# Modifying a 2 4 GHz Dipole Antenna to 5 GHz

2,942

31

4

Published

## Introduction: Modifying a 2 4 GHz Dipole Antenna to 5 GHz

In this video I convert a 2.4 GHz dipole antenna into a 5 GHz antenna. I needed quite a few 5 GHz antennas for a project I am working on and it was much cheaper to modify 2.4 GHz antennas.

5 GHz and 5.8GHz dipole antenna: http://youtu.be/ysHP_Yi8bx8

2.4 GHz dipole antenna: http://youtu.be/bs8hvXGJdhM

## Recommendations

• ### 3D CAM and CNC Class

495 Enrolled

• ### Woodworking Contest

We have a be nice policy.
Please be positive and constructive.

## Questions

Firstly love your tuts, But could you explain why shortening the antenna changes it and how to know by how much to shorten it by? I am going to do this hack but I'd like to know the science behind it if it's at all possible to do a vid about the workings of the antenna and why you had to shorten the sleeve.
Keep up the good work. Cheers

You'll have to read up on antenna theory. Something to do with the wavelength in a certain unit like meters and the length of the antenna being a fraction of the wavelength... like a wavelength, 5/8, 1/2, 1/4 wavelength.

http://en.wikipedia.org/wiki/Electrical_length

http://www.hamuniverse.com/hamantennalengths.html

There is an old device to measure wavelength of an emitter/transmitter that was called a lecher wire.

http://en.wikipedia.org/wiki/Lecher_lines

This device helped me visualize why. There is also something called a Standing Wave Ratio (SWR) Meter.

http://en.wikipedia.org/wiki/Standing_wave_ratio

This goes further to help match up the impedence of the antenna to the receiver/transmitter. The ratio of 1:1 is desired so there are not losses to heat and you have maximum efficiency.

Also I'm wanting to use a patch cable with a fishbone yagi 16dbi on a galaxy s2, the aim to pickup 4G network that's signal is 1.5 kms away. Possible or should I use a different antenna? If possible at all. TIA

Not my area of expertise at all, but very interesting!