Method of producing a simplified control module for controlling a high-frequency antenna for a magnetic resonance imaging device comprising a plurality of M control elements and a plurality of N radiating elements, said plurality N of radiating elements being greater than said plurality M of control elements, said antenna being associated with a control matrix P of dimensions NxM, of which each column represents a radiation mode of the antenna and making it possible to transform an input variable V m associated with each one of the M control elements, into an output variable V a associated with each one of the N radiating elements of said antenna, said method comprising: - a step of determining a number of stages K making it possible to distribute N ordered input signals over N different ordered output signals with a coupling, a phase displacement and a permutation specific to each signal, with each stage corresponding to a physical composition of three elements formed by hybrid couplers, phase displacement lines and line permutations, the number of stages K being less than the number of stages required for the implementation of the control matrix P of the antenna by a Butler matrix or a matrix obtained by a dividing into singular values; - a step of optimising a control matrix P̃ defined by a product of two matrices HL; - the first matrix L, of dimensions MxM, being able to transform in amplitude and in phase a plurality of M signals V m emitted by said plurality M of control elements into M signals V l, the matrix L being different from the identity matrix; - the second matrix H of dimensions NxM receiving as input said M signals V l, said matrix H being defined by a dividing of a plurality of K+1 of matrix S according to the relationship: H = S K S K − 1 ⋯ S 1 S 0 With: S 0 matrix of dimensions NxM which provides a connection between the M inputs and the N outputs without modifying the signals; S k matrix of dimensions MxM corresponding to each stage, with k = {1,...,K}; the step of optimising being carried out by means of an optimisation routine that seeks to minimise the error: ε = ∥( P̃ - P) W || where: ∥ ∥ designates the Euclidean norm; W designates a diagonal matrix of dimensions MxM of which the coefficients define the weight of each mode in the calculation of the error; - a step of manufacturing said matrix H with a number of stages K, said matrix H being implemented by coupling means formed by hybrid couplers, means of phase displacement and means of permutation; - a step of implementing said matrix L by software means using the implementation of said matrix H determined during the preceding step. - a step of determining a number of stages K making it possible to distribute N ordered input signals over N different ordered output signals with a coupling, a phase displacement and a permutation specific to each signal, with each stage corresponding to a physical composition of three elements formed by hybrid couplers, phase displacement lines and line permutations, the number of stages K being less than the number of stages required for the implementation of the control matrix P of the antenna by a Butler matrix or a matrix obtained by a dividing into singular values; - a step of optimising a control matrix P̃ defined by a product of two matrices HL; - the first matrix L, of dimensions MxM, being able to transform in amplitude and in phase a plurality of M signals V m emitted by said plurality M of control elements into M signals V l, the matrix L being different from the identity matrix; - the second matrix H of dimensions NxM receiving as input said M signals V l, said matrix H being defined by a dividing of a plurality of K+1 of matrix S according to the relationship: H = S K S K − 1 ⋯ S 1 S 0 With: S 0 matrix of dimensions NxM which provides a connection between the M inputs and the N outputs without modifying the signals; S k matrix of dimensions MxM corresponding to each stage, with k = {1,...,K}; the step of optimising being carried out by means of an optimisation routine that seeks to minimise the error: ε = ∥( P̃ - P) W || where: ∥ ∥ designates the Euclidean norm; W designates a diagonal matrix of dimensions MxM of which the coefficients define the weight of each mode in the calculation of the error; S 0 matrix of dimensions NxM which provides a connection between the M inputs and the N outputs without modifying the signals; S k matrix of dimensions MxM corresponding to each stage, with k = {1,...,K}; the step of optimising being carried out by means of an optimisation routine that seeks to minimise the error: ε = ∥( P̃ - P) W || where: ∥ ∥ designates the Euclidean norm; W designates a diagonal matrix of dimensions MxM of which the coefficients define the weight of each mode in the calculation of the error; - a step of manufacturing said matrix H with a number of stages K, said matrix H being implemented by coupling means formed by hybrid couplers, means of phase displacement and means of permutation; - a step of implementing said matrix L by software means using the implementation of said matrix H determined during the preceding step.