Design of a CMOS Differential Operational Transresistance Amplifier in 90 nm CMOS Technology

In this paper, a CMOS differential operational transresistance amplifier (OTRA) is presented. The amplifier is designed and implemented in a standard umc90-nm CMOS technology. The differential OTRA provides wider bandwidth at high gain. It also shows much better rise and fall time and exhibits a very good input current dynamic range of 50 to 50 μA. The OTRA can be used in many analog VLSI applications. The presented amplifier has high gain bandwidth product of 617.6 THz Ω. The total power dissipation of the presented amplifier is also very low and it is 0.21 mW

Sampled-Data Nonlinear Control of ECP-730 Magnetic Levitation System

This paper presents the idea of implementing various techniques related to sampled-data control for magnetic levitation systems. The control laws are designed to track time-varying signals and employ the feedback linearization technique based on the approximate discrete-time model. State feedback control is introduced with the gains adjusted via the pole placement method. A positional form proportional-integral-derivative (PID) control uses the trapezoidal summation for the integral term and the backward difference method for the derivative term. An input-output linearization feedback control is the most promising one, which incorporates the integrator in addition to the position error and velocity error. The integral action involves the manipulation of regulation error and reduces it with time to improve performance. Finally, controllers were tested in real time for practical demonstration along with a comparison for comprehensive analysis

Gain flattened S+C+L-band bidirectional thulium doped fiber/multi-section fiber optical parametric hybrid amplifier

This article demonstrates the achievement of optical amplification across the S, C, and L-bands. A hybrid amplifier is proposed that utilizes a combination of bidirectional thulium-doped fiber amplifier (TDFA) and multi-section fiber optical parametric amplifier. With careful selection of TDFA and parametric amplifier parameters, gain can be achieved over complementary bandwidth regions. Resultantly, better gain flatness is achieved over the whole effective bandwidth of 170 nm. The amplifier being proposed is evaluated for a system consisting of 18 wavelength division multiplexed channels, each with a capacity of 100 Gb/s, and a channel spacing of 10 nm. By setting the input power per channel to an optimal value of –30 dBm, the parameters are adjusted to attain a flat gain exceeding 23.52 dB, accompanied by a gain ripple of only 2.09 dB. These parameters are optimized over a wavelength range between 1460 nm and 1630 nm.Other Information Published in: Ain Shams Engineering Journal License: http://creativecommons.org/licenses/by-nc-nd/4.0/See article on publisher's website: https://dx.doi.org/10.1016/j.asej.2023.102497</p