Effect of VSWR on Transmitted Power

The VSWR is a measure, of the amount of mismatch between the load (Antenna) and the transmission lines impedance. A VSWR of 1 is a perfect match which occurs on a transmission line where there are no reflections. A VSWR less than 1.5:1 is considered good and a VSWR greater than 2:1 is usually unacceptable.

 

VSWR
Return Loss dB
Power Transmitted %
Reflected Power %
1.00
100.0
0.0
1.01
46.1
100.0
0.0
1.02
40.1
100.0
0.0
1.03
36.6
100.0
0.0
1.04
34.2
100.0
0.0
1.05
32.3
99.9
0.1
1.06
30.7
99.9
0.1
1.07
29.4
99.9
0.1
1.08
28.3
99.9
0.1
1.09
27.3
99.8
0.2
1.10
26.4
99.8
0.2
1.11
25.7
99.7
0.3
1.12
24.9
99.7
0.3
1.13
24.3
99.6
0.4
1.14
23.7
99.6
0.4
1.15
23.1
995
0.5
1.16
22.6
99.5
0.5
1.17
22.1
99.4
0.6
1.18
21.7
99.3
0.7
1.19
21.2
99.2
0.8
1.20
20.8
99.2
0.8
1.21
20.4
99.1
0.9
1.22
20.1
99.0
1.0
1.23
19.7
98.9
1.1
1.24
19.4
98.9
1.1
1.25
19.1
98.8
1.2
1.26
18.8
98.7
1.3
1.27
18.5
98.6
1.4
1.28
18.2
98.5
1.5
1.29
17.9
98.4
1.6
1.30
17.7
98.3
1.7
1.32
17.2
98.1
1.9
1.34
16.8
97.9
2.1
1.36
16.3
97.7
2.3
1.38
15.9
97.5
2.5
1.40
15.6
97.2
2.8
 
VSWR
Return Loss dB

Power Transmitted
%

Reflected
Power
%
1.42
15.2
97.0
3.0
1.44
14.9
96.7
3.3
1.46
14.6
96.5
3.5
1.48
14.3
96.3
3.7
1.50
14.0
96.0
4.0
1.52
13.7
95.7
4.3
1.54
13.4
95.5
4.5
1.56
13.2
95.2
4.8
1.58
13.0
94.9
5.1
1.60
12.7
94.7
5.3
1.62
12.5
94.4
5.6
1.64
12.3
94.1
5.9
1.66
12.1
93.8
6.2
1.68
11.9
93.6
6.4
1.70
11.7
93.3
6.7
1.72
11.5
93.0
7.0
1.74
11.4
92.7
7.3
1.76
11.2
92.4
7.6
1.78
11.0
92.1
7.9
1.80
10.9
91.8
8.2
1.82
10.7
91.5
8.5
1.84
10.6
91.3
8.7
1.86
10.4
91.0
9.0
1.88
10.3
90.7
9.3
1.90
10.3
90.4
9.6
1.92
10.0
90.1
9.9
1.94
9.9
89.8
10.2
1.96
9.8
89.5
10.5
1.98
9.7
89.2
10.8
2.00
9.5
88.9
11.1
2.50
7.4
81.6
18.4
3.00
6.0
75.0
25.0
4.00
4.4
64.0
36.0
5.00
3.5
55.6
44.4
10
1.7
33.1
66.9
20
0.9
18.9
81.9