HP HP 8753E, Service Manual, Page: 446 / 612

A Close Look at the Analyzer’s Functional Groups
The operation of the analyzer is most logically described in five functional
groups. Each group consists of several major assemblies, and performs a distinct
function in the instrument. Some assemblies are related to more than one
group, and in fact all the groups are to some extent interrelated and affect each
other’s performance.
Power Supply.
The power supply functional group consists of the post
regulator and the preregulator. It supplies power to the other assemblies
in the instrument.
Digital Control.
The digital control group consists of the Al front panel and
front panel processor, the CPU, the rear panel, the display
and the graphics system processor (GSP). The digital IF assembly is
also related to this group. These assemblies combine to provide digital control
for the analyzer.
Source. The source group consists of the source, pulse generator, All
phase lock, reference, fractional-N (analog), and fractional-N
(digital) assemblies. The sampler is also related since it is part of the
source phase lock loop. The source supplies a phase-locked RF signal to the
device under test.
Signal
Separation.
The signal separation group performs the function of an
S-parameter test set, dividing the source signal into a reference path and a
test path, and providing connections to the device under test. It consists of
the transfer switch, the test port 1 coupler, and the test port 2
coupler.
Receiver.
The receiver group consists of the sampler/mixers and
the digital IF. The reference assembly and the CPU are also
related. The receiver measures and processes input signals for display.
The following pages describe the operation of each of the functional groups.
124 Theory of Operation