Keysight N5224B, Руководство по обслуживанию

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Keysight N5224B/25B Service Guide 5-43
Theory of Operation
Signal Separation Group Operation
2-port models. The coupling coefficient of the directional couplers is nominally
15 dB for all frequencies above 500 MHz. The coupling coefficient increases for
frequencies below 500 MHz.
A38–A41 60-dB Source Step Attenuators and A42–A45 Bias Tees
On selected 4-port models, a step attenuator and a bias tee are placed in the
signal path of each test port between the A29–A32 receiver couplers and the
A33–A36 test port couplers.
On selected 2-port models, a step attenuator and a bias tee are placed in the
signal path of each test port between the A29–A32 receiver couplers and the
A33–A36 test port couplers.
The 60-dB step attenuators provide coarse power control for the test 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 A21 CPU board.
The bias tees are to provide DC biasing for the DUT.