Signal Separation: Et Models Only; A58 M/A/D/S Modulator, Amplifier, Detector, Splitter - Agilent Technologies 8719ET Service Manual

Theory of Operation

Signal Separation: ET Models Only

Signal Separation: ET Models Only
Figure 12-7 Signal Separation Simplified Block Diagram

A58 M/A/D/S Modulator, Amplifier, Detector, Splitter

The M/A/D/S microcircuit accomplishes four separate functions:
The modulator controls the output power proportionally to the signal produced by the ALC
circuit on the source interface board.
The amplifier provides up to +30 dB of amplification. For the maximum reflection output
power levels refer to
The detector outputs a voltage that is proportional to the RF power out of the amplifier.
This voltage is used by the ALC circuit on the source interface board.
The source divides the source signal into two parts. One signal is routed directly to the A64
R sampler and the other is sent through the A69 step attenuator (ET Option 004 models
only), A23 dc block (8719ET Option 004 and 8720ET Option 004 only), A62 directional
coupler, and out to the REFLECTION port. The TRANSMISSION port is routed through
the A21 fixed attenuator pad and then to the A66 B sampler.
The M/A/D/S microcircuit is controlled by the ALC circuitry on the source interface board.
The CPU provides fine control of the test port power for applications such as power sweep.
12-22
Table 12-1 on page 12-4.
8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers
Service Guide