RA45H7687M1

The RA45H7687M1 is a 45-watt RF MOSFET Amplifier Module for 12.8-volt mobile radios that operate in the 764- to 870-MHz range.

The battery can be connected directly to the drain of the enhancement-mode MOSFET transistors RA45H4452M. Without the gate voltage 1 and the gate voltage 2(V_GG1=V_GG2=0V), only a small leakage current flows into the drain and the nominal output signal (P_out=45W) attenuates up to 60 dB. When fixed i.e. 3.4V, is supplied to the gate voltage 1, the output power and the drain current increase as the gate voltage 2 increases. The output power and the drain current increase substantially with the gate voltage 2 around 0V (minimum) under the condition when the gate voltage 1 is kept in 3.4V. The nominal output power becomes available at the state that V_GG2 is 4V (typical) and 5V (maximum). At this point,
VGG1 has to be kept in 3.4V.At V_GG1=3.4V & V_GG2=5V, the typical gate currents are 0.4mA.

This module RA45H4452M is designed for non-linear FM modulation, but may also be used for linear modulation by setting the drain quiescent current with the gate voltages and controlling the output power with the input power.