Method and apparatus for automatically tuning an impedance matrix, and radio transmitter using this apparatus

摘要

The invention relates to a method and an apparatus for automatically tuning an impedance matrix, for instance the impedance matrix seen by the power amplifiers of a radio transmitter using a plurality of antennas simultaneously, and to a radio transmitter using this apparatus. An apparatus for automatically tuning an impedance matrix has 4 user ports and 4 target ports, and comprises: 4 sensing units; a signal processing unit, the signal processing unit estimating real quantities depending on the impedance matrix presented by the user ports, using the sensing unit output signals obtained for 4 different excitations applied successively to the user ports; a multiple-input-port and multiple-output-port tuning unit comprising adjustable impedance devices; and a tuning control unit delivering tuning control signals to the multiple-input-port and multiple-output-port tuning unit, the reactance of each of the adjustable impedance devices being mainly determined by one or more of the tuning control signals.

主权项

1. A method for automatically tuning an impedance matrix presented, at a given frequency, by m ports of an apparatus, where m is an integer greater than or equal to 2, each of said m ports being referred to as user port, the apparatus having said m user ports and n other ports, where n is an integer greater than or equal to 2, each of said n other ports being referred to as target port, said impedance matrix being referred to as the impedance matrix presented by the user ports, the apparatus allowing, at the given frequency, a transfer of power from the user ports to the target ports, the method comprising the steps of:
estimating q real quantities depending on the impedance matrix presented by the user ports, where q is an integer greater than or equal to m, using m or more different excitations applied successively to the user ports; using said q real quantities depending on the impedance matrix presented by the user ports, to obtain tuning control signals; adjusting the impedance matrix presented by the user ports using a multiple-input-port and multiple-output-port tuning unit, the multiple-input-port and multiple-output-port tuning unit comprising p adjustable impedance devices, where p is an integer greater than or equal to 2m, each of the adjustable impedance devices having a reactance at the given frequency, the reactance of any one of the adjustable impedance devices having an influence on the impedance matrix presented by the user ports, the reactance of any one of the adjustable impedance devices being adjustable by electrical means; applying each of the tuning control signals to one or more of the adjustable impedance devices, the reactance of each of the adjustable impedance devices being mainly determined by one or more of the tuning control signals.