On-chip magnetic resonant coupling with multi-stacked inductive coils for chip-to-chip wireless power transfer (WPT)

In this paper, we present on-chip magnetic resonant coupling using single and multi-stacked inductive coils to enhance power transfer efficiency (PTE) of chip-to-chip wireless power transfer (WPT) system. The PTE is rigorously investigated and compared for three schemes of on-chip single and multi-stacked magnetic resonant coils. For on-chip magnetic resonant coupling, the PTE is significantly affected by an effective series resistance (ESR) of on-chip inductive coils at the transmitter and the receiver chip. It is verified through full-wave simulations that the PTE is improved by 38% using the scheme of a multi-stacked coil at both the transmitter and receiver chips, compared to the scheme of a single coil at both the transmitter and receiver chips.