Also try to find the plates as smooth as possible. The size of such a screen is also not enough, the antenna gain is less than expected.
Patch antenna wifi diy full#
The size of CD and DVD discs is clearly not enough for full reflection, therefore biquadratic antennas built on them have a gain of only 8 dBi.īelow is an example of using a tea can lid as a reflector. The optimal screen size for a biquadrat is 123x123 mm or more, only in this case a gain of 12 dBi can be achieved. Reflector size affects the antenna gain in dBi. Increasing the calculated value fivefold, we get optimal distance- 15.625 mm. The wavelength at a frequency of 2.4 GHz is 0.125 m. Lambda is a wavelength equal to the speed of light in m / s divided by the frequency in Hz. To achieve useful interference, the emitter must be positioned at a multiple of a quarter wavelength from the reflector.ĭistance from emitter to reflector for antennas, the biquadrat and double biquadrat are found as lambda / 10 - determined by the features of this design / 4. The resulting amplifying interference will make it possible to spread the electromagnetic waves from the antenna as far as possible. Correctly reflected waves will superimpose their amplitudes on the vibrations just released by the active element. The main task of the iron shield behind the emitter is to reflect electromagnetic waves. We solder the places for the future fastening of the coaxial cable leads. We check the most important parameter for the finished biquadrat -31 mm along the midline. The next inward folds are made at a distance of 29 mm. We make the next bend, checking the outer dimension of 30–31 mm. Taking into account the selected frequency of 2.4 GHz, the copper core must be found with a thickness of exactly 1.8 mm (with a cross section of 2.5 mm2).įrom the edge of the wire we measure the distance of 29 mm to the bend. The question of the thickness of the wire also needs to be considered carefully. But still we do not satellite dish, therefore, some deviations in the dimensions of the active element -30–31 mm are permissible. N-type connector - useful for convenient antenna connection.įor the 2.4 GHz frequency on which the transmitter is planned to be used, the ideal size of the biquad is 30.5 mm.Plastic straws - can be cut from ballpoint pen, felt-tip pen, marker.Section coaxial cable, better with a characteristic impedance of 50 ohms.Copper wire with a cross section of 2.5 mm2.Metal reflector - a piece of foil-laminated textolite 123x123 mm, a sheet of foil, CD, DVD compact disc, aluminum lid with tea cans.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 correctly installed.Īll possible versions of the biquad antenna are easy to implement. The best of these are biquadratic designs that provide amplification up to 11-12 dBi and double biquadrates, which have a slightly better result at 14 dBi.Īccording to the experience of use, the biquadrat design is more suitable as a multifunctional emitter.
The first samples of self-made distributors of WiFi signal appeared back in 2005. Therefore, old 2.4 GHz routers will perform better in long-range mode than new high-speed ones at 5 GHz. But the 5 GHz signal is not very good for long distances, as it decays faster than the 2.4 GHz signal.
These routers are still new, they are good for high-speed data transfer. Now there are new routers operating at a doubled frequency of 5 GHz. Which antenna will work best at long range, 2.4 GHz or 5 GHz? Now to the question of the carrier frequency. The directional antenna during installation will need to be adjusted to transmit a clear signal in the desired direction. DirectionalĪntennas at 9 dBi work only in a given direction (directional action) - they are useless in the room, they are better used for long-distance communication, in the yard, in the garage next to the house.
This is why home routers have conventional, all-round, 2dBi antennas - so they are most effective over short distances.
Get up off the couch or lie down on the floor, and the connection will immediately disappear. At home, you will have to constantly catch a narrow band of signal activity with a too powerful WiFi emitter. So it turns out that with an increase in the distance of the antenna, the area of its coverage is significantly reduced. Here is a clear illustration of how with an increase in the antenna power in dBi, its coverage area decreases. If you want to assemble a long-range WiFi antenna, then you should know about some of its features.įirst and most simple: large antennas of 15 or 20 dBi (isotropic decibels) are power-limiting and don't need to be made more powerful. We make an ultra-long-range biquadratic WiFi antenna for a router with our own hands.
0 kommentar(er)
