In the last post, I explained most common antennas that are used with WiFi routers and adapters. In this post, I will explain how to place this antennas for effective transmission and reception.
Antennas are of various types.
Based on the radiation pattern, Antennas are classified into
- Omni Directional Antenna
- Semi Directional Antenna
- Directional Antenna
Omni Directional Antennas emits electromagnetic waves equally in all direction. Semi directional antennas emits radio waves in particular pattern and direction antennas transmits energy in a particular direction only.
Based in the placement, Antennas are classified into
- Indoor Antenna
- Outdoor Antenna
Indoor antennas are usually small and compact antennas, generally usually used in WiFi routers, Mobile Phones, Laptops and low powered USB WiFi Adapters. They have very low power gain (generally 2dBi-9dBi) and are designed for internal uses.
Outdoor antennas are a designed for long range transmission and reception purposes. They are usually mounted on roof top and can transmit or receive radio waves to a very long distances. They have very high power gain and are usually weather proof that are designed for external use.
How to Point the Antennas of Home Router?
This is the most common question that comes to our mind when we install a router. Before going into that question, you should know how the EM waves are radiated through the antenna.
Most of the home Routers have omni directional antennas that (as explained in my previous post) emits radiations equally in a single plane.
This is what it means. The direction of radiation emitted will be perpendicular to the direction you point the antenna. That means, If you point your antennas vertically, it will emit radiation in a a horizontal plane. If you point it horizontally, waves will be emitted vertically.
So for routers with two antennas, it is always best to keep one horizontal and the other vertical. This way we can cover both vertical and horizontal space in our house. Another advantage of keeping antennas in this position is polarization. It is observed that maximum signal can be received when the transmitter and receiving devices have same polarization. Polarization depends up on the placement of antenna in the device which will be different for different devices; some will be horizontal and some will be vertical. By pointing the antennas perpendicularly, we can match the polarization in both devices no matter which position the device is kept.
Where to place your Router at Home?
Now that you know how the waves are radiated, let us place it somewhere, where we would get maximum coverage. As mentioned in my previous post, maximum distance an antenna can cover (transmit or receive) depends up on the power gain of the antenna, which will be constant for a particular antenna. Most common home routers have a power gain of 5dBi-9dBi which is enough to cover a medium sized house if placed correctly.
It is always a good practice to keep your router at the center of the of the house rather than a corner So that it can cover maximum horizontal radius.
If it is a multistory building, the router should be placed somewhere in between the first floor and the second floor for covering maximum vertical range, like ceiling of the ground floor or somewhere near the floor of the first floor.
The use of receiving antenna (USB WiFi Adapters) depends up on whether the station of portable or not. If it is portable, it is better to use an omni directional antenna that has same polarization as that of the transmitter (Router). If it is not portable, it is better to use a directional antenna, such as a mini panel antenna or cantenna that is pointed to the access point.