Why Do Some WiFi Routers Have Fewer Antennas Than Others?

Many consumers are often puzzled by the varying number of antennas featured on different WiFi routers. This discrepancy primarily stems from marketing strategies, technological capabilities, and cost considerations. In this article, we delve into the reasons behind the different numbers of antennas and how they affect WiFi performance.

Marketing and Design Factors

Just like the shape, color, and design of a router's case, the number of antennas is often a result of marketing strategies. Manufacturers use the presence of multiple antennas to create an impression of advanced technology and superior performance. However, the reality is often different. Many newer WiFi routers boast multiple spatial streams or Mu-MIMO (Multi-User Multiple Input Multiple Output) technology to increase throughput and enhance overall WiFi performance. This marketing approach aims to attract tech-savvy consumers who are looking for the latest and greatest in WiFi technology.

Challenges with Mu-MIMO Technology

Despite its marketing hype, Mu-MIMO technology does not consistently deliver increased data throughput. According to research at SmallNetBuilder, the technology does not significantly improve WiFi performance in real-world settings. The theory behind Mu-MIMO is impressive. It allows a single WiFi channel to handle multiple data streams, mimicking a more efficient system. This technology is extensively used in advanced military radar systems, where the cost and precision of antenna feeds are not as critical. In consumer devices, the cost and precision limitations mean that Mu-MIMO offers only marginal improvements in performance.

Understanding MIMO and WiFi Performance

The number of antennas in a WiFi router directly impacts its MIMO (Multiple Input, Multiple Output) capabilities. Higher MIMO levels generally require more antennas. For example, a 4x4 WiFi router (IEEE802.11ax) will have more antennas compared to a 2x2 router. This is because the 4x4 router supports four spatial streams in both the transmit and receive paths, which can theoretically maximize data throughput and transmit efficiency. Conversely, a 2x2 router can only support two spatial streams, which limits its performance.

Earlier generations of WiFi standards, such as IEEE802.11n or IEEE802.11ac, did not support such high MIMO levels. Instead, they utilized other diversity techniques to improve signal quality and range. However, as technology advanced, manufacturers began incorporating higher MIMO levels to cater to the growing demands of modern internet usage. This advancement, while enhancing capabilities, does require more antennas and can increase the manufacturing costs.

How Antennas Are Positioned

Some routers may not have their antennas visible externally. Instead, antennas may be printed on the inside of the router's case. This design choice is due to aesthetic and functional reasons. External antennas can be visually unappealing and may interfere with the router's overall form factor. Additionally, internal antennas can be optimized for better performance and less interference.

Conclusion

In summary, the number of antennas on a WiFi router is influenced by marketing strategies, technological advancements, and cost considerations. While a higher number of antennas contributes to more advanced MIMO technology and improved performance, it’s not always necessary for every consumer. Understanding the underlying technology and how it impacts performance can help consumers make informed decisions when choosing a WiFi router.