Design and Assessment of Track Structures in High-Frequency Planar Inductors

Abstract

<p> This paper provides a practical guideline for conductor arrangement in a planar inductor by investigating various arrangements for conductors. In order to have a comprehensive study, four different structures have been considered and compared. Numerous design parameters such as track width, track length, location of the conductors between the central limb and the lateral limb, and number of transposition points among sub-tracks for both air-core and ferrite-core inductors are considered. Each structure is evaluated according to AC resistance, RAC /RDC, and inductance. Measurement results reveal that it is critical to take into account all three characteristics when deciding the suitable structure for the conductors. Studies are carried out based on measurement results for experimental prototypes in the frequency range of 10Hz-1MHz and a set of guidelines has been provided with regard to the design of planar inductors to achieve desired characteristics. </p>

A Comprehensive Review on Planar Magnetics and the Structures to Reduce the Parasitic Elements and Improve Efficiency

“…Even though FEA is an excellent tool, a 3D model is necessary for some arrangements, such as Litz structures, since 2D simulations cannot provide accurate results. A three-dimensional analysis of a planar magnetic device with a Litz structure faces two major challenges: the power and time required to simulate the model, as well as the requirement to provide accurate geometric representations of the structure [49].…”

A Comprehensive Review on Planar Magnetics and the Structures to Reduce the Parasitic Elements and Improve Efficiency

“…Even though FEA is an excellent tool, a 3-D model is necessary for some arrangements, such as litz structures, since 2-D simulations cannot provide accurate results. A three-dimensional analysis of a planar magnetic device with litz structure faces two major challenges: the power and time required to simulate the model, as well as the requirement to provide accurate geometric representations of the structure [55].…”

“…The leakage inductance may be significantly reduced with a fully interleaved system. As a result, besides winding structures, certain physical parameters, such as conductor thickness and its width, insulator thickness, and the number of turns can affect leakage inductance in planar transformers [55].…”

“…A novel Litz wire planar transformer, and two designs of Litz wire air-core inductors were presented in [75], which save a lot of space and exhibit lower resistance compared to conventional wiring methods. To achieve the Litz structure on a PCB base, at least 2 layers of PCB must be used [55]. Each of the 2 layers can have one Litz layer.…”

“…This can easily be avoided by ensuring the shield is thick enough to prevent saturation because the flux would extend around the saturated areas and still be effective [78]. By examining various conductor arrangements, [55] offers an applicable guideline for conductors in a planar inductor. Four structures have been examined in order to get a thorough examination (solid, multi-track, in layer twisted, and litzing).…”