User's Manual

AT7120 Owner Manual Rev. 1.1 – March 2009 27/76
The LO frequency is divided by two, to reduce the phase noise level by 6dB
10MHz internal reference oscillator, technology OCXO, (Oven Controlled Crystal Oscillator)
Uses hybrid amplifiers with high linearity
Overdrive protection circuit, maintains the RF output power at acceptable levels
Automatically reduces the exciter RF output power in absence of IF signal, either Q or I carriers
Stand-by for local oscillator, in case of a failure in the external reference signal
Meets or exceeds the phase noise requirements for DTV transmission
Module 4492 - General functional description - Refer to Fig.4.2.
Fig.4.2: Module 4492 – block diagram