Basic Yto And Fixed Frequency Cavity Oscillator - HP 5344S Operating Instructions Manual

Model 5344S
Operation and Programming
3-64. Basic YTO and Fixed Frequency Cavity Oscillator
3-65. To generate frequencies below the YTO's frequency range, the output of the YTO is mixed
with a fixed frequency Cavity Oscillator, as shown in
Figure 3-2.
The difference frequency between
the YTO and the Cavity Oscillator is fed to the front panel as the RF OUT. For example, the Cavity
Oscillator is fixed at 3.8 GHz, and the YTO is tunable from 3.81 GF-iz to 6.2 GHz. When the YTO
frequency is varied over its 3.81 GHz to 6.2 GHz range, the difference frequency moves from 10 MHz
(3.81 GHz - 3.8 GHz) to 2.4 GHz (6.2 GHz - 3.8 GHz). The YTO output is fed to the rear panel as the
AUX OUT. This plug-in would be specified with an output range of .01 GHz to 2.4 GHz even though
the 3.81 GHz to 6.2 GHz signal is available at the rear panel AUX OUT. The front panel RF OUT is offset
from the rear panel AUX OUT by a constant 3.8 GHz. Also located on the rear panel is an FM input to
allow the YTO frequency to be varied over a small range. The stability and accuracy of this technique
is limited by the stability of the YTO. However, when this plug-in is locked by the 5344S, the Cavity
Oscillator becomes the limit of the stability and accuracy.
Figure 3-2. Basic YTO and Fixed Frequency Cavity Oscillator