Optimization of planar coils for electromagnetic induction systems

Continuous-wave electromagnetic induction systems used for subsurface sensing often employ separate transmit and receive coils. In these systems, it is desirable to have zero mutual coupling between the transmit and receive coils and for the coils to have maximum sensitivity at a specific location. A representation of a pair of coils as stream functions on planar surfaces is created, and then a method of optimizing these stream functions for minimum mutual coupling and maximum sensitivity using a convex solver is developed. A pair of coils is optimized for varying amounts of dissipated power and stored energy, and the solutions are categorized. The sensitivity of the optimized coils is then compared to other common coil types.