Modout On/Off Fm; Modulation - HP 8360 User Handbook Manual

Function Group
Menu Map
Description
Programming Codes
See Also

Modulation

General Circuit Theory
(MOD)
4
This softkey (Option 002 only) lets you output the internally-
generated frequency modulation waveforms to the rear panel AM/FM
OUTPUT connector. When scaled exponentially at 10 dB/V, the
maximum output voltage is offset to 0 V and the minimum voltage
level is -4 V.
MODulation:OUTput:SOURce FM
MODulation:OUTput:STATe ONlOFFlllO
Analyzer:
NONE
The synthesizer's amplitude and pulse modulation performance is
directly tied to the ALC (Automatic Level Control) system. Refer to
the ALC block diagram in Figure M-l. The ALC system controls the
amplitude or power level of the RF output. A portion of the output
signal is detected, summed with the reference level signal, and the
difference (error) signal drives an integrate-and-hold circuit. The
integrator output drives the RF output power level via the linear
modulator. When the sum of the detected and reference signals is
0 volts, the output of the integrator is held at a constant level and
the RF output is leveled. This loop is bandwidth-limited by the
integrator and the integrate-and-hold circuit. Notice, however, that
there is a feedforward path that allows changes in power level that
are bandwidth-independent from the rest of the ALC loop. Power
level information supplied by the level DAC and AM input travels
the feedforward path to drive a linear modulator. (See (ALC) for
additional information on the ALC system.)
HP 8360
User's Handbook