WiFi Range Expander on Wireless Repeater Linksys WRE54G

Problem definition

Sometimes the existent operation range isn’t enough, or if there are obstacles on the route between the device and the router the distance of operation can be dramatically decreased. In this case You need to increase the sensitivity of the repeater respectively increase the radiation power.

Increasing of the radiation power on the device side isn’t legal and might be a subject only for the qualified electrical engineers. So the normal practice is to redistribute power in the volume. Thus many WiFi devices have an option to exchange their antennas. Than you can replace the original omni-directional antenna by a directional antenna. The power and sensitivity can be increased in a desired direction. The antenna of Linksys 802.11G RANGE EXTENDER - WRE54G can not be replaced for now.

This paper suggests a noninvasive method to extend the operation range in order to connect to a remote access point or client. The method is an approach to form the omni-directional radiated signal into a beam signal. This causes a reduced range/power in other directions.

1. kitchen aluminum foil
2. hard paper
3. invisible post tape
4. scissors
5. a bottle
6. a kitchen cloth
7. a ruler

You need to increase both incoming and outgoing signal strength on the antenna.

• Use an idea of circular waveguide antenna described http://flakey.info/antenna/waveguide/ to shape outgoing signal. The overall signal in the desired direction will be “amplified” by this means up to 8 times = ca. 9 dBi
• Use an idea of a parabolic antenna to collect incoming signal power. The overall signal in the desired direction will be “amplified” by this means up to 5 times = ca. 7 dBi

The antenna of the Linksys device will be virtually divided in two parts for incoming and outgoing part. So the total signal power will actually be reduced twice. The overall gain will be respectively up to 4/2 times of signal strength = 6/3 dBi. Additionally you will become a better signal/noise ratio in a noisy WiFi area because of construction. You “filter” noise from undesired directions. It is practically equal to increasing gain up to 3 dBi. It is the case if a lot of locked access points are around. After all that means you could increase the distance to your access point or user up to 2 times.

1. Take a bottle and roll a kitchen cloth over it up to diameter 3.3 in (84 mm).
2. Roll over the cloth the aluminum foil. Do a couple of turn over. The more – the better, because of harder final shell.
3. Stick tape over the foil to fix the construction
4. pull out the bottle
5. stick the tape inside the aluminum tube to fix the construction
6. Make an aluminum cover for the tube
7. measure the inside diameter on the both side of the tube.
8. calculate an average value of it
9. find the value D in the table: http://flakey.info/antenna/waveguide/
10. find the appropriate value ¼ Lg
11. Drill a hole in the tube with this distance from the cover side
12. find the appropriate value ¼ Lo
13. mark on the Linksis antenna the distance ¼ Lo + 0.2 in ( + 5 mm)
14. fix a aluminum strip on this mark as shown on the picture

15. Cut of an appropriate size paper
16. Roll aluminum foil over the paper
17. Fix foil with the tape
18. Isolate edges by means of the tape

19. Shape the paper into a parabolic kind surface. Use bottle to roll paper over and
20. transform form homogenously
21. Make more foil on paper to shield noise from undesired directions
22. Assemble construction and set up in the right direction