| VSWR
/ Return Loss
VRSR
is simply the ratio of the resistance of the termination and the
characteristic impedance of the source or line. The larger
resistance is always in the numerator by convention. For example,
a 75 ohm load termination to a 50 ohm source will yield a VSWR of
1.5 since 75/50=1.5.
Return
Loss - The number of dB that the reflected signal is below the
incident signal.
These
terms are related by the following formulas
Return
Loss = RL = -20 x logçGç dB
Refection
coefficient = G=ê(1-VSWR)/(1+VSWR) ê
VSWR=((10^d)+1)/((10^d)-1)
d=RL/20
The
table below relates VSWR, Return Loss, Transmission Loss, and
Transmission Power.
Download
Table as PDF.
| VSWR |
Return
Loss (dB) |
Trans.
Loss (dB) |
Volt.
Refl Coeff |
Power
Trans (%) |
Power
Refl (%) |
VSWR |
Return
Loss (dB) |
Trans.
Loss (dB) |
Volt.
Refl Coeff |
Power
Trans (%) |
Power
Refl (%) |
| 1 |
- |
0 |
0 |
100 |
0 |
1.64 |
12.3 |
0.263 |
0.24 |
94.1 |
5.9 |
| 1.01 |
46.1 |
0 |
0 |
100 |
0 |
1.66 |
12.1 |
0.276 |
0.25 |
93.8 |
6.2 |
| 1.02 |
40.1 |
0 |
0.01 |
100 |
0 |
1.68 |
11.9 |
0.289 |
0.25 |
93.6 |
6.4 |
| 1.03 |
36.6 |
0.001 |
0.01 |
100 |
0 |
1.7 |
11.7 |
0.302 |
0.26 |
93.3 |
6.7 |
| 1.04 |
34.2 |
0.002 |
0.02 |
100 |
0 |
1.72 |
11.5 |
0.315 |
0.26 |
93 |
7 |
| 1.05 |
32.3 |
0.003 |
0.02 |
99.9 |
0.1 |
1.74 |
11.4 |
0.329 |
0.27 |
92.7 |
7.3 |
| 1.06 |
30.7 |
0.004 |
0.03 |
99.9 |
0.1 |
1.76 |
11.2 |
0.342 |
0.28 |
92.4 |
7.6 |
| 1.07 |
29.4 |
0.005 |
0.03 |
99.9 |
0.1 |
1.78 |
11 |
0.356 |
0.28 |
92.1 |
7.9 |
| 1.08 |
28.3 |
0.006 |
0.04 |
99.9 |
0.1 |
1.8 |
10.9 |
0.37 |
0.29 |
91.8 |
8.2 |
| 1.09 |
27.3 |
0.008 |
0.04 |
99.8 |
0.2 |
1.82 |
10.7 |
0.384 |
0.29 |
91.5 |
8.5 |
| 1.1 |
26.4 |
0.01 |
0.05 |
99.8 |
0.2 |
1.84 |
10.6 |
0.398 |
0.3 |
91.3 |
8.7 |
| 1.11 |
25.7 |
0.012 |
0.05 |
99.7 |
0.3 |
1.86 |
10.4 |
0.412 |
0.3 |
91 |
9 |
| 1.12 |
24.9 |
0.014 |
0.06 |
99.7 |
0.3 |
1.88 |
10.3 |
0.426 |
0.31 |
90.7 |
9.3 |
| 1.13 |
24.3 |
0.016 |
0.06 |
99.6 |
0.4 |
1.9 |
10.2 |
0.44 |
0.31 |
90.4 |
9.6 |
| 1.14 |
23.7 |
0.019 |
0.07 |
99.6 |
0.4 |
1.92 |
10 |
0.454 |
0.32 |
90.1 |
9.9 |
| 1.15 |
23.1 |
0.021 |
0.07 |
99.5 |
0.5 |
1.94 |
9.9 |
0.468 |
0.32 |
89.8 |
10.2 |
| 1.16 |
22.6 |
0.024 |
0.07 |
99.5 |
0.5 |
1.96 |
9.8 |
0.483 |
0.32 |
89.5 |
10.5 |
| 1.17 |
22.1 |
0.027 |
0.08 |
99.4 |
0.6 |
1.98 |
9.7 |
0.497 |
0.33 |
89.2 |
10.8 |
| 1.18 |
21.7 |
0.03 |
0.08 |
99.3 |
0.7 |
2 |
9.5 |
0.512 |
0.33 |
88.9 |
11.1 |
| 1.19 |
21.2 |
0.033 |
0.09 |
99.2 |
0.8 |
2.5 |
7.4 |
0.881 |
0.43 |
81.6 |
18.4 |
| 1.2 |
20.8 |
0.036 |
0.09 |
99.2 |
0.8 |
3 |
6 |
1.249 |
0.5 |
75 |
25 |
| 1.21 |
20.4 |
0.039 |
0.1 |
99.1 |
0.9 |
3.5 |
5.1 |
1.603 |
0.56 |
69.1 |
30.9 |
| 1.22 |
20.1 |
0.043 |
0.1 |
99 |
1 |
4 |
4.4 |
1.938 |
0.6 |
64 |
36 |
| 1.23 |
19.7 |
0.046 |
0.1 |
98.9 |
1.1 |
4.5 |
3.9 |
2.255 |
0.64 |
59.5 |
40.5 |
| 1.24 |
19.4 |
0.05 |
0.11 |
98.9 |
1.1 |
5 |
3.5 |
2.553 |
0.67 |
55.6 |
44.4 |
| 1.25 |
19.1 |
0.054 |
0.11 |
98.8 |
1.2 |
5.5 |
3.2 |
2.834 |
0.69 |
52.1 |
47.9 |
| 1.26 |
18.8 |
0.058 |
0.12 |
98.7 |
1.3 |
6 |
2.9 |
3.1 |
0.71 |
49 |
51 |
| 1.27 |
18.5 |
0.062 |
0.12 |
98.6 |
1.4 |
6.5 |
2.7 |
3.351 |
0.73 |
46.2 |
53.8 |
| 1.28 |
18.2 |
0.066 |
0.12 |
98.5 |
1.5 |
7 |
2.5 |
3.59 |
0.75 |
43.7 |
56.2 |
| 1.29 |
17.9 |
0.07 |
0.13 |
98.4 |
1.6 |
7.5 |
2.3 |
3.817 |
0.76 |
41.5 |
58.5 |
| 1.3 |
17.7 |
0.075 |
0.13 |
98.3 |
1.7 |
8 |
2.2 |
4.033 |
0.78 |
39.5 |
60.5 |
| 1.32 |
17.2 |
0.083 |
0.14 |
98.1 |
1.9 |
8.5 |
2.1 |
4.24 |
0.79 |
37.7 |
62.3 |
| 1.34 |
16.8 |
0.093 |
0.15 |
97.9 |
2.1 |
9 |
1.9 |
4.437 |
0.8 |
36 |
64 |
| 1.36 |
16.3 |
0.102 |
0.15 |
97.7 |
2.3 |
9.5 |
1.8 |
4.626 |
0.81 |
34.5 |
65.5 |
| 1.38 |
15.9 |
0.112 |
0.16 |
97.5 |
2.5 |
10 |
1.7 |
4.807 |
0.82 |
33.1 |
66.9 |
| 1.4 |
15.8 |
0.122 |
0.17 |
97.2 |
2.8 |
11 |
1.6 |
5.149 |
0.83 |
30.6 |
69.4 |
| 1.42 |
15.2 |
0.133 |
0.17 |
97 |
3 |
12 |
1.5 |
5.466 |
0.85 |
28.4 |
71.6 |
| 1.44 |
14.9 |
0.144 |
0.18 |
96.7 |
3.3 |
13 |
1.3 |
5.762 |
0.86 |
26.5 |
73.5 |
| 1.46 |
14.6 |
0.155 |
0.19 |
96.5 |
3.5 |
14 |
1.2 |
6.04 |
0.87 |
24.9 |
75.1 |
| 1.48 |
14.3 |
0.166 |
0.19 |
96.3 |
3.7 |
15 |
1.2 |
6.301 |
0.88 |
23.4 |
76.6 |
| 1.5 |
14 |
0.177 |
0.2 |
96 |
4 |
16 |
1.1 |
6.547 |
0.88 |
22.1 |
77.9 |
| 1.52 |
13.7 |
0.189 |
0.21 |
95.7 |
4.3 |
17 |
1 |
6.78 |
0.89 |
21 |
79 |
| 1.54 |
13.4 |
0.201 |
0.21 |
95.5 |
4.5 |
18 |
1 |
7.002 |
0.89 |
19.9 |
80.1 |
| 1.56 |
13.2 |
0.213 |
0.22 |
95.2 |
4.8 |
19 |
0.9 |
7.212 |
0.9 |
19 |
81 |
| 1.58 |
13 |
0.225 |
0.22 |
94.9 |
5.1 |
20 |
0.9 |
7.413 |
0.9 |
18.1 |
81.9 |
| 1.6 |
12.7 |
0.238 |
0.23 |
94.7 |
5.3 |
25 |
0.7 |
8.299 |
0.92 |
14.8 |
85.2 |
| 1.62 |
12.5 |
0.25 |
0.24 |
94.4 |
5.6 |
30 |
0.6 |
9.035 |
0.94 |
12.5 |
87.5 |
|
