公开(公告)号：US11271600B2

公开(公告)日：2022-03-08

申请号：US16976657

申请日：2018-03-27

Applicant: Apple Inc.

Inventor： Alexander Belitzer ,  Yaron Yoffe ,  Yaniv Cohen ,  Michael Kerner

IPC: H04W76/23 ,  H04W24/08 ,  H04W76/10 ,  A61N1/39 ,  H04B1/04 ,  H03F1/02 ,  H03F1/32 ,  H03F3/24

Abstract: A transmitter is provided. The transmitter includes an envelope tracking circuit, wherein the envelope tracking circuit includes an envelope circuit configured to generate, based on a baseband signal, an envelope signal indicating a temporal course of the baseband signal's envelope. Further, the envelope tracking circuit includes a bandwidth reduction circuit configured to generate a bandwidth reduced envelope signal based on the envelope signal, and a DC-to-DC converter configured to generate a supply voltage for a power amplifier of the transmitter based on the bandwidth reduced envelope signal. The transmitter additionally includes a predistortion circuit configured to generate a predistorted baseband signal based on the baseband signal and an adjustable predistortion configuration. The predistortion circuit is further configured to adjust the predistortion configuration based on the bandwidth reduced envelope signal.