Rohde & Schwarz 1145.1010.04/05/06, Руководство по эксплуатации

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R&S
®
ZVA/ZVB/ZVT Calibration Overview
1145.1084.12 3.41 E-1
2. Determine the length L
1
and L
2
of the air lines from the following conditions in the center of the
subranges:
L
1
=
λ
(450 MHz)/4 = 16.7 cm; L
2
=
λ
(2.4 GHz)/4 = 3.1 cm
3. Calibrate the subranges separately using the appropriate lines.
TRL calibration is especially useful for DUTs in planar line technology (e.g. test fixtures, on-wafer
measurements) where it is difficult to design and connect accurately modeled open, short or match
standards. If TRL is not practicable, TNA may be an alternative.
TNA Calibration
A TNA (Through – Network – Attenuation) calibration requires two-port standards only. Again, the
through standard must be ideally matched and lossless. The symmetric network must have the same
properties as the reflect standard used for a TRL calibration, i.e. the magnitude of its reflection
coefficient can be unknown but must be nonzero; its phase must be roughly known (
±
90 deg). The
magnitude and phase of the reflection coefficient must be the same at both test ports. The attenuation
standard must be well matched on both sides and cause an attenuation different from zero dB; the
exact value of the transmission coefficient is not important.
As with TRL, TNA calibration is especially useful for planar DUTs. If TNA is not practicable, TRL may be
an alternative.
Enhanced TOM Calibration
Like TOM, an Enhanced TOM (Through – Open – Match) calibration requires a low-loss through
standard with an electrical length that may be different from zero, an open, and a match. The
characteristics of all standards must be fully known, however, the through and the match may be
mismatched. As a result of the latter condition, implicit verification is not possible.
TOM Enhanced calibration can replace TOM calibration if no fully matched through and match
standards are available, especially in the high frequency domain.
Enhanced TSM Calibration
An Enhanced TSM (Through – Short – Match) calibration requires a low-loss through standard with an
electrical length that may be different from zero, a short, and a match. The characteristics of all
standards must be fully known, however, the through and the match may be mismatched. As a result of
the latter condition, implicit verification (like for TOM) is not possible.
Like Enhanced TOM, Enhanced TSM calibration can replace TOM calibration if no fully matched
through and match standards are available, especially in the high frequency domain.