How-to Make a Lengthy-range Wi-Fi Antenna

2023-10-09 17:29:47

Create a cantenna to drastically lengthen your Wi-Fi sign! Works nice with a router that has exterior antennas, just like the old-school traditional WRT54G.

Supplies

A wireless router with exterior, detachable antennas, ideally with customized firmware or a wireless USB dongle with a removable antennta
Mac or PC
Empty 1qt baby formula can or different similarly-sized aluminum can
Female N-connector, chassis-mount
RP-TNC-to-N-male cable for connecting to most routers (a.ok.a. pigtail) or an N-male to RP-SMA-male cable for connecting to USB adapters
Screws (typically they arrive with the chassis-mount N connector)
12-gauge copper (you probably have scrap cables, you can additionally unsheath them and see if the copper wire is thick enough to suit into the N connector)
Soldering iron (a fine-tip with decrease warmth works greatest)
Solder
Wirecutters
Screwdriver
Digital (most popular) or analog calipers; or only a tape measure
Can opener (or one thing to take away the lid with)
High quality-tip Sharpie or different utensil to mark the situation of the screws

Downloads

None

Information, Expertise, and Skills

Means to solder
Means to put in elements with screws
Fundamental understanding of wi-fi networking ideas (radios, wavelengths, frequencies, and so forth.)

Sources

Waveguide

The aluminum can acts as a medium for the radio waves to be guided by, therefore the time period waveguide cantenna. Radio waves will probably be “guided” into the can and work together with the wire aspect, which sends a sign down the pigtail cable after which to your pc or router.

Dimensions of the Can Matter

Every radio frequency has a distinct wavelength. The wavelength of a sign is the rate of the wave divided by the frequency. When you can, think about you possibly can create waves in a small pool. The velocity is the speed at which the wave adjustments place. The frequency is what number of waves you may make in x period of time. The wavelength would be the distance between every wave you produce.

Now think about you wish to catch a few of these waves in an aluminum can. When you make actually giant waves within the water however have a very small can, you received’t catch many or they may simply break up. When you can completely match the dimensions of your waves to suit contained in the can, you’re going to get seize probably the most water, or in our case, a wi-fi sign. The one distinction is that radio waves are invisible. With a purpose to discover out the suitable dimension of the can, we have to do some math.

Pointers to Cantenna Dimensions

There are a number of primary tips to observe when making a cantenna. This can even assist conceptualize what to do when making it or if you’re modifying the can for a distinct frequency.

The size of the can ought to be longer than 3/4 of the wavelength
The diameter of the can ought to be longer than 1/2 of the wavelength
The copper aspect ought to be roughly 1/4 of the wavelength
The copper aspect ought to be x millimeters away from the again of the can (rear standoff)–that is based mostly off the general diameter of the can. Use this calculator to find out this

There may be a web based calculator, which is able to assist you determine the dimensions of your cantenna.

System for Calculating the Wavelength

First, you will need to know that radio waves journey on the velocity of sunshine, which is about 300 Mega meters (Mm) per second (the precise velocity is 299,792,458 meters/sec). For the needs of an easy-to-remember system, I rounded up and transformed meters to Mega meters.

Wavelength (mm) ≈ Velocity of wave (Mm/sec) / Frequency (GHz)

w = v / f

We all know v will probably be 300 (rounded up based mostly on the velocity of sunshine talked about above). For f, we have to plug within the Wi-Fi frequency. You would simply use 2.4, however so as to be a bit extra correct, we’ll use two extra decimal locations. For channel 6 within the 2.4GHz spectrum, we have to plug in 2.437. Fixing for w yields ~123mm.

w = 300 Mm / 2.437 GHz

w = 123.102175

Now that we all know the wavelength for our radio frequency, we will start calculating the scale of the can based mostly on the rules talked about beforehand.

Breaking Down 2.4GHz into Smaller Items

If you’re confused about utilizing 2.437 as an alternative of simply 2.4, check out the chart under to see how every channel has its personal frequency. Or if you’re feeling very daring, study the Radio Frequency Allocation chart, which provides a really broad however advanced overview of all of the accessible radio frequencies. Principally, simply know that the two.4GHz spectrum isn’t simply 2.4GHz, it’s really 2.401 to 2.483. Whereas this will likely not look like a lot, you probably have ever modified your wi-fi routers channel to get a greater sign, that it does make a distinction.

Discovering the Wavelength of Any Frequency

Making cantennas to work with any wi-fi sign

2.4GHz is a typical frequency for Wi-Fi and its wavelength makes the canntenna a great dimension–not too large, however not too small. When you begin working with different frequencies, the cantenna would possibly develop into ridiculously giant or impossibly small. However merely utilizing the system above, you can theoretically make a waveguide antenna for any frequency.

Dimensions for the Can

The dimensions of the can will make a distinction on the standard of the sign. I will probably be utilizing numbers from the How the Cantenna Works part above to calculate the scale.

When you had been capable of finding the identical can that I used (a 1qt Enfamil child system can), then you possibly can merely observe the directions under. When you have a totally different sized can, you will have to calculate the scale based mostly on directions above within the How the Cantenna Works part. It’s best to nonetheless be capable of observe alongside, however any particular dimension steps will should be modified to fit your can.

Clear the Can

Empty the can by utilizing its contents as supposed (give child system to a child; drink juice; or eat meals that the can incorporates, and so forth.)
Clear the can
Take away one of many can’s lid
Take away the can’s label

Put together the Can for the N-connector

1. Measure ~63.5cm or ~2.5in from the again of the can (this will probably be totally different if you’re not utilizing the identical can that I did)

2. Mark this location with a Sharpie marker Observe: This would be the location of the copper wire aspect

3. Drill or reduce a gap into the can ensuring that the middle of the circle traces up with the measurement above.

4. Drill 4 screw holes into the can utilizing the N-connector as a information for his or her location

Reduce the Copper Factor to Dimension

Reduce a bit of 12-gauge copper aspect to a barely longer than 31mm (this will probably be totally different if you’re not utilizing the identical can that I did)

Observe: This half is difficult as a result of it wants be 31 mm from the purpose it exits out of the N-connector. With a purpose to solder it into the connector, it must be a bit longer. I recommend slicing a bigger piece, becoming it into the connector, after which trimming it down after it’s put in.

Solder the Copper Factor into the N-connector

After getting the copper aspect reduce to dimension, it must be soldered into the connector. When you have by no means soldered earlier than, learn how, after which reduce a number of items to observe with earlier than engaged on the precise connector.

Solder the copper aspect into the N-connector

Warning: Watch out to not soften the plastic contained within the N-connector. It melts simple, so I might recommend utilizing a soldering iron that has decrease warmth and a fine-tip.

Connect the N-connector to the Can

As soon as the N-connector is full, you might be able to mount it to the can utilizing the 4 screws.

1. Screw the N-connector to the can

Join the Cantenna to a Wi-fi Router or Wi-fi USB Dongle

Your cantenna is nearly accomplished; simply join the pigtail cable from the cantenna right into a wi-fi router or wi-fi USB dongle. The router or dongle must have a detachable antenna. The image under reveals the traditional WRT54G getting used. The beauty of this router is you can add DD-WRT firmware, which offers you the power to select which antenna is transmit and which is obtain. It would additionally mean you can alter the ability so you possibly can enhance the vary much more.

1. Screw one finish of the pigtail into the cantenna’s N-connector