System Operation; The Built-In Synthesized Source - Agilent Technologies 8719D User Manual

System Operation

Network analyzers measure the reflection and transmission characteristics of devices and
networks. A network analyzer test system consists of the following:
source
n
receiver
n
display
l
The analyzer applies a signal that is transmitted through the test device, or reflected from its
input, and then compares it with the incident signal generated by the swept RF source. The
signals are then applied to a receiver for measurement, signal processing, and display.
The HP 8719D/20D/22D vector network analyzer integrates a high resolution synthesized RF
source, test set, and a dual channel three-input receiver to measure and display magnitude,
phase, and group delay of transmitted and reflected power. With Option 010, the analyzer has
the additional capability of transforming measured
time domain. Other options are explained in Chapter 1, "HP 8719D/20D/22D Description and
Options." Figure 6-l is a simplified block diagram of the network analyzer system. A detailed
block diagram of the analyzer is provided in the HP 8719o/2oo/Z~
SYNTHESIZED
SOURCE
Figure 6-1. Simplified Block Diagram of the Network Analyzer System

The Built-In Synthesized Source

The analyzer's built-in synthesized source produces a swept RF signal or CW (continuous wave)
BP 8719D: 50 MHz
BP 8720D: 50 MHz
BP 8722D: 50 MHz to 40.0
The RF output power is leveled by an internal ALC (automatic leveling control) circuit. 'lb
achieve frequency accuracy and phase measuring capability, the analyzer is phase locked to a
highly stable crystal oscillator. For this purpose, a portion of the transmitted signal is routed to
the R channel input of the receiver, where it is sampled by the phase detection loop and fed
back to the source.
Appliition and Operation Concepts
operation.
system
PHASE LOCK
I
I
to 13.5 GHz
to 20.0 GHz
from the frequency domain to the
data
TEST SET
1
Network Analyzer service
DISPLAY
RECEIVER