Article
Computer Science, Hardware & Architecture
Ali Mohammad Sanaei, Ali Biabanifard, Mohammad Saeed Khadem, Toktam Aghaee
Summary: An efficient frequency compensation method for a four-stage CMOS amplifier is investigated in this paper. The proposed compensation method, which uses lower capacitor values, leads to reduced die occupation and improved gain bandwidth products.
JOURNAL OF CIRCUITS SYSTEMS AND COMPUTERS
(2022)
Article
Engineering, Electrical & Electronic
Weihan Gao, Peng Gu, Dixian Zhao
Summary: This brief introduces a 5-bit switched-type attenuator (STA) that operates from DC to 87.8 GHz. The brief proposes a new II-type compensation method with a switched capacitor branch, which effectively reduces phase errors at high frequencies without compromising amplitude errors. The fabricated STA in 40-nm CMOS technology demonstrates a 15.5-dB attenuation range with a 0.5-dB tuning step.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2023)
Article
Engineering, Electrical & Electronic
Danial Roohbakhsh, AliMohammad Sanaee, Toktam Aghaee
Summary: In this work, a four-stage amplifier is investigated and frequency is compensated via a compensation network that includes two Miller capacitors at the outputs of differential blocks. According to the simulation results, the proposed approaches show superior performance compared with previously existing methods. Additionally, the proposed amplifier demonstrates less sensitivity to load and compensation capacitors, resulting in a stable frequency response. Such a high gain amplifier is in great demand for realizing modulators and data converters.
INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS
(2023)
Article
Automation & Control Systems
Sevda Mohammadi, Mohammad Hossein Zarifi
Summary: This article presents a differential ring-oscillator sensing platform for nanodroplet detection, which demonstrates sensitivity and small footprint.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Multidisciplinary
Prakash Chandra, Urvashi Bansal
Summary: This paper proposes a four-stage CMOS operational amplifier for driving a large capacitive load of 500 pF. The designed amplifier exhibits high stability and meets the required specifications. The unique compensation network utilized in this design, combining a negative capacitance generator (NCG) cell and a differential block with a compensation capacitor, effectively reduces parasitic capacitance and improves the gain bandwidth.
JOURNAL OF ENGINEERING RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Mahmood A. Mohammed, Gordon W. Roberts
Summary: This work introduces a multi-stage CMOS OTA design technique that allows for cascading identical gain stages and driving a wide range of capacitive loads. A new frequency compensation technique is proposed to enable the desired closed-loop behavior. Experimental results show that the proposed OTAs achieve significantly higher DC gain and CL-drivability compared to the state-of-the-art. These improvements make the proposed OTAs suitable for a wider range of applications.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2023)
Article
Multidisciplinary Sciences
Urvashi Bansal, Pankaj Masiwal, Monika Yadav, Mohit Mohlia, Niranjan Raj
Summary: This work introduces two new CMOS current mode squarer circuit designs and a four-quadrant multiplier. A resistive compensation scheme is used to improve bandwidth. The experimental results show that the proposed circuits exhibit good performance in terms of bandwidth, power consumption, and linearity error.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Electrical & Electronic
Mohammad Ali Bandari, Farbod Setoudeh, Mohammad Bagher Tavakoli, Massoud Dousti
Summary: This paper proposes an efficient three-stage amplifier with frequency compensation using a fully differential block. By enhancing the Miller effect, the size of compensation capacitors is reduced, and the differential block is shared to increase the operating frequency range. Simulation results demonstrate excellent performance and acceptable robustness against parameter mismatches and fabrication errors.
INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS
(2022)
Article
Engineering, Electrical & Electronic
Mahmood A. Mohammed, Gordon W. Roberts
Summary: The new theory demonstrates how to reduce the impact of Pole-Zero pairs on CMOS OTAs by using low-frequency zeros and cascaded-gain stages, revealing untapped opportunities for many-stage CMOS OTA design.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2021)
Article
Computer Science, Hardware & Architecture
Masoud Soltani Zanjani, Ali Biabanifard
Summary: This study utilizes two differential stages to form a frequency compensation network, enhancing Miller effect to improve frequency response. The proposed three-stage amplifier demonstrates good performance in DC gain, gain bandwidth, phase margin, and power consumption.
JOURNAL OF CIRCUITS SYSTEMS AND COMPUTERS
(2023)
Article
Computer Science, Interdisciplinary Applications
Mahdis Attar, Hadi Dehbovid, Alireza Ghorbani, Habib Adarang
Summary: This work proposes a four-stage CMOS operational amplifier that is frequency compensated via two differential blocks and two Miller capacitors. Unlike conventional approaches, the proposed compensation method uses extremely smaller capacitors but still maintains the output node. The simulation results demonstrate that the proposed amplifier is an excellent option for larger systems, with high DC-gain, unity gain frequency, and low power consumption.
ENGINEERING REPORTS
(2023)
Article
Engineering, Electrical & Electronic
Masoud Soltani Zanjani, Hassan Sadrnia, Ali Biabanifard
Summary: Nowadays, cascode structures or vertical arrangements of MOSFETs are unable to meet the demands for high gain amplifiers. Therefore, multi-stage amplifiers via cascading gain stages have become the only promising choice. The challenge lies in stability issues and frequency compensation. In this work, a new and efficient frequency compensation technique is proposed for a five-stage amplifier, with the major contribution being the use of only two Miller capacitors and two differential active stages to intensify the Miller effect and allow for simultaneous sharing of the Miller capacitor.
INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS
(2023)
Article
Computer Science, Hardware & Architecture
Behnam Babazadeh Daryan, Hassan Khalesi, Vahid Ghods
Summary: This work introduces an effective and direct frequency compensation scheme in CMOS three-stage amplifiers, with high DC gain and large GBW values. The circuit architecture is simple and requires only a single Miller capacitor for frequency compensation, making it suitable for high-speed modulators and data converters for faster operations.
JOURNAL OF CIRCUITS SYSTEMS AND COMPUTERS
(2022)
Article
Computer Science, Information Systems
Sheng-Lyang Jang, Wen-Cheng Lai, Ruei-Hung Lu
Summary: This paper designs a single-stage LC-tank injection locked frequency sixtupler (ILFS) which merges many sub-circuits in one by sharing a common supply and passive inductive elements. The circuit design, operation principle and measurement results of the ILFS are addressed. The locking range and output frequency of the ILFS are measured under different input power and frequency.
Article
Engineering, Electrical & Electronic
Mohammad Ali Bandari, Mohammad Bagher Tavakoli, Farbod Setoudeh, Massoud Dousti
Summary: This study proposes a new compensation technique for multistage amplifiers, which uses two differential stages to organize feedforward and feedback paths. The challenge of frequency compensation is addressed by driving five Miller loops and a 500-pF load capacitor with just two tiny compensating capacitors, each with a capacitance of less than 10 pF. The proposed five-stage amplifier is simulated using HSPICE and TSMC 0.18μm CMOS technology, and a straightforward iterative approach is used to optimize circuit parameters based on a known cost function. Simulation and mathematical results show that the proposed structure exhibits a DC gain of 190 dB, a gain bandwidth product of 15 MHz, a phase margin of 89 degrees, and a power dissipation of 590 μW.
Article
Computer Science, Hardware & Architecture
Hassan Khalesi, Vahid Ghods
JOURNAL OF CIRCUITS SYSTEMS AND COMPUTERS
(2019)
Article
Engineering, Electrical & Electronic
Hassan Khalesi, Abdolreza Nabavi, Sattar Mirzakouchaki
IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING
(2015)
Article
Computer Science, Artificial Intelligence
Fatemeh Naiemi, Vahid Ghods, Hassan Khalesi
Article
Computer Science, Hardware & Architecture
Behnam Babazadeh Daryan, Hassan Khalesi, Vahid Ghods, Alireza Izadbakhsh
ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING
(2020)
Article
Engineering, Mechanical
Payam Kheirkhahan, Alireza Izadbakhsh, Hassan Khalesi
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2020)
Article
Engineering, Electrical & Electronic
Tahereh Radsar, Hassan Khalesi, Vahid Ghods
JOURNAL OF COMPUTATIONAL ELECTRONICS
(2020)
Article
Engineering, Electrical & Electronic
Elham Khoobjou, Hassan Khalesi, Vahid Ghods
JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY
(2020)
Article
Chemistry, Physical
Tahereh Radsar, Hassan Khalesi, Vahid Ghods, Alireza Izadbakhsh
Summary: This paper investigates the effects of channel dimension reduction and source/drain contacts doping concentration increasing on the performance of graphene nanoribbon field effect transistors (GNRFET). It is found that these factors have different impacts on the ON-state and OFF-state currents, subthreshold swing, transconductance, drain induced barrier lowering, threshold voltage, and I(ON)/I(OFF) ratio of the GNRFET. Consideration of these effects is crucial for optimal design, fabrication, and selection of GNRFETs in various circuits and applications.
Article
Engineering, Electrical & Electronic
Elham Khoobjou, Hassan Khalesi, Vahid Ghods, Amir Esmaeili Abharian
Summary: A new structure utilizing metal nanoparticles for photonic crystal fibers is proposed to minimize dispersion and optical loss, with the number and location of nanoparticles optimized by PSO algorithm. By changing the shape, location, and type of nanoparticles, a structure with minimal dispersion and light loss is provided, leading to improved light transmission quality.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Telecommunications
Hassan Khalesi, Vahid Ghods
Summary: This study introduces a new IR-UWB signal to minimize interference with narrowband systems at a high usage 5.2 GHz frequency. By utilizing derivatives of Gaussian pulses and optimizing parameters with genetic algorithms, the signal achieves the desired spectrum characteristics. Simulations show that the proposed system not only reduces interference with narrowband systems, but also exhibits robustness against narrowband interference at 5.2 GHz frequency.
WIRELESS PERSONAL COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Tahereh Radsar, Hassan Khalesi, Vahid Ghods
Summary: The reduction in silicon-based device dimensions has led to significant advancements in electronic systems performance. Recent studies have explored the advantages and challenges of shrinking silicon devices, with many concluding that silicon technology is approaching its limits and new innovations are needed. Graphene emerges as a promising material for future nanoelectronics, offering unique properties and potential applications. This paper discusses various aspects of graphene, including production approaches, fundamental properties, defect types, application potentials, and electronic specifications of graphene nanoribbons. Simulation results indicate that properties such as band gap can be controlled by manipulating the width, defect, and doping concentration of graphene nanoribbons, making them suitable for graphene nanoribbon field effect transistors.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Review
Physics, Condensed Matter
Tahereh Radsar, Hassan Khalesi, Vahid Ghods
Summary: The downsizing of silicon-based transistors has led to significant advancements in the electronic industry, but also brought about limitations and challenges in transistor performance. In response to the near-end state of silicon technology, novel material innovations are required, with graphene emerging as a promising candidate for silicon channel replacement. Through research and simulation on graphene and graphene nanoribbons, it has been shown that graphene-based transistors are an excellent alternative to silicon-based transistors.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Engineering, Electrical & Electronic
Elham Khoobjou, Hassan Khalesi, Vahid Ghods
Summary: This paper introduces a new structure of photonic crystal fibers (PCFs) with large negative dispersion to offset positive dispersion at a wavelength of 1.55 μ m. Simulation results demonstrate a significant improvement with a minimum dispersion of -4593 ps/(nm.km) at this wavelength, compared to other similar references.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Computer Science, Hardware & Architecture
Behnam Babazadeh Daryan, Hassan Khalesi, Vahid Ghods
Summary: This work introduces an effective and direct frequency compensation scheme in CMOS three-stage amplifiers, with high DC gain and large GBW values. The circuit architecture is simple and requires only a single Miller capacitor for frequency compensation, making it suitable for high-speed modulators and data converters for faster operations.
JOURNAL OF CIRCUITS SYSTEMS AND COMPUTERS
(2022)
