Calibration Before S11 Measurement; Reflection Standard; Cable Compensation - Deepace KC901V Manual

During external cables' far-end calibration, if the external cables' electric
lengths exceed one half of the wave length of the frequency (STEP), user needs to
increase the sweeping points (or reduce SPAN) before the calibration to avoid the
phase aliasing. For example, STEP 3MHz is 100m when it's converted wave length.
The external cable can't be over 35 meter. (Electric length = cable's actual
length/speed factor)
Choose "Re CAL" in S11 mode and then operate it with the operation tips.
Sometimes, when the DUT is the printed circuit board or devices which can't be
connected with coaxial adaptors, user needs to strip off testing cable's end and then
solder it on the DUT. In these kinds of situations, user can do the open-short calibra-
tion before connect the DUT. During the open-short calibration, solder coaxial cables'
core wires on the shielding layer; in open circuit, separate them and hang them in the
air. When instrument ask for a Load, choose "Skip" in the soft menu.

3.5 Reflection Standard

S11 uses SOL calibration. It needs 3 kinds of standards: short, open and load.
During calibration, these three standards are considered as perfect. Instrument will
search the differences between the ideal values and the actual testing value. Then
use equation set to describe all errors. Therefore, these three standards should be
close to ideal.
KC951011/KC951012 is the SOL standard that we (Kexinshe) provide. User can
also use other proper standard, but keep in mind that standard's terminal effect must
be small. Because there is no compensation for KC901V (non-commercial version).
KC951011's nominal electric length is 5.26mm and KC951012's one is 0. If user
chooses other standard, the actual electric length must be input into instrument's
FUNC interface.
When user needs to connect the standard with instrument, tighten then up with
the strongest power by using the thumb and index finger's fingertip to clamp them. If
user uses torque spanner, spanner with the torque which is 135M.cm is suggested.
Standards are expensive accessory, take good care of it while using and storing it.
Also performance validation in regular period is prefered. Before calibration, adaptors
must be checked and cleaned to avoid damaging the standard.
3.6 Cable Compensation(extended)
In order to connect the instrument and DUT, usually we need some RF cables. If
it's not able to do the end calibration on cables, user can use system calibration or do
the user calibration on instrument's ports. Then use the cable compensation to re-
move the influence of cables. In this way, the accuracy will be worse than doing the
calibration on cable's end but better than nothing.
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