User`s guide

2-8 Agilent E6432A Microwave Synthesizer User’s Guide
Hardware Front Panel Connectors
Hardware Front Panel Connectors
AM Input
AM Input, available from the Hardware Front Panel, is used to supply
amplitude modulation input signals from external signal sources such
as arbitrary waveform generators and function generators.
An amplitude modulation signal can be applied by itself or at the same
time as a frequency modulation or pulse signal.
There are two AM operation modes:
❏ Exponential AM Mode
❏ Linear AM Mode
Exponential AM Mode
When the synthesizer is in exponential AM mode, the input accepts a
wider range of input signal. The RF output level (the reference power
level) is affected by the exponential input level as follows:
The dynamic range of the positive to negative power levels is dependent
on the synthesizer power level setting. The input impedance for this
input connector is factory set at 2 kilohms. Damage levels for this input
are greater than or equal to +15 Vp, or less than or equal to –15 Vp.
For complete specifications, refer to “Specifications and
Characteristics” on page 6-1.
TIP When using a signal generator to drive the AM input, the output
impedance of the signal generator must be taken into account. If the
signal generator has an output impedance of 50 ohms and it is set to
output a –0.5 Vp to +0.5 Vp signal into a 50-ohm load, the actual signal
level at the AM input will be a –1 Vp to +1 Vp. This occurs because the
AM input on the synthesizer has a 2 kilohm input impedance; a –1 Vp
to +1 Vp signal at the AM input will generate 20 dB of peak-to-peak AM
modulation.
Exponential Input Level RF Output Level
0 V Unaffected
–1 Vp Decreases by 10 dB / –1 V
+1 Vp Increases by 10 dB / +1 V