Atec Agilent-8720D - Manual (Page 17)

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One-port calibration
Uses test set port 1, or port 2, or both to correct
for directivity, frequency response, and source
match errors. Requires open, short, and load.
Two-port calibration
Compensates for directivity, source match, reflec-
tion frequency response, load match, transmission
frequency response, and crosstalk. Crosstalk cali-
bration can be eliminated. Requires open, short,
and load terminations for both ports plus a
through connection.
TRL*/LRM* calibration
Compensates for directivity, reflection and trans-
mission frequency response, and crosstalk in both
the forward and reverse directions. Especially suit-
able for calibrating non-coaxial environments, such
as in test fixtures. Requires through, reflect, and
line or match standards. TRL*/LRM* is a special
implementation of TRL/LRM calibration modified
for the three-sampler receiver in the standard
Agilent 8719D/20D/22D.
TRL/LRM calibration
With Option 400 (four-sampler receiver). TRL/LRM
provides the highest accuracy for non-coaxial test
environments such as in fixture, on-wafer or in
waveguide. Compensates for directivity, reflection
and transmission frequency response, and
crosstalk in both forward and reverse directions.
One-path, two-port calibration
Provides a full two-port error corrected measure-
ment when the device under test is turned around
and measured in both directions.
Calibration Features
Fast two-port
Compensates for 12-terms, similar to full two-port,
except that 2 of 4 raw parameters (forward or reverse)
are continuously re-measured while the remaining 2
are periodically updated at a user-selectable rate.
Improves update rate for tuning, and reduces unneces-
sary wear on transfer switch in Option 007. [Meas] key
or contact closure at rear panel foot switch connector
causes full two-port update.
Interpolated error correction
With any type of accuracy enhancement applied,
interpolated mode recalculates the error coeffi-
cients when the test frequencies are changed. The
number of points can be increased or decreased
and the start/stop frequencies can be changed, but
the resulting frequency range must be within the
original calibration frequency range. System per-
formance is not specified for measurements with
interpolated error correction applied.
Set Z
o
Redefine the characteristic impedance of a meas-
urement to a value other than 50 or 75 ohms.
Velocity factor
Enter the velocity factor of your propagation medium to
convert equivalent electrical length to physical length.
Electrical delay
Add or subtract delay (linear phase slope), up to
+10 µs, similar to “line stretchers,” both coax or
wave-guide (dispersive) modes. Secondary readout
in distance computed from velocity factor.
Reference plane extension
Redefine the reference plane after calibration. A
new reference plane is defined in seconds of delay
from the test port and ranges between ±l seconds.
Similar to electrical delay, but applied appropriate-
ly to each of four parameters.
Select default calibration kit
Select from a list of standard calibration kits: 7 mm,
3.5 mm, Type-N 50 ohm, Type-N 75 ohm, 2.4 mm,
2.92 mm, and 3.5 mm TRL. You can also define the
standards (for example, open circuit capacitance
coefficients, offset short length, or fixed loads) of a
user-defined kit.
Segmented calibration
Calibration remains valid for any frequency seg-
ment (in frequency list mode), after calibrating all
segments with a single calibration.
Receiver power calibration
Adjusts nonratioed receiver inputs to absolute (non-
ratioed) power level. Displays absolute power in dBm.
Requires reference sweep of known source power.
Data averaging
IF bandwidth
The IF bandwidth is selectable from 6 kHz to 10 Hz
bandwidth to reduce the effective displayed noise
floor of the instrument.
Weighted sweep-to-sweep averaging
Averages vector data on each successive sweep.
A(n) = S(n)/F + (1–1/F) x A(N–1) where A(n) is the
current average, S(n) is the current input signal
and F is the averaging factor. Averaging factors
range from 1 to 999.
Trace smoothing
Similar to video filtering, this function computes
the moving average of adjacent data points.
Smoothing aperture defines the trace width (num-
ber of points) to be averaged, and ranges from
0.25% to 20% of the trace width. This function also
sets the aperture for group delay measurements.