Compared to older routers which had 1 or 2 antennas, most modern Wi-Fi routers, such as The Netgear Nighthawk and TP-Link AC 1750 SMART Wi-Fi routers now come with 3-6 antennas.
This may lead you to ask “what’s the purpose of increasing the number of antennas?” Wouldn’t multiple antennas cause signal interference?
Wi-Fi routers have multiple antennas to help improve the speed and reliability of transferring data. Multiple antennas enable a router to send several streams of data at the same time (MIMO(Multiple Input/Multiple Output)), thus increasing speed. Additionally, they allow beamforming technique, which helps focus signals to the target device, to be implemented more effectively.
A router with a single receive antenna and a single transmit is referred to as having a 1×1 SISO (Single Input/Single Output) configuration, meaning that it can only transmit and receive over one radio channel.
On the other hand, a router with three transmitter and receiver antennas is referred to as having a 3×3 MIMO (Multiple Input/Multiple Output) configuration, meaning that it can send and receive data over three radio channels. This increases the data transfer rate(throughput) by three. Other antenna configurations include 2×2 MIMO, 4×4 MIMO, and 6×6 MIMO.
However, it is important to keep in mind that for you to fully benefit from the improved transfer rate that MIMO routers offer, your receiving devices must also support multiple streams of data using multiple antennas. It is possible for a Wi-Fi router to have 6-8 antennas yet only support 3 streams of data. Usually, the rest of the antennas are used for beamforming and antenna diversity.
The video below explains how beamforming in Wi-Fi routers is implemented:
Routers With External Antennas Vs Those With Internal Antennas
Wireless routers with external antennas are not necessarily better than those with internal antennas, however, they offer better directional control. This means that, provided the external antennas are positioned correctly, they can send a stronger signal in the target direction. On the other hand, routers with internal antennas are better at distributing signals more evenly.
Do Wi-Fi Router Antennas Rotate Their Direction In Relation To The Wi-Fi Device?
Wi-Fi router antennas do not physically rotate their direction in relation to the connected Wi-Fi device. However, using technologies such as beamforming and antenna diversity MIMO(Multiple Input/Multiple Output) routers are able to improve the reliability of a message signal and direct it to the target Wi-Fi device.
For instance, the Google On-hub wireless router has 13 internal antennas (six 2.5GHz and six 5GHz antennas) whose transmission/reception power is adjusted to provide the most optimal end-user experience.
How To Position The Antennas Of A Wi-Fi Router For Optimal Coverage
When a Wi-Fi router antenna is positioned vertically the signal emitted is usually sent horizontally, and with the antennas positioned horizontally, the signal is sent vertically.
To get optimal coverage, you need to position your Wi-Fi router antennas angled in opposing directions. This will allow the Wi-Fi signal emitted by your router to travel in both vertical and horizontal directions.
If you are in a single-floor house, positioning the inner antenna(s) vertically at 90 degrees and then angling the outermost antennas at about 15-30 degrees away from the center of the router will provide the best coverage.
If you need the router’s signal to travel upstairs and downstairs, then you need to position some antennas horizontally and others vertically. This will send the Wi-Fi signal in both directions, thus improving coverage.
Also, keep in mind that everyone’s router placement, house environment, and router model is different. Therefore, the only sure way to know what will work for you is to try adjusting the antennas while keeping an eye on the Wi-Fi reception of each device.
The Difference Between A Router With One, Two, Or Three Antennas
The difference between a router with one, two, or three antennas is in the number of radio channels that each is capable of transmitting and receiving in. A router with 1 antenna receives/transmits over a single radio channel, a router with 2 antennas receives/transmits over two radio channels, while a router with 3 antennas receives/transmits over three radio channels.
This means that although Wi-Fi speed is dependent on many factors, the number of antennas on a router definitely impacts speed. Theoretically, a router with three antennas transmits/receives data over three spatial streams making it three times faster than one that uses a single antenna.
How To Position The 4 Antennas On A Router For Optimal Coverage
To get optimal coverage from a router with 4 antennas, you should position the 2 middle antennas vertically at 90 degrees and then position the outer left and right antennas at 45-60 degrees against the horizontal plane. Also, ensure that the router itself is centrally located in your home or office.
Compared to older 802.11b/g routers, modern 802.11n and 802.11ac Wi-Fi routers come with more than one antenna to make the implementation of MIMO(Multiple Input/Multiple Output) technologies, which helps improve speed and reliability, more effective.
Besides implementing MIMO technology, having many antennas also allows techniques such as beamforming and antenna diversity to be applied, thus enhancing reliability and allowing for a much better end-user experience.