T. Monediere

Synthesis of Antenna Arrays and Parasitic Antenna Arrays with Mutual Couplings

A synthesis method to design multielement antennas with couplings is presented. The main objective is to perform a rigorous determination of the electromagnetic characteristics involved in the design, especially with arrays of moderate sizes. The aim is to conceive jointly and efficiently the antenna and the circuits to connect (feed distribution network, power amplifiers, reactive loads, etc.). The subsequent objective is to improve the understanding and capabilities of strongly coupled antennas. As a whole, the synthesis procedure is then applied to different antenna architectures in order to show its efficiency and versatility. A focus on some antenna concepts where the management of couplings is a key factor to improve the performances is presented. After describing the synthesis procedure, the first category of coupled multielement antenna studied concerns radiating arrays in linear or circular polarization. A design including couplings effects on an active array is also presented. Then, the method is applied to parasitic antenna arrays and a specific investigation on reflectarray antenna is performed as they can be considered as a particular case of parasitic arrays.

Interlaced feeds design for a multibeam reflector antenna using a 1-D dielectric PBG resonator

The 1-D dielectric resonator PBG allows to generate directive and interlaced reflector feeds in order to obtain optimal focal fed antenna efficiency and closely spaced beams. Our passive system is supposed to replace the complex, active and heavy reflector feeds.

Low Profile EBG Resonator Antennas

An Electromagnetic Band Gap (EBG) antenna is a planar structure which is composed of a cavity and an EBG material. In most applications, the height of the EBG antenna is half wavelength. We present in this paper the conditions to reduce the profile of an EBG antenna to subwavelength values. It could be achieved by using a cavity upper interface which exhibits negative reflection phase. Frequency Selective Surface (FSS) based on Babinet principle, that satisfies this condition, will be described using full wave analysis. These periodic metallic arrays are employed in the design of a low profile EBG antenna which has a directivity of 10 dBi. As this EBG antenna design is similar to a small antenna over an Artificial Magnetic Conductors (AMC) surfaces or High Impedance Surface (HIS), the EBG antenna principle could be a new theory approach for the AMC or HIS. This point is discussed in this paper.

Design of Sectoral Antennas Using a Metallic EBG Structure and Multiple Sources Feeding for Base Station Applications

This work aims to study and design base station antennas with metallic electromagnetic band gap (EBG) materials able to create a sectoral radiation pattern presenting at least a 60∘ beamwidth. The use of metallic structures offers a new approach to industrial partners seeking to reduce costs and facilitate design procedures. A new method allowing the improvement of both the directivity and the bandwidth by using a printed antenna array is studied.

Wide Bandwidth, High-Gain, and Low-Profile EBG Prototype for High Power Applications

In this letter, we present a wide-bandwidth, low-profile, and high-gain electromagnetic band-gap (EBG) resonator antenna that is used for high power and electronic warfare applications. It presents a bandwidth of 71% (from 1 to 2.1 GHz) and a maximum gain of 17 dB. The profile of this antenna is very low (22 mm, which is equivalent to λ/11 at 1.2 GHz). A prototype of this modeled antenna is manufactured, and the measured performances are similar to the simulated ones.

Triband Compact Antenna for Multistandard Terminals and User's Hand Effect

A novel compact wideband triband antenna for mobile terminals based on PIFA element is proposed. The antenna operates at the following frequency bands: Wireless-LAN 802.11 b, g, a and WiMAX 3.5 GHz. The antenna was studied by means of numerical simulations as well as the ground plane dimensions and users hand effects. The overall size of the radiating element which is 1.8×1.54×9 mm makes it suitable for use in terminals and appropriate to integrated as an internal laptop antenna. The measured bandwidths show that the proposed antenna can cover three bands (2.39–2.48 GHz), (3.36–3.76 GHz), and (4.7–6.3 GHz) and the total efficiency is better than 90%. The radiation patterns of the antenna were carried in an anechoic chamber and are given to demonstrate the antennas performance.

New advancements to exploit the potentialities of the EBG resonator antennas

In this paper we summarize the potentialities of the EBG resonator antenna. The theory to understand the properties of such antennas is developed and we illustrate these properties through the design of different kinds of EBG antennas.

Scan Performance and Reconfigurability of Agile Radiating Matrix Antenna Prototype

This paper is dedicated to different experimental validations concerning a novel concept of beam forming and beam steering antenna. The working principle of the antenna is based on the equivalent radiating surface approach and inspired from an electromagnetic band gap antenna. The theoretical aspect and some numerical validations have been already published in the work of Abou Taam et al. (2014). Different electromagnetic behaviors have been demonstrated, such as low mutual coupling, and high gain preservation for high scanning angles values. In this paper, some of these electromagnetic behaviors will be proven experimentally by the means of two different feeding configurations.

Low-Profile Array of Wire Patch Antennas

A low-profile antenna over a ground plane that radiates a directive lobe in the end fire direction is described in this paper. An array of 16 wire patch antenna (WPA) fed by an integrated 16 ways power divider has been designed Owing to its low height, low cost, high robustness, and mono polar radiation pattern, the WPA has been chosen as unit cell of the array that must be placed on the vehicle roof. A gain higher than 19.3 dB was achieved in the end fire direction over a 4.5% bandwidth. However, the antenna has been tilted in order to compensate the beam deviation caused by the edge diffraction. Moreover, a vertical metallic plane has been inserted to eliminate the back fire radiation. Its position and the disposition of the WPAs are explained in this paper. A prototype with four elements has been manufactured in order to validate the antenna principle. A gain difference lower than 0.5 dB is achieved between the measurements and the simulations.

Multifrequency and beam steered electromagnetic band gap antennas

EBG antennas are very thin and high gain antennas. They provide a great control of the power radiated. The antennas studied in this paper are realised with periodic dielectric materials. Classically they present directive patterns for one frequency band, but it is possible to design them to radiate directive patterns for multiple frequency bands. The methodology is described. It is also possible to control the direction of the radiated beam with this kind of periodic structure. This article explains how, with an appropriate feeding it is possible to control the direction of propagation and to create one main lobe. This technique is explained.