Behavioral VHDL-AMS modeling of nuclear magnetic resonance sensor

This paper describes the development of a model of a nuclear magnetic resonance (NMR) spiral coil sensor, using an analog hardware description. Our procedure implies several steps, with emphasis on model complexity reduction, identification of critical parameters and validation of experimental measurements. The proposed macro-model permits extremely fast simulation while providing nearly FEM accuracy. As a tool for coding the description of system level modelling, we use the analog hardware description language VHDL-AMS. For achieving the behavioural computation results, the SYSTEM VISION simulation environment from Mentor Graphics® was employed. In our proposed modelling, the different parts of the sensor and the different effects involved (electrical parameters, physical and magnetic coupling, loss effects) can be modelled within the same tool, together with the sensor environment: electrical command and detection circuit, time dependent magnetic field, and so on.