ALEXANDRIA, Va., March 26 -- United States Patent no. 12,261,581, issued on March 25, was assigned to Apple Inc. (Cupertino, Calif.).
"Tunable matching network" was invented by Alfred Erik Raidl (Linz an der Donau, Austria), Antonio Passamani (Munich) and Chia-Yu Hsieh (Munich).
According to the abstract* released by the U.S. Patent & Trademark Office: "Systems and methods for generating a radio frequency (RF) signal by a digital-to-analog converter (DAC) with transmission frequency within a wide transmission frequency range are described. An output reactance of the DAC coupled (directly or indirectly) to one or more antennas corresponds to the transmission frequency of the RF signals. Multiple embodiments of the DAC are described to incl...