1. Testing of Wi-Fi antennas By: Nayla Hamadeh Jean Ghanem Jean Ghanem

2. Outline  Constructing an antenna using a Pringles can  Theory behind Wi-Fi antenna  Testing Results  Conclusion

3. Constructing the antenna  Needed Parts: Pringles canPringles can WashersWashers NutsNuts All-thread rodAll-thread rod Aluminum TubingAluminum Tubing Female ConnectorFemale Connector Microwave Cable with SMA-RPMicrowave Cable with SMA-RP

4. Constructing the Antenna (cont’d)  Construct pipe

5. Constructing the Antenna (cont’d)  Attach the connector to the Pringles can

6. Theory behind Wi-Fi  Pringles antenna is based on the quarter-wave monopole.  The copper wire is the monopole  The can wall is the conducting ground (mirror). Radiation pattern a half-wave dipole Radiation pattern of quarter-wave monopole (same as the pringles antenna)

7. Theory behind Wi-Fi  all-thread rod and the washers act like receptive fields.  Washers amplify the signal Adding more washers separated by /4 will increase the performance but make the antenna bigger.Adding more washers separated by /4 will increase the performance but make the antenna bigger.  The rod transmit the signal

8. Gain and performance  The gain is based on the quarter- monople formulas with some modifications. G p = (4*U max )/P i U max = (20/)*I 2  Gain is 11.75dB (12 dB)  Expected range is 5Km

9. Why the antenna may not work as described in the theory?  Measurements must be exact (High frequency) No high precision tools were used.No high precision tools were used. Small adjustments will make a difference.Small adjustments will make a difference.  Copper wire must be vertical and must be close to the can wall. Small space due to the connector.Small space due to the connector.  A good conductor must be used for the mirror. Aluminum inside pringles can is not designed for antennasAluminum inside pringles can is not designed for antennas

10. Testing the Antenna  Pringles can antenna connected to Access Point (the D-Link Access Point DWL-900AP ), in turn connected to the server  On other side, laptop with wireless card (LinkSys Instant Wireless USB Network Adapter)

11. Testing the Antenna  Requirement for antenna: Have a clear line of sight  Maximum Line of sight distance we could achieve was 450 meters

12. Testing the Antenna  2 types of testing performed: Indoors: on the same floor as multimedia labIndoors: on the same floor as multimedia lab Outdoors: around the EECE Bldg up to 450 metersOutdoors: around the EECE Bldg up to 450 meters

13. Indoors Testing  Testing based on 3 parameters: “ping” command“ping” command Playing a movie over the linkPlaying a movie over the link Signal StrengthSignal Strength

14. Indoors Testing (cont’d)  Signal Strength varied between 10- 100% depending on location  “ping” performed generally well but at times the packet loss rate was 50%  Video played generally well except at specific spots

15. Indoors Testing (cont’d)  Observations: Signal provided by antenna was most of the time satisfyingSignal provided by antenna was most of the time satisfying The spots where the signal was weak was separated from the server by several wallsThe spots where the signal was weak was separated from the server by several walls

16. Outdoors Testing  Testing based on 4 Parameters: Signal strengthSignal strength Signal QualitySignal Quality BandwidthBandwidth Quality of Video played over the linkQuality of Video played over the link Provided by the LinkSys wireless card adapter Calculated by downloading file using ftp

17. Outdoors Testing (cont’d) Distance (m)Signal strengthSignal qualityBandwidth (Mbps)Quality of Video 5100% 8.8excellent 20100% 8.4excellent 50100%98%7.7Very good 10092%98%6.9Very good 15095%98%6.1good 20089%95%5.7good 25091%83%5.1good 30085%75%4.4acceptable 35085%70%3.9acceptable 40078%70%3.4poor 45073%62%2.9poor

18. Outdoors Testing (cont’d)

19. Outdoors testing (cont’d)  Observations: Bandwidth very sensitive to distance.Bandwidth very sensitive to distance. Bandwidth depends on signal quality Bandwidth depends on signal quality Effect of weather:Effect of weather: Sunny days: relatively better signal due to less interference

20. Thank you