The Logarithmic dB Scale
Antenna engineers use a logarithmic scale to express this apparent 2x (times two) mirror power doubling as “+3 dBi”. It still means “doubling”. Here are some other examples of ratios or multipliers on the engineering dBi gain log scale.
| Gain in dBi | Meaning |
|---|---|
-10 dBi | One tenth or 10 % (loss) |
-6 dBi | One quarter or 25 % (loss) |
-3 dBi | One half or 50% (loss) |
0 dBi | Same or 100% (no gain/loss) |
+1 dBi | 12% higher or x 1.12 |
+2 dBi | 58% higher or x 1.58 |
+3 dBi | 100% higher or double |
+6 dBi | 4x higher or quadruple |
+9 dBi | 8x higher |
+10 dBi | 10x higher |
+13 dBi | 20x higher |
+20 dBi | 100x higher |
Source Article: https://antennatestlab.com/antenna-education-tutorials/is-more-antenna-gain-better
