Mondher Chaoui

Electrical modeling of inductive links for high-efficiency energy transmission

This paper presents an innovative modeling method for the mutual inductance of two magnetically coupled coils in an inductive link, ensuring efficient energy and data transmission in implantable electronic devices. An electrical model, which can be used within a circuit simulator, directly takes into account the lateral and longitudinal displacements between the external coil (transmitter) and the internal coil (receiver), thus enabling to optimize the voltage gain of the link, and opening to the design of inductive links with high power transfer capabilities and high overall efficiency.

Maximum of mutual inductance by inductive link

This paper presents inductive link between various coils or various forms to protect the reserve of unidirectional energy and from bi-directional data in the implantables electronic devices. Study will rest on the increase of the efficiency allocated by the tolerance to the lateral, longitudinal and even angular displacement between the external coil (transmitter) and the implanted coil (receiver).

Design of rectangular microstrip patch antenna

The purpose of this paper is to design a microstrip rectangular antenna in Advance Design System Momentum (ADS). The resonant frequency of antenna is 4.1GHz. The reflection coefficient is less than -10dB for a frequency range of 3.1GHz to 5.1 GHz. The proposed rectangular patch antenna has been devise using Glass Epoxy substrate (FR4) with dielectric constant (εr = 4.4), loss tangent (tan δ) equal to 0.02. This rectangular patch is excited using transmission lines of particular length and width. Various parameters, for example the gain, S parameters, directivity and efficiency of the designed rectangular antenna are obtained from ADS Momentum.

Influence of the cardiac activity on the surface impedance of a multilayer model

Biological tissues are seen as multilayer structures. We will use in this article a model with three layers: skin, fat and muscle. This structure may be related to a pattern of cascaded lines where each tissue has its own characteristic impedance, permittivity and conductivity. This structure allows us to solve the problem of the surface impedance. Each layer is similar to a line of characteristic impedance. The impedance of the first layer will be transformed as soon as one progresses to the surface. This article represents, first, a detailed study of the electrical properties of a stratified propagation medium, and secondly, a study of the variation of the surface impedance according to the cardiac activity.

Design of a pulse generator for UWB communications

The Ultra Wide Band (UWB) is a technical of radio transmission which consists of using signals whose spectrum is spread out over a broad frequency band, typically ranging from MHz to several GHz frequencies. It was at first used for radar applications then applied in telecommunication applications, thus arousing a growing interest within the academic and industrial community. The present work is concerned with a research on UWB as a new technology for radar systems. Besides, it sheds light on the design of transmission system with broad ultra band an Agilent Advanced Design System modeling tool.

Modeling of the thorax of human body at 433 MHz

Nowadays, communication networks have become indispensable in our daily lives. In the last years, new networks have been developed, such as the body wireless sensor network “BAN”. So it will be necessary to highlight the influence of the body on the radiation pattern, performance and adaptation of the antenna. To understand the interaction between electromagnetic waves and the human body, it is important to have knowledge about the physical properties of biological tissues which can be seen as multilayer structures. This will be well detailed in this paper. Each layer has its own dielectric characteristics. Those properties are represented by the relative permittivity and conductivity. So to characterize tissues, we must study its properties. Then, a study of the attenuation factor is made, based on a comparison between HFSS and ADS.

Design of a digital communication system based on a XBee module for biomedical applications

This article describes the prototype of the digital communication system based on the XBee module. It consists on a universal system that transmits all type of data including the medical information such as Electrocardiogram (ECG). To validate this system, we have chosen to transmit the ECG from a computer to another through the XBee modules just to evaluate the quality of the wireless communication. For this, we have performed a series of indoor and outdoor tests.

Design of a Bell-Shaped Ultra Wideband Antenna for Indoor Localization System

In this article, a Microstrip line-fed printed Ultra-Wideband (UWB) monopole antenna for indoor localization system is introduced. The proposed antenna having a total size of 21mm × 27mm is composed of a bell-shaped radiating patch and a reduced ground plane. The designed antenna operates over impedance bandwidth 3.26 - 9.74 GHz with a maximum Gain of 3.88 dB. Moreover, it exhibits an Omni-directional radiation patterns in the H-plane within the operating band. Details of the proposed antenna design, numerical analysis and return Loss measurements are presented and discussed.

Receiver design for UWB communications

The Ultra Wide Band (UWB) is a technical of radio transmission which consists of using signals whose spectrum is spread out over a broad frequency band, typically ranging from MHz to several GHz frequencies. It was at first used for radar applications then applied in telecommunication applications, thus arousing a growing interest within the academic and industrial community. In a UWB radar system, the transmitter generates a sequence of short pulses with duration of the order of hundreds of picoseconds. These pulses excite the antenna and are radiated in space; then, the pulses are reflected by the target. The reflected pulse arrives to the same or another antenna and, if the target moves, the system is able to detect this movement from the changing in the arrival time of the received signal. The present work is concerned with a research on UWB as a new technology. This paper focuses on the design of a receiver system with ultra wide band using the tool of modelling Agilent Advanced Design System.

Design of a device for transferring power and data to a cochlear implant

Among the identified implantable electronic systems, there is a pacemaker, urinary implants, visual implants and auditory cochlear implants. This system is composed of an implant and a control unit. The implant is designed to work efficiently and autonomously for long periods. It is placed under the skin of the user. The main tasks of the implant are the stimulation of nerves or muscles and the detection and measurement of different physiological signals. As for the control unit, it serves, first to transmit all information needed to perform the various tasks to the implant. Second, it is used to retrieve and process data from the implant.