Keysight Technologies N5222B, Руководство по обслуживанию

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Keysight N5290/1A Service Guide 5-3
Theory of Operation
Theory of Operation
Theory of Operation
Overview
Refer to the block diagram in Figure 5-3 on page 5-6 through Figure 5-6 on
page 5-9 for the following paragraphs.
The N5292A Option 200 or N5292A Option 400 millimeter head controller
routes the LO and RF signals from the PNA to the test set millimeter head. The
millimeter heads separate the incident from the reflected RF signal, up convert
those signals to 110/120 GHz and then separate and down convert those
reflected signals to an IF signal.
The millimeter heads do not have their own power supplies; each head
receives dc power from the N5292A-200 or N5292A-400 millimeter head
controller, by way of a multi-pin interface cable.
LO Behavior without LFE (Low Frequency Extension):
The LO signal is sent directly to the mixers in the receiver group. The incident
signals are routed to the front panel test ports and then to the device under
test (DUT). A portion of each incident signal is coupled off (in the signal
separation group) and sent to the mixers in the receiver group as reference
signals. These reference signals are compared (mixed) with the LO signal in the
receiver group to produce the 7.438 MHz (or 0.826 MHz at frequencies below
53 MHz) IF signal.
LO Behavior with Low Frequency Extension (LFE) Operation
On the synthesizer board, there is a LFE output that is limited by the C-R filter
and by the 250 MHz low pass filter.
Below 20 MHz, the LFE is signal is directly converted. Exceptions are shown in
Figure 5-1 on page 5-4 . See also, the Service Guide for your PNA on
www.keysight.com .