R&S ZNL Series - Page 259

VNA concepts and features
R&S
®
ZNL/ZNLE
259User Manual 1178.5966.02 ─ 20
Table 9-9: Ideal standard parameters
Standard (Gender) R (Load) Electrical Length (Offset)
Open (f, m) ∞ Ω 0 mm (Delay: 0 s)
Short (f, m) 0 Ω 0 mm
Offset Short (f, m) 0 Ω 10 mm
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 Keysight mode
●
All inductance and capacitance parameters are set to zero.
9.5.2.3 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 located on a circle in the Smith chart. The center of this circle corresponds to per-
fect match. The network analyzer determines and further corrects this match point fol-
lowing I. Kása's circle-fitting algorithm.
To obtain the reflection coefficient for a perfectly matched calibration standard, the Slid-
ing 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 to 6 can
improve the accuracy. Moreover, using the predefined load positions of the standard is
recommended.
Calibration