Keysight Technologies N5247B, Service Manual

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Keysight N5247B Service Guide 5-7
Theory of Operation
Network Analyzer System Operation
Synthesized Source Group
Refer to the NOTE notice on page 5-1 .
Version 6 Synthesizers and below:
The built-in synthesized source generates a swept, stepped, or continuous
wave (CW) signal in the frequency ranges as listed in the “N5247B– (900 Hz)
10 MHz to 67 GHz -with synthesizer revision 6 or earlier”,
1
available online at:
https://www.keysight.com/upload/cmc_upload/All/N5247B_Synth6.pdf .
The source group provides five signals: an LO signal and four incident signals.
The LO signal and the four incident signals are offset in frequency by the
receiver IF. For analyzers with DSP version 4.0, the receiver IF is 7.606 MHz
(at tuned frequencies below 53 MHz the IF and the offset is 2.535 MHz). For
analyzers with DSP version 5.0, the receiver IF is 7.438 MHz (at tuned
frequencies below 53 MHz the IF and the offset is 0.826 MHz).
Version 7 Synthesizers:
The built-in direct digital synthesized (DDS) source assembly generates a
swept, stepped, or continuous wave (CW) signal in the frequency ranges as
listed in the “N5247B– (900 Hz) 10 MHz to 67 GHz Data Sheet and Technical
Specifications”,
2
available online at:
https://www.keysight.com/us/en/assets/9018-04526/data-sheets/9018-04
526.pdf (N5247-90029).
The source group provides five signals: an LO signal and four incident signals.
The LO signal and the four incident signals are offset in frequency by the
receiver IF. For analyzers with DDS assemblies, the receiver IF is 7.438 MHz
(at tuned frequencies below 53 MHz the IF and the offset is 0.826 MHz).
LO Behavior without LFE (Low Frequency Extension) – All Synthesizers:
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) as the test signal.
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.
1. Version 6 synthesizers: For PNA-X frequency ranges and maximum output power
levels, refer to the section “Test Port Output” in the online Keysight document,
“N5247B– (900 Hz) 10 MHz to 67 GHz -with synthesizer revision 6 or earlier.” See
the hyperlink above.
2. Version 7 synthesizers: For PNA-X frequency ranges and maximum output power
levels, refer to the section “Test Port Output” in the online Keysight document,
“N5247B– (900 Hz) 10 MHz to 67 GHz Data Sheet and Technical Specifications.”
See the hyperlink above.