A downhole-to-surface communication channel consisting of a long vertical cylinder (the stem) and an isolated downhole in-line cylinder (the electrode) embedded in a homogeneous earth is considered in this work. A signal voltage is applied between the electrode and stem, and the received voltage is picked up at the surface between the stem and a ground point or between two ground points. The an...

Significance Part 5 – Monitoring Instruments, laboratory measurements, and test methods This report describes in detail a surge generator producing a waveform mimicking a typical waveshape as observed during several years of recording transients in residential circuits; the source impedance is believed to be representative of real-world conditions. This packaged design, suitable for bench-top u...

In this study, four new configurations implementing first-order current-mode allpass inverse filter signals are presented. The proposed generic circuit with two inputs and a single output employs a single FfFN, three resistors and a capacitor with both the inputs supporting the first-order allpass inverse responses separately. The topologies offer high output impedance, which enable easy cascad...

A new impedance boundary condition method for calculating the series impedance of lossy quasi-TEM transmission lines is presented. Previous techniques using a more standard impedance boundary condition are typically limited to high frequency where the impedance boundary conditions can be easily approximated due to its localized characteristics in that limit. The new impedance boundary condition...

A characteristic loop locus of dc power versus RF output power was observed as the frequency was varied around the optimum point of an operational active antenna. A new technique was introduced into the simulation, plotting the dependence of parameters such as supply current, efficiency or output power on internal impedance as seen by the naked transistor. It is now clear that the loop was form...

In this paper, the performance of wireless operation of four-leg parallel inverters, at the presence of unbalanced nonlinear loads, is investigated. In order to control the parallel inverters, an inner current and external voltage control loops should be designed. In this paper, a proportional controller for the current internal loop as well as a proportional-resonant one for the voltage extern...

This study proposes a concurrent dual-band filter that consists of two single-band filters using quarter-wavelength resonators. The two single-band filters, having different feeding structures, can be designed separately. The lower-band filter has tapped feeding structure and the higher-band filter has coupling feeding structure where the input/output line and the lower-band resonator constitut...

In the last decades, wearable powered orthoses have been developed with the aim of augmenting or assisting motor activities. In particular, among many applications, wearable powered orthoses have been also introduced in the state of the art with the goal of providing lower-limb movement assistance in locomotion-related tasks (e.g.: walking, ascending/descending stairs) in scenarios of activitie...

There has been considerable progress in the construction of fundamental bandwidth limits and near optimal design realisations for several classes of passive linear electromagnetic wave devices, most notably for radar absorbent materials, antennas and meta-materials. This article seeks to place balun design on a similar footing, for an important class of baluns; in particular those which are ‘pe...

Z-Source converter or impedance-source converter is a kind of power converters, which has the responsibility to convert the direct current to alternative current. This converter with respect to its circuit diagram acts as a buck-boost converter except it doesn’t use from DC-DC converter bridge. Γ-source inverters are one of the conventional converters based on impedance-sources; which have been...