Capabilities – Atec Agilent-8720D User Manual

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Measurement capabilities

Number of measurement channels
2; each fully independent
Parameters
S

: Forward reflection (input match)

: Forward transmission (insertion loss/gain/phase)

: Reverse transmission (reverse isolation)

: Reverse reflection (output match)

A, B, R: Receiver signal level
A/R, B/R, A/B: Ratioed receiver signals
Auxiliary Input: DC voltage on AUX INPUT
Parameter conversion
Z – Reflection: equivalent parallel impedance
Y – Reflection: equivalent parallel admittance
Z – Transmission: equivalent series impedance
Y – Transmission: equivalent series admittance
1/S: complex inverse of S-parameters
Display formats
Cartesian
Log/linear magnitude, phase, group delay, SWR,
real and imaginary
Smith chart
Log/linear magnitude and phase, R+jX, G+jB, or real/imag-
inary markers
Polar
Linear/log magnitude, phase, or real and
imaginary markers

Markers

Number of markers
5 per channel; 1 “active” per channel; can be coupled
(same stimulus in both channels) or uncoupled
(independent stimulus in each channel).

Displayed marker values
All activated markers with both stimulus and
response values are displayed; with dual-channel
uncoupled, can display up to 10 markers; all but
active marker replaced by bandwidths or statistics,
when enabled.

Stimulus resolution
Discrete (actual measurement points) or continu-
ous (linearly interpolated between points, with 1 Hz
resolution).

Delta markers
Displays difference in both stimulus (e.g. frequency)
and response (e.g. dB) between active marker and
reference marker; reference marker may be any of
five markers, or a sixth fixed marker given any
arbitrary position on display.

Polar format markers
Linear magnitude and phase; log magnitude (dB)
and phase; real and imaginary.

Smith chart format markers
Linear magnitude and phase; log magnitude (dB)
and phase; real and imaginary (R+jI); complex
impedance (R+jX); complex admittance (G+jB).

Search
Finds maximum, minimum, or target value.

Bandwidth
Finds and displays center frequency, bandwidth at
a user-defined level (for example, –3 dB), Q factor,
and shape factor (ratio of 60 dB and 6 dB band-
widths); updates while tuning with tracking enabled;
valid for band-pass or band-reject (notch) filters.

Statistics
Calculates and displays mean, standard deviation,
and peak-to-peak deviation of trace; active between
two markers or over entire trace.

Tracking
Performs new search (min/max/target) at end of
each sweep; if disabled, occurs once on demand.

Marker-to functions
Set start, stop or center to active marker stimulus
values; set span to active and delta marker stimu-
lus values; set reference to active marker response
value; set electrical delay to active marker phase
response value.

Group delay characteristics

Group delay is computed by measuring the phase
change within a specified frequency step (deter-
mined by the frequency span, and the number of
points per sweep).

Aperture
Selectable. Maximum aperture: 20% of frequency
span. Minimum aperture: (frequency span)/(num-
ber of points–1).

Range
The maximum delay is limited to measuring no
more than 180° of phase change within the mini-
mum aperture. Range= 1/(2 x minimum aperture).

Accuracy
In general, the following formula can be used to
determine the accuracy, in seconds, of a specific
group delay measurement:
±(0.003 x Phase accuracy(deg))/Aperture(Hz).

Capabilities