Measurement Group; A4 Rf Board - Keysight N9912A Service Manual

Theory of Operation

Measurement Group

Measurement Group
The measurement group produces a stable output signal by phase locking a
synthesized voltage-controlled oscillator (VCO).
The measurement group consists of the:
—
—
—
—
A simplified RF block diagram is provided in
A simplified system block diagram is provided in

A4 RF Board

The basic function of the A4 RF board is to provide a signal source and
receivers for the analyzer functions.
There are three sections to the A4 RF board:
— the Common RF section,
— the CAT/NA RF section, and the
— SA RF section.
Common RF Section
This section is common to both NA and SA functions. In this common section,
an LO synthesizer produces a single LO signal from the 30 MHz time base
located on the A5 system board. The LO output is switched between the NA
mixers and the SA first converter depending on the function being used. At any
instant in time, either the NA receivers or the SA receiver may be active, but
not both at the same time.
The LO frequency bands are listed below:
1
2
3
4
5
6
7
8
9
10
5-6
A4 RF Board
A5 System Board
A6 SOM Board
Main Battery
100 kHz to 1.6 MHz
1.6 MHz to 25 MHz
25 MHz to 0.2 GHz
0.2 GHz to 0.8 GHz
0.8 GHz to 1.6 GHz
1.6 GHz to 3.2 GHz
3.2 GHz to 3.4 GHz
3.4 GHz to 4.15 GHz
4.15 GHz to 5.1 GHz
5.1 GHz to 6.2 GHz
Figure 5-2.
Figure 5-3.
Keysight N9912A Service Guide