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Testing of Wi-Fi antennas. By: Nayla Hamadeh Jean Ghanem. Outline . Constructing an antenna using a Pringles can Theory behind Wi-Fi antenna Testing Results Conclusion. Constructing the antenna. Needed Parts: Pringles can Washers Nuts All-thread rod Aluminum Tubing
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Testing of Wi-Fi antennas By: Nayla Hamadeh Jean Ghanem
Outline • Constructing an antenna using a Pringles can • Theory behind Wi-Fi antenna • Testing Results • Conclusion
Constructing the antenna • Needed Parts: • Pringles can • Washers • Nuts • All-thread rod • Aluminum Tubing • Female Connector • Microwave Cable with SMA-RP
Constructing the Antenna (cont’d) • Construct pipe
Constructing the Antenna (cont’d) • Attach the connector to the Pringles can
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)
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. • The rod transmit the signal
Gain and performance • The gain is based on the quarter-monople formulas with some modifications. Gp= (4*Umax)/Pi Umax= (20/)*I2 • Gain is 11.75dB (12 dB) • Expected range is 5Km
Why the antenna may not work as described in the theory? • Measurements must be exact (High frequency) • No high precision tools were used. • 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. • A good conductor must be used for the mirror. • Aluminum inside pringles can is not designed for antennas
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)
Testing the Antenna • Requirement for antenna: Have a clear line of sight • Maximum Line of sight distance we could achieve was 450 meters
Testing the Antenna • 2 types of testing performed: • Indoors: on the same floor as multimedia lab • Outdoors: around the EECE Bldg up to 450 meters
Indoors Testing • Testing based on 3 parameters: • “ping” command • Playing a movie over the link • Signal Strength
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
Indoors Testing (cont’d) • Observations: • Signal provided by antenna was most of the time satisfying • The spots where the signal was weak was separated from the server by several walls
Outdoors Testing • Testing based on 4 Parameters: • Signal strength • Signal Quality • Bandwidth • Quality of Video played over the link Provided by the LinkSys wireless card adapter Calculated by downloading file using ftp
Outdoors testing (cont’d) • Observations: • Bandwidth very sensitive to distance. Bandwidth depends on signal quality • Effect of weather: Sunny days: relatively better signal due to less interference