Hp 8753E System Operation - HP 8753E User Manual

HP 8753E 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
signal-separation devices
n
receiver
n
display
n
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 8753E 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 data from the frequency domain to the time
domain. other options are explained in Chapter 1, "Analyzer 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 87533iVetwork AruzZgwr Semrice ouide together
with a theory of system operation.
Figure 6-1. Simpliried 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)
signal in the range of 30 kHz to 3.0 GHz. The HP 8753E Option 006 is able to generate signals
up to 6 GHz. The RF output power is leveled by an internal ALC (automatic leveling control)
circuit. To 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. Some portion of the RF source signal must always be sent to
the R channel input. The level must be between 0 dB and -35 dDm.
The Source Step Attenuator
The step attenuator contained in the source is used to adjust the power level to the test device
without changing the level of the incident power in the reference path.
Application and Operation Concepts
P H A S E L O C K