Papers by hamadi ghariani
UWB Pulse Propagation into Layered Model of Human Body
Journal of Telecommunication, Electronic and Computer Engineering, Sep 29, 2017
The biomedical applications of Ultra-Wide Band (UWB) radar system promise a very important means ... more The biomedical applications of Ultra-Wide Band (UWB) radar system promise a very important means to remotely monitor physiological signal. Researchers have shown great interest in proposing analytical techniques to accurately predict the propagation of UWB pulse in tissues layers. This paper focuses the study of the propagation of a UWB pulse into a human body to characterize the absorption and reflection of UWB signal due to different layers. Several time behaviors for the reflected pulse were used and compared with the transmitted pulse to the feasibility of movement and heartbeat activity monitoring. Results from the simulation showed that if the UWB transmit antenna is placed far from the human body, the reflection from the interface between the air and the fat can be used to detect the movements of the activity. Therefore, we proposed designing an analytic model of tissue layers, considering some parameters. Furthermore, the frequency dependency of the different layers, tissues dielectric properties and the continuous motion of intra thoracic tissue layers were incorporated. The present work illustrates an application of UWB system for contactless detection and analysis of the human vital signal. This paper focuses on the design of a propagation UWB pulse into a layered model of the human body using the tool of modeling Agilent Advanced Design System.
On the first- and second-order statistical properties of different Rayleigh fading channel models
This paper is a continuation of our previous works on performance of different simulation models ... more This paper is a continuation of our previous works on performance of different simulation models for Rayleigh fading channels. Previously, we have compared and analyzed several Rayleigh fading simulation models in terms accuracy and complexity. Some of these models are non-ergodic and their statistical properties vary from one simulation trial to another. Thus, a focus on the convergence behavior of such models is highly recommended which is missing in our previous works. In this paper, the first- and second-order statistical properties of seven of the most popular Rayleigh fading models are reviewed. The quality of the envelope probability density function (PDF) of the different models is evaluated using a more convenient quantitative measure. The convergence of the non-ergodic stochastic models is inspected based on the variances of the time-averaged correlation properties. The simulation results reveal several important conclusions about the accuracy as well as the capacity of the different models.
Receiver design for UWB communications
ABSTRACT The Ultra Wide Band (UWB) is a technical of radio transmission which consists of using s... more ABSTRACT 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 rectangular microstrip patch antenna
The purpose of this paper is to design a microstrip rectangular antenna in Advance Design System ... more 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.
Study and design of a loop antenna for application of medical telemetry
ABSTRACT In this paper we have studied and designed a rectangular loop antenna powerful around 43... more ABSTRACT In this paper we have studied and designed a rectangular loop antenna powerful around 433.92 MHz and destiny particularly with the medical telemetry where we use band ISM (industrial scientific and medical). We start by seeing the effect of measurements on the performances of this type of antennas then we compare the theoretical results and those of simulation to check our choice. Finally we give a method allowing the improvement of the output.
Agricultural Journal, Jun 1, 2010
International Journal of Advanced Computer Science and Applications, 2016
In this paper, the EKV3.0 model used for RF analog designs was validated in all-inversion regions... more In this paper, the EKV3.0 model used for RF analog designs was validated in all-inversion regions under bias conditions and geometrical effects. A conversion of empirical data of 180nm CMOS process to EKV model was proposed. A MATLAB developed algorithm for parameter extraction was set up to evaluate the basic EKV model parameters. Respecting the substrate, and as long as the source and drain voltages remain constant, the DC currents and g m /I D real transistors ratio can be reconstructed by means of the EKV model with acceptable accuracy even with short channel devices. The results verify that the model takes into account the second order effects such as DIBL and CLM. The sizing of the elementary amplifier was considered in the studied example. The sizing procedure based on g m /I D methodology was described considering a semi-empirical model and an EKV model. The two gave close results.
Design of 3.1–5.1 GHz pulse generator for UWB communications
In this study a novel architecture of Ultra Wide Band generator is explained. This architecture i... more In this study a novel architecture of Ultra Wide Band generator is explained. This architecture is the major important component in the generator Ultra Wide band communications systems. The new generator is consists of oscillator, multiplier and triangular pulse generator. This new study of generator is consists by multiply the triangular pulse signal envelope with a sinusoidal signal in the aim to produce the nanosecond pulse. This new architecture generator circuit produces a short signal wave which is characterized by a bandwidth of 2 GHz, centered frequencies of 4.1GHz, and limited of -41.3 dBm/MHz the Power Spectral Density (PSD) is. The maximum amplitude is 154 mV, the pulse is during of 1 nanosecond and the pulse repetition period (PRP) is 10 ns. This new study focus on designing of ultra wide band generator component using the tool Agilent Advanced Design System.
Journal of Applied Sciences, Sep 1, 2007
Wireless power transmission technologies and applications
ABSTRACT In this paper, a review is given of present state of the art about the concept of wirele... more ABSTRACT In this paper, a review is given of present state of the art about the concept of wireless power transmission i.e., transmitting power as microwaves from one place to another in order to reduce losses during the transmission and distribution of electrical power or also to deliver energy in location where conventional wires are expensive, inconvenient or impossible. This concept is known as Microwave Power Transmission (MPT). We presented the technological of Wireless Power Transmission (WPT) and also its applications.
Design of a high performance rectenna for wireless powering 2.45Ghz RFIDs
This paper describes the design and the optimization of a rectenna in ISM band, dedicated to wire... more This paper describes the design and the optimization of a rectenna in ISM band, dedicated to wirelessly supplying RFID's sensors, to replace or recharge existing batteries. The circuit is based on a double voltage rectifier designed and optimized at 2.45GHz with ADS software. We detail a new methodology to design and optimize a rectenna circuit. As a result, excellent performance is achieved in terms of both output voltage level and RF to DC conversion efficiency. The described rectenna reaches approximately a conversion efficiency of 90% and produces 6Volt at 8 dBm enabling hence some RFID chips.
Design of 10.6 GHZ low phase noise LC-voltage controlled oscillator in 0.18μm CMOS technology
A low phase noise LC-voltage-controlled oscillator (LC-VCO) implemented in 0.18 μm CMOS technolog... more A low phase noise LC-voltage-controlled oscillator (LC-VCO) implemented in 0.18 μm CMOS technology is described in this paper dedicated to radio-frequency operation. The LC-VCO incorporates the differential NMOS cross-coupled pair as an active circuit to reduce the phase noise characteristic. The process to establish the oscillation frequency tuning is employing the LC tank core. Simulation results prove that the output frequency is 10.6 GHZ, an excellent phase noise (PN) which is −107.779 dBc/Hz at 1MHz offset from the 10.6 GHz carrier and the dissipated energy power is 9.8 Mw under 1.4 supply voltage.
A CPW-Fed Wide Band Bell-Form Antenna for Biotelemetry Application
International audienc
Influence of Intrinsic Impedance on the Phase of Propagation Pulse Through Biologic Tissue
IETE Journal of Research, 2021
The aim of this study is to examine the influence of the variation of the intrinsic impedance on ... more The aim of this study is to examine the influence of the variation of the intrinsic impedance on the phase of a Gaussian pulse during propagation through a biological tissue. This paper describes a...
Agricultural Journal, 2010
A comparison of methods for separation of transient and oscillatory signals in EEG
Journal of Neuroscience Methods, 2011
Brain oscillations constitute a prominent feature of electroencephalography (EEG), in both physio... more Brain oscillations constitute a prominent feature of electroencephalography (EEG), in both physiological and pathological states. An efficient separation of oscillation from transient signals in EEG is important not only for detection of oscillations, but also for advanced signal processing such as source localization. A major difficulty lies in the fact that filtering transient phenomena can lead to spurious oscillatory activity. Therefore, in the presence of a mixture of transient and oscillatory events, it is not clear to which extent filtering methods are able to separate them efficiently. The objective of this study was to evaluate methods for separating oscillations from transients. We compared three methods: finite impulse response (FIR) filtering, wavelet analysis with stationary wavelet transform (SWT), time-frequency sparse decomposition with Matching Pursuit (MP). We evaluated the quality of reconstruction and the results of automatic detection of oscillations intermingled with transients. The emphasis of our study was on epileptic signals and single channel processing. In both simulations and on real data, FIR performed generally worse than the time-frequency methods. Both SWT and MP showed good results in separation and detection, each method having its advantages and its limitations. The SWT had good results in separation and detection of transients due to the time invariance property, but still did not completely resolve the frequency overlap for the oscillation during the time-frequency thresholding. The MP provides a sparse representation, and gave good results for simulated data. However, in the real data, we observed distortions introduced by the subtractive approach, and departure from dictionary waveforms. Future directions are proposed for overcoming these limitations.
Bandwidth Enhancement of the Square Rectangular Patch Antenna for Biotelemetry applications
ABSTRACT This paper introduces the design of a wideband square and rectangular patch antennas for... more ABSTRACT This paper introduces the design of a wideband square and rectangular patch antennas for biotelemetry applications. These antennas are printed on a 1.6 mm thick FR4 with sizes 100*90 and 100*70 mm, respectively. A 2.1 mm wide microstrip line is used as a feed line. Both square and rectangular patch antennas exhibit a wide resonant frequency band. The square antenna operates from 1.41 to 4 GHz with a 95.8% impedance bandwidth, whereas the rectangular antenna covers the 1.56 -3.5 GHz range with a 76.7% impedance bandwidth. These wide band properties are achieved by using an asymmetrical feed and a reduced ground plane with an appropriate gap distance. In this Letter, experimental and simulation results are presented and discussed.
An Ultra Wideband Efficient and Linear Power Amplifier for IEEE 802.15.3a applications
2021 18th International Multi-Conference on Systems, Signals & Devices (SSD)
This paper presents 3.1-10.6 GHz efficient and linear CMOS Power Amplifier (PA) suitable for Ultr... more This paper presents 3.1-10.6 GHz efficient and linear CMOS Power Amplifier (PA) suitable for Ultra Wide-Band (UWB) applications. It incorporates a two stage using the current-reuse technique combines with load peaking and source inductive degeneration topologies to optimize group delay variations. The current reused configuration is applied to save the power consumption and improve gain. A new staggered tuning technique is adopted to lower the group delay variation while preserving high gain. The effect proves a high performance. The simulation results show an excellent gain flatness of $28.7\pm 2\ \text{dB}$ and good phase linearity property of ±60 ps. An input, output return loss were less than −10.2 dB and −13.7 dB, respectively. A good linearity revealed by the Input third-order Intermodulation Point, which is 6dBm and is unconditionally stable. Furthermore, it achieves a maximum Power Added Efficiency of 33% at 6GHz. Complying with existing trade-offs over the full bandwidth is the main contributions brought about by the proposed PA.
Flexible signal generator for facial nerve detection
First International Symposium on Control, Communications and Signal Processing, 2004.
During surgical intervention on patient face, the facial nerve must be protected. To avoid the ri... more During surgical intervention on patient face, the facial nerve must be protected. To avoid the risk of its damage, we propose an electronic device that could detect the presence of this nerve. Thanks to its excitability, it was possible therefore to record a noticeable muscular electric reaction on the face. An active stimulating electrode would be placed on the patient
Impedance Spectroscopy, 2018
Dielectric spectroscopy is becoming a popular technique in addition to the chemical and optical m... more Dielectric spectroscopy is becoming a popular technique in addition to the chemical and optical methods for oil quality assessment. It is based on the measurement of the variation of the dielectric properties of oil corresponding to the change of its chemical and physical properties. In this investigation an interface circuit for the measurement of the dielectric properties of oil is proposed using the capacitanceto-voltage conversion technique. The circuit measures the variation of capacitance of the sensor. The output voltage of the circuit is a DC voltage proportional to the capacitance of the sensor with a resolution of 5 mV/pF. The differential technique was used to eliminate stray capacitances caused by the circuit. Regression analysis has been carried out to describe a mathematical relation between the change of the capacitance and the output voltage. Simulations show a maximum relative deviation of 0.03 % for capacitance in the range of 100 pF to 1000 pF while experimental results show a maximum relative deviation of 2 % for the same capacitance range. The effects of stray capacitances and dielectric losses are also investigated. Stray capacitances decrease the measurement accuracy to 0.1 %, while the parallel resistance, which represents the dielectric losses does not affect the accuracy, if its value is higher than 10 MΩ. For resistance values lower than 10 MΩ the circuit is not stable and it is threfore not possible to estimate the capacitance value using the output voltage.
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Papers by hamadi ghariani