The Relationship Between Wi-Fi 7 and Frequency Control

Wi-Fi needs a range of radio frequencies that devices can dial into to communicate. For years, Wi-Fi has used the 2.4 GHz and 5 GHz frequency bands, and devices dial into a channel with the least interference.

The explosive growth in the number of connected devices has been straining capacity. 4.1 billion Wi-Fi enabled devices were expected to ship in 2024 alone, according to the Wi-Fi Alliance. When millions of devices compete for a limited number of access points and channels within specified frequency bands, traffic jams and broken connections are inevitable. It’s time to look for another band, which is what Wi-Fi 7 offers, along with its previous iteration, Wi-Fi 6E.

With Wi-Fi 7, devices can also use the 6 GHz frequency band. Adding a whole new spectrum band is like adding an entirely new highway with additional lanes that can absorb even more traffic. What is especially exciting about Wi-Fi 7 is that it also increases the channel size from 160 MHz to 320 MHz. As a result, using 6 GHz adds more lanes (channels) and makes each one wider, meaning data from more devices flows faster. The end result is better data throughput, greater reliability, and reduced latency.

With data rates exceeding 30 Gbps, Wi-Fi 7 delivers high-speed, low-latency coverage for a wide range of applications such as AR, VR, high-resolution video streaming, and IoT connectivity.

The problem with moving to the 6 GHz band is that other entities have already been utilizing it. Federal agencies such as the Department of Defense and NASA use the band for satellite communications and might not appreciate Wi-Fi devices elbowing into their territory. Using the 6 GHz band while simultaneously leaving the established spectrum band users alone will require additional technology known as Automated Frequency Coordination (AFC).

Complementary technologies for Wi-Fi 7

With Wi-Fi 7, we get more—and wider—channels for access to connectivity. An array of complementary technologies allows users to squeeze the most throughput out of the spectrum bands, making using each channel more efficient.

AFC

AFC enables Wi-Fi use without infringing on established users of the 6 GHz band. It works by inputting the existing users’ information—including antenna locations and their direction—and other parameters into a database. A new Wi-Fi 7 connection checks against this database to ensure it’s not infringing on the same neighborhood of the spectrum and causing interference.

Multi-Link Operations (MLO)

MLO means the ability to split up a stream of data into multiple units and route them through different channels in the same frequency band simultaneously. MLO in Wi-Fi 7 takes this capacity one step further, enabling data to stream through multiple channels and bands. In such a case, a single data stream can be routed through 2.4 GHz, 5 GHz, or 6 GHz, depending on availability. This makes data transmission faster and not prone to delays if channels are impaired or unavailable.

4K Quadrature Amplitude Modulation (4K QAM)

QAM allows the dispatch of a lot of information by superimposing signals of different amplitudes and phases to get more out of the spectrum. Because the waves don’t overlap, the transmission is not noisy. The 4K means more than 4,000 signals can go through at once. Wi-Fi 7 standardizes the technology and decreases latency by increasing capacity.

In addition, Wi-Fi 7 runs on orthogonal frequency-division multiple access (OFDMA) with Multiple Resource Units (MRUs), which splits data into smaller packets for faster throughput. MRUs lower multiple-user latency by 25%, and MLO improves single-user latency by 80%.

Frequency control for Wi-Fi

The technology that enables Wi-Fi 7 is impressive and depends on tight frequency control. Packing data into channels, however efficiently, will need absolute precision; otherwise, signals might interfere with each other and lead to poor performance.

The new Wi-Fi standards require modern radios on both the device and access points. These highly capable radios can tune simultaneously into multiple frequency bands, work around reserved channels as described by AFC, and fill the spectrum with dense information using 4K QAM. They depend on electronic components that can operate with extremely low phase noise and high stability to ensure stable signal transmission.

Keeping phase noise and jitter as low as possible is important for maintaining data integrity and reducing error rates. It’s not enough to have stable frequency now; signals can’t afford to attenuate over time and temperature. Vibration, shock, and long-term degradation can affect performance and need to be factored in during the design stage.

Components for frequency control

Crystals, oscillators, and power inductors are vital to delivering the high-precision frequency control that Wi-Fi systems need.

Oscillators check off all the tasks needed for data transfer, including producing a steady signal, ensuring timing for all communication is in sync, and determining the carrier frequency through which to operate. Often coupled with oscillators, crystals fine-tune the output that oscillators generate, acting like tuning forks to keep frequency signals tightly focused and accurate. When combined with capacitors, inductors form LC circuits, which enable Wi-Fi systems to focus on specific frequency bands and filter out extraneous noise.

ECS Inc. manufactures a wide range of crystals, oscillators, and inductors needed for Wi-Fi 7 systems. For example, surface-mount (SMD) crystals from ECS come in a wide selection of package sizes and offer wide temperature ranges up to +150°C.

The ECX-1637B series (Figure 1) is ideal for wireless applications. They are compact SMD crystals in a 2.0 mm x 1.6 mm x 0.45 mm 4-pad package. They provide low first-year ±1 ppm aging, and a tolerance and stability of ±10 ppm available over -30°C ~ +85°C.

Figure 1: The ECX-1637B Low-Aging Compact Crystal surface-mount (SMD) crystals have a wide frequency range of 16 MHz to 96 MHz and are well-suited for wireless applications. (Image source: ECS)

The ECX-2236B series features SMD quartz crystals with low ESR and low first-year aging of ±1 ppm max. The ECS-33B series offers a frequency range of 10 MHz ~ 54 MHz and tight first year ±1 ppm aging available over the standard industrial temperature range of -40°C ~ +85°C. These features are ideal for modern IoT, wireless, and Wi-Fi applications.

ECS also sells a range of ceramic oscillators. The ECS-2520MV series is ideal for the 0.750 MHz to 160 MHz range, while the ECS-2520SMV series is best suited for 8 MHz to 60 MHz. Both series offer a temperature range of -40°C to +105°C.

Figure 2: The ECS-2520MV series are miniature SMD High-speed CMOS oscillators ideal for wireless applications. (Image source: ECS Inc.)

Finally, ECS offers a range of power inductors covering a wide inductance and temperature range. Specifications vary depending on the series, whether they’re the ECS-MP12520, the ECS-MP14040, or the ECS-MPIL0530.

Figure 3: Power inductors from ECS cover a wide inductance and temperature range and are an essential component of Wi-Fi systems. (Image source: ECS Inc.)

Summing it all up

To realize the full potential of Wi-Fi 7, several components are required. The oscillator anchors the circuit, creating a base frequency that the crystal then fine-tunes. The power inductor in the circuit ensures no extraneous signals hamper the needed frequency and smooth out voltage fluctuations. This frequency control system then combines with elements like antennas for transferring signals and microcontrollers for data processing.

Conclusion

Wi-Fi 7 promises to be a quantum leap in the reliability of the medium, one that robust frequency control underwrites. Hardware components like oscillators, crystals, and inductors underpin advanced Wi-Fi circuits and are reliable workhorses for this long-standing communication technology. Over the long term, the growth of industrial automation and AI will likely increase the pressures on Wi-Fi, and communication technology will evolve yet again.