Wi-Fi 6/6E new track: How to make your device more advantageous and be one step ahead?

The Wi-Fi Alliance also reported device shipments for 2021, and the latest generation of Wi-Fi shipments are increasing at an impressive pace. In 2021, total Wi-Fi device shipments were 4.2 billion, of which Wi-Fi 6 accounted for 2.2 billion (52%) and Wi-Fi 6E accounted for 338 million (8%).

In other words, just two years after its release in 2019, Wi-Fi 6 has become an accepted standard, accounting for more than half of new Wi-Fi devices, while Wi-Fi 6E devices began shipping in large quantities just a few months after the 6GHz band used by Wi-Fi 6E was launched.

It’s easy to see why Wi-Fi 6 is gaining momentum. Enhanced overall performance, including faster high-speeds and better management of dense, crowded networks, is paired with new spectrum. This means familiar experiences like video streaming and gaming will be enhanced, and a new generation of impressive applications that require high bandwidth and low latency are now within reach.

The deployment of 5G mobile communications is another factor in the growth of Wi-Fi 6. Wi-Fi 6 and 5G are complementary technologies that use many of the same techniques, including OFDMA and MU-MIMO transmission. When a 5G mobile device enters an indoor location where the signal is weak, it can switch to Wi-Fi 6 without interrupting the signal. This capability is essential for demanding 5G applications such as self-driving cars, medical monitoring, and smart manufacturing, which must ensure uninterrupted connectivity both indoors and outdoors for seamless operation.

The Wi-Fi Alliance reports that 63% of mobile traffic was offloaded to Wi-Fi in 2021, indicating that nearly two-thirds of mobile communication sessions utilize Wi-Fi hotspots to keep mobile devices connected. As 5G continues to roll out, this number will only rise.

From a design perspective, the increase in functionality comes at the cost of increased complexity, and upgrading from Wi-Fi 5 to Wi-Fi 6 is a difficult transition for any engineer. For example, the MU-MIMO feature has been upgraded in Wi-Fi 6, moving from one-way operation to two-way operation, so designers must deal with both uplink and downlink functions. Similarly, while Wi-Fi 5 used single-user orthogonal frequency division (OFDM), Wi-Fi 6 upgrades it to a multi-user format (OFDMA), which can be more difficult to manage effectively.

But for mobile system designers, the biggest challenge may be upgrading to higher-order quadrature amplitude modulation (QAM) and bandwidth. The switch from 256 QAM in Wi-Fi 5 to 1024 QAM in Wi-Fi 6 provides higher throughput and 25% more capacity, with 10 bits per symbol instead of 8 bits. This, coupled with an increase in maximum channel bandwidth from 80MHz to 160MHz and an extension of the frequency band to 7.125GHz, places higher performance demands on the RF portion of the system. Achieving the right level of performance may require greater technical expertise.

就算在条件较好的情况下，射频优化也是出了名的困难，但Wi-Fi 6的严苛要求使此类优化更具挑战性。它们的容忍度更小，因此即使是微小的调整也会显著改变整个系列的Wi-Fi信号、性能和能效。

To avoid getting bogged down in the intricacies of RF optimization, design teams save time and effort by using pre-integrated RF products called front-end modules (FEMs). Front-end modules are solutions built specifically to complete the RF chain. Located between the antenna and the connecting system-on-chip (SoC) of the wireless system, the front-end module is a purpose-built solution that completes the RF chain and improves overall performance. In high-end mobile Wi-Fi 6/6E systems, it is a more important part of the design.

前端模块可节省时间，同时实现更好的设计。所有产品都以高度集成的小型解决方案来提供，因此设计速度更快。单个前端模块部件的放置灵活性意味着射频链的每一段都可以得到充分优化。集成射频放大器可增强微弱的输入信号，而不会对噪声性能产生显著影响，因此射频链更灵敏，能够更好地从多个输入信号进行选择。在传输（TX）端，恩智浦FEMS以高效方式提高了正在传输的信号的功率电平，因此，在上行链路中也会显著提升性能并扩展传输范围。

The first front-end modules for Wi-Fi 6/6E, including those provided by NXP, are dual front-end modules. Each front-end module is equipped with two monolithic front-end ICs. For example, our WLAN8101x series, which was launched in mid-2020, puts two front-end ICs into a QFN package with a size of 3 x 4 mm.

However, RF design doesn’t stand still for long, and our engineers are constantly striving to outdo themselves. Just eight months after the launch of the WLAN8101x series, we have broken new ground by being the first to introduce a single-channel Wi-Fi 6E front-end module. Designed specifically for smartphones, the WLAN7205C is one of the industry’s first single-channel Wi-Fi 6 solutions, offering a monolithic integrated power amplifier (PA), switch, and low-noise amplifier (LNA) in a 2 x 2 mm QFN package.

The single-IC WLAN7205C can be placed closer to the antenna than the dual-IC WLAN8101x, which requires a larger package. This reduces routing losses after the front-end module and improves performance. Low losses after the PA provide excellent transmit efficiency, and low losses before the LNA maximize receive sensitivity. A closer location to the antenna also improves range, extends battery life, and enables faster data transmission.

Now, NXP has taken single front-end modules to a new level with the introduction of the WLAN7207C (5-7GHz) and WLAN7207H (2.4GHz and Bluetooth). These fully integrated front-end modules are optimized for new smartphones, provide extremely high linearity, and support low-power modes. They do not require external matching components, making the design more compact, more economical, and easier to complete. They provide three Tx operating modes for each band for better fine-tuning of power efficiency, and two Rx operating modes for gain steps between LNA mode and bypass mode. More importantly, they are packaged in tiny packages. The WLAN7207C is packaged in a 2 x 2mm HWFLGA16 package, while the WLAN7207H is packaged in a HFCPLGA18 package that measures only 2.4 x 2.0mm.

Like NXP’s other Wi-Fi front-end modules, the WLAN7207x family is manufactured using industry-leading Qubic SiGe:C BiCMOS technology, which operates at very high efficiency, helping to ensure that Wi-Fi signals are minimally degraded in terms of noise, distortion and spurious signals.

Smartphones integrating the WLAN7207x series will improve Wi-Fi performance with little impact on battery life. Signals remain linear and manageable, increasing data rates and extending coverage. This translates into a more continuous experience, as video calls while moving around require a more reliable connection. At the same time, the high efficiency of the RF chain means that the performance improvement has little impact on battery life.

The WLAN7207x series reflects the latest capabilities of high-performance RF design, but also prepares developers for the future. The IEEE is already working on Wi-Fi 7 (802.11be), and the Wi-Fi Alliance predicts that Wi-Fi 7 will be available as early as 2023. Wi-Fi 7 is expected to build on the success of Wi-Fi 6 and Wi-Fi 6E, using three frequency bands in a more advanced way (2.4/5/6 GHz). Therefore, the WLAN7207 series supporting Wi-Fi 6/6E is a natural bridge to transition to Wi-Fi 7 designs soon.