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 2.5V (minimum), output power and drain current increases substantially. The nominal output power becomes available at 3V (typical) and 3.5V (maximum). At VGG=3.5V, 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.