A12 Reference: The Crystal Reference Frequencies; Source Block: The Yig Oscillator Signals - Agilent Technologies 8719ET Service Manual

Theory of Operation
Source Group Theory
Table 12-2 Subsweep Frequencies
Band
Low
High Mid (8722ET/ES)
High (8722ET/ES)

A12 Reference: The Crystal Reference Frequencies

This assembly provides stable reference frequencies to the rest of the instrument by
dividing down the output of a 40 MHz VCXO (voltage-controlled crystal oscillator). One of
the divided-down signals is the 100 kHz FN REF for phase locking the synthesizer signal
in A13. Another is the 1 MHz main phase-locked loop reference signal PL REF that goes to
the phase comparator in A11. (The 2nd LO signal and the timing signal for the A10 digital
IF assembly are explained in
EXT REF rear panel input provides the option of using an external reference with a
frequency of 1, 2, 5, or 10 MHz, instead of the internal 40 MHz VCXO.

Source Block: The YIG Oscillator Signals

The source block includes two YIG oscillators and a 3.8 GHz fixed oscillator. The outputs of
these oscillators produce the source signal. In phase-locked operation, this signal tracks
the stable output of the synthesizer.
block.
12-16
Synthesizer
(MHz)
60 to 120
120 to 240
120 to 240
160 to 236
141.6 to 236
147.5 to 236
157.3 to 213.3
128 to 236
131.1 to 220/6
142.5 to 234
159.7 to 235.4
178.7 to 223.3
148.9 to 238.2
"Signal Separation: ES Models Only" on page
Figure 12-4 illustrates the assemblies in the source
RF Network Analyzers
Harmonic Source (MHz)
Number (N) Frequency
1 50 - 110
1 110 - 230
2 230 - 470
3 470 - 698
5 698 - 1170
8 1170 - 1878
12 1878 - 2550
20 2550 - 4710
36 4710 - 8256
58 8256 - 13562
85 13562 - 20000
112 20000 - 25000
168 25000 - 40000
8719ET/20ET/22ET
8719ES/20ES/22ES
12-19.) The
Service Guide