Hekmet Samet

Electronic nose system and principal component analysis technique for gases identification

An electronic nose is an intelligent system consists of a sensor network and a pattern recognition system able to know simple and complex odors. As the human nose, the artificial nose must learn to recognize different odors: the learning phase. There are several types of sensors such as fiber optic sensors, piezoelectric sensors, sensor type MOSFET. The performance of the sensor network is discussed by using pattern recognition methods. In this article, we tested Principal Component Analysis (PCA) to evaluate the ability of our sensor array to distinguish between different groups of target gases according to their nature: only in binary mixture and ternary mixture.

New design of 3–10 GHz low noise amplifier for UWB receivers

In the ultra-wideband (UWB) communication system receiver, the low noise amplifier (LNA) is the critical module. The LNA is used to amplify the received signal with sufficient gain and as little additional noise as possible. This paper presents a new 3.1-10.6 GHz LNA UWB receivers. The UWB LNA was formed by two stages. The first one uses the resistive current reuse and degenerative parallel LC to provide the input matching over a wideband. The proposed UWB LNA uses an inductive-series peaking technique with cascode common-source amplifier to improve the gain, fatness and consume lower power. This LNA is designed using 0.18 μm CMOS technology. Our finding show that, the low noise amplifier LNA using these techniques allowed us to achieve a maximum power gain of 20.62 dB, a good input/output impedance matching, S11 below -10 dB and S22 below -10dB and an excellent noise figure NF between 1.6-2.5 dB.

Reconfigurable circuits design based on DG-CNTFET transistors

Controllable-polarity transistors have an interesting property, they can switch from p- to n-type behavior and vice-versa dynamically. This opens up the opportunity for building novel and complex functions in fine-grain reconfigurable logic inaccessible to MOSFETs. Double-gate carbon nanotube field effect transistors (DG-CNTFETs) is one of the major promising candidate for reconfigurable circuit reaching a good performance levels. In this paper we will demonstrate the benefit of designing a reconfigurable circuit based on a compact physical model of these transistor. First, an overview of different types of carbon nanotube field-effect, transistor (CNTFET) is given. DG-CNTFET model is described, and characterization of transistor is done. Finally a dynamically reconfigurable 8-function logic gate (CNT-DR8F) based on a (DG-CNTFET) is described, simulated and analyzed.

Design simulation and realization of solar battery charge controller using Arduino Uno

In this paper, a simple method battery charge controller has been designed to protect the battery from over-charging and deep discharges. The control of the process is entrusted to Arduino Uno board, that must be able to find out the battery state and determine when the charge process must be finished. The state of the battery is perfectly controlled all the time. The use of an Arduino Uno based on microcontroller has been considered in order to allow a good flexibility, to simplify the hardware required (only a few external components are used), and to provide an intelligent tool to undertake, through the programmed algorithm. A buck DC-DC Converter has been used to step down voltage from the panel photovoltaic to charge voltage of the battery. This paper presents a comparison between the simulation and practical realization results of the device. A good agreement is obtained.

Schottky barrier carbon nanotube transistors Op-Amp circuit

This paper presents a computationally efficient Raychowdhury compact model for the Schottky barrier (SB) carbon nanotube field-effect transistor (CNTFET). In order to achieve an accurate compact model, shot noise sources is added. Then, for the assessment of the SB on circuit performances, an operational amplifier (Op-Amp) is designed using the SB-CNTFET compact model, and results are compared with a conventional CNTFET.

Gases identification with Support Vector Machines technique (SVMs)

Air pollution is an olfactory pollution because many polluting gases have a strong odor even at low concentrations. These pollutants are natural or anthropogenic emission sources. This pollution has many harmful effects on human health or upon the environment. So it is necessary to detect the pollution to reduce its effects. An electronic nose is capable of detecting the presence of gas after learning. The artificial nose consists of an array of chemical sensors and an electronic system capable of recognizing patterns odors simple and complex. The performance of a sensor network is discussed by using pattern recognition methods. These methods can be supervised methods or unsupervised. Support Vector Machines SVMs is a supervised learning algorithm. In this article, we tested SVM based on kernel functions to evaluate the ability of our sensor array to distinguish between different groups of gases.

Full adder design based on reconfigurable ambipolar CNTFET cell

In this paper, we exploit the specific propriety of controllable polarity CNTFET transistor to design for the first time a full adder based on double gate CNTFET (DG-CNTFET) transistor with static logic. This exceptional characteristics given by complementary static logic designed with double gate CNTFETs enables us to build compact and efficient full adder using a static configurable basic cell called static_17f. After analysis and simulation of the configurable basic logic cell, we describe the new full adder. An explication of how its work and simulation is given. Feasibility of such circuit is demonstrated through functional simulation.

Design and electro-thermal analysis of a platinum micro heater for gas sensors

Micro Hotplate (MHP) is the key component in micro-sensors particularly gas sensors. In this paper, we have presented the design and simulation results of a meander micro heater based on platinum material. A comparative study by simulating two different heater thicknesses has also been presented in this paper. The membrane size is 1.4mm × 1.6mm and a thickness of 1.4μm. Above the membrane, a platinum film was deposed with a size of 1.1 × 1.1 mm and a various thickness of 0.1 μm and 0.15 μm. Power consumption and temperature distribution were determined in the Platinum micro heaters structure over a supply voltage of 5, 6 and 7 V.

Low noise amplifier for MB-OFDM UWB receivers

This paper presented a reconfigurable low noise amplifier (LNA) design. This circuit is the most critical block in a multi-band Ultra Wide Band (UWB) receiver architectures. The proposed LNA is composed of three stages. The first one is a common source (CS) stage. Its objective is to provide a good input reflection coefficient S11 and a low noise figure. The second stage composed of a programmable circuit to select the operation band. A current reuse technique is used in the third stage to achieve a high gain and low power consumption. The proposed multi-band LNA operates in 3 sub bands of Multi Band Orthogonal Frequency Division Multiplexing (MB-OFDM) of 500 MHz, centered at 3.5, 4, 4.5 GHz frequencies. The simulated results of the designed LNA show an average power gain up to 28 dB, 25 dB, 27 dB for band 1, band 2 and band 3, respectively. At a voltage supply equal to 1V, The LNA consumes only 3.4mW. This circuit is designed in CMOS 0.18 μm technology.

Performance evaluation of reconfigurable ALU based on DG-CNTFET transistors

Arithmetic and Logic Unit represent the core of all microprocessors. It performs arithmetic and logical operations. ALU is getting more complex and smaller to make more efficient circuits. This paper describes simple ALU but contains the essentials functions. It is a reconfigurable ALU based on double gate carbon nanotube field effect transistors (DG-CNTFETs). The proposed ALU is designed for one bit operation and can realize three functions (NAND, OR and FULL ADDER). We will demonstrate the benefit of designing a reconfigurable ALU using a compact physical model of DG-CNTFET transistor. First, an explanation of controllable polarity transistor is given. Then a dynamically reconfigurable circuit and 3-function ALU based on a (DG-CNTFET) are described, simulated and analyzed. Finally an overall performance comparison in term of average Power Consumption and delay with CMOS LUT is done. Results shows that this 3-functions ALU have PDP, power and delay better than all 1-bit CMOS full adders, 44% reduction in the consumption and 12% enhancement in delay time.