Keysight Technologies N5247B, Service Manual

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Keysight N5247B Service Guide 5-47
Theory of Operation
Signal Separation Group Operation
— the A31 port 4 reference coupler and the A35 test port 4 coupler
— the A32 port 2 reference coupler and the A36 test port 2 coupler
— the A33 test port 1 coupler and the A27 mixer brick receiver A
— the A34 test port 3 coupler and the A28 mixer brick receiver C
— the A35 test port 4 coupler and the A28 mixer brick receiver D
— the A36 test port 2 coupler and the A27 mixer brick receiver B
Normal Measurement Configuration
The Option 419 analyzer is equipped with a configurable test set and source
attenuators. With this configuration and inclusion of an external amplifier and
accessories, you can calibrate the analyzer and test devices at power levels up
to +30 dBm. You can make measurements in the forward, reverse, or both
directions and still achieve these high power levels.
High Dynamic Range Measurement Configuration
With a few jumper changes, you can configure the measurement configuration
for higher dynamic range measurements. By swapping the front panel jumpers
for one port, signal flow through the corresponding coupler is reversed,
increasing the test signal sensitivity by 15 dB.
In the forward direction, for example, the signal flow through the test port 2
coupler (A36) is reversed by arranging the front panel jumpers such that RCVR
B IN connects to CPLR THRU and CPLR ARM connects to SOURCE OUT.
While increasing forward (S21) dynamic range, the reverse (S12) dynamic
range is degraded by the same amount.
A29–A32 Reference Couplers
The source incident signals from the A5 and A10 26.5 GHz sources are sent to
the A29–A32 reference couplers where a portion of each signal is coupled off
to provide the R1, R2, R3, and R4 receiver reference signals for 4-port models
or R1 and R2 reference signals for 2-port models.
These reference signals are routed through front-panel jumpers to the A27 and
A28 mixer bricks. Refer to “A27 and A28 Mixer Bricks” on page 5-53 for
additional information.
The test signals each go through the through-line arm of a reference coupler,
then through a front panel jumper to the A33–A36 test port couplers.
A33–A36 Test Port Couplers
The test signals go into the through-line arm of the couplers, and from there to
the test ports and the DUT.