Rf Signal Multiplexing - Agilent Technologies 34972A User Manual

Chapter 7 Tutorial

RF Signal Multiplexing

RF Signal Multiplexing
A special type of multiplexer is the RF multiplexer. This type of
multiplexer uses special components to maintain a 50 or 75
impedance in the signal line being switched. In a test system, these
switches are often used to route a test signal from a signal source to the
device-under-test. The switches are bi-directional. The diagram below
shows two examples of a 4-to-1 channel RF multiplexer in a test system.
Signal
Generator
4 x 1 Multiplexer
By using patch cables, you can expand RF multiplexers to provide
additional test inputs or outputs. For example, you can combine two 4-to-
1 multiplexers to create a 7-to-1 multiplexer as shown below.
Oscilloscope
4 x 1 Multiplexer
On the 34905A (50) and 34906A (75) RF multiplexers, you can close
only one channel per bank at a time; closing one channel in a bank will
open the previously closed channel. These modules respond only to the
CLOSE command (OPEN does not apply). To open a channel, send the
CLOSE command to another channel in the same bank.
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External
Power Meter
4 x 1 Multiplexer
Test 1
Test 2
Test 3
Patch Cable
4 x 1 Multiplexer
Source 1
Source 2
Source 3
Source 4
Test 4
Test 5
Test 6
Test 7