Specifications

7-6 TRANSMISSION AND
REFLECTION 3-PORT
CALIBRATION
Once the two port calibration has been successfully performed, the
user may select one of presently two varieties of three port calibration
completion steps.
(1) SOLT is very similar to the standard two port method and will
require connecting an open, a short, and a load to port 3 as well as a
thru line between port 1 and 3 (and possibly between 2 and 3). The
connector type on port 3 must also be specified since open standard
coefficients must be applied. The connector type need not be the same
as for port 1 or for port 2. The SOLT calibration is quite stable for
coaxial systems and will almost always perform adequately.
(2) TRX is very similar to the LRL/LRM/TRM family of calibrations
and will require connecting a short to port 3 (presently not allowed to
be an ambiguous reflection) and a thru line between port 1 and port 3.
The offset of the short plane must be specified as in LRL/LRM/TRM
and the length of the thru must be specified as well. Fewer
connections are required for this cal and it is more amenable to
on-wafer calibrations. The required care and quality of calibration is
somewhat higher as is the case with the LRL/LRM/TRM family.
Once the calibration method is selected, some attention must be paid
to where the reference planes are located. With larger DUTs, cables
are commonly connected to all three ports and the reference planes are
established at each of the cable ends. The only important requirement
is if the port 3 reference plane is not connected to the port 1 reference
plane (that defined during the two port calibration) during the 3 port
thru step, then the appropriate length of the thru line must be
entered. The scenario just described does not fall into the common
‘zero-length-thru’ category.
The 3-port feature is an option and is only available for the MS4622B
and MS4623B.
3-Port Calibration
The following procedure calibrates the MS462XX using the 3-port
technique. A 2-port calibration must be performed first.
Step 1. Press Power (left) then the following soft keys in se
-
quence:
SOURCE 2 SETUP
SOURCE 2 POWER
Step 2. Set the power level for 7 dB, using the Data Entry
keypad and X1 key.
MEASUREMENT 3-PORT TRANSMISSION
CALIBRATION AND REFLECTION CALIBRATION
MS462XX OM 7-23
Data Entry
Power
Keyboard
Port 3
Channels
Enhancement
Stimulus
System
Port 1
Port 2
Probe Power
1
8
5
2
9
6
3
-
.
G/ns/m
M/ s/cm

k/ms/mm
X1
Enter
Local
Appl
Meas
Marker
Hold
Ch 1
Ch 2
Ch 4
Ch 3
Freq
Sweep
Power
Config
Seq
Cal
Avg
Utility
Hard
Copy
Default
Save /
Recall
0
7
4
Display
Clr
Print
Soft
Keys
Power