Extending Bandwidth of Antennas With Coupling Theory for Characteristic Modes

Simulation of Characteristic of Linear Degradation with Failure Modes

Low-Frequency Characteristic Modes for Aperture Coupling Problems

In this paper, a recently suggested general procedure which leads to an eigenvahre eqnation for apertnre problems is specialized to the range of frequencies for which the maximnm linear dimension of the aperture [ is much smaller than the wavelengths, known as the Rayleigh region. As kl asymptotically approaches zero, we arrive at a set of two eigenvahre equations which aided by the edge condit...

Coupling Effects and Performance of Loran Transmitter Antennas

It is known that if a conductor resides in the neighboring of an antenna with a small distance relative to the wavelength, it induces a reverse current on the conductor. This paper involves the unavoidable coupling effects on some common types of LF antennas, due to the large wavelength in this frequency band. In particular, after some discussions about top-loaded antennas, the coupling effect ...

Design of a High-Bandwidth Y-Shaped Photonic Crystal Power Splitter for TE Modes

In this paper, a Y-shaped power splitter based on a two dimensional photonic crystal (PhC) for TE modes is designed and optimized. A triangular lattice of air holes is used for Y-shaped power divider. For analyzing these structures, plane wave expansion (PWE) and finite difference time domain (FDTD) methods are used. The simulation results show that more than 98% of the input power is transmitt...

Transformation optics for antennas: why limit the bandwidth with metamaterials?

In the last decade, a technique termed transformation optics has been developed for the design of novel electromagnetic devices. This method defines the exact modification of magnetic and dielectric constants required, so that the electromagnetic behaviour remains invariant after a transformation to a new coordinate system. Despite the apparently infinite possibilities that this mathematical to...