Study of optimal separation of two circular phased-array coils via an equivalent circuit

The coil separation of phased-array coils is an important issue if a wide area of interest is to be imaged. An equivalent circuit of two circular-shaped coils was used to compute the optimal distance in a two phased-array coil. This circuit included the mutual inductance of two circular coils. An expression for the mutual inductance was derived and the resulting values included in the circuit. With all these elements an equivalent circuit of two overlapped circular coils was built to simulate a phased-array coil. To find a solution to this circuit, specifically written programmes in Spice Opus Light were used. Optimal separations were calculated from separation-vs-attenuation for different coil radii. Results compare very well with those reported in the literature