Agilent Technologies E5500 Phase Noise Measurement System
18-21
Reference Graphs and Tables
Agilent/HP 8665A Frequency Limits
How to Access Special
Functions
Press the “Special” key and enter the special function number of your
choice. Access the special function key by pressing the “Enter” key. Press
the [ON] (ENTER) key to terminate data entries that do not require specific
units (kHz, mV, rad, for example)
Example:
[Special], [1], [2], [0], [ON] (ENTER).
Description of Special
Functions 120 and 124
120: FM Synthesis
This special function allows you to have the instrument synthesize the FM
signal in a digitized or linear manner. Digitized FM is best for signal-tone
modulation and provides very accurate center frequency at low deviation
rates. Linear FM is best for multi-tone modulation and provides a more
constant group delay than the Digitized FM. The preset condition is FM
Digitized.
124: FM Dly Equalizer
This special function allows you to turn off FM Delay Equializer circuitry.
When [ON] (The preset condition), 30
µ
sec of group delay is added to the
FM modulated signal to get better FM frequency response.
You may want to turn [OFF] the FM Delay Equializer circuitry when the
signal generator is used as the VCO in a phase-locked loop application to
reduce phase shift, of when you want to extend the FM bandwidth to
200 kHz. When [OFF], FM Indicator Accuracy is worse for rates of 1-5 kHz
and better beyond 30 kHz. Refer to the Agilent/HP 8643A/8644B User’s
Guide for specific details.
