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Architecture
wbarnha edited this page May 25, 2020
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TBD
| Model | 2M4 Yagi Antenna |
|---|---|
| Nominal Isotropic Gain | 9.6 dBi |
| Front to Back Gain Ratio | 20 dB |
| Optimal Frequency Range | 144-148 MHz |
| Feed Type | T-match |
| Input Connector | N Female |
| Maximum VSWR | 1.5:1 |
| Model | Downeast Microwave L144LNA |
|---|---|
| Nominal Gain | 17 dB |
| Measured Gain | 21 dB |
| Noise Figure | <0.5 dB |
| Frequency | 144 - 148MHz |
| P1dB | +19 dBm output |
| Input VSWR | >6 dB |
| Output VSWR | >10 dB (DC - 3 GHz) |
| Voltage | +7 - +22 VDC |
| Nominal Current Drain | 100mA |
| Measured Current Drain | 100mA |
| Connectors | N-type |
TBD
When we performed a loopback test from the Communications and Networking Laboratory (CNL) to the roof, and back to the CNL, we transmitted a signal of -5.09 dBm in strength. The following values were obtained via a spectrum analyzer:
| Frequency (MHz) | Loopback 1,2 (dBm) | Loopback 3,4 (dBm) | Loopback 5,6 (dBm) |
|---|---|---|---|
| 100 | -13.34 | -12.41 | -12.73 |
| 146 | -13.78 | -13.14 | -13.01 |
| 160 | -13.77 | -13.74 | -13.28 |
| 440 | -18.91 | -18.08 | -17.73 |
Overall, the line loss in a loopback test is roughly 8 dBm in our intended operating frequency of 146 MHz. Thus, we approximate our connection directly from the roof-mounted antenna to the CNL to be roughly 4 dBm, which is close to the value estimated in our link budget (3.8 dBm).