User`s guide

368 Agilent E5505A User’s Guide
16 Reference Graphs and Tables
Voltage Controlled Source Tuning Requirements
Peak Tuning Range (PTR) ≈ Tune Range of VCO x VCO Tune Constant.
Min. PTR = 0.1 Hz
Max. PTR = Up to 200 MHz, depending on analyzer and phase detector LPF.
Drift Tracking Range = Allowable Drift During Measurement
The tuning range that the software actually uses to maintain quadrature is
limited to a fraction of the peak tuning range (PTR) to ensure that the tuning
slope is well behaved and the VCO Tune Constant remains accurate. After
phase lock is established, the test system monitors the tuning voltage required
to maintain lock. If the tuning voltage exceeds 5% of the PTR during the
measurement, the test system again informs the user and requests the
oscillator be retuned or the problem be otherwise corrected before proceeding
with the measurement. These limits have been found to guarantee good
results. Refer to Figure 294.
.
Figure 294 Tuning voltage required for phase lock
Total peak-to-peak tuning range of VCO
System
peak tuning range
Drift
tracking range
Capture
range
VCO Source center frequency
24% 24%
5% 5%
E5505a_capt_drift_trk_range
26 Feb 04 rev 1