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1 – 10 of 88G. Dou, Y.C. Chan, J.E. Morris and D.C. Whalley
The resistance, capacitance and inductance of anisotropic conductive film (ACF) connections determine their high frequency electrical characteristics. The presence of capacitance…
Abstract
Purpose
The resistance, capacitance and inductance of anisotropic conductive film (ACF) connections determine their high frequency electrical characteristics. The presence of capacitance and inductance in the ACF joint contributes to time delays and cross‐talk noise as well as simultaneous switching noise within the circuit. The purpose of this paper is to establish an experimental method for estimating the capacitance and inductance of a typical ACF connection. This can help to provide a more detailed understanding of the high frequency performance of ACF assemblies.
Design/methodology/approach
Experiments on the transient response of an ACF joint were performed using a digital oscilloscope capable of achieving the required ns resolution. An equivalent circuit model is proposed in order to quantify the capacitance (C) and inductance (L) of a typical ACF connection and this model is fitted to the experimental data. The full model consisted of two resistors, an inductor, and a capacitor.
Findings
The capacitance and inductance of a typical ACF connection were estimated from the measured transient response using Kirchhoff's voltage law. The method for estimation of R, L, and C from the transient response is discussed, as are the RLC effects on the high frequency electrical characteristics of the ACF connection.
Research limitations/implications
There was decay time deviation between the calculation and the experiment. It may have resulted from the skin effect in the high frequency response and the adhesive surrounding joint as well. The main reason may be the capacitance zctric lost. Further research work will be done to determine more accurately the dielectric losses in anisotropic conductive adhesive (ACA) joint.
Originality/value
This paper presents a new method to characterise the high frequency properties of ACA interconnections and will be of use to engineers evaluating the performance of ACF materials in high frequency applications.
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Atul Varshney and Vipul Sharma
This paper aims to present the design development and measurement of two aerodynamic slotted X-bands back-to-back planer substrate-integrated rectangular waveguide (SIRWG/SIW) to…
Abstract
Purpose
This paper aims to present the design development and measurement of two aerodynamic slotted X-bands back-to-back planer substrate-integrated rectangular waveguide (SIRWG/SIW) to Microstrip (MS) line transition for satellite and RADAR applications. It facilitates the realization of nonplanar (waveguide-based) circuits into planar form for easy integration with other planar (microstrip) devices, circuits and systems. This paper describes the design of a SIW to microstrip transition. The transition is broadband covering the frequency range of 8–12 GHz. The design and interconnection of microwave components like filters, power dividers, resonators, satellite dishes, sensors, transmitters and transponders are further aided by these transitions. A common planar interconnect is designed with better reflection coefficient/return loss (RL) (S11/S22 ≤ 10 dB), transmission coefficient/insertion loss (IL) (S12/S21: 0–3.0 dB) and ultra-wideband bandwidth on low profile FR-4 substrate for X-band and Ku-band functioning to interconnect modern era MIC/MMIC circuits, components and devices.
Design/methodology/approach
Two series of metal via (6 via/row) have been used so that all surface current and electric field vectors are confined within the metallic via-wall in SIW length. Introduced aerodynamic slots in tapered portions achieve excellent impedance matching and tapered junctions with SIW are mitered for fine tuning to achieve minimum reflections and improved transmissions at X-band center frequency.
Findings
Using this method, the measured IL and RLs are found in concord with simulated results in full X-band (8.22–12.4 GHz). RLC T-equivalent and p-equivalent electrical circuits of the proposed design are presented at the end.
Practical implications
The measurement of the prototype has been carried out by an available low-cost X-band microwave bench and with a Keysight E4416A power meter in the microwave laboratory.
Originality/value
The transition is fabricated on FR-4 substrate with compact size 14 mm × 21.35 mm × 1.6 mm and hence economical with IL lie within limits 0.6–1 dB and RL is lower than −10 dB in bandwidth 7.05–17.10 GHz. Because of such outstanding fractional bandwidth (FBW: 100.5%), the transition could also be useful for Ku-band with IL close to 1.6 dB.
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Yograj Singh Duksh, Brajesh Kumar Kaushik, Sankar Sarkar and Raghuvir Singh
The purpose of this paper is to explore and evaluate the performance comparison of carbon nanotubes (CNT) and nickel silicide (NiSi) nanowires interconnects as prospective…
Abstract
Purpose
The purpose of this paper is to explore and evaluate the performance comparison of carbon nanotubes (CNT) and nickel silicide (NiSi) nanowires interconnects as prospective alternatives to copper wire interconnects.
Design/methodology/approach
The increasing resistivity of the copper wire with scaling and rising demands on current density drives the need for identifying new wiring solutions. This paper explores the various alternatives to copper. The metallic bundle CNTs and NiSi nanowires are promising candidates that can potentially address the challenges faced by copper. This paper analyzes various electrical models of carbon nanotube and recently introduced novel interconnect solution using NiSi nanowires.
Findings
The theoretical studies proves CNTs and NiSi nanowires to be better alternatives against copper on the ground of performance parameters, such as effective current density, delay and power consumption. NiSi nanowire provides highest propagation speed for short wire length, and copper is the best for intermediate wire length, while bundle CNTs is faster for long wire length. NiSi nanowire has lowest power consumption than copper and CNTs.
Originality/value
This paper investigates, assess and compares the performance of carbon nanotubes (CNT) and NiSi nanowires interconnects as prospective alternatives to copper wire interconnects in future VLSI chips.
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Atul Varshney, Vipul Sharma, T. Mary Neebha and N. Prasanthi Kumari
This paper aims to present a low-cost, edge-fed, windmill-shaped, notch-band eliminator, circular monopole antenna which is practically loaded with a complementary split ring…
Abstract
Purpose
This paper aims to present a low-cost, edge-fed, windmill-shaped, notch-band eliminator, circular monopole antenna which is practically loaded with a complementary split ring resonator (CSRR) in the middle of the radiating conductor and also uses a partial ground to obtain wide-band performance.
Design/methodology/approach
To compensate for the reduced value of gain and reflection coefficient because of the full (complete) ground plane at the bottom of the substrate, the antenna is further loaded with a partial ground and a CSRR. The reduction in the length of ground near the feed line improves the impedance bandwidth, and introduced CSRR results in improved gain with an additional resonance spike. This results in a peak gain 3.895dBi at the designed frequency 2.45 GHz. The extending of three arms in the circular patch not only led to an increase of peak gain by 4.044dBi but also eliminated the notch band and improved the fractional bandwidth 1.65–2.92 GHz.
Findings
The work reports a –10dB bandwidth from 1.63 GHz to 2.91 GHz, which covers traditional coverage applications and new specific uses applications such as narrow LTE bands for future internet of things (NB-IoT) machine-to-machine communications 1.8/1.9/2.1/2.3/2.5/2.6 GHz, industry, automation and business-critical cases (2.1/2.3/2.6 GHz), industrial, society and medical applications such as Wi-MAX (3.5 GHz), Wi-Fi3 (2.45 GHz), GSM (1.9 GHz), public safety band, Bluetooth (2.40–2.485 GHz), Zigbee (2.40–2.48Ghz), industrial scientific medical (ISM) band (2.4–2.5 GHz), WCDMA (1.9, 2.1 GHz), 3 G (2.1 GHz), 4 G LTE (2.1–2.5 GHz) and other personal communication services applications. The estimated RLC electrical equivalent circuit is also presented at the end.
Practical implications
Because of full coverage of Bluetooth, Zigbee, WiFi3 and ISM band, the proposed fabricated antenna is suitable for low power, low data rate and wireless/wired short-range IoT-enabled medical applications.
Originality/value
The antenna is fabricated on a piece (66.4 mm × 66.4 mm × 1.6 mm) of low-cost low profile FR-4 epoxy substrate (0.54
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Daniel Roger and Ewa Napieralska-Juszczak
High-temperature (HT°) motors are made with inorganic coils wound with a ceramic-coated wire. They must be carefully designed because the HT° insulating materials have a lower…
Abstract
Purpose
High-temperature (HT°) motors are made with inorganic coils wound with a ceramic-coated wire. They must be carefully designed because the HT° insulating materials have a lower breakdown voltages than the polymers used for insulating standard machines.
Design/methodology/approach
The voltage distribution between stator coils is computed with high-frequency (HF) equivalent circuits that consider the magnetic couplings and the stray capacitances. Two time scales are used for getting a fast computation of very short voltage spikes. For the first step, a medium time scale analysis is performed considering a simplified equivalent circuit made without any stray capacitance but with the full PWM pattern and the magnetic couplings. For the second step, a more detailed HF equivalent circuit computes voltage spikes during short critical time windows.
Findings
The computation made during the first step provides the critical time windows and the initial values of the state variables to the second one. The rise and fall time of the electronic switches have a minor influence on the maximum voltage stress. Conversely, the connection cable length and the common-mode capacitances have a large influence.
Research limitations/implications
HF equivalent circuits cannot be used with random windings but only to formed coils that have a deterministic position of turns.
Practical implications
The proposed method can be used designing of HT° machine windings fed by PWM inverter and for improving the coils of standard machine used in aircraft’s low-pressure environments.
Originality/value
The influence of grounding system of the DC link is considered for computing the voltage spikes in the motor windings.
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Stefan Ludwig and Wolfgang Mathis
This paper aims to present a method for the efficient reduction of networks modelling parasitic couplings in very‐large‐scale integration (VLSI) circuits.
Abstract
Purpose
This paper aims to present a method for the efficient reduction of networks modelling parasitic couplings in very‐large‐scale integration (VLSI) circuits.
Design/methodology/approach
The parasitic effects are modelled by large RLC networks and current sources for the digital switching currents. Based on the determined behaviour of the digital modules, an efficient description of these networks is proposed, which allows for a more efficient model reduction than standard methods.
Findings
The proposed method enables a fast and efficient simulation of the parasitic effects. Additionally, an extension of the reduction method to elements, which incorporate some supply voltage dependence to model the internal currents more precisely than independent current sources is presented.
Practical implications
The presented method can be applied to large electrical networks, used in the modelling of parasitic effects, for reducing their size. A reduced model is created which can be used in investigations with circuit simulators requiring a lowered computational effort.
Originality/value
Contrary to existing methods, the presented method includes the knowledge of the behaviour of the sources in the model to enhance the model reduction process.
Yograj Singh Duksh, Brajesh Kumar Kaushik, Sankar Sarkar and Raghuvir Singh
The purpose of this paper is to analyze the effect of driver size and number of shells on propagation delay and power for multi‐walled carbon nanotubes (MWCNT) interconnects at…
Abstract
Purpose
The purpose of this paper is to analyze the effect of driver size and number of shells on propagation delay and power for multi‐walled carbon nanotubes (MWCNT) interconnects at 22 nm technology node.
Design/methodology/approach
An equivalent circuit model of MWCNT is used for estimation and analysis of propagation delay and power. The delay and power through MWCNT and Cu interconnects are compared for various driver sizes and number of MWCNT shells.
Findings
The SPICE simulation results show that the MWCNT interconnect has lower propagation delay than Cu interconnects. The delay ratio of MWCNT to Cu decreases with increase in length for different driver size and number of MWCNT shells. However, the delay ratio increases with reduction in number of MWCNT shells. The ratio of average power consumption (MWCNT/Cu) also decreases with the variation in driver size and numbers of shells with respect to the length of interconnect. The theoretical study proves CNTs to be better alternatives against copper on the ground of performance parameters.
Research limitations/implications
Several challenges remain to be overcome in the areas of fabrication and process integration for CNTs. Lowering of metal nanotube contact resistance would be vital, especially for local interconnect and via applications. Moreover, rigorous characterization and modeling of electromagnetic interactions in CNT bundles; 3‐D (metal) to 1‐D (CNT) contact resistance; impact of defects on electrical and thermal properties; and high‐frequency effects are being seen as additional challenges.
Originality/value
This paper investigates, assesses and compares the performance of carbon nanotubes (CNT) based interconnects as prospective alternatives to copper wire interconnects in future VLSI chips. Multi walled CNTs assure for long/global interconnect applications.
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D. Roger, E. Napieralska‐Juszczak and A. Henneton
The paper gives a new measurement method of the parameters characterising the magnetic laminations for broadband low‐level signals defined at any operational point.
Abstract
Purpose
The paper gives a new measurement method of the parameters characterising the magnetic laminations for broadband low‐level signals defined at any operational point.
Design/methodology/approach
High frequency phenomena machines fed by PWM inverters are related to low‐level signals corresponding to minor hysteresis loops around the instantaneous working point, which moves on the main loop at the basic frequency. The minor loops are assimilated to ellipses, which are characterised by only two parameters: the incremental magnetic permeability (μ) and the electric conductivity (σ).
Findings
For small signals high frequency field components, the laminated steel behaviour can be described by two local parameters (μ, σ) and skin effect. The values of μ and σ do not depend on frequency up to 1 MHz, but only on the operating point.
Research limitations/implications
The proposed broadband characterisation should be associated with a Priesach model that defines the operating point for computer simulation of high frequency phenomena.
Practical implications
The broadband characterisation of magnetic laminations is useful for studying the behaviour of the windings of the PWM‐fed machines.
Originality/value
Broadband measurements are now possible on small magnetic steel lamination samples.
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Elakkiya A., Radha Sankararajan and Sreeja B.S.
The proposed structure consists of copper as a ground plane and 50 µm polyimide dielectric layer is placed in between the ground panel and top radiating patch. Octagon and…
Abstract
Purpose
The proposed structure consists of copper as a ground plane and 50 µm polyimide dielectric layer is placed in between the ground panel and top radiating patch. Octagon and pentagon shapes are combined to form a unit cell. This structure exhibits seven absorption peaks within the short frequency range 0.3–0.5 terahertz (THz) without any interference. Under normal incidence, this structure achieves the absorption of 96.9%, 95.3%, 98.7%, 91.7%, 96.5%, 95% and 97.8% at 0.3136 THz, 0.377 THz, 0.4060 THz, 0.4085 THz, 0.4240 THz, 0.4436 THz and 0.4648 THz, respectively. This study aims to provide a range of applications in THz dielectric sensing, thickness sensing, communications, wavelength selective radiation and detecting.
Design/methodology/approach
Multi-band THz metamaterial absorbers (MMA) from previous research are having a large unit size because of the presence of stacked layers and multiple resonators within a single unit cell. This leads to difficulty while implementing in practical applications. In this study, a new MMA has been presented at seven distinct frequencies without using stacked layers and multiple resonators.
Findings
This structure exhibits seven absorption peaks within the short frequency range 0.3–0.5 THz without any interference. Under normal incidence this structure achieves the absorption of 96.9%, 95.3%, 98.7%, 91.7%, 96.5%, 95% and 97.8% at 0.3136 THz, 0.377 THz, 0.4060 THz, 0.4085 THz, 0.4240 THz, 0.4436 THz and 0.4648 THz, respectively. The polarization and angle insensitivity of the design have been validated by numerical simulation up to 90° of oblique incidence. The effects of variation in geometrical parameters on absorption response are demonstrated. The physical mechanism of the structure is analysed by electric and magnetic field distributions. The resonant frequency ranges and the number of bands in this work are compared with previously reported papers. In THz range, this is the first time a single planar structure provides seven-band high-level absorption performance.
Originality/value
The highlights of the proposed seven-band THz MMA structure, in comparison with previous THz metamaterials, are as follows: this has a simple unit-cell structure and high resonant mechanism within the short frequency range 0.3–0.5 THz; this MMA can provide seven-band high-level absorption performance in a single planar structure for the first time in THz range; and this structure is polarization and incident angle independent in nature.
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Jonas Sjolte, Gaute Tjensvoll and Marta Molinas
The purpose of this paper is to describe the design and function of Fred. Olsen's wave energy converter (WEC) system Lifesaver with special focus on the stand-alone electrical…
Abstract
Purpose
The purpose of this paper is to describe the design and function of Fred. Olsen's wave energy converter (WEC) system Lifesaver with special focus on the stand-alone electrical system that is implemented for operation without grid-connection.
Design/methodology/approach
The paper focus on the detailed design of the DC-Link system that drives the industrial 400 VAC inverters and generators for the production system. The DC-Link is stabilized by an ultra capacitor bank and has no external source or grid-connection.
Findings
The system has been tested through extensive sea trials since April 2012 and has proved its function. Some results from real sea testing are presented.
Practical implications
This paper proves the viability of the specified design and may serve as a basis for the design if similar systems in the future.
Originality/value
This paper presents a WEC system that has proven successful operation through practical tests, and is therefore regarded as a high-value paper as there is limited experience on this subject.
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