HP 85106D, Manual

Page: 63 / 244

2-18 HP 85106D mm-Wave System
Operation
Measurement System Calibration
Selecting the
Averaging Factor
It is also advisable to turn averaging ON; an averaging factor of 128 is
acceptable and improves the measurement results without substantially
increasing measurement time.
In the RESPONSE [
MENU
] press:
{
AVERAGING ON/restart
} [
128
] [
x1
]
Checking the
Instrument State
Verify that System Z
o
is set to 1. This is used to normalize impedance in
waveguide.
In the [CAL] {MORE} menu press:
{
SET Zo
} [
1
] [
x1
]
Entering the Exact
Offset Delay
For the 1-Port and Full 2-Port calibrations, improve accuracy by entering the
actual the exact length of the waveguide section instead of the nominal
length as provided in the standard calibration kit definition. For TRL 2-port
calibration either the actual or nominal length may be used.
NOTE The disk file describing the calibration kit definition includes the “nominal”
length of the waveguide section used to make the quarter-wave offset short
and the quarter-wave offset load. The actual physical length of the
waveguide section is printed on the waveguide section or can be found in the
summary data sheet or calibration report. This value can be converted and
entered into the Cal Kit standard definitions thereby improving the accuracy
of the offset calibration. Please refer to the HP 11644 Series Calibration Kit
manual for instructions to enter the actual offset length. You may want to
store this definition onto a disk for future use. For further information on
modifying the cal kit definition see the standard HP 8510C Operating and
Programming manual and Product Note 8510 - 5A.