On the basic of fractal theory and folded technique, a miniature antenna for 2.45 GHz radio frequency identification (RFID) tag applications is designed and analyzed in the present paper. In order to realize the miniaturization of tag antenna, a Hilbert fractal structure is used. Impedance matching between antenna and IC chip is of great importance for improving tag performances. A folded techn...

Capillary-based systems for measuring the input impedance of musical wind instruments were first developed in the mid-20th century and remain in widespread use today. In this paper, the basic principles and assumptions underpinning the design of such systems are examined. Inexpensive modifications to a capillary-based impedance measurement set-up made possible due to advances in computing and d...

Detecting and removing minor faults in power transformer winding is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. In this paper in order to detect the position of short-circuit in the winding, frequency response of the input impedance of a power transformer is analyzed. Common short-circuits are categorized and the results are compa...

A step-down procedure is described for establishing voltage standards in the 2 mV to 200 mV range at frequencies between 10 Hz and 1 MHz. The step-down employs low-voltage thermal voltage converters and micropotentiometers. Techniques are given for measuring input impedance and calculating loading errors.

This work is part of a project aiming at helping craftsmen to design and characterize their musical instruments. Starting from a given wind instrument shape, our objective consists in choosing the most relevant physical model able to predict the acoustical input impedance of this musical instrument once constructed. The modeling of bells in brass instruments is still problematic as the limits o...

A theore tical analysis is made of the effect of antenna s ize on parameters such as gain, bandwidth, and efficiency . Both near-zone and far-zon e direct ive gains are considered . It is found that t he maximum gain obtainable from a broad-band antenna is approxima tely equal t o that of the uniformly illumina ted aper t ure. If higher gain is desired , the antenna mus t necessarily be a narro...

This paper presents a modal-expansion analysis of the electromagnetically coupled coaxial dipole antenna. The analysis of the antenna problem is initially simplified using the even-odd mode excitation and then the resultant half structure is divided into two parts; one is the characterization of a coaxial feeding network and the other is the modeling of a sleeve monopole antenna driven by a coa...

This article is the third in a three-part tutorial series covering antenna terminology. As noted, our intention is to discuss standardized antenna terminology as published in the IEEE Standard Definitions of Terms for Antennas, and how this terminology compares with the nomenclature that is commonly used in the EMC community. In the first part of this series, we discussed radiation efficiency a...

In this paper, the modal theory of antennas is re-visited, believing that it brings invaluable information towards facilitating the design of multi-feed multi-band antennas. First, some subtle changes are proposed to enhance the applicability of the theory. Next, using some efficient computational techniques, the proposed formulations are shown to predict, to a very high accuracy, the input imp...