GRF-1300 User Manual and Teaching Materials
The relationship between dB and dBc
The figures in the table above are based on a 50
Ω
load. As an
example, as -30dBm is equal to 0.001mW or 10
-6
W, therefore with
a 50
Ω
load it is 7071.07 uV or 0.007071mV. The formulas and
derivations from the above table are:
10
10
dBm
inmW
P
=
=>
R
P
V
×
=
=>
)
log(
20
uV
V
dBuV
×
=
further
)
log(
10
mW
P
dBm
×
=
)
log(
20
mV
V
dBmV
×
=
As for dB and dBc, they are relative units. In terms of power, a
difference of 20dB is equal to a difference of 100 times.
Question
What is the difference between 0dBm and-50dBm? Is it 50dB or
50dBm?
Answer
50dB
Explanation
0dBm = 1mW, -50dBm = 10
-5
mW, therefore the difference of both
is 10
5
times which equal to 50dB or a difference of 0.99999mW
And 0.99999mW is equal to -0.0000434dBm
≈
0dBm.
50dBm = 10
5
mW = 100W. Obviously 50dBm is the wrong
answer.
104
Summary of Contents for GRF-1300
Page 15: ...Introduction to the GRF 1300 Figure A 10 Operation interface for HyperTerminal 13 ...
Page 19: ...Overview of the Time and Frequency Domain Time domain Frequency domain 17 ...
Page 20: ...GRF 1300 User Manual and Teaching Materials NOTES 18 ...
Page 21: ...Overview of the Time and Frequency Domain NOTES 19 ...
Page 22: ...GRF 1300 User Manual and Teaching Materials NOTES 20 ...
Page 23: ...Overview of the Time and Frequency Domain NOTES 21 ...
Page 24: ...GRF 1300 User Manual and Teaching Materials 22 NOTES ...
Page 30: ...GRF 1300 User Manual and Teaching Materials NOTES 28 ...
Page 31: ...An Introduction to Spectrum Analyzers NOTES 29 ...
Page 56: ...GRF 1300 User Manual and Teaching Materials NOTES 54 ...
Page 57: ...RF Communication and Signals Experiments NOTES 55 ...
Page 58: ...GRF 1300 User Manual and Teaching Materials NOTES 56 ...
Page 59: ...RF Communication and Signals Experiments NOTES 57 ...
Page 95: ...RF Communication and Signals Experiments 10MHz frequency deviation test results 93 ...
Page 101: ...Test for Learning Outcomes NOTES 99 ...
Page 102: ...GRF 1300 User Manual and Teaching Materials NOTES 100 ...
Page 103: ...Test for Learning Outcomes NOTES 101 ...
Page 104: ...GRF 1300 User Manual and Teaching Materials 102 NOTES ...
Page 109: ...Appendix Modulation Index and Sideband Amplitude Comparison Table 107 ...