A11 13.5 Ghz Lo Synthesizer Board (Option 108); A21 Multiplier/Amplifier 26.5 Board (Hma26.5) (Option 108); A19 Test Set Motherboard - Keysight N5264A Service Manual

Theory of Operation
Synthesized LO Group Operation (Option 108)
Rear-Panel Interconnects
10 MHz REF INPUT
10 MHz REF OUTPUT

A11 13.5 GHz LO Synthesizer Board (Option 108)

The A11 13.5 GHz LO synthesizer board uses the 50 MHz reference signal from
the A10 frequency reference board to tune two VCO circuits: one that sweeps
from 2 GHz to 4 GHz and one that is set to a fixed CW frequency of 3.4 GHz.
In bands 2-13, the 3.4 GHz signal is mixed with 3.41 GHz to 3.90 GHz signals
from the 2–4 –GHz oscillator to produce the output frequencies of 10 MHz to
500 MHz as listed in
In bands 14 and 15, the output of the swept VCO is passed through a
divide-by-4 circuit to produce the output frequencies listed in
In bands 16 and 17, the swept VCO signal is passed through a divide-by-2
circuit to produce the output frequencies listed in
In bands 18–20, the swept VCO signal is passed directly to the output of the
synthesizer board to produce the output frequencies listed in
In bands 21–36, the swept VCO signal is passed through a doubler circuit
where bands 21–23 and 29–30 are sent directly to the output of the
synthesizer board while bands 26–28 and 34–36 are passed through another
doubler circuit then to the output of the synthesizer board to produce the
output frequencies listed in

A21 Multiplier/Amplifier 26.5 Board (HMA26.5) (Option 108)

In bands 2–28, the synthesized LO input is filtered, amplified, and passed
through to the rear panel LO OUT connector. In bands 29–36, the input is
amplified, doubled, and filtered, then sent to the output.
Together, these signal paths create the full output frequency range of 12.5
MHz to 26.508 GHz that is sent to the rear panel LO OUT connector.

A19 Test Set Motherboard

The A19 test set motherboard serves these functions:
— to act as an interface between the A17 CPU board and the auxiliary rear
Keysight N5264A Service Guide
A BNC connector that allows an external frequency reference signal to be used to
phase lock the analyzer for increased frequency accuracy.
The analyzer automatically enables the external frequency reference feature when
a signal is connected to this input. When the signal is removed, the analyzer
automatically switches back to its internal frequency reference.
A BNC connector that allows a 10 MHz reference signal, produced by the A10
frequency reference board, to be output for use in phase locking external test
equipment.
Table
panel interconnects.
5-2.
Table 5-2.
Table 5-2.
Table 5-2.
Table 5-2.
5-7