Optimization and Analysis of Wire-Wound Coil Heads for EMI Systems

Many different coil head configurations are used in electromagnetic induction (EMI) systems for sensing buried targets; however, very little has been published on comparing the configurations. Comparing different coil head designs to one another is cumbersome because many factors determine how well different coil heads perform when constructed and attached to a system. Calculating the voltage received by a particular coil under ideal conditions is trivial, but this requires accounting for such factors as overall coil size, wire diameter, and conductivity. Comparing how only the winding geometries of various coil heads affect performance is much less straightforward. A set of normalized metrics that are independent of design decisions other than winding geometry are needed. This paper details a set of metrics for the characterization and comparison of EMI coil heads. These metrics are then used to optimize double-D, concentric, and dipole/quadrupole coil heads, which are then analyzed and compared to one another.