With the slow-down of Moore's law and the increasing requirements on energy efficiency, alternative logic styles compared to complementary static CMOS have to be revisited for digital circuit implementations. Pass Transistor Logic (PTL) gained much attention in the '90s, however, only a limited number of recent investigations and publications regarding PTL exist that use advanced technology nodes. This paper compares key performance metrics of 22 different PTL based 1-bit full adder designs to a complementary static CMOS logic reference, using a recent 12nm FinFET technology. The figures of merit are the propagation delay, the energy consumption, and the energy-delay-product (EDP). Our investigations show that PTL based adder circuits can have an up to 49% decreased delay and a 48% and 63% reduced energy consumption and EDP, respectively, compared to a state-of-the-art complementary CMOS logic reference. In addition, we analyzed the impact of PVT variations on the delay for selected PTL full adder designs.

In order to improve the effective transfer range and then enhance the interoperability of magnetic coupling wireless power transfer (MC-WPT) systems, an electromagnetically induced transparency (EIT)-like MC-WPT system is proposed in this paper, which can maintain a reasonable level of power and efficiency over a wide range of transfer distance. Firstly, the circuit model of the tri-coil MC-WPT system is presented along with several key concepts, including EIT mechanism and eigen parameters. Then the energy efficiency characteristic of the system in eigen state is investigated, based on which the energy efficiency improvement principle and corresponding parameter design condition of the EIT-like mechanism are derived. Finally, practical systems are designed, simulated and measured to show the accuracy and effectiveness of the proposed method. The simulation and experimental results show that, with the proposed method, the effective transfer range that takes into account both output power and transfer efficiency is greatly improved. The method is particularly suitable for the design of electric vehicle charging piles, based on which the effective charging of vehicles with different chassis heights on a charging pile can be achieved.

A design methodology for making magnetic coupling wireless power transfer (MC-WPT) systems resonate at given frequencies is proposed in this paper. Proposing such a method not only can improve the energy efficiency against frequency splitting, but also can satisfy the requirement of frequency standards and then promote its industrial application. The method is based on eigenvalues configuration and comprehensively considers all electric parameters. The quantitative relationship between the performance indexes and electric parameters is derived, based on which the expected electric parameters can be quickly and accurately determined. The design theory and design flow are provided, and practical systems are designed, simulated and measured to show the effectiveness of the proposed method. The results show that the proposed method can: 1) eliminate frequency splitting to make MC-WPT systems resonate at a given frequency; 2) utilize frequency splitting to make MC-WPT systems resonate at two given frequencies.