Concepts and Features
R&S
®
ZNC
79
User Manual 1173.9557.02 ─ 13
Standard (Gender)
R (Load)
Electrical Length (Offset)
Match (f, m)
Z
0
(characteristic impedance of the
connector type)
0 mm
Sliding Match (f, m)
–
0 mm
Reflect (f, m)
∞
Ω
0 mm
Through (ff, mm, mf)
–
0 mm
Line (ff, mm, mf)
–
10 mm
Attenuation (ff, mm , mf)
–
0 mm
Symm. Network (ff, mm, mf)
–
0 mm
The following additional parameters are used:
●
Characteristic impedance: Z
0
(characteristic impedance of the connector type)
●
Loss: 0 dB / sqrt(GHz) or (0 GΩ / s) in Agilent mode
●
All inductance and capacitance parameters are set to zero.
3.5.2.3
Sliding Match Standards
The Sliding Match is a one-port standard consisting of an air line with a movable, low-
reflection load element (sliding load). This standard is used because a no perfect Match
is available over a wide frequency range. However, a series of measurements at a given
frequency with equal mismatch and varying phase yields reflection factors that are loca-
ted on a circle in the Smith chart. The center of this circle corresponds to perfect match.
The network analyzer determines and further corrects this match point following I. Kása's
circle-fitting algorithm.
To obtain the reflection coefficient for a perfectly matched calibration standard, the Sliding
Match must be measured at least at 3 positions which should be unequally spaced to
avoid overlapping data points. Increasing the number of positions to 4 – 6 can improve
the accuracy. Moreover it is recommended to use the predefined load positions of the
standard.
A calibration is valid (and can be applied to the calibrated channel) if either the Match or
three positions of the Sliding Match have been measured. However, it is often desirable
to acquire calibration data from both standards.
The analyzer combines the data in an appropriate manner:
●
The Match results are used up to the lower edge of the specified frequency range of
the Sliding Match (Min Freq).
●
The Sliding Match results are used for frequencies above the Min Freq. In general,
the Sliding Match will provide better results than the Match within its specified fre-
quency range.
3.5.2.4
Cal Kit Files
Calibration kit files can be used to store the parameters of a particular calibration kit, to
re-load the data and to exchange calibration kits from one network analyzer to another.
Calibration
