Keysight Technologies X Series Service Manual page 205

RF Section Troubleshooting (Millimeter-Wave Analyzers)
RF Section Description
The RF section is comprised of the following major assemblies:
— A9 Input Attenuator A
— A10 Input Attenuator B
— A11 Low Band Switch Assembly
— A12 YTF Preselector
— A13 RF Front End Assembly - shown on the block diagram as A13 and
— A15 Front End Control Assembly
— Option MPB - Microwave Preselector Bypass
1. RF input frequencies < 3600 MHz route through the low band path. Refer
The RF input signal can route through the Electronic Attenuator section or the Preamplifier, but
not both. All RF input frequencies < 3600 MHz go to Mixer #1.
Keysight N9010A EXA Service Guide
A13A1, however replacement A13 assemblies include the A13A1.
to the RF Lowband Path Block Diagram in
The RF input signal level can be optimized by Input Attenuator A and/or
Input Attenuator B. The low band switch assembly contains a limiter that
offers added protection for the mixer, and routes the input signal to the
low band input of the A13 RF Front End assembly. There are (3) different
signal paths on the input of the RF Front End assembly that the signal can
be routed through depending on installed options and front panel settings.
— Electronic Attenuator path, 0-24 dB (Option EA3)
— Low Band Preamplifier path, 20 dB nominal gain
(Any preamp option)
— Direct to Mixer #1
The RF input signal is then mixed with the 1st LO from the A20 YTO
assembly to a 1st intermediate frequency of 5122.5 MHz. Since the RF
input signal is <3600 MHz for low band, this RF input signal is upconverted
in Mixer #1 to the 1st IF. This 1st IF signal is then downconverted in Mixer
#2 using the 4800 MHz 2nd LO generated on the A16 Reference assembly
to a 2nd intermediate frequency of 322.5 MHz (5122.5 MHz (1st IF) −
4800 MHz (2nd LO)). The 2nd IF output is at A13A1J7. This signal path is
used for all frequency range options when the RF input frequencies are
< 3600 MHz. The control voltages and biasing for these assemblies come
from the A15 Front End Control assembly.
Chapter 12 for details.
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