Simultaneous 6-Gb/s Data and 10-mW Power Transmission Using Nested Clover Coils for Noncontact Memory Card

An inductive power and data transmission link for a noncontact memory card interface is reported. Nested clover coils improve signal-to-interference ratio and enable simultaneous power and data transmission. This capability is then used in the design of a closed-loop feedback system for improving power transfer efficiency. Interference cancellation mechanism is analyzed with both 3-D EM simulations and a newly developed compact model of coupled inductors. Performance of the proposed solutions was confirmed experimentally using a scaled-down stacked-chip prototype fabricated in a 65-nm CMOS process. Maximum data transmission rate is 6 Gb/s and the total power transfer efficiency is 5.2%-10.2% over a load resistance range of 0.1-2 kΩ.