ACTIVE TRANSMITTER RINGDOWN FOR SWITCHING POWER AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To provide active transmitter ringdown for a switching power amplifier. SOLUTION: A method for controlling signal decay of electromagnetic transmission from a transmitter is described. The method includes measuring an amount of current induced to the transmitter by a residual decaying electromagnetic field after electromagnetic transmission, and using the current measurement to control a decay rate of the decaying electromagnetic field. A transmitter 10 for an electronic article surveillance (EAS) system is also described which is configured to output a transmission signal to an external load and includes a current sensing circuit 12 configured to at least sense an amount of current induced back into the transmitter by the load after the transmission of the signal, and a transmitter control circuit configured to utilize the sensed current to determine an amount and a polarity of current to be applied to the load to reduce the induced current to a desired value. COPYRIGHT: (C)2006,JPO&NCIPI