Bei Electronics LLC

Broadcast Electronics, Inc.

Brian Lindemann

Dan Prysby

David Kroeger

Doug Foote

John Ribe

A high power class D amplifier/modulator for use in Radio Frequency ranges that is capable of digital modulation schemes at high efficiencies is disclosed. The new amplifier design features an envelope tracker unit that uses digital pulse-width modulation (PWM) generation to create analog I and Q phase high voltage signal components and sign bits. The I and Q phase signal components and sign bits are fed into an Fs/4 modulator stage to produce an analog output that is an high power RF signal modulated by the analog input signal.

Class D amplifier using Fs/4 modulation and envelope tracking power supplies

An analog radio frequency input and an analog feedback from an output of a radio frequency amplifier are digitized and down-converted. Pre-distortion coefficients are calculated based on the down-converted input and down-converted feedback and the down-converted input is filtered using the pre-distortion coefficients. The filter output is then up-converted to a carrier frequency and converted to analog to be provided to the radio frequency amplifier.

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Quincy, IL, United States of America

Brian Lindemann