توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱An Optimized High Gain CMOS LNA using Simulated Annealing and Modified Genetic Algorithm
نویسنده(ها): ، ،
اطلاعات انتشار: نوزدهمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۶
This paper proposes two simulation–based evolutionary and statistical approaches for designing a 18 GHz Low Noise Amplifier (LNA) with using 0.13 μm technology. Based on genetic algorithm (GA), simulated annealing (SA), the Levenberg– Marquardt (LM), and circuit simulator, the simulation–based methods simultaneously optimize the electrical specifications, such as S–parameters, the noise figure, and the input–referred third–order intercept point in the process. In the designed LNA, the structure of one–stage cascode amplifier with source inductive degeneration is used. This LNA draws 12 mA from the 1.2V power supply. The LNA demonstrates 17.62 dB for S21 and 18.6 dB for MAG at the peak gain frequency of 17.49 GHz. The optimized simulation results show that the proposed LNA has a noise figure (NF) of 1.8 dB in the 17.49 GHz frequency. For large input signal level, P1dB, OIP3, and IIP3 are: –8 dBm, +23 dBm and +11 dBm, respectively<\div>

۲A Compact and Broadband Backward Coupler with High Coupling– Level Based on Composite Right\Left–Handed Transmission Line
نویسنده(ها): ، ،
اطلاعات انتشار: نوزدهمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۵
Based on composite right\left handed (CRLH) transmission lines (TLs) we propose a backward coupled–line coupler characterized by reduced size and enhanced bandwidth with respect to many other CRLH coupled–line couplers which have been introduced. This symmetric microstrip coupler with quadrature phase difference has also higher coupling–level and wider bandwidth than conventional coupled–line couplers. The proposed CRLH coupled–line coupler has been realized only by conventional TL and grounded stubs without series capacitor (e.g. interdigital capacitor). The design procedure to reach the coupler with predefined coupling–level and characteristic impedance of its ports is clearly presented. The design prototype is a 3–dB microstrip coupler with 0.2 mm spacing between coupled lines over a wide bandwidth of 60% from 2.2 GHz to 4.1 GHz (amplitude balance of 2 dB) centered at 3 GHz. The coupled–line length of the proposed structure is approximately λ g\4. To characterize this structure an equivalent circuit model also has been established. Good agreement between the full–wave simulation and equivalent circuit model has been achieved and the effectiveness of the proposed equivalent circuit model is verified.<\div>

۳A Compact Dual–Band Branch–Line Coupler Based on the Interdigital Transmission Line
اطلاعات انتشار: نوزدهمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۵
A dual–band (DB) microstrip branch–line coupler with quadrature phase difference based on the interdigital transmission line (TL) is presented. Interdigital TLs are realized by cascading interdigital capacitors (cells of the structure) in series. The design procedure to reach the dual–band interdigitaltransmission lines at two arbitrary frequencies is presented. Dual–band operation for branch–line coupler is achieved by implementing the interdigital TLs with 3 cells in each branch to provide a phase of – 900 at the lower operation frequency band (2GHz) and – 2700 phase shift at the upper frequency band(3GHz). Branches length is approximately g λ 0.8 and as compared to the conventional DB composite right\left handed (CRLH) branch–line couplers, the proposed structure achievessmaller dimension. Also, simulation results show that the dualband proposed coupler exhibits an amplitude balance of ±2 dBfrom 1.9 GHz to 2.2 GHz in the lower band and from 2.8 GHz to 3.2 GHz in the upper band. Moreover, at mentioned frequency bands, the phase difference between the coupled and through ports is 900 ±100<\div>

۴A Comprehensive Evaluation of Crosstalk Noise in Partially Coupled Nano Scale VLSI Interconnects
نویسنده(ها): ، ،
اطلاعات انتشار: نوزدهمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۶
Interconnects' crosstalk plays a key role in ultra dense nano scale VLSI circuits because of its multi dimensional impact on overall reliability and performance of ICs. Many researches have been conducted to evaluate the crosstalk and derive expressions for the analysis. This paper presents evaluation of the crosstalk in a different structure utilizing both rigorous simulations and analytical formulations. In the partially coupled interconnects structure, considered in this work, the crosstalk effects are investigated while the position and coupled length of the interconnect wires (aggressor and victim) are varied. We show that in all the cases where the victim line stay behind the aggressor line, the crosstalk is larger than the opposite cases for which the victim line is placed ahead of the aggressor line. Consequently, for a structure of relevant parameters, the crosstalk can be reduced up to 92% compared to the interconnect system of the opposite structure<\div>

۵Filtering Structure CMOS Distributed Amplifier with Extended Flat Bandwidth and Improved Input Matching Using Coupling Inductors in The Gate Line
اطلاعات انتشار: بیستمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۵
In this paper, we present a design method of bandwidth enhancement for Distributed Amplifiers (DAs), by using filter structures. Instead of using classical constantksection in conventional DA we use both Chebyshev and Butterworth filters in both transmission lines in order to form respectively the gate and drain transmission lines ofthe new DA. In order to improve the bandwidth, the filter structure and series–peaking inductor are used. Thecomplete designed circuit was implemented in TSMC 0.13μm CMOS technology. The simulated results provide 15dB as gain, the bandwidth is 14GHz. The input\outputreturn loss is –10dB, the IIP3 is 5.66 dBm at 6.7 GHz<\div>

۶A Wideband Low–Noise Downconversion Mixer with Positive–Negative Feedbacks
نویسنده(ها): ، ،
اطلاعات انتشار: بیستمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۵
This paper presents a wideband low–noise mixer in CMOS 0.13–um technology that operates between 2–10.5 GHz. The mixer has a Gilbert cell configuration that employsbroadband low–noise transconductors designed using the negative–positive feedback technique used in low–noise amplifierdesigns. This method allows broadband input matching. The current–bleeding technique is also used so that a high conversion gain can be achieved. Simulation results show excellent noise andgain performance across the frequency span with an average double–sideband noise figure of 2.9 dB and a conversion gain of15.5 dB. It has a third–order intermodulation intercept point of – 8.7 dBm at 5 GHz<\div>

۷An Adaptive Beltrami Detail Preserving Filter for Image De–noising
نویسنده(ها): ، ،
اطلاعات انتشار: بیستمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۵
Short time Beltrami kernel is a well known method for image de–noising using diffusion on image manifold. In this paper we propose an adaptive short time Beltrami. In theproposed method we adapt two effective parameters in Beltrami algorithm according to local variance of image. To evaluate the performance of the proposed method, several comparative experiments are performed. The obtained results confirm the efficiency of the proposed method<\div>

۸An Adaptive Short Time Beltrami Kernel forImage De–noising
نویسنده(ها): ، ،
اطلاعات انتشار: هفتمین کنفرانس ماشین بینایی و پردازش تصویر، سال
تعداد صفحات: ۵
Short time Beltrami kernel is a well known method forimage de–noising using diffusion on image manifold. In thispaper we propose an adaptive short time Beltrami. In theproposed method we adapt an effective parameter in Beltramialgorithm according to local variance of image. To evaluate theperformance of the proposed method, several comparativeexperiments are performed. The obtained results confirm theefficiency of the proposed method.<\div>

۹A New Robust Harmonic Balance Calculation Method Based On Feedback Control Loop
اطلاعات انتشار: کنگره ملی مهندسی برق، کامپیوتر و فناوری اطلاعات، سال
تعداد صفحات: ۵
Numerical solution of non–linear circuits excited by a periodic input involved in electronics and communications is one of the most popular usages of applied mathematics inengineering. The classic method for solving problems of that type is The Harmonic Balance Method. This method separatesthe circuit into linear and non–linear parts that are connected to each other in some nodes. Whenever nodal KVL and KCL equations are satisfied in those nodes in some desiredfrequencies, the solution is achieved. In this paper a new reformation of harmonic balance method is introduced basedon the idea of feedback control–loop. The proposed method has an obviously better stability and robust performance under different variations of circuit parameters while its convergence rate is almost the same in various situations.<\div>

۱۰Design of broadband high–gain cascaded multi–stage distributed amplifier using coupled inductors in 0.13 mm technology
اطلاعات انتشار: اولین کنفرانس سراسری توسعه محوری مهندسی عمران، معماری، برق و مکانیک ایران، سال
تعداد صفحات: ۴
Broadband amplifiers are significant components which are utilized in electronic warfare, high–speed communication, and wideband Instrumentation systems[1]. William S. Percival is presented one of the first examples of distributed circuit design in 1936. In that time Percival present a design with the transconductanceof single vacuum tubes. Therefore approach at a circuit that attained a gain–bandwidth product greater than that of a single tube. Distributed circuits are very common in the microwave. Besides, these circuits have another applications like distributed oscillators [2], distributedmixers [3] and power splitter and combiner [4] on compound semiconductor technology such as GaAs or InP. CMOS implementation of distributed circuits hasnewly gained more interest because it's lower cost and good performance [5] and higher level integration. Deepsubmicron CMOS technology prepares the high–speed active devices together with on–chip passive elements needed for implementation of the wideband amplifiers[6]. CMOS distributed amplifiers (DA) with highly large bandwidths about several tens of gigahertz in [7], [8], [9],[10] have been reported. Nevertheless, the DAs that mentioned above present comparatively not high gains. A four–stage DA using waveguide design was informed in[7] has a bandwidth about 27 GHz and a gain nearby 6 dB. A capacitive division technique was employed in [8] to obtain a bandwidth as important as 80 GHz, besides a7.4 dB gain was attained that is not high because of low voltage in the input of amplifier stages. Two four–stageDAs with either body–contacted (BC) or floating–body (FB) MOSFETs were reported in [9], they presented 7.1 dB and 5.4 dB gains, respectively, and unity–gain bandwidth (UGB) of 27 and 23 GHz, respectively. Negative resistor techniques were used in an eight–stage DA to obtain a 44 GHz high bandwidth and a gain as lowas 10 dB was reported in [10], because the extra capacitors created restricts the size of transistors more. Inthis paper, we use operative techniques to achieve high gain and extension bandwidth.<\div>

۱۱A Novel Architecture for Low Noise Amplifier in 0.13μm CMOS Technology
اطلاعات انتشار: اولین کنفرانس سراسری توسعه محوری مهندسی عمران، معماری، برق و مکانیک ایران، سال
تعداد صفحات: ۵
In this paper, the new architecture of high gain and low power broadband low noise amplifier (LNA) is proposed, that has two non–uniform stages. In order toachieve high power gain (S21) and low power consumption, a current reused with resistive feedback based on an inverter–type amplifier is used in the firststage. By employing resistive feedback and inductor, wideband input matching is achievable. A self biased common source amplifier which its drain engages twoshunt peaking inductors are used in the second stage. The second stage of this circuitis used to increase thebandwidth and power gain. Simulation results show thatthe proposed LNA achieves a power gain between 15.6~16.7 dB. Also the input return loss (S11) andoutput return loss (S22) better than 10dB. The noise figure (NF) of the proposed LNA is between 2.3~3.7 dB and reverse gain (S12) below –32 dB for 1~12 GHzfrequencies. The input referred third–order intercept point (IIP3) and power consumption of this LNA are –8.5 dBm and 7.99 mw respectively<\div>

۱۲A Wide–Band Optimized Distributed Amplifier in 0.13 –μm CMOS Technology
نویسنده(ها): ،
اطلاعات انتشار: اولین کنفرانس سراسری توسعه محوری مهندسی عمران، معماری، برق و مکانیک ایران، سال
تعداد صفحات: ۷
A 1–25 GHz performance–optimized CMOS distributed amplifier (DA) comprising bandwidth–enhanced cascade cells demonstrated. In this study instead of single resistance, an RL terminating network is used for the gate termination line in order to decrease noise figure (NF).Besides, Deploying the bandwidth extension capacitor, Optimization in cascade gain cells ,utilization of bulk–biasing technique, optimization of transistors width and usages of negative–capacitors leads to a flat and high<\div>

۱۳A Low–Noise 15GHz Divide–by–3 Colpitts Injection Locked Frequency Divider
نویسنده(ها): ،
اطلاعات انتشار: هفتمین کنفرانس ملی مهندسی برق و الکترونیک ایران، سال
تعداد صفحات: ۴
A new LC–injection–locked frequency divider (LC A new LC–injection–locked frequency divider (LCILFD) based on voltage controlled oscillator is proposed. The proposed circuit is realized with two current–switching Colpitts CMOS LC–tank oscillator in which no extra elements are usedfor injecting. At the supply voltage of 1.5 v, the locking range of the proposed divider is from 14.15 to 15.95 GHz. The proposed circuit was designed using a 0.18 μm RF CMOS technology and simulation results are presented.<\div>

۱۴An Ultra–broadband and Low Noise distributed Drain Mixer with Filtering Structure
نویسنده(ها): ،
اطلاعات انتشار: Majlesi Journal of Telecommunication Devices، سوم،شماره۳، Sep ۲۰۱۴، سال
تعداد صفحات: ۴
This paper presents a 6 to 64 GHz passive distributed drain mixer implemented by using a standard 0.13 um CMOS process. To improve the bandwidth, low conversion loss and low noise figure, filtering structures is utilized for wideband matching. Both Chebyshev and Butterworth filters are used instead of the classical constant–k sections of the conventional DA in order to form respectively the gate and drain transmission lines. This mixer consumes zero dc power and exhibits a conversion loss of 4.9–7.9 dB and noise figure (DSB) of 6.8–8.1 dB from 6 to 64 GHz.

۱۵Gain Enhancement and Noise Figure Improvement of Low Noise Amplifiers in 0.13 µm CMOS Technology for UWB Applications
اطلاعات انتشار: Majlesi Journal of Telecommunication Devices، پنجم،شماره۲، Jun ۲۰۱۶، سال
تعداد صفحات: ۶
A novel CMOS wideband low–noise amplifier (LNA) with a new architecture of high gain, low NF and low power–consumption is proposed. This architecture consists of two non–uniform stages. In order to achieve high power gain (S21) and low power consumption, a current reused with resistive feedback based on an inverter–type amplifier is utilized at the first stage. The second stage of this circuit is used to increase the bandwidth and power gain. Simulation results show that the proposed LNA achieves a power gain between 19±.3 dB. The input return loss (s11) and output return loss (s22) are better than –10 dB. The noise figure (NF) of the proposed LNA is between 2~3.6 dB and reverse gain (S12) is below –30 dB for 3.1~10.6 GHz bandwidth. The input third–order intercept point (IIP3) and power consumption of the proposed LNA are –5 dBm and 13.6 mW, respectively.

۱۶A Chaos–Based Video Watermarking Algorithm
نویسنده(ها): ،
اطلاعات انتشار: International Journal of Information Security، چهارم،شماره۱، Jan ۲۰۱۲، سال
تعداد صفحات: ۱۰
The intriguing characteristics of chaotic maps have prompted researchers to use these sequences in watermarking systems to good effect. In this paper we aim to use a tent map to encrypt the binary logo to achieve a like–noise signal. This approach makes extraction of the watermark signal by potential attacker very hard. Embedding locations are selected based on certain principles. Experimental results demonstrate that our proposed watermarking method is highly superior to other techniques reported in literature and readily achieves the desired robustness and security level.

۱۷A Wideband Low–Noise Downconversion Mixerwith Positive–Negative Feedbacks
نویسنده(ها): ،
اطلاعات انتشار: Journal of Information Systems and Telecommunication، اول،شماره۲، Apr– Jun ۲۰۱۳، سال
تعداد صفحات: ۸
This paper presents a wideband low–noise mixer in CMOS 0.13–um technology that operates between 2–10.5 GHz. The mixer has a Gilbert cell configuration that employs broadband low–noise trans conductors designed using the negative–positive feedback technique used in low–noise amplifier designs. This method allows broadband input matching. The current–bleeding technique is also used so that a high conversion gain can be achieved. Simulation results show excellent noise and gain performance across the frequency span with an average double–sideband noise figure of 2.9 dB and a conversion gain of 15.5 dB. It has a third–order intermodulation intercept point of –8.7 dBm at 5 GHz.

۱۸An Ultra–Wideband Common Gate LNA With Gm–Boosted And Noise Canceling Techniques
نویسنده(ها): ،
اطلاعات انتشار: Journal of Information Systems and Telecommunication، دوم،شماره۲(پياپي ۶)، Apr-Jun ۲۰۱۴، سال
تعداد صفحات: ۶
In this paper, an ultra–wideband (UWB) common gate low–noise amplifier (LNA) with gm boosted and noise–cancelling techniques is presented. In this scheme we utilize gm–boosted stage for cancelling the noise of matching device. The bandwidth extension and flat gain are achieved by using of series and shunt peaking techniques. Simulated in .13 um Cmos technology, the proposed LNA achieved 2.38–3.4dB NF and S11 less than –11dB in the 3.1–10.6 GHz band. Maximum power gain (S21) is 11dB and –3dB bandwidth is 1 .25–11.33 GHz. The power consumption of LNA is 5.8mW.

۱۹A Novel Ultra–Broad Band, High Gain, and Low Noise Distributed Amplifier Using Modified Regulated Cascode Configuration (MRGC) Gain–Cell
نویسنده(ها): ،
اطلاعات انتشار: Journal of Information Systems and Telecommunication، چهارم،شماره۱(پياپي ۱۳)، Jan-Mar ۲۰۱۶، سال
تعداد صفحات: ۹
In this paper, an ultra–broad bandwidth, low noise, and high gain–flatness CMOS distributed amplifier (CMOS–DA) based on a novel gain–cell is presented. The new gain–cell that enhances the output impedance as a result the gain substantially over conventional RGC is the improved version of Regulated Cascode Configuration (RGC). The new gaincell based CMOS–DA is analyzed and simulated in the standard 0.13 μm–CMOS technology. The simulated results of the proposed CMOS–DA are included 14.2 dB average power gain with less than ± 0.5 dB fluctuations over the 3–dB bandwidth of 23 GHz while the simulated input and output return losses (S11 and S22) are less than –10 dB. The IIP3 and input referred 1–dB compression point are simulated at 15 GHz and achieved +8 dBm and –6.34 dBm, respectively. The average noise figure (NF) in the entire interest band has a low value of 3.65 dB, and the DC power dissipation is only 45.63 mW. The CMOS–DA is powered by 0.9 V supply voltage. Additionally, the effect of parameters variation on performance specifications of the proposed design is simulated by Monte Carlo simulations to ensure that the desired accuracy is yielded.

۲۰Two Novel Chaos–Based Algorithms for Image and Video Watermarking
نویسنده(ها): ، ،
اطلاعات انتشار: Iranian Journal of Electrical and Electronic Engineering، هشتم،شماره۲، Jun ۲۰۱۲ ، سال
تعداد صفحات: ۱۱
In this paper we introduce two innovative image and video watermarking algorithms. The paper’s main emphasis is on the use of chaotic maps to boost the algorithms’ security and resistance against attacks. By encrypting the watermark information in a one dimensional chaotic map, we make the extraction of watermark for potential attackers very hard. In another approach, we select embedding positions by a two dimensional chaotic map which enables us to satisfactorily distribute watermark information throughout the host signal. This prevents concentration of watermark data in a corner of the host signal which effectively saves it from being a target for attacks that include cropping of the signal. The simulation results demonstrate that the proposed schemes are quite resistant to many kinds of attacks which commonly threaten watermarking algorithms.
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