Specifications

In the Auto-Reversing Module 2, a coupler provides a signal path for the
built-in level detector that provides a DC signal for the ALC circuits lo
-
cated in the Source 2 Module. Then the source signal is switched between
two paths and routed to the front panel Port 3 and Port 4 connectors, re
-
spectively. Two couplers on these two paths provide samples of these
stimulus signals that feed the reference input of the Down Conversion
Module via J5 of the Auto-Reversing Module 1. The stimulus signals are
then output to the DUT via the Port 3 Module and Port 4 Module
mounted directly to the Port 3 and Port 4 front panel connectors.
The reflected and transmitted DUT signals of the directional couplers in
the Port 1 and Port 2 Modules, along with a sample of the output RF
stimulus (reference) signal, are sent to the Down Conversion Module.
The reflected and transmitted DUT signals of the directional couplers in
the Port 3 and Port 4 Modules are first sent to the High Isolation Switch,
then they are sent to the Down Conversion Module along with a sample
of the output RF stimulus (Reference) signal. This is due to the Down
Conversion Module having a limited number of test signal inputs.
Option 3—Second
Source
Option 3 adds the items listed below to the basic Receiver Module:
q
Port 3 Module
q
Port 3 Step Attenuator
q
Secondary Switched Doubler or Tripler Module
The 10 MHz to 3 GHz signal from the Secondary Source Module is routed
to the Port 3 Module. For operation above 3 GHz, the signal is doubled in
6 GHz models or tripled in 9 GHz models prior to sending it to the Port 3
Module.
The MS462XB Port 3 Module serves many functions. In addition to pro
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viding a directional coupler for receiving the Port 3 test signal, the Port 3
Module provides a DC signal for the ALC circuits located in the Second
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ary Source Module and a sample of the Reference signal from the Second
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ary Source Module for the Down Conversion Module. It also handles the
signal switching of Port 2 and Port 3 Test signals for the Down Conver
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sion Module.
For the MS462XC, the Port 3 Module provides a DC signal for the ALC
circuits located in the Secondary Source Module.
The Port 3 stimulus signal can be attenuated in 10 dB steps viaa0to
70 dB Step Attenuator that is part of the Port 3 source signal path.
Option 4—Noise
Figure
Measurement
Capability
Option 4 adds the items listed below to the basic Receiver Module:
q
Port 1 Switch Module
q
Port 2 Switch Module
q
Low Noise Pre-Amplifier Assembly
The Port 1 and Port 2 Switch Modules are of the same part, which is a
bidirectional single pole double throw switch.
2-20 MS462XX MM
FRONT END RF COMPONENTS THEORY OF OPERATION