Agilent Technologies E5500 Phase Noise Measurement System
18-15
Reference Graphs and Tables
Agilent/HP 8643A 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 125
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.
125: Wide FM Deviation (Agilent/HP 8643A only)
Mode 1 operation can be selected using this special function, which allows
you to turn on wide FM deviation. The Agilent/HP 8643 defaults to Mode 2
operation. Wide FM deviation provides the maximum FM deviation and
minimum RF output switching time. In this mode, the maximum deviation is
increased, by a factor of 10, to 10 MHz (for a 1 GHz carrier). The noise level
of the generator is also increased in this mode, however.
Table 18-2
Operating Characteristics for Agilent/HP 8643A Modes 1, 2, and 3
Charateristic
Synthisis Mode
Mode 1
Mode 2
RF Frequency Switching Time
90 ms
200 ms
FM Deviation at 1 GHz
10 MHz
1 MHz
Phase Noise (20 kHz offset at 1 GHz)
-120 dBc
-130 dBc
