RF power amplifier linearity compensation for MRI systems

Abstract

In this thesis, a polar-feedback linearization system for use with MRI RF power amplifiers was designed and simulated. The design here presented is intended to replace Analogic's (located in Peabody, Massachusetts) feed-forward, digital linearization scheme. This involved the selection and testing of components meeting the stringent specifications required for a high enough level of fidelity, as well as a simulation of the amplitude loop of the linearization system designed using the data acquired from one of Analogic's RF power amplifiers and the components selected. The intention of the simulation is to show that a polar-feedback solution is an effective method for linearizing the response of the RF power amplifier. A protype system to test the feasibility of the design in real conditions was also constructed.