OTRA Based Voltage Mode Third Order Quadrature Oscillator

Two topologies of operational transresistance (OTRA) based third order quadrature oscillators (QO) are proposed in this paper. The proposed oscillators are designed using a combination of lossy and lossless integrators. The proposed topologies can be made fully integrated by implementing the resistors using matched transistors operating in linear region, which also facilitates electronic tuning of oscillation frequency. The nonideality analysis of the circuit is also given and for high frequency applications self-compensation can be used. Workability of the proposed QOs is verified through PSPICE simulations using 0.5 μm AGILENT CMOS process parameters. The total harmonic distortion (THD) for both the QO designs is found to be less than 1%.

Comprehensive Review and Comparative Analysis of Hardware Architectures for Sobel Edge Detector

This paper presents a comprehensive review and a comparative study of various hardware/FPGA implementations of Sobel edge detector and explored different architectures for Sobel gradient computation unit in order to show the various trade-offs involved in choosing one over another. The different architectures using pipelining and/or parallelism (key methodologies for improving the performance/frame rates) are explored for gradient computation unit in Sobel edge detector. How the different architectures affected performance (in terms of video frame rate and image size) and area (in terms of FPGA resources usages) has been demonstrated. By exploiting the trade-offs between video frame rate, image size, and FPGA resources a designer should be able to find an optimal architecture for a given application.

Estimation of Different Performance Parameters of Slotted Microstrip Antennas with Air-Gap Using Neural Networks

Over the past decade, artificial neural networks have emerged as fast computational medium for predicting different performance parameters of microstrip antennas due to their learning and generalization features. This paper illustrates a neural network model for instantly predicting the resonance frequencies, gains, directivities, antenna efficiencies, and radiation efficiencies for dual-frequency operation of slotted microstrip antennas with air-gap. The proposed neural model is valid for any arbitrary slot-dimensions and inserted air-gap within their specified ranges. A prototype is fabricated using Roger’s substrate and its performance is measured for validation. A very good agreement is achieved in simulated, predicted, and measured results.

Study of Linearity and Power Consumption Requirements of CMOS Low Noise Amplifiers in Context of LTE Systems and Beyond

This paper presents a study of linearity in wideband CMOS low noise amplifiers (LNA) and its relationship to power consumption in context of Long Term Evolution (LTE) systems and its future developments. Using proposed figure of merit (FoM) to compare 35 state-of-the-art LNA circuits published over the last decade, the paper explores a dependence between amplifier performance (i.e., combined linearity, noise figure, and gain) and power consumption. In order to satisfy stringent linearity specifications for LTE standard (and its likely successors), the paper predicts that LNA FoM increase in the range of +0.2 dB/mW is expected and will inevitably translate into a significant increase in power consumption—a critical budget planning aspect for handheld devices, active antenna arrays, and base stations operating in small cells.

A Novel Dual-Polarization Total Power Radiometer with Single Channel

A dual-polarization total power millimeter wave (MMW) radiometer with single channel was proposed in this paper. It completed the subtraction of two orthogonally polarized signals in the RF front end. The system used one channel to achieve the function of two channels. On the basis of discussing the theory and the configuration of the system, the performance of the system and the ability to identify the false target were analyzed and simulated. The results showed the radiometer could solve the problem that the performance of dual-polarization radiometer becomes weak because of gain inconformity with two channels. The system was cheap and small and could identify the false target which has different apparent temperatures at vertical- and horizontal-polarized radiations.

Low Voltage Floating Gate MOS Transistor Based Differential Voltage Squarer

This paper presents novel floating gate MOSFET (FGMOS) based differential voltage squarer using FGMOS characteristics in saturation region. The proposed squarer is constructed by a simple FGMOS based squarer and linear differential voltage attenuator. The squarer part of the proposed circuit uses one of the inputs of two-input FGMOS transistor for threshold voltage cancellation so as to implement a perfect squarer function, and the differential voltage attenuator part acts as input stage so as to generate the differential signals. The proposed circuit provides a current output proportional to the square of the difference of two input voltages. The second order effect caused by parasitic capacitance and mobility degradation is discussed. The circuit has advantages such as low supply voltage, low power consumption, and low transistor count. Performance of the circuit is verified at ±0.75 V in TSMC 0.18 μm CMOS, BSIM3, and Level 49 technology by using Cadence Spectre simulator.

Low Frequency Axial Flux Linear Oscillating Electric Drive Suitable for Short Strokes

The design, analysis, and control methodology of an energy efficient and high force to weight ratio rare earth N42 NdFeB based permanent magnet linear oscillating motor has been described. For this axial flux machine the mover is consisting of Aluminium structure embedded with rare earth permanent magnets of high energy density. Microcontroller based drive is developed for frequency and thrust control of the machine. Finite element method using FEMM is employed for analysis of various performance parameters of machine. The same parameters are also compared with the measured ones, which yields a good agreement to the proposed design.

Output Signal Power Analysis in Erbium-Doped Fiber Amplifier with Pump Power and Length Variation Using Various Pumping Techniques

The scope of this paper is to analyze the output signal power with pump power and length variation in cascaded EDFA simulation model performance. This paper describes the simulation model of Erbium-Doped Fiber Amplifier (EDFA) of variable lengths (10 m, 50 m, and 120 m) with dual pumping techniques (dual forward pumping with two 980 nm wavelengths, dual forward and backward pumping with two 980 nm wavelengths) and Tri-pumping techniques. The simulation models consist of input source and pump power coupled by WDM coupler which gives optimized signal power in the above-mentioned simulation model. The simulation model consists of source with multiple wavelengths (1520 nm–1618 nm), pumping source with the wavelength 980 nm, isolator, and filter. The resulting models accurately represent EDFA optimized output signal power. Simulation results show that choosing careful fiber length 120 m and pump power 1 W in dual pumping provided 0.07 W optimized output signal power compared to other pumping techniques.

Transformer Magnetizing Inrush Currents Using a Directly Coupled Voltage-Source Inverter

The connection of a power transformer to the grid is associated with magnetizing inrush currents that may result in power quality issues as well as faulty relay tripping. In distributed generation, the transformer may instead be premagnetized from the source to avoid this. In this paper, a VSI is directly coupled to a transformer. Three different strategies of premagnetization are implemented into the control system, and the inrush currents are measured for various values of the remanent flux in the core. The results show good reduction in the peak magnetizing inrush currents without using any external circuitry.

Third-Order Quadrature Oscillator Circuit with Current and Voltage Outputs

The paper presents a new quadrature oscillator of third order which can provide four quadrature current outputs and two quadrature voltage outputs. The new circuit employs three differential voltage current conveyors and six passive components, most of which are in grounded form. Circuit operation at high frequencies is verified along with nonideality and parasitic study. The circuit enhancement for generation of four phase clock waveforms is also given. The proposed circuit is a novel addition to the oscillator family.