Overview - Agilent Technologies FieldFox N9912A User Manual

Overview

In the FieldFox, both 1-port and 2-port measurement types use a different
configuration setup from the HP/Agilent 8508A Vector Voltmeter.
Typical 8508A measurement configuration – taken from the 8508A manual.
The above block diagram requires an external source and directional coupler to
measure the electrical length of a DUT or cable to be trimmed. Separate paths
are used to measure the Incident signal (A) and Reflected signal (B). To measure
the ratio of the Reflected / Incident signals, you were required to select B/A for
both the Magnitude and Phase display.
In the following FieldFox block diagram, the source and directional coupler are
inside the instrument. This allows you to connect the DUT to ONLY the FieldFox
RF Out port, with NO external instruments, in order to make Cable Trimming
measurements.
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FieldFox block diagram
 The
R receiver measures incident signal (green
line) out of the source.
 The
A receiver measures reflected signal (red
line) from the end of the DUT (black line).
 In VVM mode, the display ALWAYS shows ratioed
(A/R) measurements which is the electrical length
of the DUT.
N9912A FieldFox User's Guide