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 ...

The design of a novel volcano smoke antenna for UWB indoor applications is presented. The design method is based on a general description for the geometry of UWB monopole antennas which is capable of producing most possible shapes for these antennas. It is also compatible with different optimization methods. In addition to a volcano smoke antenna, this method is used to design two optimized mon...

A low-cost and portable vector network analyzer (VNA) which covered operating frequency between 1MHz to 3GHz is used for vector reflection coefficient and standing wave ratio (swr) of the various microstrip antennas. This paper presents measurements of various ultra wideband (uwb) microstrip antennas for applications in biomedical field. Selection of antenna is an important key for detection of...

Abstracr We construct simal constellations for differential transmission with multiple basestation antennas. The signals are derived using the theory of fixed-point-free groups and are especially suitable for mobile cellular applications because they do not require the handset to have more than one antenna or to know the time-varying propagation environment. Yet we achieve full transmitter dive...

This paper proposes a bandwidth-eecient fading-resistant transmission scheme which implements transmitter diversity using L antennas at the base station. When the antennas are spaced suuciently far apart, the transmission from each antenna undergoes a diierent degree of fading. These transmissions are coordinated to mitigate the eeects of Rayleigh fading and the mobile receiver can recover the ...

analysis of aperture-coupled microstrip antennas with a superstrate using space domain closed form greens functions is presented. integral equations are derived from applying the boundary conditions on the radiating patch, across the aperture, and on the microstrip feedline. the computation of space domain greens functions is performed using the closed-form. the solution of the integral equatio...

In In this paper, two low profile, single fed cavity backed slot antennas providing a circularly polarized (CP) wave are introduced. One of the antennas presents a right-handed CP (RHCP) wave, while the other one offers a left handed CP (LHCP) wave. The proposed antennas consist of a square shaped Substrtae Integrated Waveguide (SIW) cavity incorporatng two couples of radiating slots to radiate...

The purpose of this paper is three fold. First, the major theoretical pattern relationships of TV and/or FM transmitting antennas are dealt with. Secend, the computer calculation method and designing of such patterns using the given relationships. And third, a method in which a computer graphic system can be used to design such antennas for a specific pattern is introduced and its results are p...

Directional antennas offer many potential advantages for wireless networks such as increased network capacity, extended transmission range and reduced energy consumption. Exploiting these advantages requires new protocols and mechanisms at various communication layers to intelligently control the directional antenna system. With directional antennas, many trivial mechanisms, such as neighbor di...