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Math Engine
Decibel Calculator
Professional logarithmic operations for RF power summation, subtraction, and linear conversions.
power addition
combining power from multiple sources (incoherent addition). result = 10 × log₁₀(Σ 10^(dbi/10))
incoherent summation
dbm/dbi
primary signal power level
dbm/dbi
secondary signal power level
logarithmic scalars
standard power ratios (db ⇄ linear)
magnitude
ratio
description
-20 db
0.01
1% power
-10 db
0.1
10% power
-3 db
0.5
half power
0 db
1
unity base
+3 db
2
double power
+10 db
10
10x magnitude
+20 db
100
100x magnitude
+30 db
1000
1000x magnitude
summation cases
incoherent addition behaviors
delta
combined
log logic
30/30
33.0 db
equidistant (+3.0)
30/27
31.8 db
3db gap (+1.8)
30/24
31.0 db
6db gap (+1.0)
30/20
30.4 db
10db gap (+0.4)
30/10
30.0 db
20db gap (~0.0)
40/37
41.8 db
shifted base (+1.8)
50/50
53.0 db
high base (+3.0)
engineering heuristic
signals with >20 db difference are mathematically negligible. the stronger signal defines the system output with <0.1 db error.