Electromagnetic coupling

AC loss is one of the important parameters in HTS (high temperature superconducting) AC devices. Among the HTS AC power devices, the transformer is an essential part in the electrical power system. The AC losses in an HTS tape depend on the magnetic field. One of the techniques usually adopted to mitigate the unwanted magnetic field is using a system of coils that produce a magnetic field opposite to the incident one, reducing the total magnetic field. In this paper adding two auxiliary windings to the HTS transformer to produce this opposite magnetic field is proposed. The proper use of these auxiliary windings could reduce the leakage flux and, therefore, the AC loss. A mathematical model is used to describe the behaviour of a transformer operating with auxiliary windings, based on the theory of electromagnetic coupled circuits. The influence of the auxiliary windings on the leakage field is studied by the finite element method (FEM) and the AC loss of an HTS transformer was calculated. Also, the simulation results show that employing auxiliary windings will improve the HTS transformer efficiency.

Capacitively-driven on-chip wires reduce both latency and energy compared to repeaters. A series coupling capacitance offers preemphasis to lower wire delay, reduces the driven load, and lowers the wire voltage swing without a second power supply. A 0.18mum CMOS testchip shows 10.5times energy savings at a 50mV swing compared to full-swing repeated wires, and a 3times gain in wire bandwidth

This paper presents the application of two numerical methods in the analysis of the coupling of an incident wave with a conducting wire inside a metallic cavity having a small aperture. The Finite Element Method (FEM) in the frequency domain and the Transmission-line Modeling Method (TLM) are the numerical methods used in the analysis. Earlier published experimental results are used in order to evaluate the obtained numerical results