A20 If Multiplexer Board - Agilent Technologies N5242A Service Manual

Theory of Operation
Receiver Group Operation
The analog IF signal is sent to the A20 IF multiplexer board where it is processed and then
sent to the A12 SPAM board.
The A23 mixer brick sends the EXT TSET DRIVE LO OUT signal to a rear-panel
connector for use with an external test set. This same output connector on the A24 mixer
brick is terminated.

A20 IF Multiplexer Board

This assembly provides pulse modulation capability and routes the IF signal out through
the rear panel connectors for external use and routes external signals in through rear
panel connectors to be included in the signal processing.
In this assembly, on 4-port models, the R1, R2, R3, and R4 reference signals are combined
to create one reference signal, R. On 2-port models the R1 and R2 reference signals are not
combined.
The analog IF signals (A, B, C, D, and R for 4-port models and A, B, R1, and R2 for 2-port
models) are sent to the A12 SPAM board where they are converted to digital information.
Rear Panel Interconnects
The A20 IF multiplexer board includes the following rear panel interconnects.
PULSE I/O
5-22
A DB-15 female connector. Pin assignments are listed in
page 5-23.
PNA Series Microwave Network Analyzers
Table 5-6 on
Service Guide N5242-90001
N5242A