Zuolan Microelectronics debuts at the International Electronics Show: Domestic RF filters demonstrate technical strength

Zuolan Microelectronics debuts at the International Electronics Show: Domestic RF filters demonstrate technical strength

The development of 5G and the Internet of Things has led to a continuous increase in demand for RF front-end devices. However, in the context of global semiconductor production capacity shortages and Sino-US trade frictions, the "chip shortage and price increase" situation has intensified. How to ensure the normal operation of enterprises and maintain product supply in difficult times is a problem that Chinese companies have to think about. Domestic terminal manufacturers, who are increasingly paying attention to the independent control of key components, are increasingly willing to cooperate with local RF device suppliers.

Recently, at the 2021 ELEXCON Shenzhen International Electronics Exhibition and Embedded System Exhibition, Zuolan Microelectronics, which has been deeply involved in the field of RF front-end devices for many years, showed the audience a series of products such as filters, duplexers and modules. As a local manufacturer that develops and sells all kinds of RF filters, Zuolan Microelectronics and other domestic manufacturers have persisted in innovation and have shown their "transcripts" through hard work, reflecting more competitive products and optimization solutions.

Photo: Zuolan Microelectronics booth

Increasing local supply volume by entering into SAW filter market

The filter is a key component of the RF front-end module and is the key to restricting domestic manufacturers from moving from the current low-end discrete devices to mid-to-high-end modules. SAW filters are mainly used in 2G/3G/4G/5G frequency bands below 2.5GHZ and are a key link in modularization. SAW filters (including TC-SAW) account for about 70%-80% of the filter market share, but domestic manufacturers only account for about 3%, and the supply is seriously insufficient. At present, domestic mobile phones are not only lacking baseband chips. Due to procurement restrictions on high-end RF chips, Huawei's newly launched P50 series mobile phones all only support 4G. This embarrassing situation exposes that there is still a lot of room for exploration and development of mid-to-high-end domestic RF devices, especially domestic manufacturers have almost zero mature technology in 5G RF front-end devices. Domestic manufacturers need to "patiently" settle down, not only to have a full range of products, but also to have strong technology.

Faced with the current situation of the Chinese market being restricted by people and the global crisis of "chip shortage and price increase", Zuolan Microelectronics believes that only by achieving technological and performance breakthroughs can the chip supply gap problem be truly solved. The premise of domestic substitution of RF front-end devices is comparable performance, not cheap price. The urgent problem for domestic manufacturers is to accurately position their products and concentrate all resources to complete technical research and development. Zuolan Microelectronics is positioned in the research and development of mid-to-high-end filters, first using SAW filter research and development as the entry point, and then moving towards the high-end through technological breakthroughs in filters such as TC-SAW and FBAR.

Zuolan Microelectronics displayed a variety of SAW filters and duplexer products at the exhibition, and the products have been mass-produced and shipped. Zuolan Microelectronics' SAW filters and duplexer products have excellent performance such as small size, low insertion loss, and high suppression, which are recognized not only by the market but also by capital. The company has recently successfully completed a nearly 100 million yuan round of A financing, and the products are also continuously receiving orders and have been delivered in batches, with a current shipment volume of nearly 100 million units.

Figure: Zuolan Microelectronics SAW filter/duplexer

In addition, in order to make up for the shortcomings of conventional SAW filters, Zuolan Microelectronics has made certain breakthroughs in the TC-SAW products developed, which is an important step in promoting the high-end development of domestic filters. Conventional SAW can cover the full frequency band of Rx (receiving end) and part of the frequency band of Tx (transmitting end), while TC-SAW can cover the high, medium and low frequency bands of Tx, which can solve the problems of poor temperature characteristics and severe frequency drift of conventional SAW filters. Zuolan Microelectronics is one of the earliest manufacturers in China to officially start mass production of TC-SAW.

Figure: Zuolan Microelectronics TC-SAW filter

Bring more high-end products and RF modules to 5G

By the time 5G matures, the RF front-end market will reach 40 billion US dollars, and the value of a single mobile phone RF device will exceed 30 US dollars. The filter market will be the largest part of the RF front-end market, accounting for about 60%, and the demand growth rate will be the fastest. However, the filters in the 4G and 5G eras have different requirements for power and device quality. 4G requires more than 30 frequency bands, while 5G has 70-80 frequency bands, which greatly increases the demand for the number of filters. At the same time, because the RF architecture of 5G is more complex, the RF link has basically doubled, and the market demand for filters has also doubled.

With the upgrade of 4G to 5G communication technology, modularization is an inevitable trend. The higher the brand positioning of mobile phones in the market, the higher the integration of mobile phone RF front-end modules, and the higher the value of high-end modules. Zuolan Microelectronics, relying on its technical advantages in filters, provides customers with a variety of high-performance, highly integrated RF module solutions, such as DivFEM, FEMiD, PAiD, PAMiD, etc., which bring higher performance and more saved PCB area to 5G terminals.

Figure: Zuolan Microelectronics RF front-end module

Zuolan Microelectronics uses innovative design and packaging technologies to promote the adaptation of filters and other devices to achieve modular integration. While improving the integration level, it has conducted in-depth technical research on the technical challenges that 5G brings to RF filters. For example, by improving the device structure and adopting multi-layer alloy film electrodes, it has proposed various solutions to the problems of device power tolerance, high-frequency selectivity reduction, and device heat dissipation.

Figure: Suppression of the lateral modes of a SAW resonator by optimized design (red)

As the demand for RF front-end devices represented by filters grows exponentially due to 5G, and the future millimeter wave technology continues to evolve, it is possible that more new filter technologies and technological innovation integration will emerge in the future. At present, the market demand for domestic filters is urgent, especially in the high-end filter market. This is a process that requires Chinese manufacturers to make steady progress. With the joint breakthroughs of upstream and downstream companies in design and technology, the market share can be gradually expanded after the industrialization advantages are formed.

Now the domestic industrial chain is paying attention to the reputation of domestic products. As the industrial ecology gradually matures, it is expected that the head effect after integration will gradually be formed in the next few years, and it will have a certain degree of competitiveness with overseas giants. This is also the goal that the domestic industry is striving for.

Forming complete supply chain capabilities to promote product quality and quantity improvement

Filters have extremely high technical and process barriers. Foreign leading manufacturers not only have the ability to develop, but also have the ability to produce and package and test, while most domestic companies only have design and development capabilities. In order to catch up with foreign manufacturers, domestic manufacturers not only need to have a deep understanding of design and process know-how, but also need to accumulate supply chain resources to accelerate the mass production of high-performance products.

At present, Zuolan Micro's products have passed the performance verification of more than 100 customer projects and are actively expanding shipments. Zuolan Microelectronics has selected the global supply chain to open up the entire process of domestic modeling and simulation design, global laboratory sample production, domestic and foreign OEM production and packaging testing, and can achieve large-scale reliable production and supply. Zuolan Microelectronics said that it has formed a close strategic partnership with the industry's leading suppliers to ensure the company's control over core technologies. This not only guarantees production capacity, but also ensures that product quality is controllable.

Product diversification and serialization can enhance the overall market competitiveness of enterprises. While Zuolan Microelectronics is deeply engaged in the new technology and miniaturization of discrete devices, it is also actively launching a series of diversity module products. With the accumulation of technology and business development of Zuolan Microelectronics, its products will exceed 100.

Zuolan Microelectronics firmly believes that only with first-class R&D, first-class equipment, and first-class manufacturing can we make good products for customers. Currently, mobile phone manufacturers pay more attention to cost control. The RF front end accounts for about 10% of the total material cost of the whole machine, and the RF front end is the core of the increase in the material cost of 5G mobile phones. Therefore, domestically produced RF front ends with comparable performance and low cost are attractive to terminal manufacturers.