HP 85106D, Manual

Page: 65 / 244

2-20 HP 85106D mm-Wave System
Operation
TRL 2-Port Calibration
The isolation measurement is made with both Port 1 and Port 2 terminated in
an appropriate one-port device. Since there is only one load in the standard
calibration kit, the measurement is performed with a load on one port and a
short circuit on the other.
Performing the
Optional Isolation
Calibration
To perform the isolation cal:
1. Set the averaging factor to at least 512.
2. Connect the load to Port 1 and a short circuit to Port 2.
3. Press {
FWD IOS’N ISOL’N STD
}. The HP 8510 measures S
1l
and S
21
.
4. Connect the load to Port 2 and the short circuit to Port 2.
5. Press {
FWD IOS’N ISOL’N STD
}.
6. After the HP 8510 measures S
22
and S
12
.
7. Press {
ISOLATION DONE
}.
8. Set the Averaging Factor back to 128.
9. Connect the waveguide shim between Port 1 and Port 2.
10. Press {
LINE
}. The system makes 6 measurements.
11. Press {
SAVE TRL 2-PORT
}. The error coefficients are computed and the Cal
Set selection menu is displayed.
12. Press a {
CAL SET
} key to store the error coefficients and turn correction
on. The HP 8510 begins to measure all four S-parameters, automatically
switching between forward and reverse parameters.
13. To measure a device, connect it between the test ports, and select a
parameter to measure by pressing [
S11
], [
S21
], or [
S22
]. Any of the four
S-parameters may now be selected and displayed. To restart the
measurement, press [
MEASUREMENT RESTART
].