Simple Omnidirectional 3G 4G Wi-Fi Antenna

Now in amateur radio practice, antennas for amplifying 3G, 4G, Wi-Fi signals of the “Biquadrat” type are very common.

Such an antenna has a directional effect, which may not always be an advantage, but even a disadvantage. An example is this: you need to strengthen the signal of your router so that you can catch it in any part of your house. If you use a directional antenna, the signal will most likely be well accessible only within the field of action of this antenna. Surely there will be only one room where it will be directed. It is good to use such an antenna only for long-distance communications, provided that you know where to point it.
To strengthen your WI-FI signal in all directions, an antenna is suitable, which I will show you. Its directivity characteristics are close to those of a whip antenna, with the exception of greater sensitivity.
In structure, it is actually the same biquadrate, only twice directed in opposite directions. Plus, this antenna is many times simpler than a classic biquad antenna, since it has neither a stand nor a reflector.

How to calculate an antenna?

Just please don't be scared, fifth grade math. We only need to calculate one arm since the antenna is square. But first we need to find out at what frequency we will make the antenna. Personally, in the example I will do it under WI-FI. It is known that the Wi-Fi frequency is approximately 2.4 GHz or 2400 MHz (there is also an even more modern Wi-Fi - 5500 MHz). If you do it under 3G - 2100 MHz, and 4G (YOTA) - 2600 MHz.
We take the speed of propagation of radio waves (300,000 km/s) and divide by the desired frequency (2400 MHz) in kilohertz.
300.000/2.400.000 = 0.125 m
This is how we got the wavelength. Now divide by four and get the length of the arm of the square.
0.125/4 will approximately turn out to be 0.0315 m. Let's convert it to millimeters for convenience and get 31.5 mm.

Making a simple DIY Wi-Fi antenna

Brem thick wire 2-3 mm thick. And a template cut from a piece of aluminum. You can, of course, do without it, but it’s easier with it.


We bend two loops from one wire and two from the other. The gap should be between the squares.



Then, I temporarily fix the squares crosswise with masking tape to make soldering easier. And I solder the middle on top so that the structure becomes rigid.



Now you need to take a thick piece of cable with a connector (you can take it from the same whip antenna).


Insert the antenna inside and solder it. The middle wire goes to the top, and the lower arms of the squares go to the common wire.



The antenna is ready. To finish, you can fill the solder joint with hot glue and paint it.

Antenna tests

Let's compare the signal strength with the whip antenna that originally came with the router.

Whip antenna:

Now in comparison. The first one is pin and then our omnidirectional biquad.

It can be seen that our antenna receives and amplifies the signal 30% better. Here is the result of the work.
A good signal level is the key to high Internet speed, which means stable operation. 30 percent is a very high figure, considering the fact that nothing had to be changed radically.
Make your own simple antenna for 3G, 4G or Wi-Fi and no longer suffer with an unstable and weak signal.

Watch a video about building an antenna