Measurements with the APPLICATION NOTE LeCroy SPARQ and Cascade Microtech Probes Using WinCal XE Calibrations LeCroy Corporation and Cascade Microtech 1 Introduction Measurements on two printed circuit boards (PCB) were taken using probing solutions from Cascade Microtech and network analysis solutions from LeCroy. The goal was to determine the quality of measurements taken on a LeCroy SPARQ 4004E Signal Integrity Network Analyzer, and to determine the compatibility with Cascade Microtech probes. Two model ACP40-D-GSSG-400 Cascade Microtech probes were used. The probe’s part number can be understood as follows: ‘ACP’ specifies an air coplanar probe, ‘40’ means 40 GHz (using 2.92 mm connectors), ‘D’ means differential (dual) tips, ‘GSSG’ means that the tips are arranged in a ground-signal-signal-ground geometry, and ‘400’ means that the tips have 400 micron pitch. The testing was performed using two boards. The first board was the standard demo board utilized with the SPARQ. This board comes with two adjacent differential coupled traces with 2.92 mm edge connectors and two differential loss measurement traces. The differential loss measurement traces were utilized for this exercise. The second board was a test board manufactured by Connected Community Networks, Inc. (CCN). CCN is a test lab run by Dr. Don DeGroot, formerly of NIST, who performs test services and works closely with LeCroy. In order to de-embed the probes, we used two distinctly different methods. The first method utilized a second-tier calibration of the SPARQ. The second method utilized the SPARQ application’s time domain gating feature. Figure 1 – LeCroy SPARQ with Cascade Microtech probe station
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Measurements with the APPLICATION NOTE
LeCroy SPARQ and Cascade Microtech Probes
Using WinCal XE Calibrations
LeCroy Corporation and Cascade Microtech
1
Introduction Measurements on two printed circuit
boards (PCB) were taken using probing
solutions from Cascade Microtech and
network analysis solutions from LeCroy.
The goal was to determine the quality of
measurements taken on a LeCroy SPARQ
4004E Signal Integrity Network Analyzer,
and to determine the compatibility with
Cascade Microtech probes. Two model
ACP40-D-GSSG-400 Cascade Microtech
probes were used. The probe’s part
number can be understood as follows:
‘ACP’ specifies an air coplanar probe,
‘40’ means 40 GHz (using 2.92 mm
connectors), ‘D’ means differential
(dual) tips, ‘GSSG’ means that the tips are arranged in a ground-signal-signal-ground geometry, and ‘400’
means that the tips have 400 micron pitch.
The testing was performed using two boards. The first board was the standard demo board utilized with
the SPARQ. This board comes with two adjacent differential coupled traces with 2.92 mm edge
connectors and two differential loss measurement traces. The differential loss measurement traces
were utilized for this exercise. The second board was a test board manufactured by Connected
Community Networks, Inc. (CCN). CCN is a test lab run by Dr. Don DeGroot, formerly of NIST, who
performs test services and works closely with LeCroy.
In order to de-embed the probes, we used two distinctly different methods. The first method utilized a
second-tier calibration of the SPARQ. The second method utilized the SPARQ application’s time domain
gating feature.
Figure 1 – LeCroy SPARQ with Cascade Microtech probe station
2
The second-tier calibrations were performed by first measuring Cascade Microtech impedance standard
substrates (ISSs). These substrates contain calibration standards with models provided by Cascade
Microtech. Two substrates were utilized: the 106-683A, which contains shorts, opens, and loads for GS
and SG probes between 250 and 1250 µm, and the 129-248 GP Thru, which provides thru standards for
GSSG probes for pitches between 300 and 950 µm. The models for the standards are shown later in this
document. After taking calibrated measurements of these standards, error terms were generated for
use in the SPARQ application in two manners. First, models were generated for the calibration
standards, and the standards measurements and models were converted into an error model using the
SPARQ’s internal SOLT calibration algorithms. Second, the measurements were read into WinCal XE™, a
sophisticated piece of software developed and sold by Cascade Microtech, and various calibration
algorithms were applied. All of the available four-port calibrations were utilized, including SOLT, SOLR,
hybrid SOLT-SOLR and LRRM-SOLR.
The results of the measurements utilizing all of the WinCal XE algorithms, the SPARQ internal SOLT
algorithm (specifically comparing to the WinCal XE generated error terms), and the internal time-gating
features of the SPARQ were compared; all of these measurements performed favorably. The remainder
of this document describes the process utilized and documents our results.
Probing System and Measurement Arrangement Figure 1 shows the arrangement of the SPARQ in the probing station. The cables that connect to the
SPARQ are provided with the instrument. In this arrangement, it is advantageous to use right-angle
connectors with the probes. (Only one set was needed, but in retrospect, applying the right-angle
connectors to both probes would have been easier.) The SPARQ is located off to the left and slightly
above the platen. The probe station employs a vacuum table, which holds the board down and in
position. Two positioners are used that are magnetically attached to the platen and that offer x, y, and z
adjustment along with planarity adjustment of the probes.
Planarity Adjustment Before any measurements were taken, each probe was adjusted for planarity. Planarity adjustment was
performed with a contact substrate which is an alumina substrate with a gold top layer. While examining
the probe under the microscope, the probe is landed on substrate and a small amount of over-travel is
dialed-in. Then, the probe is lifted off the substrate and the substrate is examined under the
microscope. Ideally, four identical black lines are seen on the substrate, each corresponding to one of
the four GSSG probe tips. If darker lines are drawn on one side of the probe with corresponding dimmer
lines on the other, the planarity is adjusted and the exercise is repeated until the lines are symmetric.
Interestingly, the dark lines are not caused by the probes scraping gold of the substrate. Instead, the
gold is burnished at the probe touchdown point and the shinier gold reflects the light away from the
microscope causing it to look dark.
3
Board Measurements The four-port measurements of the boards were performed first using the SPARQ. The SPARQ software
includes an interesting feature that saves all of the TDR and TDT traces acquired during a measurement
to a single file. These traces can be played back later and any manner of correction or readjustment of
various features of the measurement can be
changed, and S-parameters recalculated.
This is a degree of flexibility is not found in
any other type of instrument.
The four-port measurements were
performed on:
1. The CCN 4.9 inch differential trace (seen
in Figure 2)
2. The CCN 3 inch differential trace
3. The CCN 100 mil trace
(utilized for rough calibration of the
time gating feature in SPARQ)
4. The LeCroy SPARQ demo board 4 inch
trace (seen in Figure 1)
SPARQ Setup As mentioned in the last section, the SPARQ has the unique capability for recording all of the TDR/T
traces acquired during a measurement for playback at a later time. Therefore, the measurements taken
of the board traces were really taken with the intention of storing the measurement traces after
acquisition, and then to perform the various calibration algorithms after playback. Toward that goal,
measurement characteristics were setup that made sense for examination of the measurements
without the probes de-embedded.
Figure 3 shows the setup utilized. Of key interest are the DUT length mode, which is set to <20 inches,
and the Normal mode sequence control, which specifies that all TDR acquisitions are taken with 10
software averages for both measurement and calibrations. The SPARQ averages 250 waveforms in
hardware, a total of 2500 total averages per acquisition were taken for each trace, which, as shown,
takes about 5 minutes per measurement. Each measurement is performed by first internally calibrating
the SPARQ, which occurs automatically. The SPARQ is configured to de-embed automatically all cables
used in the measurement, which sets the reference plane at the cable ends (i.e. the point where the
probes are connected to the unit). The SPARQ is configured to generate results to 40 GHz, even though
the final measurement is not valid to this frequency. This can be changed later when the calibrations on
the stored TDR traces are performed.
Figure 2 – CCN Board Measurement using a Cascade
Microtech ACP-Dual probe
4
Figure 3 – SPARQ setup for 3 in. CCN Board Measurement
Figure 4 – Port Configuration for differential trace measurements
Raw Board Measurements All of the previously listed board traces were probed, and the TDR/T traces from the measurements
were saved. One SPARQ feature that was heavily employed prior to measuring the S-parameters was the
“live TDR” mode. This feature was indispensible for confirming that the probe was making good contact,
and saved a large amount of time. An example probe touchdown on the boards is shown in Figure 5.
The results for the CCN 3 inch trace is shown in Figure 6. Five sets of measurements are shown. In the
upper left quadrant the differential insertion loss (lime green) and the common-mode insertion loss
(olive green) are shown. The upper right quadrant shows the differential return loss (pink) and the
common-mode return loss (blue).
5
Figure 5 – Probe Touchdown on CCN board (left) and LeCroy demo board (right)
Figure 6 – CCN 3 inch trace raw measurements
The lower left quadrant shows the differential impedance trace (blue) and the common-mode
impedance (red). Cursors are placed on the impedance measurements which show a differential
impedance of about 105 Ohms and a common-mode impedance of 45 Ohms. The lower right quadrant
shows the impedance trace looking into differential port 2. The right side of the screen shows the Smith
chart with the differential match (yellow) and the differential insertion loss (green).
Of particular interest are the effects of the probe. These are most obvious when viewed from the
impedance profile perspective. Figure 7 shows only traces of the differential and common-mode
impedance profiles looking into port 1. Figure 8 shows only the differential and common-mode
impedance looking into port 2. Here we find that at mixed-mode port 1, the probe is about 255 ps long
(including a portion of the tip to board interface) and at mixed-mode port 2 the probe is about 165 ps
long (also including a portion of the tip to board interface).
6
Figure 7 – Differential (blue) and Common-Mode (red) impedance for CCN 3 inch line looking into port 1
Figure 8 – Differential (blue) and Common-Mode (red) impedance for CCN 3 inch line looking into port 2
7
Calibration Measurements In order to perform a second-tier calibration, multiple measurements were taken utilizing two
impedance standard substrates (ISSs) from Cascade Microtech. Figure 9 shows the probes in the
alignment setup on the ISS for the 106-683A substrate for short, open and load for GS and SG probes.
Figure 9 – Cascade probes probing ISS for calibration
Before performing the calibration measurements, the probes are aligned using alignment marks on the
ISS. The key is to arrange the two sets of probes so the tips contact the ISS at a small tick mark offset
from the lines and that as the probes our brought down further, the over-travel slides the tips up to the
edge of the line.
After alignment, the probes were lifted and the open measurement was performed. The open standard
was a measurement with the probes in the air out of contact with the substrate. Then, each GS pair
(single-ended ports 1 and 3) and each SG pair (single-ended ports 2 and 4) were utilized to measure
loads and shorts. Then, a straight thru measurement was performed, followed by a loopback thru
measurement, followed by two diagonal thru measurements.
: <2nd Tier Cal> : Second Tier Calibration Conversion Started: 4 ports, 8000 points, 4.000000e+010 end frequency : <2nd Tier Cal> : File Path Specified: C:\Cascade\SoltSecondTier : <2nd Tier Cal> : Second Tier Calibration is SOLT : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\SM1.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\OM1.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\LM1.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\SM2.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\OM2.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\LM2.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\SM3.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\OM3.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\LM3.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\SM4.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\OM4.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\LM4.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\TM12.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\TM13.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\TM14.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\TM23.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\TM24.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\TM34.s2p was found and read : <2nd Tier Cal> : cable files not used : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Short1.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Short2.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Short3.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Short4.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Short.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Open1.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Open2.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Open3.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Open4.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Open.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Load1.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Load2.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Load3.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Load4.s1p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Load.s1p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru12.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru21.s2p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru13.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru31.s2p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru14.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru41.s2p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru23.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru32.s2p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru24.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru42.s2p not read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru34.s2p was found and read : <2nd Tier Cal> : file: C:\Cascade\SoltSecondTier\Thru43.s2p not read : <2nd Tier Cal> : Second Tier Calibration LeCroy 12-term file: C:\Cascade\SoltSecondTier\SecondTierCalibration.L12T written
15
SecondTier_x.s8p files
After the conversion, four files were created which contain the same error-terms as in the .L12T file, but
in an easily readable form readable by any s-parameter viewing tool. These files are for viewing the
error terms only and are not used by the system.
The format for these files is such that they have the error-terms in an 8 port device model at the
appropriate locations. The eight port device has four ports on the left numbered one through four,
which correspond to the measurement ports. The other four ports on the right numbered five through
eight correspond to the DUT ports. There is one device per left port driven so that the file
SecondTier_1.s8p corresponds to the port 1 driving condition, SecondTier_2.s8p corresponds to the port
2 driving condition and so on.
If we refer to the s-parameters of the file SecondTier_m.s8p as mE , then we have the following s-
parameter formats:
1 1
21 21
31 31
41 41
1
1
21
31
41
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
1 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
Ed Et
Ex Et
Ex Et
Ex Et
Es
El
El
El
E
12 12
2 2
32 32
42 42
2
12
2
32
42
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0 0
0 1 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
Ex Et
Ed Er
Ex Et
Ex Et
El
Es
El
El
E
13 13
23 23
3 3
43 43
3
13
23
3
43
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 1 0 0 0 0
0 0 0 0 0 0 0
Ex Et
Ex Et
Ed Er
Ex Et
El
El
Es
El
E
14 14
24 24
34 34
4 4
4
14
24
34
4
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 0 0 0 0
0 0 0 1 0 0 0
Ex Et
Ex Et
Ex Et
Ed Er
El
El
El
Es
E
[ 2 ] – Error-term s-parameter file format
16
Error
Term
Term Error
Term
Term Error
Term
Term Error
Term
Term
1Ed 111E 12Ex
122E 13Ex 133E 14Ex
144E
1Es 551E 12El
552E 13El 553E 14El
554E
1Er 151E 12Et
152E 13Et 153E 14Et
154E
21Ex 211E 2Ed
222E 23Ex 233E 24Ex
244E
21El 661E 2Es
662E 23El 663E 24El
664E
21Et 261E 2Er
262E 23Et 263E 24Et
264E
31Ex 311E 32Ex
322E 3Ed 333E 34Ex
344E
31El 771E 32El
772E 3Es 773E 34El
774E
31Et 371E 32Et
372E 3Er 373E 34Et
374E
41Ex 411E 42Ex
422E 43Ex 433E 4Ed
444E
41El 881E 42El
882E 43El 883E 4Es
884E
41Et 481E 42Et
482E 43Et 483E 4Er
484E
Table 1 – Error term locations in second-tier calibration s-parameter files
WinCal XE WinCal XE is a very sophisticated tool provided by Cascade Microtech that performs many advanced
functions including advanced calibration algorithms, direct network analyzer control, probe positioned
control, error analysis and more. In this application note WinCal XE was used only for the calibration of
the SPARQ. Although WinCal XE has many features and looks quite daunting, it is in fact very easy to set
up and the error terms exported from WinCal XE are readily usable in the SPARQ.
When WinCal XE is executed, we have the screen as shown in Figure 16. We will utilize the System and
Calibrate dialog choices. We will start with the System Setup, which configures the probes and probe
orientation along with the calibration substrate selections. Then we will enter calibration measurement
data in the Calibration dialogs and calculate and export error-terms.
17
Figure 16 – WinCal XE main dialog
WinCal XE System Setup
The system setup involves choosing the network analyzer, probes, probe orientation, calibration
substrates and probe positioner.
When System is selected from the dialog in Figure 16, a multi-tab dialog is shown. The first tab shows
the VNA selection: Virtual VNA is selected as shown in Figure 17. Then select the Station tab and select
Manual Station as shown in Figure 18.
Figure 17
Figure 18
Then, the Probes tab is selected and the probe is selected as: ACP base probe, GSSG signal
configuration, wide pitch probe with pitch of 400 um. The probes are selected as dual tip probes and
their port and orientations are selected as shown in Figure 19.
18
Figure 19
Figure 20
One thing to notice in Figure 19 is the port numbering relative to the probe numbering. When specifying
the west probe, VNA port 1 and 2 are specified as a GSSG probe and port 1 is specified with dual probe
signal 1 and port 2 is specified with dual probe signal 2. For the east probe, VNA port 3 is specified with
dual probe signal 2 and port 4 is specified with dual probe signal 1.
The diagram shown by WinCal XE helps in this orientation. It is advantageous to match this orientation
to the SPARQ port orientation, although both WinCal XE and the SPARQ can be operated with port
renumbering employed. The port numbering chosen here means that the default WinCal XE numbering
is utilized which helps to avoid confusion. This default port numbering is shown in Figure 20.
19
Figure 21
Figure 21 shows the substrate selections. The 106-683A substrate is selected, which contains shorts,
opens, and loads for GS and SG probes for between 250 and 1250 um and the 129-248 GP Thru which
provides thru standards for GSSG probes for pitches between 300 and 950 um.
A picture of the 106-683A substrate is shown in Figure 22; the 129-248 substrate is shown in Figure 23.
Note that generally the serial number of the substrate should be entered. This is because some of the
elements in the substrate may not be calibrated and the serial number is required to provide a map
showing the valid calibration standard locations. In our case, we knew the valid locations and opted to
skip this step.
The specification of these substrates is mostly used by automatic positioners to locate the standards. It
also enables WinCal XE to know the model for the standards as outlined previously.
20
Figure 22
Figure 23
WinCal XE Calibration Setup
To begin the calibration setup, we select Calibration from the WinCal XE main dialog, shown in Figure
16. A menu as shown in Figure 24 is displayed. To begin, we select the 4-port SOLT (4-6 Thru) from the
calibration method selection. This is best for the first choice because it requires all of the
measurements. We will only need to load these measurements one time. Select the Second-tier
calibration box since this will be a second-tier calibration applied to the SPARQ. This is important
because unless this box is checked, WinCal XE will require switch-terms for the SPARQ which are
irrelevant for a second-tier calibration.
When the 4-port SOLT (4-6 Thru) calibration method is selected, WinCal XE defaults to using the
loopback thru and straight thru, avoiding the diagonal thrus. Selecting Setup and then Calibration Setup
in the pull-down menu exposes the dialog as shown in Figure 25 where you can see all of the standards
measurements listed for each port. Expanding the thrus shows a checklist of thru connections. Here, the
unchecked Thru (1-4) and Thru (2-3) are selected so that the diagonal thrus are now required.
21
Figure 24
Figure 25
Note that in Figure 25, when the Thru (2-3) is selected, the substrate where the thru is taken from along
with the model of the thru is shown in a window on the right. This model can be verified against the
standards models previously discussed.
Returning to the dialog in Figure 24, the next step is to load each of the standards measurements. Using
the same files with the naming conventions as provided in the section entitled SOLT Second-Tier
Calibration Directory Information, The files are loaded in turn by selecting each measurement, right
clicking, and selecting Load Measurement From File as shown in Figure 26. Once each measurement is
selected, WinCal XE loads the measurement, and the View button is ungrayed – you can then view each
of the files loaded for verification. The ports 2,3 (Thru 2-3) measurement is shown in Figure 27.
The need for reloading the data can be prevented when the calibration method is changed by saving all
of the data. The data is saved by selecting Calibration, then Data from the pull-down, then Save All…, as
shown in Figure 28. The data can be saved anywhere – the user needs to remember where it is saved so
that it can be loaded again later.
Make sure the Second Tier Calibration box is set prior to loading and saving the data, otherwise the
saved data may not be readable and the data will need to be loaded again!
22
Figure 26
Figure 27
Figure 28
Figure 29
23
Calibration Data Generation
After all of the measurements are loaded and the data saved, select Calibration then Error Terms from
the pull-down menu and select Compute. When WinCal XE has finished, select Calibration then Error
Terms from the pull-down menu and select Save. Save these files to a directory where you will want the
LeCroy 12-term error-term calibration file to be generated.
Here we can cycle through the calibrations and generate WinCal XE error-terms data for any calibration
method possible. Here we repeat the calibrations for the following types of calibrations (selected in the
Calibration Methods selection area of the Calibration dialog):
4-Port SOLT (4-6 Thru)
4-Port SOLR (4-6 Thru)
4-Port Hybrid SOLT-SOLR (4 Thru)
4-Port Hybrid LRRM-SOLR (4 Thru)
These selections are shown in Figure 30.
To summarize the procedure for generating the WinCal XE calibrations, do the following once the
measurement data has been loaded once and saved:
1. Select the Calibration Method – when a new calibration method is selected, the measurement
data will be cleared. Ensure that the second-tier calibration box is checked.
2. Select Calibration, then Data from the pull-down, then Load All… and then select the folder
where the measurement data was stored. You will see the measurements available because the
View buttons will be ungrayed.
3. Select Calibration, then Error Terms from the pull-down, then compute – the error terms are
computed.
4. Select Calibration, then Error Terms from the pull-down, then Save… - select the folder where
the LeCroy error-terms calibration file will be placed.
24
Figure 30
Converting WinCal XE Error-Terms in SPARQ Figure 31 shows the SPARQ Calibration dialog configured for WinCal XES1P conversion. The floating
dialog in the middle appears when the Convert… button is pressed. Here, four ports are selected with
8000 points to 40 GHz. As previously described, in general, the SPARQ software prefers these number of
points and end frequency (although it will always automatically resample data if provided in alternate
forms). There is no implication here that the calibration is truly valid to this frequency, but using this
configuration provides the most flexibility.
Here, the conversion type is set to WinCal XES1P and an output file is selected for the result. The key
here is the output file directory, where it is expected to find various information required by SPARQ to