Why do wifi routers have 3 antennas

QRZ Forums. Why do wi-fi routers have two antennas My D-Link unit has two 4 inch long antennas separated by 10 inches? To extend range, I am thinking of buying a high gain antenna. Would one work, or are two required? Most WiFi routers have two antennas because they use a diversity receiver system. Even if the WIfi router seems to only have one antenna there is often a second antenna made out of a trace on the circuit board inside.

Basically, there are two receivers each with their own antenna trying to receive the signal and a voting circuit that compares the signals from each of the receivers and using the strongest one. This allows the coverage area to be extended. The use of three antennas creates a good basis. With three antennas, they can be aligned so that each antenna addresses an axis x, y, z and the coverage is similar on all levels.

To make use of this synergy effect, the router should be placed as centrally as possible in the house or building in order to radiate the resulting field evenly to the surrounding rooms. Depending on the size of the house, building, office or hall, using a single router as a Wi-Fi source may not be sufficient for the required Wi-Fi coverage. The Wi-Fi network near the source is good in principle, but becomes weaker the further away it is from the source. This could be remedied by using a so-called repeater, i.

Wi-Fi repeaters come in various forms and with different connection options. Wi-Fi repeaters can be integrated for example via a network cable, an existing Wi-Fi or via Power over Line. Power over Line, also known as Powerline, refers to the use of the existing power grid to network end devices. Wi-Fi is a wireless communication link.

In the case of a network cable, excessive pinching of the cable could increase the resistance and reduce the possible performance accordingly. In the case of a radio signal, there is no bruising in this sense, but of course there are other resistances which can also reduce the power. One of the best known interferences in this area are simply walls.

Almost every wall attenuates radio signals and weakens them. Put simply, the more walls there are between the transmitter and receiver, the weaker the incoming signal. The respective attenuation of the walls depends on various factors, such as the thickness and the material used.

Walls and the architecture of a building are decisive factors when planning wireless networks and have a significant influence on the use of repeaters.

Wi-Fi reception depends on various factors. Depending on the area of application, coverage of Wi-Fi reception is, for example, desired or industrially mandatory. The basis is provided by the inventory by simply measuring the Wi-Fi signal.

Depending on the specifications, various parameters of this signal are of importance. One of the simplest parameters is the measurement of the signal strength. This ratio of the useful signal to the noise signal, also known as the signal-to-noise ratio, serves as a measure for assessing the quality of a signal transmission. The selected measurement should always be adapted to the respective requirements and thus always be performed by a specialist and determined with suitable measurement equipment.

The Wi-Fi reception strength decreases with distance to the Wi-Fi source. Observation in outdoor areas without interference can be calculated and estimated relatively well. However, in the case of internal building supplies, there are also various interfering influences such as walls or floors.

The range is therefore attenuated by these interferences and precisely this attenuation is additionally dependent on the material and thickness of the walls, as already described in section 2. In this case a calculation is basically possible, but unfortunately only as good as the definition of the parameters of the walls.

This increases the difficulty enormously. A simpler solution would be direct measurement of the signal at different positions in the whole building, the apartment etc. Based on these measurements, it is possible to create a so-called heat map. This heat map shows the reception quality within a colour scale. Areas with good or bad coverage are made directly visible.

When viewing a heat map, the focus is therefore on the displayed colours of the areas. The spectrum here ranges from dark green for a very good signal strength to red for a poor supply of radio signals. The transmission speed of a wireless application, such as Wi-Fi, can be influenced by various factors.

A quick, easy and first step is to measure the signal strength. If the signal strength of the received signal is low, the transmission speed is also reduced. A disturbance of the signal by electrical objects in the household is also possible.

Microwaves, like Wi-Fi, also operate in the 2. It is therefore advisable to examine the channels and, in addition, to change the channel for your own Wi-Fi, which could be a remedy. AIt is also advisable to take a look at the general distribution of the channels, because in most cases not only your own Wi-Fi is within range, but also external wireless networks from, for example, other residential units, floors or even neighbouring buildings. When choosing the Wi-Fi channel, the expert should take into account that networks that are too close together can also influence each other and reduce the respective transmission speed.

It is therefore advisable to choose a channel for your own Wi-Fi that is sufficiently distant from other existing Wi-Fi networks. The distance should be channels so that there is no overlap. If a simple observation does not provide a cause for a weak transmission speed, a more detailed analysis must be carried out. Think of it this way. With three witnesses, you can combine all of their stories to get a fuller, more accurate understanding of what happened.

One thing to note is that wireless clients, like wireless routers, also have transmit and receive antennas and the number of spatial streams utilized will always be limited by the device with the lowest number of supported signals. I also love a lot of other things.

So much so that I made a food map. All rights reserved. Connect with. Remember Me. Username or Email. Speed and reliability. Multiple antennas and Wi-Fi speed While many dynamics play a part in affecting Wi-Fi speed, one of the main factors is the number of antennas a router has, and by extension the number of spacial streams it can communicate over. Share Tweet. Fiona Hutcheson Hi. Popular Comments Tags.