Rf Generator Section - Agilent Technologies E8285A Manual

RF Generator Section

Frequency Generation
NOTE Test Sets with firmware revision A.04.5X and above operate only at RF
frequencies from 800 to 1000 MHz and 1700 to 2000 MHz. A text only error
message "Input value out of range" , will be displayed if invalid
frequencies are set.
The Signal Generator Synthesizer
500 MHz to 1000 MHz signal which is phase-locked to the 200 kHz
reference from the Reference Assembly
out-of-lock indicator LED lights if the phase-lock-loop is out-of-lock.
When you turn the Test Set's power on, the LED lights for a few seconds
then goes out. If it stays on or comes on again, the loop is out-of-lock.
The RF Output Section assembly
RF Generator's 30 to 2000 MHz frequency range by mixing, dividing, or
passing the 500 MHz to 1000 MHz from the Signal Generator
Synthesizer. The frequencies are derived as shown in
The Upconverter assembly
generator's 1.7 to 2.0 GHz range by mixing the 800-1000 MHz signal
from the output section with a 1.5-3.0 GHz LO.
Table 8-3
Level Control
The RF Output Section assembly
automatic-level-control (ALC) loop that acts as a vernier control of RF
level between − 2 and +9 dBm. A step attenuator in the RF I/O assembly
(figure 8-2 on page
at the RF IN/OUT connector) in 5 dB steps.
Assemblies that affect output level calibration have factory-generated
calibration data stored in the Test Set's EEPROM. Calibration data is
fed to digital-to-analog-converters which control level-adjustable
devices in the RF path. These assemblies are:
• RF I/O
Output Frequency
30 MHz - 250 MHz
250 MHz - 500 MHz
500 MHz - 1 GHz
1.7 GHz - 2.0 GHz
254) takes the level down to − 127 dBm ( − 137 dBm
(figure 8-21 on page
(figure 8-24 on page
(figure 8-22 on page
(figure 8-23 on page
Derivation
mix
divide
pass
mix
(figure 8-22 on page
Block Diagrams
RF Generator Section
281) develops a
285). An
282) develops the
table 8-3.
283) develops the RF
282) has an
279