Agilent Technologies N5230A, Service Manual, Page: 136 / 262

5-16 Service Guide N5230-90014
Theory of Operation PNA Series Microwave Network Analyzers
Signal Separation Group Operation N5230A
A19 Switch/Splitter/Leveler/Amplifier/Multiplier (SSLAM)
After the source signal has been amplified, filtered, and multiplied, it is sent to a switch
where it is switched to one of the two test port couplers
A portion of this signal is split off to provide the R1 and R2 channel reference signals.
Another portion is split off and sent to the ALC circuitry, located on the A16 test set
motherboard, to provide leveling control.
Refer also to “A19 Switch/Splitter/Leveler/Amplifier/Multiplier (SSLAM)” on page 5-9 .
A21 and A22 Test Port Couplers
The test port signal goes into the through-line arm of the couplers, and from there to the
test ports and the DUT. The coupled arm of the couplers carries the signal reflected from or
transmitted through the DUT, to the receiver (through a front panel jumper for
Option 014) for measurement. The coupling coefficient of the directional couplers is
nominally 15 dB over the full frequency range.
A25 and A26 60-dB Source Step Attenuators (Option 1E1)
A step attenuator is placed in the signal path of each test port between the A19 SSLAM
and the test port coupler. These 60-dB step attenuators provide coarse power control for
the test port signals. They are electro-mechanical step attenuators that provide 0 to 60 dB
of attenuation in 10-dB steps. They adjust the power level to the DUT without changing
the level of the incident power in the reference path. These attenuators are controlled by
the A15 CPU board.
Configurable Test Set (Option 014)
The Option 014 analyzer allows you to measure devices with higher power and higher
dynamic range limits than the standard analyzer. The theory of operation is the same as
for the standard analyzer except that there are six front panel SMA jumpers.
As shown in Figure 5-4 on page 5-17 , these jumpers are installed between:
• the A25 test port 1 step attenuator and the A21 test port 1 coupler
• the A26 test port 2 step attenuator and the A22 test port 2 coupler
• the A19 SSLAM and the A20 mixer brick channel R1
• the A19 SSLAM and the A20 mixer brick channel R2
• the A21 test port 1 coupler and the A20 mixer brick channel A
• the A22 test port 2 coupler and the A20 mixer brick channel B