Specifications

insufficient power at the L input port on the HP 11848A can cause excessive
conversion loss through the phase detector. In addition, the beatnote
may be compressed causing an incorrect calibration of the Phase Detector
Constant.
The input level at the R input port of the HP 11848A determines the
system's sensitivity. Amplification of the input signal to the R port will
increase the Phase Detector Constant thereby decreasing the system's
noise floor.
The Phase Detector Constant cannot be measured if the system cannot
generate a beatnote of less than 50 kHz (20 MHz for systems with an
RF Analyzer), or if the sources are injection locking. Also, the system
cannot measure the Phase Detector Constant if the beatnote deviates too
much from a sine wave, or is excessively noisy. In these cases, you may
need to enter the Phase Detector Constant using a power level estimate
or from examination of the beatnote.
If the beatnote is less than 1 kHz, and the system cannot locate three
zero-crossings within the time record of the HP 3561A Dynamic Signal
Analyzer, the system cannot measure the Phase Detector Constant. In
this case, you should abort the measurement, verify all of the entered
parameters and initiate a New Measurement.
The recommended range for the Phase Detector Constant when making
a phase lock loop measurement using the 5 MHz to 1.6 GHz Phase
Detector is 20 mV to IV. The recommended range when making a phase
lock loop measurement using the 1.2 GHz to 18 GHz Phase Detector is
100 mV to 0.3V. Detector Constants down to 20 mV may work but, proper
operation may be inhibited by dc offsets up to 50 mV.
Adequate isolation must be provided to insure that the injection locking
range is much less than the Phase Lock Loop Bandwidth. Injection Locking
removes or distorts the beatnote from which the Phase Detector Constant
is measured.
2-48 Calibr Process: $N w/PLL