Radio frequency signal transmission method for electromagnetic transponder system, involves controlling gain of transmitter amplifier by microcontroller to control modulation factor of transmission signal

摘要

The method involves measuring information representative of current in an inductive unit (L2) of an oscillating circuit by a current transformer (35) to find a present value of a magnitude representative of a modulation factor of a transmission signal. Gain of a transmitter amplifier (32) is controlled by a microcontroller (31) to control the factor for controlling amplitude of modulation. An independent claim is also included for a radiofrequency transmitter.