Patent ID: 8254854
Filing Date: 2012-08-28
Classification: H03F

Abstract:
1. A method of amplifying an RF signal consisting of a data signal modulated onto a carrier signal, comprising: separating an RF signal into a carrier signal and a data signal; feeding the carrier signal into a first amplifier having a gate and an output; feeding the carrier signal through a first quarter-wave transmission line into a second amplifier having a gate and an output; feeding the data signal into a modulator to digitize the data signal into a digitized data signal having rectangular pulses with duty cycles proportional to output current; switching the gates of said first and second amplifiers simultaneously in accordance with said digitized data signal; passing the output of said first amplifier through a second quarter-wave transmission line and combining it with the output of said second amplifier to produce an amplified RF signal; and passing said amplified RF signal through a high-Q bandpass filter having high-impedance in its stop-band to reject quantization noises of said digitized data signal and form a dynamically varying impedance inversely proportional to the duty cycles of said rectangular pulses from said modulator when driven by said first and second amplifiers which are pulse switched.