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The VNA screen (shown here in narrow format) will allow you to directly view impedance magnitude
and phase characteristics of virtually any single-ended device. Keep in mind that the instrument must
be calibrated (either broadband or frequency-specific) as when doing RL and SWR measurements.
The calibration process is identical, and occurs whenever center frequency or span is changed (when
in frequency specific mode).
Once calibrated, use the UP arrow to select the left or right scales. With a scale selected, <ENTER>
will switch the kind of measurement for that scale. The possible selections are Z-Mag (|S11| or
Impedance Magnitude in
Ω), Z-Ang (S11 phase angle in degrees), Rs (resistance) and Xs
(reactance). With the desired parameter selected, press <SCALE> to select the scale to best view
the traces. With the cursor enabled via the <CRSR> key, the measurements at the cursor location
are displayed along with the cursor frequency.
VNA Screen shown above in wide format.
S21 VNA Screen (Two-Port Model only)
The S21 VNA Screen shown above illustrates how the MRI-3000's Two-port capabilities can be used
to analyze a two-port device; in this case, a low-pass filter. Unlike for a single-port measurement, the
parameters measured cannot be changed: This always displays GAIN and PHASE (although, the
phase trace can be turned off). The cursors work the same as for a single-port measurement,
although this display is always in 'wide' format.
Calibration, Measurement Information and Helpful Tips
Calibration Processes
The MRI-3000 has two types of calibrations; Broadband and Frequency Specific.
