Wi-Fi 7 brings many new technologies and challenges. How do RF front-end products respond?

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Wi-Fi 7 brings many new technologies and challenges. How do RF front-end products respond?

Posted Date: 2024-01-25

Electronic Enthusiast Network reported (Text/Wu Zipeng) Not long ago, the Wi-Fi Alliance announced that it had completed and launched the certification of the Wi-Fi 7 advanced wireless standard, which will improve the connection performance of home, office and industrial equipment, and also bring new certification mark. This is undoubtedly a major industry benefit, and Wi-Fi 7 will usher in a larger explosion in 2024. However, the industry has been preparing for this new Wi-Fi standard for a long time.

Jeff Lin, Senior Marketing Manager of Qorvo Wireless Connection Business Department in Asia, said in an interview with a reporter from Electronic Enthusiast Network that because Wi-Fi 7 itself has many innovative functions, it has higher requirements for processor instruction cycles and memory space. , coupled with the increase in energy costs caused by the severe international situation in recent years, various factors have added up, causing network equipment manufacturers to consider changing Wi-Fi RF front-end devices from traditional "linear amplifiers" to lower power consumption " Nonlinear Amplifier".

Jeff Lin, Senior Marketing Manager, Asia, Qorvo Wireless Connectivity Business Unit (Lin Jianfu)

The Qorvo team saw this trend, so they started working on the radio frequency front-end module of the nonlinear power amplifier of Wi-Fi 7 in 2023. At present, the nonlinear power amplifier radio frequency front-end module of Qorvo Wi-Fi 7 has been successively certified by Qualcomm, Broadcom and MediaTek. It is about to enter the mass production stage.

As the "first standard built from scratch for the 6GHz band", Wi-Fi 7 has many innovations, such as multi-link operation (MLO), 320 MHz channels, etc. What changes will these innovative features bring to terminal applications? What kind of RF front-end is needed? Let’s listen to Lin Jianfu’s interpretation.

Wi-Fi 7’s 6GHz band, 320MHz bandwidth and MLO

Wi-Fi 7 is based on IEEE 802.11be technology. IEEE 802.11be is called "Enhancements for Extremely High Throughput (EHT)", so the changes in data throughput of Wi-Fi 7 are very intuitive. The theoretical speed of Wi-Fi 7 can reach up to 46 Gbps, which is several times higher than the 9.6 Gbps of Wi-Fi 6. A very important reason for this is that Wi-Fi 7 makes better use of the 6GHz frequency band.

Lin Jianfu pointed out that the Wi-Fi Alliance officially opened the 6GHz (5925MHz – 7125MHz) frequency band in January 2020, and Wi-Fi has officially entered the “tri-band” era. Both Wi-Fi 6E and Wi-Fi 7 incorporate the 6GHz frequency band into the standard. In the world of wireless communications, spectrum is the most important and valuable thing. The larger the frequency band, the greater the data throughput that can be transmitted.

According to the Wi-Fi Alliance's plan, 6GHz (UNII5-UNII8) opens 14 additional 80MHz channels, 7 additional 160MHz channels, and 3 additional 320MHz channels. These additional channels do not overlap with each other and can effectively reduce The problem of Wi-Fi channel congestion is of great value to densely populated places and large public facilities such as schools, large supermarkets, gymnasiums, shopping streets, and performance halls.

With the successive launch of Wi-Fi 6E and Wi-Fi 7, Wi-Fi network system solution providers will upgrade the tri-band architecture from the current 2.4G+5G (Low-Band)+5G (High-Band) to 2.4G+5G(U-NII 1-3)+6G(U-NII 5-8). Lin Jianfu said that in response to Wi-Fi 7 technical specifications and related upgrade requirements, Qorvo has developed 2.4G, 5G and 6G radio frequency front-end modules. “Under the three-band architecture, each frequency band cannot be interfered by other frequency bands, and its own frequency band cannot interfere with other frequency bands. Therefore, the RF front-end module of each frequency band needs to have a certain degree of isolation. Qorvo is very good at wireless RF. We have accumulated a lot of experience in the field, and compared with other competitors, we must have certain advantages in Wi-Fi 7 product development." He mentioned in the introduction.

Although both Wi-Fi 6E and Wi-Fi 7 have 6G frequency bands, there are still differences between the two. One of them is that Wi-Fi 7 provides 320MHz bandwidth in the 6G frequency band. From 160MHz to 320MHz, the channel capacity has doubled. However, Lin Jianfu believes that while the 320MHz bandwidth provides greater capacity, it also brings two problems: transmission distance and signal penetration. "The usage scenarios of 320MHz bandwidth will be limited to short-distance but high-speed transmission, such as point-to-point or Backhaul Network applications. Most Wi-Fi routers still operate in low-to-medium throughput modes. And the usage scenarios of medium and long distance transmission.”

Regarding Wi-Fi 7, the innovation that the industry is more concerned about is MLO. This is a MAC layer improvement scheme that uses MLD (Multi-Link Device) seamless dynamic switching to achieve load balancing and low latency. "MLO can be said to be one of the most innovative key technologies in Wi-Fi 7. MLO is mostly implemented through the powerful computing power of the processor of the Wi-Fi main chip itself and the smooth process and solid software algorithms. For the radio frequency front-end There are no special requirements for the device. It only needs that the EVM Floor of the RF front-end itself can support the Wi-Fi 7 specification and have good linearity and receiving sensitivity. Basically, whether it is STR (simultaneous transmission and reception) or NSTR (non- MLO in synchronous sending and receiving operation mode can achieve good results." Lin Jianfu said in the interview.

What challenges does Wi-Fi 7 bring and what are the requirements for the radio frequency front-end?

According to forecast data from the Wi-Fi Alliance, more than 233 million Wi-Fi 7 devices are expected to enter the market in 2024, increasing to 2.1 billion units by 2028. Of course, since Wi-Fi 7 is the "first standard built from scratch specifically for the 6GHz band", when building related devices, a new radio frequency front end is required and some new challenges need to be addressed.

For example, we started by talking about nonlinear amplifiers. Lin Jianfu pointed out that although the nonlinear amplifier itself has lower power consumption compared to the linear amplifier, it must be matched with the main chip manufacturer's DPD (Digital Pre-Distortion; digital pre-distortion compensation) algorithm to correct the output distortion of the nonlinear amplifier itself. , and improve the EVM of the amplifier itself. This part needs to be jointly developed by FEM manufacturers and Wi-Fi chip suppliers. "It has been verified that taking the 4x4x4 tri-band Wi-Fi 7 router as an example, the design using non-linear RF front-end modules can save about 5W of power consumption compared to the design using linear RF front-end modules. Non-linearity The RF front-end module allows Wi-Fi 7 routers to save power consumption without sacrificing wireless signal output power and EVM, allowing Wi-Fi 7 routers to strike a balance between performance and energy saving."

This actually extends to another problem, that is, after using high frequency bands and high concurrency, Wi-Fi 7 will inevitably need to deal with power consumption challenges. System power consumption has always been a severe challenge to the design of Wi-Fi AP, especially for high-end tri-band routers or network extenders. 8-channel or even 12-channel designs are common. However, Lin Jianfu emphasized that this can exactly bring into play the advantages of Qorvo's products. "Qorvo's RF front-end devices have always been known for their low power consumption in the industry. This is also a difference between Qorvo's own products and its competitors. It is not the same in Wi-Fi 7." Exceptionally, in addition to the high linearity of the power amplifier, low EVM and high receiving sensitivity of the low-noise amplifier, the power consumption is also lower than other competitors in the industry."

After overcoming these challenges and problems, the explosion of Wi-Fi 7 in the terminal market has become unstoppable. According to the imagination of the Wi-Fi Alliance, Wi-Fi 7 will bring obvious enabling value to use cases such as multi-user AR/VR/XR, immersive 3D training, video games, mixed reality work, industrial Internet of Things, and automobiles. Some industry insiders believe that due to its outstanding features such as high speed, high stability and high security, Wi-Fi 7 will make industrial users more determined to use Wi-Fi to replace wired optical fiber. Lin Jianfu also expressed his views on this.

He pointed out that “Wi-Fi 7 is feasible for industrial applications because breakthrough technological innovations such as multi-AP collaborative scheduling, MLO, Multi-RU, and Preamble Puncturing can improve the reliability and availability of the entire Wi-Fi network. (Capacity&Utilization) has been greatly improved, and Wi-Fi 7 has opened up the 6G frequency band. Users can use specific frequency bands to transmit specific data, and have the ability to connect to more terminal devices at the same time without serious transmission delays or It's a problem of Time Out. As far as I know, some wireless network equipment companies focusing on enterprise and industrial applications have begun to develop special commercial and industrial wireless routers and equipment based on the Wi-Fi 7 standard. I am very happy to see Wi-Fi. The future of Fi 7 is groundbreaking and brings new energy to the market."

Of course, from an application perspective, Wi-Fi 7 represents innovation, but it is also perfectly compatible with past use cases. For example, for the "One Pod per Room" concept proposed by Qorvo, Wi-Fi transmission technology is responsible for the transmission backbone of the entire smart home, using a mesh Wi-Fi network architecture to achieve network coverage without blind spots. With Wi-Fi 7, the innovative technologies provided by Wi-Fi 7, such as MLO, Multi-AP Coordination, Multi-RU, etc., can provide more efficient and stable Wi-Fi connections and better implement One Pod Per Room architecture and make this concept truly come true.

In the field of Wi-Fi 7, Qorvo has currently launched a variety of RF front-end products, which have been certified by mainstream Wi-Fi wireless network solution chip manufacturers in the market, such as Qualcomm, Broadcom, MediaTek, and Mailing Technology, and have been included in its affiliated "Reference design", with the assistance of reference design, product developers can shorten product development time and simplify product verification work, accelerating the commercialization and shipment of Wi-Fi 7.

Qorvo also attaches great importance to the development of the domestic Wi-Fi 7 market. “Although China currently does not open the 6GHz frequency band, breakthrough technological innovations such as multi-AP collaborative scheduling, MLO, and Multi-RU defined in the Wi-Fi 7 specification can not only solve the current pain points in Wi-Fi use, but also Allow Wi-Fi systems to have higher throughput, lower latency, support the connection of more terminal products, higher connection efficiency, better encryption, etc. These advancements and innovations in Wi-Fi technology have allowed more and more terminal products to be connected. More and more novel and imaginative applications will become truly "wireless" and truly come to fruition. Lin Jianfu said, "For the Chinese market, Qorvo will develop more integrated and more price-optimized products to face the increasingly "involved" China Netcom market, and will accelerate and simplify product development through collaborative cooperation with customers. Development and Design. "

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