This article delves into Wi-Fi 7 technology and the critical importance of frequency control, exploring how technologies like Automatic Frequency Coordination (AFC), Multi-Link Operation (MLO), and 4K Quadrature Amplitude Modulation (4K QAM) further enhance Wi-Fi 7 performance.


Wi-Fi relies on a range of radio frequencies for device communication. Historically, Wi-Fi has utilized the 2.4 GHz and 5 GHz bands, which minimize interference. However, the explosive growth in connected devices has overwhelmed capacity. The Wi-Fi Alliance predicts that by 2024, Wi-Fi-enabled devices will reach 4.1 billion. With millions of devices competing for limited access points and channels within designated bands, congestion and connection drops are inevitable. It's time to explore another frequency band, and Wi-Fi 7, along with its predecessor Wi-Fi 6E, has emerged to address this. Wi-Fi 7 allows devices to use the 6 GHz band, akin to adding a new highway with more lanes to accommodate increased traffic. Notably, Wi-Fi 7 also expands channel size from 160 MHz to 320 MHz, enabling more channels and wider bandwidth, which translates to faster data flow from more devices. The result is greater data throughput, higher reliability, and lower latency. With data rates exceeding 30 Gbps, Wi-Fi 7 supports high-speed, low-latency applications like AR, VR, HD video streaming, and IoT connectivity.

However, transitioning to the 6 GHz band presents challenges, as other entities, such as the U.S. Department of Defense and NASA, already use this band for satellite communications and may resist Wi-Fi device encroachment. To prevent interference with existing users, additional technology like Automatic Frequency Coordination (AFC) is required.

Complementary Technologies of Wi-Fi 7

Wi-Fi 7 offers more and wider access channels, and through a series of complementary technologies, users can maximize throughput and utilize each channel more efficiently.

• AFC (Automatic Frequency Coordination): AFC ensures Wi-Fi usage does not interfere with existing 6 GHz band users. It works by inputting existing user information, including antenna location and direction, into a database. New Wi-Fi 7 connections are checked against this database to prevent interference within the same spectrum neighborhood.
  

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• Multi-Link Operation (MLO): MLO advances multiplexing by enabling data to stream through multiple channels and bands. A single data stream can route through 2.4 GHz, 5 GHz, or 6 GHz (depending on availability), speeding up data transmission and preventing delays if a channel is compromised or unavailable.
  

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• 4K Quadrature Amplitude Modulation (4K QAM): QAM distributes large amounts of information by superimposing signals of different amplitudes and phases, optimizing spectrum use. With 4K QAM, over 4,000 signals can transmit simultaneously. Wi-Fi 7 standardizes this technology, increasing capacity and reducing latency. Additionally, Wi-Fi 7 employs Orthogonal Frequency-Division Multiple Access (OFDMA) with Multiple Resource Units (MRU), which segments data into smaller packets to improve throughput. MRU reduces multi-user latency by 25%, while MLO improves single-user latency by 80%.
  

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Frequency Control in Wi-Fi 7

The impressive capabilities of Wi-Fi 7 rely on stringent frequency control. Efficiently packing data into channels requires absolute precision; otherwise, signals may interfere, leading to poor performance. The new Wi-Fi standard demands modern radio equipment in both devices and access points. These powerful radios can simultaneously tune into multiple bands, bypass reserved channels as described by AFC, and utilize 4K QAM to densely pack information into the spectrum. They depend on electronic components with low phase noise and high stability to ensure consistent signal transmission. Minimizing phase noise and jitter is crucial for maintaining data integrity and reducing error rates. Stability alone is insufficient; signals must withstand attenuation over time and temperature. Factors like vibration, shock, and long-term degradation also affect performance and must be considered during design.

Frequency Control Components

Crystals, oscillators, and power inductors are essential for providing the high-precision frequency control required by Wi-Fi systems. Oscillators handle all tasks necessary for data transmission, including generating stable signals, ensuring time synchronization for all communications, and determining the carrier frequency for operation. Crystals, often paired with oscillators, fine-tune the oscillator's output, maintaining highly concentrated and precise frequency signals, much like a tuning fork. When inductors are combined with capacitors, they form LC circuits, enabling Wi-Fi systems to focus on specific frequency bands and filter out external noise.

To fully harness the potential of Wi-Fi 7, multiple components must work in concert. Oscillators form the foundation of the circuit, generating the base frequency, which is then fine-tuned by crystals. Power inductors within the circuit ensure that no extraneous signals interfere with the desired frequency and can smooth out voltage fluctuations. This frequency control system is then integrated with components such as antennas for signal transmission and microcontrollers for data processing.

Conclusion

Wi-Fi 7 promises to be a leap forward in the reliability of communication mediums, with robust frequency control at its core. Hardware components like oscillators, crystals, and inductors are the bedrock of advanced Wi-Fi circuits and have been the reliable workhorses of this long-standing communication technology. In the long run, advancements in industrial automation and artificial intelligence may increase the demands on Wi-Fi, prompting further evolution in communication technologies.

As the article highlights, crystals, oscillators, and power inductors play a crucial role in providing the high-precision frequency control required by Wi-Fi systems. These components work together to ensure that Wi-Fi 7 can achieve high-speed, low-latency data transmission while maintaining reliability and performance in complex wireless environments. This enables Wi-Fi 7 to operate efficiently across broader frequency bands. Therefore, the selection of these critical hardware components is also of great importance. Do you have any experiences or questions regarding high-precision frequency control in Wi-Fi systems and the selection of related components? Feel free to leave a comment and share your insights!