Analysis of current crowding effects in multiturn spiral inductors

Abstract

The effective trace resistance of a multiturn spiral inductor operating at high frequencies is known to increase dramatically above its dc value, due to proximity effect or current crowding. This phenomenon, which dominates resistance increases due to skin effect, is difficult to analyze precisely and has generally required electromagnetic simulation for quantitative assessment. Current crowding is studied in this paper through approximate analytical modeling, and first-order expressions are derived for predicting resistance as a function of frequency. The results are validated through comparisons with electromagnetic simulations and compared with measured data taken from a spiral inductor implemented in a silicon-on-sapphire process.

Hf-Band Wireless Power Transfer System: Concept, Issues, and Design

“…As a result of relatively long wires and eddy current loss between the trace of coils, the resistance of a LF-band coil is relatively higher than a HF-band resonator. Therefore, they have relatively low Q values [13]. Similarly, if a large coil can be made to reduce eddy current crowding effect in a LF-band, the coil of the LF-band has relatively high Q values.…”

Investigation of Proximity Effects in Ferromagnetic Inductors with Different Topologies: modeling and solutions

“…When considering a spiral, the multi-turn geometry suggests proximity effects promoting current crowding and excess joule losses in the neighbouring metal traces [6]. Indeed, as shown in Fig.…”

“…Some theoretical aspects are now detailed. Based on [6], the current density (Jprox) induced in a metal trace "n" by the normal magnetic field (BnN) generated by the others N turns is given b :…”

High-Q Spiral Zeroth-Order Resonators for Wireless Power Transmission

“…맴돌이 전류에 의한 손실(Reddy)은 흔히 전류 폭주 효과(current crowding effect)에 의해 발생된다 [9] . 그 림 6(a)는 이 효과를 도식화 한 것이다.…”