Vaisala RVP900 - Treatment of Losses in Calibration; Figure 48 Overview of Losses that Affect LOG Calibration

7.6.3 Treatment of Losses in Calibration
When calibrating the dBm level of the test signal, you must account for any losses that may
occur between the antenna feed and the injection point, and in the cable and coupler that
connect the signal generator to the injection point.
The following
figure shows the nomenclature of the losses that are involved in the
calibration.
Transmitter
P
t
revieceRrelpuoC
Sig Gen
dBm
siggen
IFDR
L
t
L
Feed:Coupler
Feed
Receive Path
Transmit
Path
dBm
Feed
L
Cable
L
Coupler
P
t Feed
Figure 48 Overview of Losses that Aect LOG Calibration
The relationship between the injected test signal and the value of the received power
relative to the feed is:


= 

+ 
: 


= 

 

 

+ 
: 
For example, assume the following:
Loss
Relationship Value
Loss between the feed and the coupler 
: 
3 dB
Loss caused by the coupler 

30 dB
Loss in the cable from siggen to coupler 

2 dB
RVP900 User Guide M211322EN-J
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