FM Modulation
frequency list mo de, step sweep mo de, search leveling mo de, sweep
frequency mo de, AM or pulse mo dulation, among others. (For a
complete explanation of the selection sequence, see \Getting Started,
Advanced".)
FM Modulation
Frequency mo dulation can be accepted from an external source at
the FM connector or can b e internally generated byswept signal
generators with Option 002. The damage level of the FM input is
6
15 V DC. The input imp edance is set to 50 . A jumper on the
A11 FM Driver b oard allows you to change the input imp edance to
600 . (See \Adjustments" in the
Agilent Technologies 8360 B-Series
Swept Signal Generator/8360 L-Series Swept CW Generator Service
Guide
.) The FM sensitivity can b e scaled to either 100 kHz/V,
1 MHz/V, or 10 MHz/V.
When internal FM is chosen (Option 002), the rate and deviation
are set by softkeys in the FM menu. The waveform menu provides
achoice of sine, square, triangle, ramp, or noise waveforms. The
monitor menu lets you output the internally generated mo dulation
waveforms to the rear panel AM/FM OUTPUT connector. The
scale of the FM output depends on the FM deviation c
hosen. The
following table shows the scale versus deviation. The monitor menu
also lets you display the value of the FM deviation.
Internal
FM Deviation
FM Scale
1Hz to

100 kHz 100 kHz/V
>
200 kHz to

2 MHz 1 MHz/V
>
2 MHz to 10 MHz 10 MHz/V
FM Coupling
Whether provided from an external source or generated internally
(Option 002), the FM system can be either AC or DC coupled. If
you cho ose AC coupled FM, you will b e mo dulating a phase-lo c
ked
carrier. This is the sp ecied synthesized op eration. The mo dulation
rate must be 100 kHz or greater. If not, the frequency c
hanges
caused by the mo dulation are inside the phase-lo ck lo op bandwidth
and the output will not b e linear FM. For mo dulation frequencies
below 100 kHz, choose DC coupled FM. In this mo de, the phase
lo cked lo op is de-activated. This means that the swept signal
generator is op erating as an op en lo op sweeper. The swept signal
generator will not b e phase lo cked, and therefore, be aware that the
phase noise and CW frequency accuracy sp ecications do not apply.
Operating and Programming Reference M-17
To Next Page
Loading...
Need help?
General
