Diary of Saturday, 19th February 2005
Prepared by: Jared Baraza
REPORTER: DIPL. ING. JARED BARAZA
START TIME: 9.00 HRS, END: 12.00 HRS
LABORATORY WORK:
TASK: MEASURE ANTENNA PATTERNS
PROJECT MANAGERS: C. FONDA, M. ZENNARO & PROF. PIETROSEMOLI
Equipment used:
Transmitter Station:
Signal generator
Reference antenna for callibration
different transmit antennas ( Can Antenna, Biquad Antenna, Omni Collinear antenna 4 elements)
Reference antenna.
angle measuring device
cables with connectors
Power supply
Receiver station
Spectrum Analyzer
Omni directional Antenna
Cables and connectors
Power supply
PROCEDURE:
The Signal generator was calibrated using the reference Antenna at 2400 MHz. The Receiver was set at a constant height and direction to the Transmitter. The receiver has an omni antenna for receiving the signals. The measurements were done outside at the side building to avoid interference in the laboratory room. The receive station was about six meters from transmitter station.
The Antenna was turned in range of zero degrees to 360 degrees and receive signal measured at the receiver every 10 degrees at 2400 MHz. This was repeated at 2450 and 2500 MHz. The RSL was measured by Prof. Pietrezemoli who was shouting the results very loud for each recorder to hear. The figures of received signal ranged for -30dB to -6 dB. The Measurement was repeated for each Antenna at 2400, 2450 and 2500 GHz. The figures will be plotted on a Smith chart to show the Antenna radiation pattern.
Table 1. Some Results:
Device Under Test: Collinear Antenna, omni 4 Elements
TX Power 0 dBm
| Degrees | RX Level dB at 2400 Mhz | Rx Level dB at 2450 Mhz | RX level dB at 2500 MHz |
| 0 | -30 | -25.5 | -30.2 |
| -30 | -29.8 | -25.5 | -29.5 |
| -60 | -29.7 | -25.6 | -28.5 |
| -90 | -29.1 | -25.9 | -27.9 |
| -120 | -34 | -26.4 | -38.5 |
| -150 | -34.9 | -26.9 | -34.1 |
| -180 | -35.4 | -27.1 | -30 |
| -210 | -35.65 | -26.2 | -30.4 |
| -240 | -35.5 | -26 | -30.7 |
| -270 | -35.1 | -26 | -31.3 |
| -300 | -35.8 | -26 | -31.5 |
| -330 | -35.8 | -25.3 | -31.4 |
| -360 | -35.8 | -26.2 | -30.5 |
The above results can be plotted on a Smith chart to show the horizontal Antena pattern.
Observations:
One side of the transmitter station was so close to the wall. This means some of the transmitted signals were reflected back to the receiver resulting in poor readings.
The angle of rotation and the beam f the signals were not very accurate because of the strong wind that was blowing at the test site.
Only the horizontal antenna measurement was done and not the vertical.
The Tests ended at 12.00.