R&S ZVA8 - Page 426

Repairs R&S ZVA
1177.5333.02 3.118 E-11
Frequency
Level
level ax and bx
10 MHz
0 dBm
> -2 dBm
100 MHz
0 dBm
> -2 dBm
1 GHz
0 dBm
> -2 dBm
3 GHz
0 dBm
> -2.1 dBm
8 GHz
0 dBm
> -2.3 dBm
10 GHz
0 dBm
> -2.4 dBm
12 GHz
0 dBm
> -2.5 dBm
15 GHz
0 dBm
> -2.6 dBm
18 GHz
0 dBm
> -2.7 dBm
20 GHz
0 dBm
> -2.8 dBm
25 GHz
0 dBm
> -3 dBm
30 GHz
0 dBm
> -3.2 dBm
35 GHz
0 dBm
> -3.4 dBm
40 GHz
0 dBm
> -3.6 dBm
45 GHz
0 dBm
> -3.8 dBm
50 GHz
0 dBm
> -4 dBm
55 GHz
0 dBm
> -4.2 dBm
60 GHz
0 dBm
> -4.4 dBm
67 GHz
0 dBm
> -4.7 dBm
With the stated levels, the cable loss must still be taken into account.
If the measured values are more than 2 dB below the levels given in the table, the coupler unit must be
replaced.
Coupler Directivity
The following is assumed:
 The generator and receiver sections of the reflectometer associated with the coupler are OK.
 Perform a sweep from 10 MHz to 67 GHz, measure Ratio bx/ax Source Portx
 Screw the SHORT from the calibration kit to the port connector, save measured values (Data ->
Mem).
 Screw the OPEN from the calibration kit to the port connector, save measured values (More Mem :
Data -> Mem3).
 Screw the MATCH from the calibration kit to the port connector.
 Select User Def Math : linMag(Data) / (linMag(Mem2) + linMag(Mem3)) / 2 : Math = User Def
 The trace gives the directivity.
Frequency range
Directivity
10 MHz to 20 GHz
< -14 dB
20 GHz to 35 GHz
< -10 dB
35 GHz to 40 GHz
< -8 dB
40 GHz to 50 GHz
< -6 dB
50 GHz to 67 GHz
< -3 dB
If the measured values are more than 2 dB greater than the values stated in the table, the coupler must
be replaced.