Agilent Technologies N5230A Service Manual page 124

Theory of Operation
Network Analyzer System Operation
Synthesized Source Group
The built-in synthesized source generates a swept, stepped, or continuous wave (CW)
signal in the frequency ranges as listed in
signals: an LO signal and an incident signal. These two signals are normally at the same
frequency (except for a 7.66 MHz offset) except for Option 080, frequency offset mode,
where they can be set to different frequencies.
The LO signal is sent directly to the mixers in the receiver group. The incident signal is
routed to the front panel test ports and then to the device under test (DUT) as the test
signal. A portion of the incident signal is either split or 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.
The incident signal output power is leveled by an internal automatic leveling control (ALC)
circuit. The maximum output power level of the network analyzer at the test ports is
shown in Table 5-1.
Refer to "Synthesized Source Group Operation" on page
Table 5-1 Frequency Range and Maximum Output Power Level
Nominal
Output Power
at Instrument
Preset
Standard
0 dBm
Test Set
Configurable
0 dBm
Test Set
a. Specifications are for Port 1 only; the values shown are typical characteristics for Port 2.
b. Values for 300 kHz to 10 MHz are typical.
Signal Separation Group
The incident signal from the source group is separated into a reference path and a test
path. The reference signal is transmitted to the receiver group. The test signal is
transmitted through—and reflected from—the DUT and is then transmitted to the
receiver group.
The signal separation group also provides:
• RF path switching to allow forward and reverse measurements
• external connections for the DUT (Option 014)
• step attenuators in the source path to reduce power to the DUT (Option 1E1)
Refer to "Signal Separation Group Operation" on page
5-4
Table
Maximum Leveled Output Power
300 kHz
10 MHz
to
to
b
45 MHz
10 MHz
+10 dBm +10 dBm
+9 dBm +9 dBm
PNA Series Microwave Network Analyzers
5-1. The source group provides two
5-6.
45 MHz 6 GHz
to to
6 GHz 9 GHz
+10 dBm +8 dBm
+9 dBm +8 dBm
5-15.
Service Guide N5230-90014
N5230A
a
9 GHz 12.5 GHz
to to
12.5 GHz 13.5 GHz
+4 dBm +2 dBm
+4 dBm +1 dBm