DIY parabolic wifi antenna. How to make an inexpensive WiFi antenna

If you want to assemble a long-range WiFi antenna, then you should know about some of its features.

The first and simplest: large antennas of 15 or 20 dBi (isotropic decibels) are the maximum power, and there is no need to make them even more powerful.

Here is a clear illustration of how, as the antenna power in dBi increases, its coverage area decreases.

It turns out that as the antenna’s operating distance increases, its coverage area decreases significantly. At home, you will have to constantly catch a narrow band of signal activity if the WiFi emitter is too powerful. Get up from the couch or lie down on the floor, and the connection will immediately disappear.

That's why home routers have conventional 2 dBi antennas that radiate in all directions - so they are most effective over short distances.

Directed

Antennas at 9 dBi work only in a given direction (directional action) - they are useless in a room, they are better used for long-distance communications, in the yard, in the garage next to the house. The directional antenna will need to be adjusted during installation to transmit a clear signal in the desired direction.

Now to the question of carrier frequency. Which antenna will work better at long range, 2.4 or 5 GHz?

Now there are new routers operating at double the frequency of 5 GHz. These routers are still new and are good for high-speed data transfer. But the 5 GHz signal is not very good for long distances, as it fades faster than at 2.4 GHz.

Therefore, old 2.4 GHz routers will work better in long-range mode than new high-speed 5 GHz ones.

Drawing of a double homemade biquadrat

The first examples of homemade WiFi signal distributors appeared back in 2005.

The best of them are the biquadrate designs, which provide a gain of up to 11–12 dBi, and the double biquadrate, which has a slightly better result of 14 dBi.

According to usage experience, the biquadrate design is more suitable as a multifunctional emitter. Indeed, the advantage of this antenna is that with the inevitable compression of the radiation field, the signal opening angle remains wide enough to cover the entire area of ​​​​the apartment when installed correctly.

All possible versions of the biquad antenna are easy to implement.

Required Parts

• Metal reflector - a piece of foil-textolite 123x123 mm, a sheet of foil, a CD, a DVD CD, an aluminum lid from a tea can.
• Copper wire with a cross section of 2.5 mm2.
• A piece of coaxial cable, preferably with a characteristic impedance of 50 Ohms.
• Plastic tubes - can be cut from a ballpoint pen, felt-tip pen, marker.
• A little hot glue.
• N-type connector - useful for conveniently connecting an antenna.

For the 2.4 GHz frequency at which the transmitter is planned to be used, the ideal dimensions of the biquadrate would be 30.5 mm. But still, we are not making a satellite dish, so some deviations in the size of the active element - 30–31 mm - are acceptable.

The issue of wire thickness also needs to be considered carefully. Taking into account the selected frequency of 2.4 GHz, a copper core must be found with a thickness of exactly 1.8 mm (section 2.5 mm2).

From the edge of the wire we measure a distance of 29 mm to the bend.

We make the next bend, checking the outer size of 30–31 mm.

We make the next inward bends at a distance of 29 mm.

We check the most important parameter of the finished biquadrat -31 mm along the center line.

We solder the places for future fastening of the coaxial cable leads.

Reflector

The main task of the iron screen behind the emitter is to reflect electromagnetic waves. Correctly reflected waves will superimpose their amplitudes on the vibrations just released by the active element. The resulting amplifying interference will make it possible to propagate electromagnetic waves as far as possible from the antenna.

To achieve useful interference, the emitter must be positioned at a distance that is a multiple of a quarter of the wavelength from the reflector.

Distance from emitter to reflector for biquad and double biquad antennas we find lambda / 10 - determined by the features of this design / 4.

Lambda is a wavelength equal to the speed of light in m/s divided by the frequency in Hz.

Wavelength at a frequency of 2.4 GHz is 0.125 m.

Increasing the calculated value five times, we get optimal distance - 15.625 mm.

Reflector size affects the antenna gain in dBi. The optimal screen size for a biquad is 123x123 mm or more, only in this case can a gain of 12 dBi be achieved.

The sizes of CDs and DVDs are clearly not enough for complete reflection, so biquad antennas built on them have a gain of only 8 dBi.

Below is an example of using a tea jar lid as a reflector. The size of such a screen is also not enough, the antenna gain is less than expected.

Reflector shape should only be flat. Also try to find plates that are as smooth as possible. Bends and scratches on the screen lead to the dispersion of high-frequency waves due to disruption of reflection in a given direction.

In the example discussed above, the sides on the lid are clearly unnecessary - they reduce the signal opening angle and create scattered interference.

Once the reflector plate is ready, you have two ways to assemble the emitter on it.

1. Install the copper tube using soldering.

To fix the double biquadrat, it was necessary to additionally make two stands from a ballpoint pen.

1. Secure everything to the plastic tube using hot glue.

We take a plastic box for discs for 25 pieces.

Cut off the central pin, leaving a height of 18 mm.

Use a file or file to cut four slots in the plastic pin.

We align the slots to the same depth

We install the homemade frame on the spindle, check that its edges are at the same height from the bottom of the box - about 16 mm.

Solder the cable leads to the emitter frame.

Taking a glue gun, we attach the CD to the bottom of the plastic box.

We continue to work with a glue gun and fix the emitter frame on the spindle.

We fix the cable on the back of the box with hot glue.

Connecting to a router

Those who have experience can easily solder to the contact pads on the circuit board inside the router.

Otherwise, be careful, thin traces may come off the printed circuit board when heated for a long time with a soldering iron.

You can connect to an already soldered piece of cable from a native antenna via an SMA connector. There should be no problem purchasing any other N-type RF connector from your local electronics retailer.

Antenna tests

Tests have shown that an ideal biquad gives a gain of about 11–12 dBi, and this is up to 4 km of directional signal.

The CD antenna gives 8 dBi, since it can pick up a WiFi signal at a distance of 2 km.

Double biquadrate provides 14 dBi - slightly more than 6 km.

The opening angle of antennas with a square emitter is about 60 degrees, which is quite enough for the yard of a private house.

About the range of Wi-Fi antennas

From a native router antenna of 2 dBi, a 2.4 GHz signal of the 802.11n standard can spread over 400 meters within line of sight. Signals of 2.4 GHz, old standards 802.11b, 802.11g, travel worse, having half the range compared to 802.11n.

Considering a WiFi antenna to be an isotropic emitter - an ideal source that distributes electromagnetic energy evenly in all directions, you can be guided by the logarithmic formula for converting dBi to power gain.

Isotropic decibel (dBi) is the antenna gain, determined as the ratio of the amplified electromagnetic signal to its original value multiplied by ten.

AdBi = 10lg(A1/A0)

Conversion of dBi antennas into power gain.

Judging by the table, it is easy to conclude that a directional WiFi transmitter with a maximum permissible power of 20 dBi can distribute a signal over a distance of 25 km in the absence of obstacles.

We make a Wi-Fi antenna with our own hands.

Wi-Fi wireless data technology has taken over the world. Almost every house and every apartment has devices that support this standard. For example, routers (routers) “distributing” a Wi-Fi signal throughout an apartment or house.

Unfortunately, the power of these devices is not always sufficient to provide more or less acceptable signal strength in all rooms and rooms of apartments, and especially houses. For example, the TP-LINK router I use is located in a corner room and provides the signal level at almost the minimum limit for the rooms farthest from it. It’s not surprising - the signal has to break through four walls.

What to do in such cases in order to increase the level of the router’s Wi-Fi signal to acceptable values? That's right - make your own Wi-Fi antenna.

The network is full of designs for such antennas. More effective are those antennas that can be connected instead of the standard whip antennas of routers.

This option is not suitable for me. The antenna of my router is not removable, I don’t want to climb inside the router to solder the cable of a homemade antenna - the router is still under warranty.

Therefore, we find another option - an antenna attachment.

This antenna attachment is simply put on the standard whip antenna of the router. There is no need to solder anything anywhere.

The attachment antenna is a six-element “wave channel” and has directional properties. Provides maximum gain in the direction coinciding with the longitudinal axis of the antenna. In addition, the back lobe of radiation is suppressed (decreased) to some extent. The antenna has five director elements and one reflector.

Antenna sketch:

For the manufacture of the traverse, fiberglass laminate with a thickness of 2 mm was selected.

The standard whip antenna of my TP-LINK router has an irregular geometric shape in cross section, in full accordance with the perverted tastes of modern design designers))).

The completed traverse looks like this:

The radiating elements of the antenna attachment are made of copper wire in enamel insulation with a diameter of 0.96 mm. The diameter of the wire is quite critical and must be within 0.8...0.95 mm, otherwise the antenna parameters will change and the antenna attachment will be tuned to frequencies different from those of the Wi-Fi range.

The lengths of the radiating elements must also be maintained with an accuracy of +/- 0.5 mm. The same applies to the distance between elements.

Antenna elements:

To install radiating elements, holes with a diameter slightly larger than the diameter of the wire elements are drilled in the fiberglass traverse. I fixed the wire elements with small drops of cyanoacrylate glue.

The assembled antenna attachment looks like this:

This is what the Wi-Fi antenna looks like installed on the standard antenna of the router:

To achieve maximum efficiency of this Wi-Fi antenna, a small adjustment is required: the Wi-Fi antenna should be placed at the point where there is maximum RF current from the standard whip antenna of the router.

To do this, you need to move the Wi-Fi antenna in height, starting from the upper tip of the router’s standard antenna. The effectiveness can be checked either with some kind of field strength indicator, or by checking the signal strength with a tablet, smartphone, etc. in the rooms farthest from the router.

In my case, the most efficient Wi-Fi antenna works when installed 25 mm below the top tip of the standard router pin. This antenna gave an increase of one notch on the signal strength indicator in those rooms where the signal was at its minimum.

A weak WiFi signal is a pressing problem for residents of apartments, country houses and office workers. Dead zones in a WiFi network are typical for both large rooms and small apartments, the area of ​​which even a budget access point can theoretically cover.

The range of a WiFi router is a characteristic that manufacturers cannot clearly indicate on the box: the WiFi range is influenced by many factors that depend not only on the technical specifications of the device.

This material presents 10 practical tips that will help eliminate the physical causes of poor coverage and optimize the range of your WiFi router; you can easily do it yourself.

The radiation from the access point in space is not a sphere, but a toroidal field, shaped like a donut. In order for WiFi coverage within one floor to be optimal, radio waves must propagate in a horizontal plane - parallel to the floor. For this purpose, it is possible to tilt the antennas.

The antenna is a donut axis. The angle of signal propagation depends on its inclination.

When the antenna is tilted relative to the horizon, part of the radiation is directed outside the room: dead zones are formed under the “donut” plane.

A vertically mounted antenna radiates in a horizontal plane: maximum coverage is achieved indoors.

On practice: Mounting the antenna vertically is the easiest way to optimize indoor WiFi coverage.

Place the router closer to the center of the room

Another reason for the occurrence of dead zones is the poor location of the access point. The antenna emits radio waves in all directions. In this case, the radiation intensity is maximum near the router and decreases as it approaches the edge of the coverage area. If you install an access point in the center of the house, the signal will be distributed throughout the rooms more efficiently.

A router installed in a corner transmits some of the power outside the house, and distant rooms are at the edge of the coverage area.

Installation in the center of the house allows you to achieve even distribution of the signal in all rooms and minimize dead zones.

In practice: Installing an access point in the “center” of the house is not always feasible due to the complex layout, lack of sockets in the right place, or the need to lay a cable.

Provide direct visibility between the router and clients

WiFi signal frequency is 2.4 GHz. These are decimeter radio waves that do not bend well around obstacles and have low penetrating ability. Therefore, the range and stability of the signal directly depend on the number and structure of obstacles between the access point and clients.

Passing through a wall or ceiling, an electromagnetic wave loses some of its energy.

The amount of signal attenuation depends on the material the radio waves travel through.

*Effective distance is a value that determines how the radius of a wireless network changes in comparison with open space when a wave passes an obstacle.

Calculation example: WiFi 802.11n signal propagates under line-of-sight conditions over 400 meters. After overcoming the non-permanent wall between the rooms, the signal strength decreases to 400 m * 15% = 60 m. The second wall of the same type will make the signal even weaker: 60 m * 15% = 9 m. The third wall makes signal reception almost impossible: 9 m * 15 % = 1.35 m.

Such calculations will help calculate dead zones that arise due to the absorption of radio waves by walls.

The next problem in the path of radio waves: mirrors and metal structures. Unlike walls, they do not weaken, but reflect the signal, scattering it in arbitrary directions.

Mirrors and metal structures reflect and scatter the signal, creating dead zones behind them.

If you move interior elements that reflect the signal, you can eliminate dead spots.

In practice: It is extremely rare to achieve ideal conditions when all gadgets are in direct line of sight to the router. Therefore, in a real home, you will have to work separately to eliminate each dead zone:

• find out what interferes with the signal (absorption or reflection);
• think about where to move the router (or piece of furniture).

Place the router away from sources of interference

The 2.4 GHz band does not require licensing and is therefore used for the operation of household radio standards: WiFi and Bluetooth. Despite the low bandwidth, Bluetooth can still interfere with the router.

Green areas - stream from the WiFi router. Red dots are Bluetooth data. The proximity of two radio standards in the same range causes interference, reducing the range of the wireless network.

The magnetron of a microwave oven emits in the same frequency range. The radiation intensity of this device is so high that even through the protective screen of the furnace, the magnetron radiation can “illuminate” the radio beam of the WiFi router.

Microwave oven magnetron radiation causes interference on almost all WiFi channels.

On practice :

• When using Bluetooth accessories near the router, enable the AFH parameter in the settings of the latter.
• The microwave is a powerful source of interference, but it is not used very often. Therefore, if it is not possible to move the router, then you simply won’t be able to make a Skype call while preparing breakfast.

Disable support for 802.11 B/G modes

WiFi devices of three specifications operate in the 2.4 GHz band: 802.11 b/g/n. N is the newest standard and provides greater speed and range compared to B and G.

The 802.11n (2.4 GHz) specification provides greater range than legacy B and G standards.

802.11n routers support previous WiFi standards, but the mechanics of backward compatibility are such that when a B/G device appears in the N-router's coverage area - for example, an old phone or a neighbor's router - the entire network is switched to B/G mode. Physically, the modulation algorithm changes, which leads to a drop in the speed and range of the router.

In practice: Switching the router to “pure 802.11n” mode will definitely have a positive effect on the quality of coverage and throughput of the wireless network.

However, B/G devices will not be able to connect via WiFi. If it is a laptop or TV, they can be easily connected to the router via Ethernet.

Select the optimal WiFi channel in the settings

Almost every apartment today has a WiFi router, so the density of networks in the city is very high. Signals from neighboring access points overlap each other, draining energy from the radio path and greatly reducing its efficiency.

Neighboring networks operating at the same frequency create mutual interference, like ripples on the water.

Wireless networks operate within a range on different channels. There are 13 such channels (in Russia) and the router switches between them automatically.

To minimize interference, you need to understand which channels neighboring networks operate on and switch to a less loaded one.
Detailed instructions for setting up the channel are provided.

In practice: Selecting the least loaded channel is an effective way to expand the coverage area, relevant for residents of an apartment building.

But in some cases there are so many networks on the air that not a single channel provides a noticeable increase in WiFi speed and range. Then it makes sense to turn to method No. 2 and place the router away from the walls bordering neighboring apartments. If this does not bring results, then you should think about switching to the 5 GHz band (method No. 10).

Adjust the router transmitter power

The power of the transmitter determines the energy of the radio path and directly affects the range of the access point: the more powerful the beam, the further it hits. But this principle is useless in the case of omnidirectional antennas of household routers: in wireless transmission, two-way data exchange occurs and not only clients must “hear” the router, but also vice versa.

Asymmetry: the router “reaches” a mobile device in a distant room, but does not receive a response from it due to the low power of the smartphone’s WiFi module. The connection is not established.

In practice: The recommended transmitter power value is 75%. It should be increased only in extreme cases: turning the power up to 100% not only does not improve the quality of the signal in distant rooms, but even worsens the stability of reception near the router, since its powerful radio stream “clogs” the weak response signal from the smartphone.

Replace the standard antenna with a more powerful one

Most routers are equipped with standard antennas with a gain of 2 - 3 dBi. The antenna is a passive element of the radio system and is not capable of increasing the flow power. However, increasing the gain allows you to refocus the radio signal by changing the radiation pattern.

The higher the antenna gain, the further the radio signal travels. In this case, the narrower flow becomes similar not to a “donut”, but to a flat disk.

There is a large selection of antennas for routers with a universal SMA connector on the market.

In practice: Using an antenna with high gain is an effective way to expand the coverage area, because simultaneously with the signal amplification, the sensitivity of the antenna increases, which means the router begins to “hear” remote devices. But due to the narrowing of the radio beam from the antenna, dead zones appear near the floor and ceiling.

Use signal repeaters

In rooms with complex layouts and multi-story buildings, it is effective to use repeaters - devices that repeat the signal from the main router.

The simplest solution is to use an old router as a repeater. The disadvantage of this scheme is that the throughput of the child network is half as much, since along with client data, the WDS access point aggregates the upstream flow from the upstream router.

Detailed instructions for setting up a WDS bridge are provided.

Specialized repeaters do not have the problem of reducing bandwidth and are equipped with additional functionality. For example, some Asus repeater models support the roaming function.

In practice: No matter how complex the layout, repeaters will help you deploy a WiFi network. But any repeater is a source of interference interference. When there is free air, repeaters do their job well, but with a high density of neighboring networks, the use of repeater equipment in the 2.4 GHz band is impractical.

Use 5 GHz band

Budget WiFi devices operate on the 2.4 GHz frequency, so the 5 GHz band is relatively free and has little interference.

5 GHz is a promising range. Works with gigabit streams and has increased capacity compared to 2.4 GHz.

In practice: “Moving” to a new frequency is a radical option, requiring the purchase of an expensive dual-band router and imposing restrictions on client devices: only the latest models of gadgets work in the 5 GHz band.

The problem with WiFi signal quality is not always related to the actual range of the access point, and its solution broadly comes down to two scenarios:

• In a country house, most often it is necessary to cover an area in free air conditions that exceeds the effective range of the router.
• For a city apartment, the range of a router is usually sufficient, but the main difficulty is eliminating dead zones and interference.

The methods presented in this material will help you identify the causes of poor reception and optimize your wireless network without resorting to replacing the router or the services of paid specialists.

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Setting up Wi-Fi networks demonstrates quite a lot of nuances. I came across someone trying to share the Internet with home users. One computer is connected to the provider via cable. An access point mode is created, a security protocol and a password are selected. Home users use the Internet in parallel. The technique does not work, thanks to the provider using a private line. The exit is located. The obstacles that stand between people and high-speed Internet are powerless to prevent a homemade Wi-Fi antenna from improving signal reception and transmission; communication range and speed naturally increase.

Purpose of homemade Wi-Fi antennas

Antennas adorn many devices. Let's list:

1. Tablet.
2. IPhone.
3. Laptops.
4. Wi-Fi modems.
5. Wi-Fi routers, access points.
6. Cell towers.

A homemade antenna for a Wi-Fi adapter will expand the capabilities of electronics. The access point is distinguished by its ability to transmit the signal omnidirectionally. The power spreads, filling the azimuths. By supplementing the access point with a special external purchased, homemade antenna, it can impart directional properties to the radiation. Will increase the range of reliable reception in the selected azimuth.

Stop breaking your smartphones by connecting an external antenna and assemble it yourself for an access point. Most antennas sold in stores have a circular radiation pattern, radiating equally, omnidirectionally, dividing the power in azimuths.

Powerful homemade Wi-Fi antennas have a much smaller field of view and will provide more reliable reception in some cases. Reflector-equipped devices have a radiation pattern with one central lobe. Remove the reflector and you get a figure eight. There will be a dead zone in the plane of the emitter; there will be no signal. A homemade antenna for a Wi-Fi router is unable to receive directional signals. The access point installation scheme is as follows:

1. The device is connected to a computer (electrical network).
2. The channel is selected.
3. The setting is carried out at full power.
4. The protocol type is selected.
5. The password and network name are set.

People walk around happy with the new accessible point. Let's take a closer look at the process; let's take a moment to grab a soldering iron and pliers. Like a transmitter, a radio-electronic device, an antenna, or a router have a certain peak of capabilities in the middle of the range. For example, on 2.4 GHz there are often 14 channels. The power of the transmitted signal is higher in the middle, for example, the sixth channel. Although each line occupies 22 MHz of the spectrum, the measurement is carried out at a field level of 0.707 (√2/2) maximum on both sides of the carrier frequency.

For reference. Determined by the modulation type, sometimes only the pilot signal remains, one band. Rectangular pulses, computer signals are just like that, have a pronounced maximum, a bunch of side lobes. As a result, the spectrum width of the real signal is infinity. The cyclic voltage band is limited, to which the process emitted by the Wi-Fi protocol does not come close.

A homemade omnidirectional Wi-Fi antenna is not the best option. Nothing will change. A homemade directional Wi-Fi antenna is better; we will make it from wire, foil PCB, or copper tube. They are so sensitive. Transmitted and received powers are concentrated in a narrow sector. It will improve the quality of transmission by carefully positioning users and the access point. You can judge how important the arrangement is by one curious case:

• The office called a technician. They said: between 12.00 and 14.00 the access point collapses. The technician took out a special device for estimating occupied frequencies and began the study. Similar programs are provided by the Android OS of smartphones. Use by selecting a channel before installation. Conduct research throughout the day for several days in a row, avoiding incidents. We bring to light what the master discovered: the neighboring office, separated by a wall, painted lunch. The workers took turns using the microwave (using the 2.4 GHz frequency). Poor insulation of household appliances and lack of grounding allowed the radiation to expose narrow-band interference at the frequency of the magnetron. The solution to the problem turned out to be simple: the access point was moved to the opposite end of the office.

If they had at hand a simple homemade Wi-Fi antenna from a beer can with a reflector, the heroes might not have known that there was a powerful source of harmful radiation next door. The reflector gives the access point directionality and will dampen the radiation coming from behind the wall. Another advantage of directional antennas, which we will make with our own hands today. By the way, when buying a microwave, try to determine safety. You need to plug the device into a grounded outlet, put your cell phone in the working compartment, close the door, and dial the number. The signal passes - harmful radiation from the magnetron will come out. Avoid sitting nearby. Let's discuss how to make a homemade Wi-Fi antenna.

DIY directional Wi-Fi antenna

Tools you will need:

1. Soldering iron (solder, rosin, stand).
2. Pliers.
3. Small flathead screwdriver.
4. Vernier caliper, ruler.
5. Drill with a drill for a copper pipe.

Materials you will need:

1. A piece of foil double-sided PCB as a reflector.
2. Copper wire with a diameter of 1.2 mm and a length of 30 cm (only 26 cm of which will be needed).
3. The RK-50 cable is not too long so as not to dampen the signal.
4. A piece of copper tube 10 cm long for the RK-50 cable to pass inside.

Let's start with a copper tube. We saw through one end by 1.5 mm, removing two-thirds of the wall. The antenna will be soldered to the remaining piece. We create a bi-square contour with a side of 30.5 mm from wire. The size is selected based on the 2.4 GHz band setting condition.

In a similar way, you can make any antenna with a horizontal or vertical polarization signal. Including television. A homemade Wi-Fi antenna is suitable for a tablet, phone, or modem. If you know where to connect.

Please note that the side of the squares is given according to the middle section of the wire. Between the nearest edges there will be 30.5 - 1.2 = 29.3 mm. You can use it. We begin to bend, finding the middle. We use the edge of the ruler as a support and determine the state when the cut begins to balance. We make a bend of 90 degrees, this will be the point where the central core of the RK-50 will connect. We bend the wire, getting a “square eight”, both ends should return strictly symmetrically. We cut it a couple of millimeters short of the initial bend. We tin the ends and put the figure eight aside.

We mark the middle of the PCB and drill a hole so that the copper tube can barely fit in. We fool both sides. We take a copper tube and tin the outer edge of the thin wall left by the first stage. The figure eight is 1.5 cm away from the reflector. We tin the tube in a circle, with the rim at the specified distance from the edge (without taking into account the thin wall). Solder the tube to the board, preferably at an angle of 90 degrees. We place both ends of the figure eight on a thin wall so that the initial bend does not touch the tube. We orient the figure eights parallel to the larger side of the PCB at a distance of 1.5 cm. Now the reflector is grounded.

The RK-50 cable is pulled inside, the screen is placed on the copper tube, the core is placed on the initial bend of the figure eight. We mount the connector on the opposite end, simply solder the cut to the required contacts of the modem, telephone, or any other device. Let's start the test. The figure eight must be mounted vertically for horizontal polarization. If it works, we find silicone sealant that is not afraid of frost and precipitation, and fill the place where the cable exits with the antenna with a good layer. After hardening, the antenna will successfully withstand rain.

If you replace the wire with a thick conductor PV1 of a sufficiently large cross-section (2.5 mm 2), we will strip the braid at the point of initial bending and at the ends. A homemade Wi-Fi antenna for a laptop will be protected against bad weather. Today, heat-shrinkable materials are produced. The heated film tightly fits the product, protecting it from the vagaries of bad weather.

Instructions for making a “double” Bi-Quad (double eight) W-LAN antenna - 2.4 Ghz antennas for wi-fi.

"Double Eight" is a continuation of Bi-Quad, the gain of which is 2 dB higher, i.e. is approximately 12 dB. During construction, pay attention to the fact that the copper wires do not touch at the intersection points. After construction, it is advisable to varnish the “double eight” to avoid oxidation/corrosion. The two photographs below demonstrate how important it is to maintain a distance of 15 mm between the reflector and the copper wire:

In order to avoid questions (there were in the first post), let's consider building an antenna with a circular diagram, in this case something around 270°.

First, from a copper plate (or other sheet metal/material), you need to bend a pipe with a diameter of 70 mm and a height of approx. 100 mm. Then bend a straight 6-element Quad from copper wire and, using, for example, a bottle, give it a corresponding, curved shape. I repeat for those who are not reading very carefully: the distance from the copper wire to the reflector in a circle should be 15 mm! It is important that the crossing wires do not touch each other!

Of course, this is not the only correct option for building such an antenna. The antenna with a pie chart can be made larger,

In this case, signal loss in the antenna cable will be minimized.

Ideally it should look a little different, something like this:

but this is not so important, the main thing is that you can repeat the dimensions by printing. For those bending the “double eight” - the outer squares are not used. Those who do not have a printer can use the following drawing to make a frame: the dimensions are for a wire with a diameter of 2.5 mm

"Triple Eight" is another continuation of the "double eight", the gain coefficient of the "triple eight" can be 14 dB or a little more. This is what a colored “triple eight” looks like, in general, not bad:

For beginners! Please note that the stands supporting the antenna at a distance of 15 mm from the reflector must be made of dielectric material!

The “double eight” and the antenna with a pie diagram discussed above can be mounted together in one housing:

From another.

The antenna is closed. To make the protective housing, a piece of plastic pipe with a diameter of 125 mm, which is used in plumbing, was used; the lid is made of 2 cm plastic. The top fastening nut is made of plastic. Can be painted any color.