Design of Multi-Antenna System for UMTS Clamshell Mobile Phones with Ground Plane Effects Considerations

In this paper, the influence of the ground plane dimensions on the port-to-port isolation of two closely-spaced Universal Mobile Telecommunications System (UMTS) Planar Inverted-F Antennas (PIFAs) with and without neutralization line is first presented. Parametric studies show the existence of an optimal size of the ground plane allowing optimizing the isolation and the efficiency of the considered antenna-system. The results obtained with this study are used in the second part to develop an efficient neutralized multi-antenna system for clamshell-type mobile phones. The obtained results, in terms of isolation, matching and diversity for the two possible configurations of the clamshell system in use namely the open and the closed states, show that good performance are obtained in the open state and preserved in the closed state. Prototypes of these two configurations are realized and measurement results are in good agreement with the simulations

Diversity Characterization of Optimized Two-Antenna Systems for UMTS Handsets

This paper presents the evaluation of the diversity performance of several two-antenna systems for UMTS terminals. All the measurements are done in a reverberation chamber and in a Wheeler cap setup. First, a two-antenna system having poor isolation between its radiators is measured. Then, the performance of this structure is compared with two optimized structures having high isolation and high total efficiency, thanks to the implementation of a neutralization technique between the radiating elements. The key diversity parameters of all these systems are discussed, that is, the total efficiency of the antenna, the envelope correlation coefficient, the diversity gains, the mean effective gain (MEG), and the MEG ratio. The comparison of all these results is especially showing the benefit brought back by the neutralization technique

Diversity performance of multiantenna systems for UMTS cellular phones in different propagation environments

We present the evaluation of the diversity performance of several two-antenna systems for UMTS terminals. First, a two-antenna system with poor antenna-to-antenna isolation is described. Then, with the help of a neutralization technique, we introduced an optimized structure with high antenna-to-antenna isolation. The key parameters for an efficient diversity performance are then discussed, some of them being actually dependent on the propagation environment (uniform, indoor, outdoor, and outdoor-toindoor chosen here). All these parameters, the total efficiency, the envelope correlation coefficient, the mean effective gain, the diversity gain, and the effective diversity gain, are computed with the help of the simulated radiation patterns of both antenna systems. Next, these key parameters are measured in a reverberation chamber to validate the simulations we achieved in the uniform environment. The comparison of the performance of the two prototypes is especially showing the usefulness of using a neutralization technique for enhanced diversity antenna systems

Self-adjusting microstrip antenna

International audienc

Broadband low-profile wire-patch antenna

International audienceThis paper describes a wire‐patch air‐filled antenna, made up of two metallic stacked plates and center fed by a coaxial probe. This radiating element, which uses the original resonance phenomenon due to the presence of wires between the ground plane, the first and the second metallic stacked patches, has a wide bandwidth. This antenna also works like a short monopole for frequencies located below the fundamental cavity resonance mode, and close to the GSM frequency band

Microstrip antenna with integrated phase shifter

International audienc

Visualisation de la polarisation du champ rayonné par des antennes microruban disposées sur des surfaces planes ou conformées

National audienc

Compact Internal Multiband Antenna for Mobile Phones and WLAN Standards

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Microstrip Phased Array Antennas Printed on Inclined Planes

This paper presents an analysis of the electromagnetic field radiated by micro-strip patch antennas printed on inclined surfaces. The theoretical approach allows to apply spatial rotations to each source. The computer simulation developed permits us to experiment different antenna structures and two original realisations are proposed: a 2-element array printed on two inclined planes and a 4-element array laid out on a pyramidal surface. In addition, it enables the choice of the phase applied to each radiator to produce a beam deflection function. A good accuracy is obtained between theoretical and experimental results. The aim of this study is to optimise the parameters of such antennas to achieve the desired radiation patterns, from printed phased arrays on conformal surfaces. We also present the theoretical behaviour of a octagonal pyramid

A Miniature Quadband Antenna For Mobile Communications

International audienc