Antenna biquadrat with own hands

Radio waves pervade the space around us. We are all used to wireless technologies, especially to Wi-Fi, but not everyone is happy with the coverage of home routers. Walls, trees and other obstacles weaken the signal. If the quality of communication for an apartment is quite appropriate, then for a suburban area of several hundred standard capacity of routers is clearly not enough. Not far from the house, for example in the garage, would also like to use the home Internet without laying additional cables or installing powerful equipment. Yes, you never know where it might be necessary to amplify the radio signal! In any case, the use of the antenna will be the simplest and most profitable option.

We use the experience of radio engineering

A simple piece of conductor attached to the antenna, of course, can improve the signal, but often does not work. And all because of the properties of radio waves. The TV model also will not give any results for Wi-Fi, since it is designed to work with broadcasting frequencies. To create the correct antenna, you need to know the wavelength of the signal, the amplification of which is planned. The form of the device should be borrowed from radio amateurs. For example, the antenna biquadrat has long established itself as an easy-to-manufacture and reliable signal amplification device. These compact devices give a decent gain from 11 dBi and higher, while the built-in routers do not exceed 5 dBi.

For people who are very far from the electromagnetic part of physics, you can decipher these figures like increasing the connection speed over Wi-Fi by several times, and also increasing the connection distance. The antenna of the biquadrat is directional, covering the sector 40-50 ° in front of it, which is quite suitable for connecting a building remote from the main building, and also for creating a local wireless network between stationary stations. Different craftsmen note a steady signal at a distance from 400 to 2500 m, but this is hardly necessary, it is enough and several tens of meters.

In the store with money or with a soldering iron in their hands?

It is always easier to purchase a finished factory product, but the price of such a device is commensurate with the cost of a new router, and performance is not always reliable. Inexpensive models from the friendly East are quite fragile, and contacts and connections in them are far from perfect. Where to get a good biquadrat device? антенна своими руками может быть собрана любым радиолюбителем. WiFi - the antenna itself can be collected by any radio amateur. To do this, you need a soldering iron. If you are familiar with this tool, the instruction will tell you what to do and how.

Biquadrat is an antenna consisting of two squares made of wire or other electrically conductive material. They are located in the same plane and connected in a certain way. This circuit is the main working part of the antenna, a vibrator intended for receiving and transmitting radio waves. To make such an element of the antenna is best from a piece of single-core power copper wire of at least 2 mm2 cross section.

The thickness of the copper wire depends more on the selected antenna size, the number of fastenings and the conditions of use. This only affects the strength of the structure, and not the quality of the signal, so it is better to select it based on the planned size and availability of the material. The simplest self-made biquadrat-antenna is assembled only from a loop connected to a coaxial cable, as shown in the figure above.

Additional materials and tools

Of course, to improve the quality of the antenna will require additional details. As a reflector, a plate made of any electrically conductive material is suitable, only requirements for wear resistance and strength are required. Suitable even CD-disk or aluminum foil, used in cooking for baking. The main thing is to fix it on a solid solid base made of wood or plastic, where the rest of the antenna will be installed. In addition, dielectric fasteners will be needed to fix the antenna rigidly with respect to the reflector, as well as a 50-ohm coaxial cable .

Connect the device to the router will allow a special plug, which will have to be purchased at the store. If there are no connectors on the router, like most inexpensive models, you will have to disassemble it and solder the cable directly to the card. Remember, such actions with the router will deprive him of the guarantee, and all responsibility for such actions will lie entirely with you. The rest of the materials can be picked up from the place that is found in the pantry of the house master.

As is clear from the foregoing, a soldering iron, a bit of solder and flux is an indispensable tool. The ruler with millimetric divisions will allow to observe exact sizes of a product, and pliers or pliers are required for exact bending of a wire in a circuit. A knife and side cutters (nippers) will be needed to work with the cable, and when drilling holes, you need a drill or a screwdriver and a drill bit.

Safety Tips and Techniques

Beginners may encounter difficulties in soldering, but remember that skill comes with time. Do all work with the heated soldering iron slowly, observing the precautions and all the necessary steps in order not to burn yourself and make a strong connection. Before using the appliance, always check the integrity of the enclosure, cable and plug.

Protect the workspace of the table from possible damage by molten solder or drops of hot flux, covering it with a wooden shield or special refractory material. Do not leave the heated soldering iron unattended even after it is turned off. A warmed-up appliance can ignite surfaces and objects from flammable materials. Those who hold the soldering iron in their hands for the first time, it is recommended to make several connections on the remnants of the material or pieces of similar wire to fill the hand.

Some formulas

Before starting the work, let's make a small calculation of the biquadrat antenna. The range of most Wi-Fi routers, according to the IEEE 802.11n standard, is 2.4 GHz. Applying the formula of the ratio of wavelength, speed and frequency, you need to divide the speed of light into frequency. 0,1249 m or 125 mm - this is approximately the size we need, so the side of the squares of the antenna should be a multiple of this distance to work in the required range. For a small antenna, described here, a distance of 32 mm was chosen. Of course, a multiple increase in this distance will lead to an improvement in the signal over a larger coverage area.

Optimum reflector

There were a lot of ideas to use as a reflector, but for these sizes an empty 10 x 10 cm board was the best fit. First, it simplified the connection of the braid of the coaxial cable to the reflector. With conventional solder, the cable is firmly installed in the right place. Secondly, the hardness of the textolite completely satisfies the dimensions of the product and allows to refuse additional fasteners. Problems with the use of a model of this size can arise in the case of inaccurate observance of the dimensions, therefore all actions are performed using a millimeter ruler.

Progress

The homemade biquadr antenna for wifi is pretty simple to manufacture. In the center of the circuit board or other suitable metal sheet, drill a hole according to the diameter of the coaxial cable or slightly more. The cable should be cleaned from the top insulation by 2.5 cm and gently inserted into the hole in the board. The upper shield braid or cable sheath is propped around the entire circumference. The cable must sit tightly in the reducer plate, because in addition to this, there are no mountings for the antenna in this model. You can additionally use a metal tube to enhance the design, this is especially true if you are thinking about increasing the size of the antenna.

Antenna Arrangement

For a biquadrator, 256 mm of copper wire is required. You can mark the markings on the folding locations every 32 mm and take a little more wire to cut off the excess at the end. And you can bend the precisely measured piece of wire each time exactly in the middle. The ends must be carefully soldered and taken away from the opposing corner by 2 mm, and you can also leave the ends connected to the next stage.

The last step is soldering the biquadrator and cable joints. Watch its location relative to the reflector, the distance between them should be kept about 15 mm on the entire plane. Such a gap is measured by various testers by experience. If you have the equipment, you can manually search for the optimal distance with the best standing wave ratio for a particular model.

Perfection of the limit is not present

Point your antenna towards the work area and connect it to the router using a special plug, or install it directly on the workpiece with a soldering iron. The increase in the range of the Wi-Fi signal will not keep you waiting. What else can you do to increase the power of the antenna, besides increasing the size? Those who have already built something similar, may be interested in a double or triple antenna biquadrat. With their own hands, the craftsmen achieve amplification of the signal by 2 and 4 dBi more, and this is a tangible improvement.

This is accomplished by increasing the number of squares and, correspondingly, the area of the reflector (metal reducer). The craftspeople also create arched or circular antennas based on a biquadrat, the basic rule in the manufacture of which is a clear observance of a distance of 15 mm from the reflector over the entire area of the device. It is also worth mentioning that the intersections of the wires should be isolated so that there are no connections of the conductor.

The places where the biquadrat antenna is installed can be very diverse. Most often, these products are mounted on windows or outside the building. To protect from the weather of a small model, like the one described above, a plastic container is perfect. The amplification of the signal obtained by the biquadrat antenna corresponds to the models of factory production, and sometimes exceeds them.