R&S ZVA24, Руководство по обслуживанию

Страница: 427 / 606

R&S ZVA Repairs
1177.5333.02 3.119 E-11
Coupler Port Matching
It is assumed that there is a functioning reflectometer in the instrument.

Loosen cables W514A (GEN -> coupler), W515A (coupler -> MEAS) and W518A (coupler -> REF)
at both ends and unscrew at the coupler.

Terminate the coupler input and coupler outputs with three K-terminations (three V-terminations).

Connect test cable to a functioning instrument port and perform a 1-port calibration at the end of the
cable.

Connect the end of the test cable to the port of the coupler under test and display the Sxx
magnitude on the screen.
Frequency range Sxx dB
10 MHz to 5GHz < -20 dB
5 GHz to 20 GHz < -15 dB
20 GHz to 30 GHz < -12 dB
30 GHz to 40 GHz < -11 dB
40 GHz to 60 GHz < -10 dB
60 GHz to 67 GHz < -6 dB
If the measured values are more than 2 dB greater than the values stated in the table, the coupler must
be replaced.
Testing the Reflectometers on ZVA80-BU
Port1 and port2: See Testing the Reflectometer RM 44 and RM50
Port3 and port4:
Generator levels
It is assumed that the synthesizer section (source section of synthesizer1 or synthesizer2) associated
with the reflectometer to be tested is OK.

Loosen cable W514 (GEN -> coupler unit) at both ends and screw off at the generator output GEN.

Connect the generator output to the spectrum analyzer using the SMA cable ().

Set the ZVA to the CW sweep mode.

Set the frequencies listed in the table.

Set the power listed in the table.
Frequency Set power to Level on GEN output 2nd harmonic 3rd harmonic
10 MHz 10 dBm 13.0 dBm --- ---
100 MHz 10 dBm 13.0 dBm < - 21 dBc < - 21 dBc
1 GHz 10 dBm 13.2 dBm < - 21 dBc < - 21 dBc
4 GHz 10 dBm 13.7 dBm < - 21 dBc < - 21 dBc
8 GHz 10 dBm 14.3 dBm < - 21 dBc < - 21 dBc
9 GHz 10 dBm 14.5 dBm < - 21 dBc ---
12 GHz 10 dBm 15.0 dBm --- ---
15 GHz 5 dBm 7.5 dBm --- ---
18 GHz 5 dBm 8.0 dBm --- ---
20 GHz 5 dBm 8.3 dBm --- ---
With the stated levels, the cable loss must still be taken into account. For the specified cable it is
0.25 dB/GHz.