An automated design flow for synthesis of optimal multi-layer multi-shape PCB coils for inductive sensing applications

Abstract

This paper presents an automated flow to quickly design and layout an optimal multi-layer square, hexagonal, octagonal spiral printed circuit board (PCB) coils for inductive sensing applications. The flow takes into account several constraints including via connections in the center of the coil well ahead in the calculations for minimum inner diameter in order avoid any iteration later. Step-by-step instructions on how to find the optimal solution for a given optimization criteria e.g. coil area, coil performance parameter, application performance parameters are presented including trade-off between area vs layers and area vs coil fill ratio. Next, the paper discusses the algorithm to generate the multi-layer multi-shape coil in order to layout the coil on a PCB using computer aided design tools. An online design tool is developed based on flow proposed in this paper for inductive sensing applications and results from the tool are discussed and generated PCB coil layout to five popular PCB CAD tools is presented. The online design tool has reduced the PCB coil design time to a fraction of a minute and is being actively used by hundreds of designers worldwide.