Search results for: day/night band
1285 Experimental Demonstration of Broadband Erbium-Doped Fiber Amplifier
Authors: Belloui Bouzid
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In this paper, broadband design of erbium doped fiber amplifier (EDFA) is demonstrated and proved experimentally. High and broad gain is covered in C and L bands. The used technique combines, in one configuration, two double passes with split band structure for the amplification of two traveled signals one for the C band and the other for L band. This new topology is to investigate the trends of high gain and wide amplification at different status of pumping power, input wavelength, and input signal power. The presented paper is to explore the performance of EDFA gain using what it can be called double pass double branch wide band amplification configuration. The obtained results show high gain and wide broadening range of 44.24 dB and 80 nm amplification respectively.Keywords: erbium doped fiber amplifier, erbium doped fiber laser, optical amplification, fiber laser
Procedia PDF Downloads 2541284 Design of a Phemt Buffer Amplifier in Mm-Wave Band around 60 GHz
Authors: Maryam Abata, Moulhime El Bekkali, Said Mazer, Catherine Algani, Mahmoud Mehdi
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One major problem of most electronic systems operating in the millimeter wave band is the signal generation with a high purity and a stable carrier frequency. This problem is overcome by using the combination of a signal with a low frequency local oscillator (LO) and several stages of frequency multipliers. The use of these frequency multipliers to create millimeter-wave signals is an attractive alternative to direct generation signal. Therefore, the isolation problem of the local oscillator from the other stages is always present, which leads to have various mechanisms that can disturb the oscillator performance, thus a buffer amplifier is often included in oscillator outputs. In this paper, we present the study and design of a buffer amplifier in the mm-wave band using a 0.15μm pHEMT from UMS foundry. This amplifier will be used as a part of a frequency quadrupler at 60 GHz.Keywords: Mm-wave band, local oscillator, frequency quadrupler, buffer amplifier
Procedia PDF Downloads 5441283 Labor Legislation and Female Economic Empowerment: Evidence from Night Work, Regulatory and Seating Laws
Authors: Lamis Kattan, Joanne Haddad
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This paper examines the impact of gender focused labor legislation on women's labor force participation and economic empowerment. We rely on historical legislative acts passed by state legislatures and exploit whether or not states passed regulatory laws regulating overall and industry specific employment and work conditions for women, night work laws and labor laws requiring provision of seats for working women. We exploit the fact that not all states enacted these laws as well as the variation in the timing of enactment of such laws. Our results show that women in comparison to men in treated states are more likely to be in the labor force post introduction of night work laws in comparison to control states. We also document the effect of industry-specific labor policies on women's likelihood to be employed in the affected industry and in higher-wage occupations within the industry of interest. Policy implications of our findings endorse the adoption of labor laws in favor of women to advocate their empowerment through a higher involvement in the labor market and financial independence.Keywords: female employment, labor laws, marriage, fertility
Procedia PDF Downloads 961282 Peculiarities of the Clinical Course of the Osteoarthritis in Shift-Workers: Analysis of Clinical Data and Questionnaries
Authors: Oksana Mykytyuk
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Chronic desynchronosis is an important factor of progression of osteoarthritis in shift workers. 80 patients with primary osteoarthritis (female:male ratio = 3:1, average age: 57.6 years, average disease duration: 6.4 years, radiological stage: II-III) were examined, 42% reported systematic night shift-work for more than two years. Full clinical examination was performed, all patients filled in SF-36, WOMAC questonnaries, marked visual analog scales for estimation of pain intensity and general well-being. Patients who had been exposed to night work had significantly worse clinical course of osteoarthritis marked by more (27.5%, p < 0.05) extensive pain syndrome, especially at night hours, (10.00 pm-2.00 am period) and estimated life quality as poorer comparing those working at day time. Osteoarthritis initiation occurred at earlier age in them comparing those who worked in non-shifted regimen. They showed a trend to generalized affliction of bigger quantity of joint groups, higher frequency of synovitis as well. Shift-workers administered higher doses of non-steroid anti-inflammatory drugs (NSAIDs) and estimated their effect as lower (39.6% average daily relief vs 62.5% in non-shift workers after 10 days of regular application of therapy). Frequency of chronic NSAID-induced gastropathy was 25% higher among night-workers. Shift-workers are predisposed to worse course of osteoarthritis with marked clinical symptoms, requiring higher doses on NSAIDs and with inclination towards bigger frequency of complication. That should be kept in mind while developing individual treatment and secondary prophylaxis strategy.Keywords: desynchronosis, osteoarthritis, questionnaries, shift-work
Procedia PDF Downloads 1271281 Design and Analysis of Proximity Fed Single Band Microstrip Patch Antenna with Parasitic Lines
Authors: Inderpreet Kaur, Sukhjit Kaur, Balwinder Singh Sohi
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The design proposed in this paper mainly focuses on implementation of a single feed compact rectangular microstrip patch antenna (MSA) for single band application. The antenna presented here also works in dual band but its best performance has been obtained when optimised to work in single band mode. In this paper, a new feeding structure is applied in the patch antenna design to overcome undesirable features of the earlier multilayer feeding structures while maintaining their interesting features.To make the proposed antenna more efficient the optimization of the antenna design parameters have been done using HFSS’s optometric. For the proposed antenna one resonant frequency has been obtained at 6.03GHz, with Bandwidth of 167MHz and return loss of -33.82db. The characteristics of the designed structure are investigated by using FEM based electromagnetic solver.Keywords: bandwidth, retun loss, parasitic lines, microstrip antenna
Procedia PDF Downloads 4621280 Comparative Study of Electronic and Optical Properties of Ammonium and Potassium Dinitramide Salts through Ab-Initio Calculations
Authors: J. Prathap Kumar, G. Vaitheeswaran
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The present study investigates the role of ammonium and potassium ion in the electronic, bonding and optical properties of dinitramide salts due to their stability and non-toxic nature. A detailed analysis of bonding between NH₄ and K with dinitramide, optical transitions from the valence band to the conduction band, absorption spectra, refractive indices, reflectivity, loss function are reported. These materials are well known as oxidizers in solid rocket propellants. In the present work, we use full potential linear augmented plane wave (FP-LAPW) method which is implemented in the Wien2k package within the framework of density functional theory. The standard DFT functional local density approximation (LDA) and generalized gradient approximation (GGA) always underestimate the band gap by 30-40% due to the lack of derivative discontinuities of the exchange-correlation potential with respect to an occupation number. In order to get reliable results, one must use hybrid functional (HSE-PBE), GW calculations and Tran-Blaha modified Becke-Johnson (TB-mBJ) potential. It is very well known that hybrid functionals GW calculations are very expensive, the later methods are computationally cheap. The new developed TB-mBJ functionals use information kinetic energy density along with the charge density employed in DFT. The TB-mBJ functionals cannot be used for total energy calculations but instead yield very much improved band gap. The obtained electronic band gap at gamma point for both the ammonium dinitramide and potassium dinitramide are found to be 2.78 eV and 3.014 eV with GGA functional, respectively. After the inclusion of TB-mBJ, the band gap improved by 4.162 eV for potassium dinitramide and 4.378 eV for ammonium dinitramide. The nature of the band gap is direct in ADN and indirect in KDN. The optical constants such as dielectric constant, absorption, and refractive indices, birefringence values are presented. Overall as there are no experimental studies we present the improved band gap with TB-mBJ functional following with optical properties.Keywords: ammonium dinitramide, potassium dinitramide, DFT, propellants
Procedia PDF Downloads 1571279 A Novel Design of Inset Feed Patch Antenna for Ultra Wide Band Application
Authors: Priyanka Aggarwal, Priyanka Mangla
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This work has focused on the aspect of UWB antenna design, which is very suitable for portable UWB applications. The design of new UWB antenna faces some challenges. The antenna should be compact, preferably conformal, and low cost for manufacture, and have good electrical performance, such as good matching, directional radiation performance over a wide band, good time response, etc. Keeping these goals in mind a compact and directional compact open-slot antenna was built. The antenna radiating structure is in the form of two exponentially tapered arms that lie on the opposite sides of the substrate. The antenna operates over the frequency band from 2.95 GHz to more than 12.1 GHz. It exhibits a directive radiation performance with a peak gain which is between 5.4 dBi and 8.3 dBi in the specified band. The antenna has linear phase response over the entire UWB frequency range and hence constant group delay which is vital for transmission and reception of sub-nanosecond pulses. Due to its planar profile, physically compact size, wide impedance bandwidth, directive performance over a wide bandwidth proposed antenna is a good candidate for portable UWB applications and other UWB integrated circuits.Keywords: inset feed patch antenna, ultra wide band, radiation performance, geometry, antenna
Procedia PDF Downloads 4371278 Sunshine Hour as a Factor to Maintain the Circadian Rhythm of Heart Rate: Analysis of Ambulatory ECG and Weather Big Data
Authors: Emi Yuda, Yutaka Yoshida, Junichiro Hayano
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Distinct circadian rhythm of activity, i.e., high activity during the day and deep rest at night are a typical feature of a healthy lifestyle. Exposure to the skylight is thought to be an important factor to increase arousal level and maintain normal circadian rhythm. To examine whether sunshine hours influence the day-night contract of activity, we analyzed the relationship between 24-hour heart rate (HR) and weather data of the recording day. We analyzed data in 36,500 males and 49,854 females of Allostatic State Mapping by Ambulatory ECG Repository (ALLSTAR) database in Japan. Median (IQR) sunshine duration was 5.3 (2.8-7.9) hr. While sunshine hours had only modest effects of increasing 24-hour average HR in either gender (P=0.0282 and 0.0248 for male and female) and no significant effects on nighttime HR in either gender, it increased daytime HR (P = 0.0007 and 0.0015) and day-night HF difference in both genders (P < 0.0001 for both) even after adjusting for the effects of average temperature, atmospheric pressure, and humidity. Our observations support for the hypothesis that longer sunshine hours enhance circadian rhythm of activity.Keywords: big data, circadian rhythm, heart rate, sunshine
Procedia PDF Downloads 1621277 Investigation of a Novel Dual Band Microstrip/Waveguide Hybrid Antenna Element
Authors: Raoudane Bouziyan, Kawser Mohammad Tawhid
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Microstrip antennas are low in profile, light in weight, conformable in structure and are now developed for many applications. The main difficulty of the microstrip antenna is its narrow bandwidth. Several modern applications like satellite communications, remote sensing, and multi-function radar systems will find it useful if there is dual-band antenna operating from a single aperture. Some applications require covering both transmitting and receiving frequency bands which are spaced apart. Providing multiple antennas to handle multiple frequencies and polarizations becomes especially difficult if the available space is limited as with airborne platforms and submarine periscopes. Dual band operation can be realized from a single feed using slot loaded or stacked microstrip antenna or two separately fed antennas sharing a common aperture. The former design, when used in arrays, has certain limitations like complicated beam forming or diplexing network and difficulty to realize good radiation patterns at both the bands. The second technique provides more flexibility with separate feed system as beams in each frequency band can be controlled independently. Another desirable feature of a dual band antenna is easy adjustability of upper and lower frequency bands. This thesis presents investigation of a new dual-band antenna, which is a hybrid of microstrip and waveguide radiating elements. The low band radiator is a Shorted Annular Ring (SAR) microstrip antenna and the high band radiator is an aperture antenna. The hybrid antenna is realized by forming a waveguide radiator in the shorted region of the SAR microstrip antenna. It is shown that the upper to lower frequency ratio can be controlled by the proper choice of various dimensions and dielectric material. Operation in both linear and circular polarization is possible in either band. Moreover, both broadside and conical beams can be generated in either band from this antenna element. Finite Element Method based software, HFSS and Method of Moments based software, FEKO were employed to perform parametric studies of the proposed dual-band antenna. The antenna was not tested physically. Therefore, in most cases, both HFSS and FEKO were employed to corroborate the simulation results.Keywords: FEKO, HFSS, dual band, shorted annular ring patch
Procedia PDF Downloads 4021276 The Design and Analysis of a Novel Type High Gain Microstrip Patch Antenna System for the Satellite Communication
Authors: Shahid M. Ali, Zakiullah
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An individual feed, smooth and smart, completely new shaped, dual band microstrip patch antenna has been proposed in this manuscript. Right here three triangular shape slots are usually presented in the 3 edges on the patch and along with a small feed line has utilized another edge on the patch to find out the dual band. The antenna carries a condensed framework wherever patch is around about 8.5mm by means of 7.96mm by means of 1.905mm leading to excellent bandwidths covering 13. 15 GHz to 13. 72 GHz in addition to 16.04 GHz to 16.58GHz. The return loss(RL) decrease in -19. 00dB and will be attained in the first resonant frequency at 13. 61 GHz and -28.69dB is at second resonance frequency at 16.33GHz. The stable average peak gain that may be observed along the operating band in lower and higher frequency is actually three. 53dB in addition to 5.562dB correspondingly. The radiation designs usually are omni directional along with moderate gain within equally most of these functioning bands. Accomplishment is proven within double frequencies at 13.62GHz since downlink in addition to 16.33GHz since uplink. This kind of low and simple configuration of the proposed antenna shows simplest fabrication and make it ensure that it is adaptable for your application within instant in satellite and as well as for the wireless communication system.Keywords: dual band, microstrip patch antenna, HFSS, Ku band, satellite
Procedia PDF Downloads 3611275 Shielding Effectiveness of Rice Husk and CNT Composites in X-Band Frequency
Authors: Y. S. Lee, F. Malek, E. M. Cheng, W. W. Liu, F. H. Wee, M. N. Iqbal, Z. Liyana, B. S. Yew, F. S. Abdullah
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This paper presents the electromagnetic interference (EMI) shielding effectiveness of rice husk and carbon nanotubes (RHCNTs) composites in the X-band region (8.2-12.4 GHz). The difference weight ratio of carbon nanotubes (CNTs) were mix with the rice husk. The rectangular wave guide technique was used to measure the complex permittivity of the RHCNTs composites materials. The complex permittivity is represented in terms of both the real and imaginary parts of permittivity in X-band frequency. The conductivity of RHCNTs shows increasing when the ratio of CNTs mixture increases. The composites materials were simulated using Computer Simulation Technology (CST) Microwave Studio simulation software. The shielding effectiveness of RHCNTs and pure rice husk was compared. The highest EMI SE of 30 dB is obtained for RHCNTs composites of 10 wt % CNTs with 10 mm thick.Keywords: EMI shielding effectiveness, carbon nanotube, composite materials wave guide, x-band
Procedia PDF Downloads 4091274 Coherent Ku-Band Radar for Monitoring Ocean Waves
Authors: Richard Mitchell, Robert Mitchell, Thai Duong, Kyungbin Bae, Daegon Kim, Youngsub Lee, Inho Kim, Inho Park, Hyungseok Lee
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Although X-band radar is commonly used to measure the properties of ocean waves, the use of a higher frequency has several advantages, such as increased backscatter coefficient, better Doppler sensitivity, lower power, and a smaller package. A low-power Ku-band radar system was developed to demonstrate these advantages. It is fully coherent, and it interleaves short and long pulses to achieve a transmit duty ratio of 25%, which makes the best use of solid-state amplifiers. The range scales are 2 km, 4 km, and 8 km. The minimum range is 100 m, 200 m, and 400 m for the three range scales, and the range resolution is 4 m, 8 m, and 16 m for the three range scales. Measurements of the significant wave height, wavelength, wave period, and wave direction have been made using traditional 3D-FFT methods. Radar and ultrasonic sensor results collected over an extended period of time at a coastal site in South Korea are presented.Keywords: measurement of ocean wave parameters, Ku-band radar, coherent radar, compact radar
Procedia PDF Downloads 1691273 Many-Body Effect on Optical Gain of n+ Doping Tensile-Strained Ge/GeSiSn Quantum Wells
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The many-body effect on band structure and optical gain of n+ doping tensile-strained Ge/GeSiSn quantum wells are investigated by using an 8-band k•p method. Phase diagram of Ge/GeSiSn quantum well is obtained. The E-k dispersion curves, band gap renormalization and optical gain spectra including many-body effect will be calculated and discussed. We find that the k.p method without many-body effect will overestimate the optical gain and transition energy.Keywords: Si photonics, many-body effect, optical gain, Ge-on-Si, Quantum well
Procedia PDF Downloads 7341272 Physicochemical and Optical Characterization of Rutile TiO2 Thin Films Grown by APCVD Technique
Authors: Dalila Hocine, Mohammed Said Belkaid, Abderahmane Moussi
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In this study, pure rutile TiO2 thin films were directly synthesized on silicon substrates by Atmospheric Pressure Chemical Vapor Deposition technique (APCVD) using TiCl4 as precursor. We studied the physicochemical properties and the optical properties of the produced coatings by means of standard characterization techniques of Fourier Transform Infrared Spectroscopy (FTIR) combined with UV-Vis Reflectance Spectrophotometry. The absorption peaks at 423 cm-1 and 610 cm-1 were observed for the rutile TiO2 thin films, by FTIR measurements. The absorption peak at 739 cm-1 due to the vibration of the Ti-O bonds, was also detected. UV-Vis Reflectance Spectrophotometry is employed for measuring the optical band gap from the measurements of the TiO2 films reflectance. The optical band gap was then extracted from the reflectance data for the TiO2 sample. It was estimated to be 3.05 eV which agrees with the band gap of commercial rutile TiO2 sample.Keywords: titanium dioxide, physicochemical properties, APCVD, FTIR, band gap
Procedia PDF Downloads 3961271 Some Fundamental Physical Properties of BiGaO₃ Cubic Perovskite
Authors: B. Gueridi, T. Chihi, M. Fatmi, A. Faci
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Some fundamental physical properties of BiGaO₃ were investigated under pressure and temperature effect using generalized gradient approximation and local density approximation approaches. The effect of orientation on Debye temperature and sound waves velocities were estimated from elastic constants. The value of the bulk modulus of BiGaO₃ is a sign of its high hardness because it is linked to an isotropic deformation. BiGaO₃ is a semiconductor and ductile material with covalent bonding (Ga–O), and the Bi-O bonding is ionic. The optical transitions were observed when electrons pass from the top of the valence band (O-2p) to the bottom of the conduction band (Ga-4p or Bi-6p). The thermodynamic parameters are determined in temperature and pressure ranging from 0 to 1800 K and 0 to 50 GPa.Keywords: BiGaO₃ perovskite, optical absorption, first principle, band structure
Procedia PDF Downloads 1271270 Effect of Manganese Doping Percentage on Optical Band Gap and Conductivity of Copper Sulphide Nano-Films Prepared by Electrodeposition Method
Authors: P. C. Okafor, A. J. Ekpunobi
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Mn doped copper sulphide (CuS:Mn) nano-films were deposited on indiums coated tin oxide (ITO) glass substrates using electrodeposition method. Electrodeposition was carried out using bath of PH = 3 at room temperature. Other depositions parameters such as deposition time (DT) are kept constant while Mn doping was varied from 3% to 23%. Absorption spectra of CuS:Mn films was obtained by using JENWAY 6405 UV-VIS -spectrophotometer. Optical band gap (E_g ), optical conductivity (σo) and electrical conductivity (σe) of CuS:Mn films were determined using absorption spectra and appropriate formula. The effect of Mn doping % on these properties were investigated. Results show that film thickness (t) for the 13.27 nm to 18.49 nm; absorption coefficient (α) from 0.90 x 1011 to 1.50 x 1011 optical band gap from 2.29eV to 2.35 eV; optical conductivity from 1.70 x 1013 and electrical conductivity from 160 millions to 154 millions. Possible applications of such films for solar cells fabrication and optoelectronic devices applications were also discussed.Keywords: copper sulphide (CuS), Manganese (Mn) doping, electrodeposition, optical band gap, optical conductivity, electrical conductivity
Procedia PDF Downloads 7221269 An Investigation into the Isolation and Bandwidth Characteristics of X-Band Chireix Power Amplifier Combiners
Authors: Daniel P. Clayton, Edward A. Ball
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This paper describes an investigation into the isolation characteristics and bandwidth performance of RF combiners that are used as part of Chireix PA architectures, designed for use in the X-Band range of frequencies. Combiner designs investigated are the typical Chireix and Wilkinson configurations which also include simulation of the Wilkinson using manufacturer’s data for the isolation resistor. Another simulation was the less common approach of using a Branchline coupler to form the combiner, as well as simulation results from adding an additional stage. This paper presents the findings of this investigation and compares the bandwidth performance and isolation characteristics to determine suitability.Keywords: bandwidth, Chireix, couplers, outphasing, power amplifiers, Wilkinson, X-Band
Procedia PDF Downloads 2571268 Low Profile Wide-Band Broad Side RMSA Suitable for On-Board Applications
Authors: Qaisar Fraz, H. M. Jafar, Mojeeb Bin Ihsan
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This paper presents simulation and experimen-tal results for wide band U-shaped side slots loaded linearly polarized rectangular microstrip antenna with broad side radiation characteristics suitable for onboard applications. The structure has been evolved in rugged and compact form to make it suitable for on-board applications. In addition to U-shaped central slot, pair of parallel narrow slots has been embedded close to non-radiating edges. The size and shape of these side slots have been optimized to improve the matching at upper frequency of the band. The impedance bandwidth of 34.8% as compared to 2-5% bandwidth of conventional microstrip antenna has been achieved. The frequency ratio of the two well-matched operating sections is found to be f2 / f1=1.33. The experimental results are in good agreement with the numerical results.Keywords: low profile antennas, u-slot antennas, broad band antennas, broad-side radiation pattern, high gain antennas
Procedia PDF Downloads 3701267 Miniaturized Wideband Single-Feed Shorted-Edge Stacked Patch Antenna for C-Band Applications
Authors: Abdelheq Boukarkar, Omar Guermoua
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In this paper, we propose a miniaturized and wideband patch antenna for C-band applications. The antenna miniaturization is obtained by loading shorting vias along one patch edge. At the same time, the wideband performance is achieved by combining two resonances using one feed line. The measured results reveal that the antenna covers the frequency band 4.32 GHz to 6.52 GHz (41%) with a peak gain and a peak efficiency of 5.5 dBi and 87%, respectively. The antenna occupies a relatively small size of only 26 x 22 x 5.6 mm3, making it suitable for compact wireless devices requiring a stable unidirectional gain over a wide frequency range.Keywords: miniaturized antennas, patch antennas, stable gain, wideband antennas
Procedia PDF Downloads 2171266 A Fast Convergence Subband BSS Structure
Authors: Salah Al-Din I. Badran, Samad Ahmadi, Ismail Shahin
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A blind source separation method is proposed; in this method we use a non-uniform filter bank and a novel normalisation. This method provides a reduced computational complexity and increased convergence speed comparing to the full-band algorithm. Recently, adaptive sub-band scheme has been recommended to solve two problems: reduction of computational complexity and increase the convergence speed of the adaptive algorithm for correlated input signals. In this work the reduction in computational complexity is achieved with the use of adaptive filters of orders less than the full-band adaptive filters, which operate at a sampling rate lower than the sampling rate of the input signal. The decomposed signals by analysis bank filter are less correlated in each sub-band than the input signal at full bandwidth, and can promote better rates of convergence.Keywords: blind source separation, computational complexity, subband, convergence speed, mixture
Procedia PDF Downloads 5551265 First and Second Order Gm-C Filters
Authors: Rana Mahmoud
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This study represents a systematic study of the Operational Transconductance Amplifiers capacitance (OTA-C) filters or as it is often called Gm-C filters. OTA-C filters have been paid a great attention for the last decades. As Gm-C filters operate in an open loop topology, this makes them flexible to perform in low and high frequencies. As such, Gm-C filters can be used in various wireless communication applications. Another property of Gm-C filters is its electronic tunability, thus different filter frequency characteristics can be obtained without changing the inductance and resistance values. This can be achieved by an OTA (Operational Transconductance Amplifier) and a capacitor. By tuning the OTA transconductance, the cut-off frequency will be tuned and different frequency responses are achieved. Different high-order analog filters can be design using Gm-C filters including low pass, high pass and band pass filters. 1st and 2nd order low pass, high pass and band pass filters are presented in this paper.Keywords: Gm-C, filters, low-pass, high-pass, band-pass
Procedia PDF Downloads 1301264 Influence of Chemical Treatment on Elastic Properties of the Band Cotton Crepe 100%
Authors: Bachir Chemani, Rachid Halfaoui, Madani Maalem
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The manufacturing technology of band cotton is very delicate and depends to choice of certain parameters such as torsion of warp yarn. The fabric elasticity is achieved without the use of any elastic material, chemical expansion, artificial or synthetic and it’s capable of creating pressures useful for therapeutic treatments.Before use, the band is subjected to treatments of specific preparation for obtaining certain elasticity, however, during its treatment, there are some regression parameters. The dependence of manufacturing parameters on the quality of the chemical treatment was confirmed. The aim of this work is to improve the properties of the fabric through the development of manufacturing technology appropriately. Finally for the treatment of the strip pancake 100% cotton, a treatment method is recommended.Keywords: elastic, cotton, processing, torsion
Procedia PDF Downloads 3871263 Performance Analysis of VoIP Coders for Different Modulations Under Pervasive Environment
Authors: Jasbinder Singh, Harjit Pal Singh, S. A. Khan
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The work, in this paper, presents the comparison of encoded speech signals by different VoIP narrow-band and wide-band codecs for different modulation schemes. The simulation results indicate that codec has an impact on the speech quality and also effected by modulation schemes.Keywords: VoIP, coders, modulations, BER, MOS
Procedia PDF Downloads 5151262 An Approach For Evolving a Relaible Low Power Ultra Wide Band Transmitter with Capacitve Sensing
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This work aims for a tunable capacitor as a sensor which can vary the control voltage of a voltage control oscillator in a ultra wide band (UWB) transmitter. In this paper power consumption is concentrated. The reason for choosing a capacitive sensing is it give slow temperature drift, high sensitivity and robustness. Previous works report a resistive sensing in a voltage control oscillator (VCO) not aiming at power consumption. But this work aims for power consumption of a capacitive sensing in ultra wide band transmitter. The ultra wide band transmitter to be used is a direct modulation of pulses. The VCO which is the heart of pulse generator of UWB transmitter works on the principle of voltage to frequency conversion. The VCO has and odd number of inverter stages which works on the control voltage input this input is now from a variable capacitor and the buffer stages is reduced from the previous work to maintain the oscillating frequency. The VCO is also aimed to consume low power. Then the concentration in choosing a variable capacitor is aimed. A compact model of a capacitor with the transient characteristics is to be designed with a movable dielectric and multi metal membranes. Previous modeling of the capacitor transient characteristics is with a movable membrane and a fixed membrane. This work aims at a membrane with a wide tuning suitable for ultra wide band transmitter.This is used in this work because a capacitive in a ultra wide transmitter need to be tuned in such a way that all satisfies FCC regulations.Keywords: capacitive sensing, ultra wide band transmitter, voltage control oscillator, FCC regulation
Procedia PDF Downloads 3911261 Electronic and Optical Properties of Orthorhombic NdMnO3 with the Modified Becke-Johnson Potential
Authors: B. Bouadjemi, S. Bentata, T. Lantri, A. Abbad, W. Benstaali, A. Zitouni, S. Cherid
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We investigate the electronic structure, magnetic and optical properties of the orthorhombic NdMnO3 through density-functional-theory (DFT) calculations using both generalized gradient approximation GGA and GGA+U approaches, the exchange and correlation effects are taken into account by an orbital independent modified Becke Johnson (MBJ). The predicted band gaps using the MBJ exchange approximation show a significant improvement over previous theoretical work with the common GGA and GGA+U very closer to the experimental results. Band gap dependent optical parameters like dielectric constant, index of refraction, absorption coefficient, reflectivity and conductivity are calculated and analyzed. We find that when using MBJ we have obtained better results for band gap of NdMnO3 than in the case of GGA and GGA+U. The values of band gap founded in this work by MBJ are in a very good agreement with corresponding experimental values compared to other calculations. This comprehensive theoretical study of the optoelectronic properties predicts that this material can be effectively used in optical devices.Keywords: DFT, optical properties, absorption coefficient, strong correlation, MBJ, orthorhombic NdMnO3, optoelectronic
Procedia PDF Downloads 9091260 Combline Cavity Bandpass Filter Design and Implementation Using EM Simulation Tool
Authors: Taha Ahmed Özbey, Sedat Nazlıbilek, Alparslan Çağrı Yapıcı
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Combline cavity filters have gained significant attention in recent years due to their exceptional narrowband characteristics, high unloaded Q, remarkable out-of-band rejection, and versatile post-manufacturing tuning capabilities. These filters play a vital role in various wireless communication systems, radar applications, and other advanced technologies where stringent frequency selectivity and superior performance are required. This paper represents combined cavity filter design and implementation by coupling matrix synthesis. Limited filter length, 50 dB out-of-band rejection, and agile design were aimed. To do so, CAD tools and intuitive methods were used.Keywords: cavity, band pass filter, cavity combline filter, coupling matrix synthesis
Procedia PDF Downloads 721259 Interesting Behavior of Non-Thermal Plasma Photonic Crystals
Authors: A. Mousavi, S. Sadegzadeh
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In this research, the effect of non-thermal micro plasma with non-Maxwellian distribution function on the one dimensional plasma photonic crystals containing alternate plasma-dielectric layers, has been studied. By using Kronig Penny model, the dispersion relation of electromagnetic modes for such a periodic structure is obtained. In this study we take two plasma photonic crystals with different dielectric layers: the first one with Silicon monoxide named PPCI, and the second one with Tellurium dioxide named PPCII. The effects of the plasma layer thickness and the material of the dielectric layer on the plasma photonic crystal band gaps have been illustrated in the dispersion relation and the group velocity figures. Results revealed that in such a system, the non-thermal plasma exerts stronger limit on the wave’s propagation. In another word, for the non-thermal plasma photonic crystals (NPPC), there are two distinct regions in the dispersion plot. The upper region consists of alternate band gaps in such a way that both width and length of the bands decrease gradually as the band gaps order increases. Whereas in the lower region where v_ph > 20 c (for PPCI), waves will not be allowed to propagate.Keywords: band gap, dispersion relation, non-thermal plasma, plasma photonic crystal
Procedia PDF Downloads 5391258 Flowering Response of a Red Pitaya Germplasm Collection to Lighting Addition
Authors: Dinh-Ha Tran, Chung-Ruey Yen, Yu-Kuang H. Chen
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A collection of thirty cultivars/clones of red pitaya was used to investigate flowering response to lighting supplementation in the winter season of 2013-2014 in southern Taiwan. The night-breaking treatment was conducted during the period of 10 Oct. 2013 to 5 Mar. 2014 with 4-continuous hours (22.00–02.00 hrs) of additional lighting daily using incandescent bulbs (100W). Among cultivars and clones tested, twenty-three genotypes, most belonging to the red-magenta flesh type, were found to have positive flowering response to the lighting treatment. The duration of night-breaking treatment for successful flowering initiation varied from 33 - 48 days. The lighting-sensitive genotypes bore 1-2 flowering flushes. Floral and fruiting stages took 21-26 and 46-59 days, respectively. Among sixteen fruiting genotypes, the highest fruit set rates were found in Damao 9, D4, D13, Chaozou large, Chaozhou 5, Small Nick and F22. Five cultivars and clones (Orejona, D4, Chaozhou large, Chaozhou 5, and Small Nick) produced fruits with an average weight of more than 300 g per fruit which was higher than those of the fruits formed in the summer of 2013. Fruits produced during off-season contain total soluble solids (TSS) from 17.5 to 20.7 oBrix, which was higher than those produced in-season.Keywords: flowering response, long-day plant, night-breaking treatment, off-season production, pitaya
Procedia PDF Downloads 3021257 Half Mode Substrate Integrated Wave Guide of Band Pass Filter Based to Defected Ground Structure Cells
Authors: Damou Mehdi, Nouri Keltoum, Feham Mohammed, Khazini Mohammed, Bouazza Tayb Habibi Chawki
Abstract:
The Half mode SIW filter is treated by two softwares (HFSS (High Frequency Structure Simulator) and CST (Computer Simulation Technology)). The filter HMSIW has a very simple structure and a very compact size. The simulated results by CST are presented and compared with the results simulated by a high-frequency structure simulator. Good agreement between the simulated CST and simulated results by HFSS is observed. By cascading two of them according to design requirement, a X-band bandpass filter is designed and simulated to meet compact size, low insertion loss, good return loss as well as second harmonic suppression. As an example, we designed the proposed HMSIW filter at X band by HFSS. The filter has a pass-band from 7.3 GHz to 9.8 GHz, and its relative operating fraction bandwidth is 29.5 %. There are one transmission zeros are located at 14.4 GHz.Keywords: substrate integrated waveguide, filter, HMSIW, defected ground structures (DGS), simulation BPF
Procedia PDF Downloads 5871256 Microstrip Bandpass Filter with Wide Stopband and High Out-of-Band Rejection Based on Inter-Digital Capacitor
Authors: Mohamad Farhat, Bal Virdee
Abstract:
This paper present a compact Microstrip Bandpass filter exhibiting a very wide stop band and high selectivity. The filter comprises of asymmetric resonator structures, which are interconnected by an inter-digital capacitor to enable the realization of a wide bandwidth with high rejection level. High selectivity is obtained by optimizing the parameters of the interdigital capacitor. The filter has high out-of-band rejection (> 30 dB), less than 0.6 dB of insertion-loss, up to 5.5 GHz spurii free, and about 18 dB of return-loss. Full-wave electromagnetic simulator ADSTM (Mom) is used to analyze and optimize the prototype bandpass filter. The proposed technique was verified practically to validate the design methodology. The experimental results of the prototype circuit are presented and a good agreement was obtained comparing with the simulation results. The dimensions of the proposed filter are 32 x 24 mm2.The filter’s characteristics and compact size make it suitable for wireless communication systems.Keywords: asymmetric resonator, bandpass filter, microstrip, spurious suppression, ultra-wide stop band
Procedia PDF Downloads 189