METHOD AND APPARATUS FOR AUTOMATICALLY TUNING AN IMPEDANCE MATRIX, AND RADIO TRANSMITTER USING THE SAME

摘要

The invention relates to a method and an apparatus for automatically matching an impedance matrix, for example the impedance matrix seen by the power amplifiers of a radio transmitter using a plurality of antennas simultaneously. The invention also relates to a radio transmitter using this apparatus. An apparatus for automatically tuning an impedance matrix has 4 user accesses (112) (122) (132) (142) and 4 target accesses (111) (121) (131) (141), and comprises: 4 detection units (1 ); a signal processing unit (2) estimating actual quantities dependent on the impedance matrix presented by the user accesses, using detection unit output signals obtained for four excitations applied to the user accesses, at least two of the excitations being applied simultaneously, the signal processing unit delivering a tuning instruction; a multiple input access tuning unit and multiple output ports (3) having adjustable impedance devices; and a tuning control unit (4) delivering tuning control signals to the tuner unit with multiple input and multiple output ports.