The RA30H4047M is a 30-watt RF MOSFET Amplifier
Module for 12.5-volt mobile radios that operate in the 400- to
470-MHz range.

The battery can be connected directly to the drain of the
enhancement-mode MOSFET transistors. Without the gate
voltage (VGG=0V), only a small leakage current flows into the
drain and the RF input signal attenuates up to 60 dB.

The output power and drain current increase as the gate voltage increases.
With a gate voltage around 4V (minimum), output power and
drain current increases substantially. The nominal output power
becomes available at 4.5V (typical) and 5V (maximum). At
VGG=5V, the typical gate current is 1 mA.

This module is designed for non-linear FM modulation, but may
also be used for linear modulation by setting the drain quiescent
current with the gate voltage and controlling the output power with
the input power.