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Chapter 8 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
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 HP 34905A (50 ) and HP 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.
390
Test 1
Test 2
Test 3
Power Meter
Test 4
4 x 1 Multiplexer
Test 1
Test 2
Test 3
Patch Cable
4 x 1 Multiplexer
External
4 x 1 Multiplexer
Test 4
Test 5
Test 6
Test 7
Source 1
Source 2
Source 3
Source 4
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