This paper presents a comparative review study on ultra-wideband (UWB) antenna technology for Ground Penetrating Radar (GPR) applications. The proposed antenna designs for UWB ground penetrating radar include a bow-tie antennas, Vivaldi antennas, horn antennas, planar antennas, tapered slot antennas, dipole antennas, and spiral antennas. Furthermore a comprehensive study in terms of operating f...

Using directional antennas can be beneficial for wireless ad hoc networks consisting of a collection of wireless hosts. To best utilize directional antennas, a suitable Medium Access Control (MAC) protocol must be designed. Current MAC protocols, such as the IEEE 802.11 standard, do not benefit when using directional antennas, because these protocols have been designed for omnidirectional anten...

A new Fresnel Zone (FZ) Antenna to focus the microwave power in the radiation near field region is presented. FZ Antennas, in comparison with array antennas or reflector antennas, conventional focused antennas, take the advantages of design simplicity as well as lower sidelobe levels (SLL) in both axial and transverse directions. Simulation results and comparisons made between the new structure...

This paper presents results from an experiment that used a variety of antennas inside two buildings. A profound result is that directional circularly-polarized (CP) antennas reduce rms delay spreads when compared with omni-directional and directional linearly-polarized (LP) antennas at identical locations. The variation of rms delay spread over distances of several wavelengths is also greatly r...

This paper presents an overview of the results of the development of Ku-Band Low-Profile antennas for Mobile Satellite Communications. The antennas are based on a hybrid mechanical-electronic steerable array architecture. Different prototypes have been developed and demonstrated. We present the results for two receive-only antennas for satellite broadcasting applications and two Transmit-Receiv...

In this paper we consider a wireless network, where each transceiver is equipped with a directional antenna, and study two direction assignment problems, determined by the type of antennas employed. Given a set S of transceivers with directional antennas, located in the plane. We investigate two types of directional antennas — quadrant antennas and half-strip antennas, and show how to assign a ...

A new approach to wideband and smart re-configurable antennas using RF MEMS switches and fractal antennas is presented. Index Terms – Smart antennas, wideband, fractals, RF-MEMS.

UWB (ultra wide-band) pulse radar is a promising candidate for surveillance systems. The fast SEABED (Shape Estimation Algorithm based on BST and Extraction of Directly scattered waves) imaging algorithm is deployed in the application of UWB pulse radar in fields that require real-time operations. However, since the SEABED algorithm uses signals received at multiple locations, this method eithe...

Massive MIMO systems promise high data rates by employing large number of antennas. By growth of number of antennas in a system, both data rate and power usage rise. This creates an optimisation problem which specifies how many antennas we should have for an optimum operation to achieve the best possible Energy-Efficiency. Since the number of user terminals varies over time, number of operation...

The K-user single-antenna Gaussian Interference Channel (GIC) is considered, where the channel coefficients are NOT necessarily time-variant or frequency selective. It is proved that the total Degrees-Of-Freedom (DOF) of this channel is K 2 almost surly, i.e. each user enjoys half of its maximum DOF. Indeed, we prove that the static time-invariant interference channels are rich enough which all...