WIRELESS COMMUNICATION UNIT, LINEARISED TRANSMITTER CIRCUIT AND METHOD OF LINEARISING THEREIN

摘要

A wireless communication unit (300) comprises a linearised transmitter (325) having a forward path and a feedback path, respectively comprising at least one up- mixer and down-mixer, and forming two loops in quadrature. A phase training signal is applied to the at least one down-mixer in the feedback path in an open loop mode of operation to identify a loop phase adjustment to be applied. At least one of the two loops is switched to a closed loop mode of operation and the loop phase adjustment is applied to at least one up-mixer located in the forward path.