Amplitude modulated radio frequency signal generator

摘要

A class E amplifier 80 includes an inductor 62 coupled via series resistor 58 to a supply voltage 54 and connected to ground by amplifier transistor MOSFET 64. The inductor 62 acts as the current source for the amplifier. A modulation transistor MOSFET 60 is connected in parallel across the resistor 58 and is controlled by controller 24 to vary the supply voltage to inductor 62 to cause amplitude modulation of the signal supplied to antenna load 53 of the amplifier. The amplifier transistor MOSFET 64 is switched at a radio frequency (13.56 MHz) by controller 24 at 50% duty cycle to produce the output signal to the antenna.