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1 – 10 of 84
Article
Publication date: 7 June 2021

Jincan Zhang, Min Liu, Jinchan Wang and Kun Xu

High-speed Indium Phosphide (InP) HBTs have been widely used to design high-speed analog, digital and mixed-signal integrated circuits. The purpose of this study is to…

Abstract

Purpose

High-speed Indium Phosphide (InP) HBTs have been widely used to design high-speed analog, digital and mixed-signal integrated circuits. The purpose of this study is to propose a new parameter extraction procedure for determining an improved T-topology small-signal equivalent circuit of InP heterojunction bipolar transistors (HBTs).

Design/methodology/approach

The alternating current crowding effect is considered through adding the intrinsic base capacitance in the small-signal equivalent circuit. All of the circuit parameters are extracted directly without using any approximation.

Findings

The extraction technique is more easily understood and clearer than other extraction methods, as the equations are derived from the S-parameters by peeling peripheral elements from small-signal models to get reduced ones and extracting each equivalent-circuit parameter using each equation.

Originality/value

To validate the presented parameter extraction technology, an n-p-n emitter-up InP HBT was analyzed adopting the method. Excellent agreement between measured and modeled S-parameters is obtained up to 40 GHz.

Article
Publication date: 2 January 2018

Rahis Kumar Yadav, Pankaj Pathak and R.M. Mehra

This paper aims to report small-signal parameter extraction and simulation of enhanced dual-channel dual-material gate AlGaN/GaN high electron mobility transistor (HEMT…

Abstract

Purpose

This paper aims to report small-signal parameter extraction and simulation of enhanced dual-channel dual-material gate AlGaN/GaN high electron mobility transistor (HEMT) for the first time for the characterization of a device in microwave range of frequency.

Design/methodology/approach

For parameter extraction, a standard and well-known direct parameter extraction methodology is applied. Extrinsic elements of small-signal circuit model are extracted from measured S-parameters obtained using pinch-off cold field effect transistor (FET) biasing in the first step at a low frequency range and at a higher frequency range in the second step to ensure higher extraction accuracy. Intrinsic elements are extracted from intrinsic Y-parameters that are obtained after de-embedding all the extrinsic parasitic elements of the device. Figure of merits of radio frequency are also derived from the measured results and S-parameters of the proposed device.

Findings

Small signal parameters of the proposed device circuit model are extracted using the standard direct parameter extraction technique. Analysis of microwave figure of merits for device include maximum oscillation frequency, cut-off frequency, current gain, transducer power gain, available power gain, maximum stable gain, transconductance, drain conductance, stern stability factor and time delay.

Practical implications

The paper bridges the gaps between theory and experimental practices by validating extracted results with reported results of structurally matching devices.

Originality/value

An enhanced device structure investigated for small signal parameters incorporates field plate over dual metal engineered gate to provide better electric field uniformity, effective suppression of short channel effect, reduction in current collapse, improvement in carrier transport efficiency and enhancement in drain current capabilities.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 3 September 2019

Hamed Aminzadeh

Multistage amplifiers require a reliable frequency compensation solution to remain stable in a closed-loop configuration. A frequency compensation scheme creates an inner…

Abstract

Purpose

Multistage amplifiers require a reliable frequency compensation solution to remain stable in a closed-loop configuration. A frequency compensation scheme creates an inner negative feedback loop amongst different amplifying stages and shapes the frequency response such that an unconditionally stable single-pole amplifier results for closed-loop operation. The frequency compensation loop is thus responsible for the placement of the poles and zeros and the final stability of multistage amplifiers. An amplifier incorporating a sophisticated frequency compensation network cannot be, however, analyzed in the presence of a complex ac feedback loop. The purpose of this study is to provide a reliable model for the compensation loop of multistage amplifiers at the higher frequencies.

Design/methodology/approach

In this paper, the major part of the amplifier, including a two-port network comprising the compensation network, is characterized using a reliable feedback model.

Findings

The model integrates all the frequency-dependent components of the frequency compensation network, and it can evaluate the nondominant real or complex poles of an amplifier.

Originality/value

The reliability of the proposed model is verified through analysis of the frequency response of the amplifiers and by comparing the analytic results with the simulation results in standard CMOS process.

Details

Circuit World, vol. 45 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 April 1993

Hamid Z. Fardi

An empirical velocity‐field relationship, based on Monte Carlo simulation, is used to modify a drift‐diffusion model for the characterization of short gate GaAs MESFET's…

Abstract

An empirical velocity‐field relationship, based on Monte Carlo simulation, is used to modify a drift‐diffusion model for the characterization of short gate GaAs MESFET's. The modified drift‐diffusion model is used to generate both the steady‐state and the small‐signal parameters of submicron GaAs MESFET's. The current, transconductance, and cutoff frequency are compared with two‐dimensional Monte Carlo simulation results on a 0.2 µm gate‐length. The model is also used to predict measured I‐V and s‐parameters of a 0.5 µm gate‐length ion‐implanted GaAs MESFET. The comparison and the analysis made, support the accuracy of the modified drift‐diffusion simulator and makes it computationally efficient for analysis of short‐gate devices.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 4
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 9 March 2010

Zehong Li, Yong Liu, Lijuan Wu, Li Yi, Bo Zhang and Zhaoji Li

The purpose of this paper is to present a novel n‐buried‐PSOI sandwiched radio frequencies (RF) power lateral diffused metal‐oxide semiconductor (LDMOS) and analyze its…

Abstract

Purpose

The purpose of this paper is to present a novel n‐buried‐PSOI sandwiched radio frequencies (RF) power lateral diffused metal‐oxide semiconductor (LDMOS) and analyze its output characteristics.

Design/methodology/approach

The small‐signal equivalent circuit for RF power LDMOS method is used to analyze the proposed structure and the simulation and optimization are done using the computer‐aided design tools.

Findings

This improved structure is clearly decreasing drain‐substrate parasitic capacitance. At 1 dB compression point, its output power, the power‐added efficiency and the breakdown voltage are higher than that of the conventional LDMOS.

Originality/value

This paper puts forward a novel n‐buried‐PSOI sandwiched structure of RF power LDMOS. The analysis indicates that the output characteristics of this device are a great improvement on the conventional LDMOS and the n‐buried‐PSOI, RF power LDMOS proposed by earlier authors.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 March 2003

H.I. Sewell, D.A. Stone and C.M. Bingham

It is not normally possible to heat a static steel work‐piece past the Curie temperature without incurring reduced inverter utilisation. Since the inverter cost increases…

Abstract

It is not normally possible to heat a static steel work‐piece past the Curie temperature without incurring reduced inverter utilisation. Since the inverter cost increases with rated power, reduced utilisation implies an increase in investment costs for a given performance. The paper shows that third‐order resonant work‐head circuits can intrinsically allow better utilisation of the inverter for variable‐load heating operations. A further refinement is then shown to allow control of the load impedance, thereby allowing the utilisation to approach 100 percent over the heating cycles.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 22 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 January 2013

Ebrahim Babaei and Hamed Mashinchi Mahery

The purpose of this paper is to propose a new method for mathematical modeling of the buck dc‐dc converter in discontinuous conduction mode (DCM). By using the presented…

Abstract

Purpose

The purpose of this paper is to propose a new method for mathematical modeling of the buck dc‐dc converter in discontinuous conduction mode (DCM). By using the presented modeling method, the analysis of the transient and the steady states of the buck dc‐dc converter can be performed.

Design/methodology/approach

The proposed method is based on the two Laplace and Z transforms. In the proposed method, at first, the equations of the inductor current and the capacitor voltage are obtained as the power switch is on and off. Then by using the Laplace and Z transforms, the obtained equations are solved and the relations of the inductor current and the output voltage are obtained. In the proposed method, the Laplace transform is used for determining of the general relations of the inductor current and the output voltage. Also the Z‐transform is used as a tool for determining the initial values of the inductor current and the output voltage.

Findings

The transient and the steady state response of the dc‐dc converter is analyzed by the proposed method. By using the Z‐transform, the transient response of the converter and the effect of the elements of the converter on the time constant of the transient response are investigated. In addition, the effect of the elements of the converter and the load resistance on the electrical parameters of the converter such as the output voltage ripple and the inductor current ripple are investigated.

Originality/value

The proposed method in this paper is a suitable method for mathematical modeling of dc‐dc converters. The acernote of this method is that it can be used in both transient and steady state response, analysis of the dc‐dc converters. By using the final value theorem of the Z‐transform, the steady state response of the converter is investigated. Also by using this transform, the time constants of the transient response of the converter are determined. Finally, the results of the theoretical analysis are compared with the results of simulation in PSCAD/EMTDC and also the experimental results to prove the validity of the presented subjects.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 4 January 2016

Vladica Ðorđević, Zlatica Marinković, Vera Marković and Olivera Pronić-Rančić

– The purpose of this paper is the development of an efficient approach for extraction of the microwave FET noise wave temperatures.

Abstract

Purpose

The purpose of this paper is the development of an efficient approach for extraction of the microwave FET noise wave temperatures.

Design/methodology/approach

The proposed approach is based on an artificial neural network (ANN) trained to determine the noise wave temperatures from the given measured transistor noise parameters.

Findings

The presented approach enables not only efficient, but also an accurate direct extraction of the noise wave temperatures. This is confirmed by the validation of the proposed approach that is done by comparison of the transistor noise parameters obtained using the extracted noise wave temperatures with the measured noise parameters.

Originality/value

Application of ANN is a novel approach to extract the noise wave temperatures, which provides more efficient microwave FET noise wave modeling.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 January 2018

Pragash Sangaran, Narendra Kumar, Jagadheswaran Rajendran and Andrei Grebennikov

This paper aims to propose a practical design methodology of high-power wideband power amplifier.

Abstract

Purpose

This paper aims to propose a practical design methodology of high-power wideband power amplifier.

Design/methodology/approach

The distributed power amplification method is used for a Gallium Nitride device to achieve wideband operation. To achieve the high power without trading-off the bandwidth and gain, a methodology to extract the package-loading effect is proposed and verified.

Findings

A maximum output power of 10 W is achieved from 100 MHz to 2 GHz with a wideband power gain of 32 dB in measurement. This performance is achieved through a single section matching network.

Research limitations/implications

Measurement accuracy is dependable to the thermal behaviour of the high-power device.

Practical implications

The proposed technique is an excellent solution to be used in the two way radio power amplifier that minimizes the fundamental trade-off issue between power, gain, bandwidth and efficiency.

Originality/value

In this work, a practical distributed power amplifier (DPA) design methodology is proposed that reduces the development cycle time for industrial engineers working on high-power circuit design application.

Details

Microelectronics International, vol. 35 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 October 1998

Laurens Weiss and Wolfgang Mathis

The conventional treatment of thermal noise is based on Nyquist’s theorem. This theorem has only been derived for linear, reciprocal (we define “reciprocal networks” as…

Abstract

The conventional treatment of thermal noise is based on Nyquist’s theorem. This theorem has only been derived for linear, reciprocal (we define “reciprocal networks” as networks that are built of reciprocal network elements) networks. In this paper a description of thermal noise in reciprocal non‐linear RLC networks is presented. This description is derived from first principles, i.e. from a direct application of non‐equilibrium thermodynamics (irreversible thermodynamics) to electrical networks. As an example, the class of “complete” non‐linear networks is considered. Using the idea of equivalent n‐ports, the theory’s extension to certain classes of transistor circuits should be possible.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 17 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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