the United States.
For a company that relies on BAW filters for its livelihood, the massive damages were already unbearable, and the inability to sell products made matters worse, directly leading to its bankruptcy a few months later. By 2025, most of Akoustis's core assets, including its BAW filter business, were acquired by a company under SpaceX for USD 30.2 million.
A single patent lawsuit directly brought down a BAW company that had been established for over a decade. It is evident that patents are not only the foundation of this industry but also the most critical weapon for a company to stay in the game.
This industry structure also directly led to another outcome—leading companies possess absolute bargaining power, making it difficult for even a super client like Apple to hold a strong position against them.
In 2023, Apple was reportedly planning to gradually develop some RF chips in-house. The market generally believed at the time that this was not only Apple's attempt to reduce supply chain dependency but also a consideration to increase its bargaining power against Broadcom. Ultimately, however, Apple did not exclude Broadcom's FBAR (Film Bulk Acoustic Resonator) filters from its supply chain; instead, it signed a multi-year agreement with Broadcom that same year to continue purchasing 5G RF components, including FBAR.
Broadcom And this year, this cooperation continues to deepen. Apple and Broadcom have extended their partnership to 2031, with the new multi-year agreement valued at an estimated over USD 30 billion, under which Broadcom will expand its RF component capacity in the U.S., including FBAR filters. Apple stated this would be the largest commitment to date for its U.S. manufacturing program.
Although the entire BAW industry scale is less than USD 10 billion, it is a highly profitable business. In 2015, Broadcom, then still Avago, was already selling FBAR filters (a technology route of BAW) in large volumes in its wireless communications business. That year, Avago's overall gross margin reached 52%; and Qorvo's overall gross margin for fiscal year 2026 has reached 45.9%. Of course, the businesses of both companies go far beyond BAW filters, but this at least demonstrates that leading manufacturers mastering core RF technologies and high-value products indeed possess strong profitability.
By contrast, Murata, the most important Japanese manufacturer of global SAW filters, has an overall operating profit margin of only 16.0%, and the operating profit margin for businesses such as SAW filters, RF modules, and high-frequency communication modules is only 1.4%.
Domestic BAW: Now There is Something to Compete For Turning our attention back to the domestic market, the development speed of domestic BAW over the past two years has been astonishing.
It should be noted that in 2024, the overall localization rate of filters was still around 10%-15%, with the localization rate for high-frequency (above 3GHz) products being almost zero; at that time, hardly any domestic manufacturer had achieved shipments of high-frequency BAW filters. Even earlier in 2021, in the U.S. sanctions against Huawei, key components including high-frequency filters were among the sanction tools.
But today in 2026, a batch of domestic players has begun to emerge in the BAW sector. Companies such as Nosontek, Wuhan Minsound, HunterSun, NEWSONIC, and Kaiyuan Communications have all formed their own products and technology routes in the BAW field; meanwhile, companies like Silex and Runxin Sensing have begun to provide the wafer fabrication capabilities required for BAW. The entire industry has crossed the technological breakthrough phase and entered the stage of industrial differentiation.
Nosontek and HunterSun have chosen the IDM (Integrated Device Manufacturing) model, keeping design, process, and manufacturing entirely in-house; Wuhan Minsound and Silex adopt a "design + foundry" approach, separating device design and manufacturing capabilities—Wuhan Minsound is responsible for BAW product R&D, design, and marketing, while Silex provides an 8-inch MEMS wafer fabrication platform, with both parties jointly building a BAW joint production line; HunterSun and NEWSONIC are deploying both BAW and SAW simultaneously, hoping to extend from filters further into RF front-end modules.
In other words, domestic BAW is no longer just about a few companies conducting technical verification in laboratories; it is beginning to form a true industrial cluster.
This change can also be seen from shipment volumes. In 2025, the D-BAW filters developed through the collaboration between NEWSONIC and Runxin Sensing, under CR Micro, shipped over 300 million units in the past year, entering smartphones and tablets of mainstream brands, with some models even making it into high-end flagship products both domestically and internationally.
Wuhan Minsound's speed is equally impressive. By April 2026, the company's cumulative shipments of RF filter chips had exceeded 800 million units. Once its headquarters production base currently under construction reaches full capacity, it is expected to achieve a monthly capacity of 10,000 wafers for domestic RF filters. Sun Chengliang, Chairman of Wuhan Minsound and a professor at Wuhan University, mentioned in an interview that technical issues are no longer the biggest obstacle at present: "How to transform our technological leading advantage into a sustainable market edge and commercial success is the issue I am thinking about the most right now."
HunterSun, on the other hand, has taken a different route, having already built its own BAW wafer fabrication production line with a maximum monthly capacity of 3,000 wafers, and is further expanding into filter products such as SAW.
Once entering the commercial market, friction is almost inevitable. Whose patents are more solid, whose product performance is better, whose costs are lower, who can secure more customers, and who can scale up capacity larger—these will all determine the ultimate winner.
Viewed from this perspective, the patent lawsuit between Nosontek and Wuhan Minsound takes on a completely different significance. It is not an isolated case of "internal friction" in the domestic BAW industry; rather, it is a very normal, and one could even say inevitable, phenomenon after the industry begins to form competition.
From this angle, what domestic BAW has truly crossed may not be a specific technological threshold, but the transition from being unable to produce to having the qualification to compete.
Moving forward, the determinant of victory will no longer be just technology, but who can ultimately turn patents, processes, yield rates, and customers into real market share. This highly lucrative yet tough segment once firmly occupied by overseas giants is now something Chinese companies finally have something to compete for.