Analysis of Wireless Power Transfer system design on active silicon interposer for low voltage applications in 3D-IC

In this study, a Wireless Power Transfer (WPT) system design on active silicon (Si) interposer for low voltage applications in 3D-IC is proposed. The proposed WPT system includes magnetically coupled coils, a full-bridge rectifier, and a voltage regulator. In order to validate the proposed system, we first design all of the system components. First, we design a three dimensional helix-type transmitter (Tx) coil with the size of 1.6 mm by 1.6 mm on PCB, and a spiral-type receiver (Rx) coil using 3 μm top metal CMOS process with the size of 1.5 mm by 1.5 mm on Si-interposer. Second, a CMOS full-bridge rectifier is designed on the active Si-interposer to convert the AC voltage received from the Tx coil to DC voltage, which will then be fed to the input of the voltage regulator. Third, we design a voltage regulator to deliver 1.5 V DC voltage supply to multiple low voltage devices in 3D-IC. Power transfer efficiency of the coil system, full-bridge rectifier including a filtering capacitor, and voltage regulator is calculated to be 55 %, 69.5 %, and 71 %, respectively from circuit simulations. The simulated whole system efficiency is found to be 27 %.