A novel wideband rectangular dielectric resonator antenna (DRA) is proposed in this paper. A hybrid structure with an isolated dielectric resonator (DR) and an equivalent air-dielectric DR is introduced by lifting the resonator from the ground plane. The hybrid structure is excited by a slot-fed mechanism to obtain a smooth transition between each resonant mode. The resonant modes of the isolat...

This paper focuses on turbo packet combining for hybrid AF/DF multi-relay systems operating over multipleinput–multiple-output (MIMO) broadband channels. We consider virtual antenna based combining strategy that has been widely studied for the point-to-point hybrid ARQ. However, the extension of this combining strategy to hybrid AF/DF cooperative communications is not straightforward. In this p...

An efficient method based on the hybrid model with breeding and subpopulations, between genetic algorithm and a modified particle swarm optimizer for the linear antenna arrays pattern synthesis with prescribed nulls in the interference direction and multi-lobe beam forming by the complex weights of each array element is presented. In general, the pattern synthesis technique that generates a des...

Reduced graphene oxide (rGO) has been studied as a resistive ammonia gas sensor at room temperature. The sensitive hybrid material composed of rGO and nano-silver ink (Ag-ink) was loaded on a microstrip patch antenna to realize high-performance wireless ammonia sensors. The material was investigated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Firstly, in...

The electromagnetic radiation of a handset antenna to a human head model is rigorously analyzed by a new hybrid approach. In the analysis, human head is modeled by a double layered prolate spheroid with complex permittivity. A hybrid Null Field Method/Method of Moments (NFM/MoM) approach is proposed for the first time. The method is general and capable of dealing with multiple scatterers and ra...

The design of a new L-band antenna for DLR’s airborne synthetic aperture radar system (E-/F-SAR) is presented. Beside operations in L-band new components for a system upgrade were developed. These components are introduced. Special interest of this paper is the development of the dual-polarized L-Band antenna with enhanced bandwidth of 150MHz. The antenna feed network is equipped with 2bit hybr...

.............................................................................................. 3 1 Theoretical Background ..................................................................... 5 1.1 What is an Active Phased Array Antenna? ............................................................... 5 1.1.1 Switched Beam Antenna ....................................................................

This paper presents the study on a compact polarization diversity antenna array consisting of two orthogonally placed hybrid dielectric resonator antenna (DRA) elements. A prototype antenna array for IEEE802.11a WLAN application is designed and measured. Over 20 dB isolation and 18% input impedance bandwidth is achieved while symmetrical and unidirectional radiation patterns are maintained over...

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...