User`s guide

Agilent E6432A Microwave Synthesizer User’s Guide 2-9
Hardware Front Panel Connectors
Hardware Front Panel Connectors
One solution to remedy this impedance mismatch is to place a BNC tee
connector on the AM input with a 50-ohm load connected to one port of
the BNC tee connector. The input signal from the signal generator
would be connected to the other port so that the output impedance of
the signal generator sees approximately a 50-ohm input impedance as a
load. If the signal generator is set to output a –1 Vp to +1 Vp signal, the
actual signal level at the AM input should be a –1 Vp to +1 Vp, +/– the
accuracy of the signal generator itself.
Another way to assure that the output level of the signal generator is
set to the expected level, is to measure the signal generator output with
an oscilloscope or multimeter. When measuring the output level of the
signal generator with these devices, it should be noted that many
models have switchable inputs that may allow 50 ohm, 1 megohm, or
some other value to be selected as the input impedance. If the incorrect
input impedance is selected, you could also generate an incorrect signal
level.
Related Topics
Deep AM
AM Mode (Linear/Exponential)
HPE6432_SetAmMode
Spectrum Analysis AM and FM (Application Note 150-1) requires
Adobe Acrobat Reader and QuickTime Software
Linear AM Mode
When the synthesizer is in linear AM mode, the input accepts a –1 Vp
to +1 Vp signal. The RF output level (the reference power level) is
effected by the AM input level as follows:
Therefore, there must be greater than or equal to 3 dB of margin
between the reference power level and the maximum available at a
given frequency. The unmodulated (0 V input) to modulated (–1 Vp
input) ratio is a function of power level and frequency, but is always
greater than 20 dB. The amplitude of the RF output changes linearly
as the AM input changes.
Linear Input Level RF Output Level
0 V Unaffected
–1 Vp Minimum Power
+1 Vp 100% (3 dB) Higher than the
Reference Power Level