Tolerance Analysis of Near-Field Focused Arrays to Safe-for-Humans Microwave and RF Applications

A methodology is proposed in this work to characterise the complex vector near-field of focused antenna arrays with arbitrary geometry, subject to random errors. Starting with the problem formulation, a proper mathematical relationship for the actual electric field is established, and a partial statistical characterisation is then performed. Subsequently, the mean squared errors are computed between the actual and the desired electric field, and between the actual and the ideal squared magnitude of the electric field. Finally, a method to determine the cumulative distribution function of the squared magnitude of the electric field is discussed for obtaining appropriate percentile functions. The presented numerical results show the validity of the proposed technique, which is particularly useful in those applications, such as the biomedical ones, where high performance is required to control the electric field values such to guarantee human safety conditions.