A. Attaran

Recent Advances in Delay Cell VCOs [Application Notes]

In this article, a review of commonly used delay cell techniques in ring VCO design was covered. Design limitations such as area, power, jitter, and phase noise performance were compared for ring and LC VCOs. These parameters were compared for several delay cell topologies throughout the paper. The tunable and flexible bandwidth criterion combined with low-noise characteristics, low power, and small-area properties are the main concern of industrial engineers in design ing and choosing a proper resonator topology suitable for their respective applications. We described a num ber of the most common delay cell structures to make it easier for engineers to have a wider perspective on ring resonators.

Circuit Model of Fano Resonance on Tetramers, Pentamers, and Broken Symmetry Pentamers

This paper presents the representation circuit model for Fano resonance of plasmonic nanoparticles in the optical domain. An intuitive explanation is provided for the physical nature of Fano resonance based on the three-level quantum system, and the Fano resonance effects of three basic nanoparticle arrangements, namely tetramer, pentamer, and symmetry broke pentamer are discussed. A coupling capacitor is calculated as an equivalent component in the proposed circuit model in order to describe the coupling effect between subradiant and superradiant mode in the Fano resonance. The circuit impedances of tetramer, pentamer, and broken symmetry pentamer are simulated, with resultant circuit models in agreement with the calculated results based on S-parameters.

Performance Review of High-Quality-Factor, Low-Noise, and Wideband Radio-Frequency LC-VCO for Wireless Communication [Application Notes]

The rapid growth in the network-communication-system market has placed higher demands on radio-frequency (RF) transceivers. The voltage-controlled oscillator (VCO) is one of the most important building blocks of any communications system, and a high-performance VCO is critical to cover new requirements in communication systems such as required frequency bandwidth recommended by ITU-R, high phase noise performance, power consumption, die size and its cost.

A Compact Analytical Design of Dual-Loop 18 GHz Frequency Synthesizer to Enhance Signal Reliability in Digital Millimeter Radio Link System

Abstract In this paper a high resolution dual-loop 17.7–19.7 GHz frequency synthesizer is presented which is compatible with ITU-R (F.595-6) standards. The investigations of phase noise and spur frequency contents are discussed in detail. The simulated and measured phase noise and spur frequency contents are similar to one another. Phase noise of –81 dBc/Hz in 17.7 GHz at 10 KHz offset frequency is measured by (HP8560) series Spectrum analyzer and it matches with predicted measurements.

FGMOS-based NMC-RC frequency compensation differential amplifier for low power low voltage applications

This paper presents how to add flexibility to reduce the overall power consumption in a CMOS operational amplifier by replacing few MOS transistors with floating gate MOSFET (FGMOS). The disadvantages of doing this are also discussed. The performance of the proposed circuit using unity gain bandwidth (GBW) and slew rate (SR) as figure of merit is presented. The Nested Miller compensation (NMC) is used and the pole is positioned far away from first pole in frequency spectrum for frequency compensation resulting. The zero from RC network is also matched to the non-dominant pole at the left-side of the Nyquist plot of the loop to increase stability and control the bandwidth operation. The circuit operates with a voltage supply of 0.5V and has 26.7uW power consumption.

Planning of low-cost 77-GHz radar transceivers for automotive applications

The key to prevent driving accidents by automotive radar systems at high speed is to have optimum and accurate estimation of position representation and fast visualization of the environment.

EEG artifact signals tracking and filtering in real time for command control application

Brain machine interface (BMI) is a direct communication pathway between human’s brain and an external device. In some researches it is also called Brain-Computer interface (BCI). There are two types of motor BMIs: invasive and non-invasive. Research on non-invasive BMIs started in the 1980s by measuring brain electrical activity over the scalp electroencephalogram (EEG). In this paper, an attempt in made to present initial steps on a non-invasive BMI design based on pattern recognition algorithm method on EEG signals. These artifact signals are converted to command signals to control and steer an external object. The EEG signal is contaminated with numerous artifact signals which make the assembly of usable artifact signal very difficult. With help of MATLAB program, tracking and filtering of artifact signals in real time application is presented as well.