5-14 Keysight N5227B Service Guide
Theory of Operation
Synthesized Source Group Operation
5-
A4, A15, and A17 13.5 GHz Synthesizer Boards
The A17 13.5 GHz synthesizer board is included only on 4-port models.
The A4, A15, and A17 13.5 GHz synthesizer boards use the 50 MHz reference
signal from the A14 frequency reference board to tune a VCO circuit that
sweeps from 2 GHz to 4 GHz.
Refer to
and
for band numbers and frequencies discussed
here.
In bands 2-10, the output of the swept VCO is passed directly or through a
divide-by-2, 4, or 8 circuit to produce the output frequencies as listed in
In band 6, the output of the swept VCO is passed through a divide-by-4 circuit
and then sent to a Direct Digital Synthesizer to produce the output frequencies
for bands 2-4 as listed in
In bands 11-35, the swept VCO signal is passed through a doubler circuit
where the signal for some bands are sent directly to the output of the
synthesizer board while other bands are passed through another doubler
circuit then to the output of the synthesizer board to produce the output
frequencies listed in
The output of the A15 13.5 GHz synthesizer board (the LO synthesizer) is 7.438
MHz higher than the output of the A4 and A17 13.5 GHz synthesizer boards
(the source synthesizers). This is because the output of the A15 13.5 GHz
synthesizer board is routed through the A25 LO multiplier/amplifier 26.5 board
to the A27 and A28 mixer bricks where they are mixed with the test signals to
46
3
10.0013 to
10.6679
20.0025 to
21.3359
7.500 to
8.000
15.000 to
16.000
30.000 to
32.000
60.000 to
64.000
47
3
10.6679 to
11.1679
21.3359 to
22.3359
8.000 to
8.375
16.000 to
16.750
32.000 to
33.500
64.000 to
67.000
48
3
11.1679 to
11.6679
22.3359 to
23.3359
8.375 to
8.750
16.750 to
17.500
33.500 to
35.000
67.000 to
70.000
Table 5-1
Subsweep Frequencies
Band Mixer
Brick
L.O.
Harmoni
c
Number
(N)
A15
Synthesizer
Frequency
(GHz)
A25
HMA26.5
Frequency
(GHz)
A4/A17
Synthesizer
Frequency
(GHz)
A5/A10
Source
Frequenc
y (GHz)
A7/A8/A1
2/A13 50
GHz
Doubler
Frequenc
y (GHz)
A60/A61
/
A62/A63
70 GHz
Doubler
Frequenc
y (GHz)
