Specifications

Detector Selection
The Select Detect, softkey provides selection between the HP 11848A
Phase Detectors. Verify that the selected Phase Detector is:
• Within the frequency range of the Detector/Discr. Input Frequency
entered.
• Installed in the HP 11848A Phase Noise Interface. (Option 201 adds
the 1.2 to 18 GHz Phase Detector to the HP 11848A).
Detector Selection
Internal
5 MHz to 1.6 GHz
Internal
1.2 GHz to 18 GHz
External
Required Level (dBm)
LPort
+15 to+23
+7 to+10
As specified for
the detector used
R Port
0 to +23
0to+10
As specified for
the detector used
External Detectors
Using an External Phase Detector to measure a device with fundamental
frequency less than 5 MHz or greater than 18 GHz requires special
considerations. The HP 3048A limits the Detector/Disc. Input Frequency
range to from 5 MHz to 18 GHz. If you are measuring a device that
exceeds the limits of the Detector/Disc. Input Frequency, enter a frequency
of less than 95 MHz for a device with a frequency of less than 5 MHz to
enable the 2 MHZ LPF, or enter a frequency of greater than 95 MHz for a
device with a frequency greater than 18 GHz to remove the 2 MHZ LPF.
Also when measuring frequencies less than 5 MHz you must filter out the
fundamental feedthrough and additive product prior to the HP 11848A
Noise Input. This is necessary to prevent overloading.
2-26 Instr. Params: $N w/PLL
rev.05SEP89