Appendix A. Appendix
Path Loss Calculations
Here’s a simple table of path loss calculations in free space for channels 1 and 11, with clear line of sight. See Chapter 6 for how to use these numbers to figure out how far your network can reach. Distances are in miles, losses are in dB.
|
Distance (miles) |
2.412GHz (ch. 1) |
2.462 GHz (ch. 11) |
|---|---|---|
|
0.5 |
98.2 |
98.4 |
|
1 |
104.2 |
104.4 |
|
2 |
110.3 |
110.4 |
|
3 |
113.8 |
114.0 |
|
4 |
116.3 |
116.5 |
|
5 |
118.2 |
118.4 |
|
7 |
121.1 |
121.3 |
|
10 |
124.2 |
124.4 |
|
15 |
127.8 |
127.9 |
|
20 |
130.3 |
130.4 |
|
25 |
132.2 |
132.4 |
|
30 |
133.8 |
134.0 |
This path loss table was calculated with the following formula, rounded up to the nearest tenth:
| L = 20 log(d) + 20 log(f ) + 36.6 |
For possibly the most authoritative source of radio information on the planet, check out the ARRL online at http://www.arrl.org, or see any of their excellent books (in particular, their UHF/Microwave Experimenter’s Manual and Antenna Book are definitive sources for learning about microwave communications).
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