Electronics Letters

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• Vertical-cavity surface-emitting lasers integrated onto silicon substrates by PdGe contacts

Publication Year: 1994, Page(s):1235 - 1236
Cited by:  Papers (8)  |  Patents (8)
| | PDF (152 KB)

Vertical-cavity surface-emitting lasers (VCSELs) have been integrated onto an aluminium coated silicon substrate. The InGaAs top-emitting VCSELs were grown by molecular beam epitaxy and individual lasers were defined by high energy proton implantation. The substrate was removed by a new substrate removal process and the lasers were bonded to an aluminised silicon substrate using a Pd/Ge/InSn conta... View full abstract»

• Basic characteristics of two layered substrate coplanar waveguides

Publication Year: 1994, Page(s):1236 - 1237
Cited by:  Papers (14)
| | PDF (156 KB)

The conformal mapping technique is used to obtain simple CAD oriented closed form expressions for the effective dielectric permittivity, line capacitance and impedance of two layered coplanar waveguides (CPWs) View full abstract»

• X-ray diffraction studies of high-quality GaN heteroepitaxial films grown by metal organic chemical vapour deposition

Publication Year: 1994, Page(s):1252 - 1254
Cited by:  Patents (4)
| | PDF (272 KB)

The authors report the growth and characterisation of high-quality GaN films grown on (0001)-oriented sapphire (Al2O3) substrates by metal organic chemical vapour deposition (MOCVD). These films were analysed using five-crystal X-ray diffraction, optical transmission spectroscopy, transmission electron microscopy (TEM) and cathodoluminescence. The X-ray diffraction FWHM value... View full abstract»

• 2.5 Gbit/s, 4 channel, 1200 km densely spaced coherent WDM recirculating-loop experiments

Publication Year: 1994, Page(s):1240 - 1241
Cited by:  Papers (4)
| | PDF (168 KB)

2.5 Gbit/s, 4 channel, densely spaced coherent WDM recirculating-loop transmission experiments were performed over 1200 km using unequal channel spacings to demonstrate the alleviation of the effect of accumulated gain unflatness' of EDFAs View full abstract»

• Direct finite element computation of dispersion parameters of optical waveguides

Publication Year: 1994, Page(s):1217 - 1219
Cited by:  Papers (1)
| | PDF (260 KB)

A direct numerical procedure associated with the finite element method is presented to evaluate in optical waveguides with any arbitrary index profile and geometry, the propagation constant of a given mode and its first and second derivatives, from which the dispersion parameters may be obtained. Numerical differentiation from the computed values of the propagation constant at different frequencie... View full abstract»

• Microwave performance of GaN MESFETs

Publication Year: 1994, Page(s):1248 - 1249
Cited by:  Papers (4)  |  Patents (8)
| | PDF (156 KB)

GaN MESFETs have been fabricated with a 0.25 μm thick channel on a high resistivity GaN layer grown by metal organic vapour phase epitaxy. These devices have a transconductance of 20 mS/mm. For a 0.7 μm gate length device, the measured fT and fmax were 8 and 17 GHz, respectively View full abstract»

• All-optical frame synchronisation recovery

Publication Year: 1994, Page(s):1243 - 1244
Cited by:  Papers (1)  |  Patents (1)
| | PDF (188 KB)

All-optical frame synchronisation recovery is demonstrated experimentally. A frame encoded input data signal forces a fibre laser to modelock. The fixed header is copied onto the laser output, whereas in the payload area the clock is recovered. The authors propose to use this frame synchronisation signal in an all-optical demultiplexer that unambiguously identifies each individual channel View full abstract»

• Fabrication and characterisation of a 4×4 array of polymer-based asymmetric Fabry-Perot reflection modulators

Publication Year: 1994, Page(s):1219 - 1220
Cited by:  Papers (1)
| | PDF (204 KB)

The fabrication and optical characterisation of a 4×4 array of asymmetric Fabry-Perot (AFP) electro-optic modulators is reported. The electro-optic material used, a cross-linked polymer based on an azo-benzene derivative, offers the potential for high time-bandwidth modulation. The uniformity of the spatial light modulator is evaluated, and a contrast ratio exceeding 4:1 can be obtained simu... View full abstract»

• 160 Gbit/s (8×20 Gbit/s WBM) 300 km transmission with 50 km amplifier spacing and span-by-span dispersion reversal

Publication Year: 1994, Page(s):1241 - 1243
Cited by:  Papers (11)  |  Patents (5)
| | PDF (248 KB)

Eight WDM channels each operating at 20 Gbit/s (231-1 PRBS NRZ) were transmitted through 300 km of fibre with 50 km amplifier spacing. To minimise four-photon mixing effects, fibres with nonzero dispersion were used. Dispersion penalties were avoided by changing the sign of dispersion on adjacent spans View full abstract»

• Multiple stage dispersion compensation in long haul optical fibre systems using chirped fibre Bragg gratings

Publication Year: 1994, Page(s):1244 - 1245
Cited by:  Papers (1)
| | PDF (188 KB)

Modelling is used to assess the performance of an optical fibre link which has fibre grating dispersion compensators spaced at intervals along its length. A 10 Gbit/s electroabsorption modulator with high positive chirp is shown to transmit in excess of 158 km in normal dispersion fibre using two 2 cm long compensators, incurring a dispersion penalty of only 1.0 dB. Thus the transmission range is ... View full abstract»

• Wideband dual polarised aperture-coupled stacked patch antenna array operating in C-band

Publication Year: 1994, Page(s):1196 - 1198
Cited by:  Papers (2)  |  Patents (3)
| | PDF (260 KB)

The design and experimental results of a wideband (16%) and directive (21 dB), dual polarised antenna array are presented in C-band around 6.9 GHz. This compact 8×4 element array tapered by a Dolph-Chebyshev distribution (fabricated with Wilkinson power dividers) is composed of dual polarised aperture-coupled stacked patch antenna elements. Use of these elements in the antenna array leads to... View full abstract»

• Novel two-arm microwave transmission line for high-speed electro-optic polymer modulators

Publication Year: 1994, Page(s):1220 - 1222
Cited by:  Papers (3)  |  Patents (1)
| | PDF (260 KB)

The authors demonstrate the use of a novel microwave design for high-speed electro-optic polymer modulators. A two-arm Mach-Zehnder-like transmission line may be used to reduce Vπ in a push-pull modulator without problems of dielectric breakdown or crosstalk during poling View full abstract»

• Increased swing convertor for low-internal-voltage ULSI circuits

Publication Year: 1994, Page(s):1213 - 1214
Cited by:  Papers (2)
| | PDF (152 KB)

The authors present an increased swing convertor. It features the switching supply of the input stage, which enables a low operating voltage ratio Vint/Vext(<0.4) to be achieved without consuming DC current. With parallel driving, speed performance is improved View full abstract»

• Frequency selective surfaces on biased ferrite substrates

Publication Year: 1994, Page(s):1193 - 1194
Cited by:  Papers (28)  |  Patents (15)
| | PDF (184 KB)

The frequency characteristics of frequency selective surfaces printed on ferrite substrates are discussed. The application of a DC magnetic bias field to the ferrite allows tuning of the resonance frequency by several gigahertz View full abstract»

• Novel ELFIN (embedded-metal-layer process for fully integrated NOR) cell for 16/64 Mbit flash EEPROM

Publication Year: 1994, Page(s):1209 - 1210
Cited by:  Patents (3)
| | PDF (172 KB)

A novel cell structure named ELFIN (embedded-metal-layer process for fully integrated NOR) is proposed for the 16/64 Mbit flash EEPROM. The ELFIN cell introduces the selfaligned metal drain-pad and source-line technology. It is demonstrated in a 3.0 μm2 cell using the 0.6 μm design rule, i.e. a 25% reduction in cell size is attained compared with the conventional NOR-type cell wit... View full abstract»

• Silicon-on-insulator HRes' circuit

Publication Year: 1994, Page(s):1238 - 1240
| | PDF (252 KB)

Retinal circuits in bulk CMOS are complicated by the need to compensate for the back-gate effect. However, partially depleted silicon-on-insulator devices have a greatly reduced back-gate effect compared to bulk CMOS. Silicon retinae implemented using SOI technology would therefore be smaller and simpler than the bulk CMOS equivalent. This could lead to considerable improvements in resolution and ... View full abstract»

• Modelling dispersive optical fibres with a circuit simulator

Publication Year: 1994, Page(s):1245 - 1246
Cited by:  Papers (4)
| | PDF (176 KB)

The authors describe a new approach to modelling the optical electric field envelope function using a standard circuit simulator, show application to the calculation of dispersive linear propagation in a uniform single-mode optical fibre, and demonstrate that such a model can be integrated with an existing model of a semiconductor laser View full abstract»

• Dual-modulus frequency dividers with minimum gate count

Publication Year: 1994, Page(s):1198 - 1199
| | PDF (172 KB)

A method for minimising the gate count in dual-modulus frequency dividers is presented. The gate count is minimised by identification of a set of Boolean equations with one type of Boolean operator only, using internal gates of D-flipflops to realise the Boolean functions. Circuit diagrams for divide-by-2/3 and divide-by-4/5 static frequency dividers are shown. The minimised circuits have higher s... View full abstract»

• Selective gate recess etching of GaInAs/AlInAs based HEMTs using a CH4/H2 plasma without subsequent annealing

Publication Year: 1994, Page(s):1251 - 1252
Cited by:  Papers (1)
| | PDF (184 KB)

A methane hydrogen plasma has been used to define gate recesses through a polymer mask selectively on GaInAs/InAlAs based HEMT devices. No subsequent annealing was necessary and the devices exhibited comparable gm and idss values with much better uniformity than conventional wet etched devices View full abstract»

• Planar ring resonator realisation of symmetric 3×3 fibre coupler

Publication Year: 1994, Page(s):1222 - 1223
| | PDF (164 KB)

A ring resonator with threefold symmetry is proposed as a planar realisation of the symmetric 3×3 fibre coupler to be used in compact integrated optics interferometers and passive optical signal processing schemes. The effect of system parameter perturbations, arising from manufacturing errors, is analysed and the device would be usable over an ambient temperature range of ±5°C al... View full abstract»

• Silicon bipolar 1:16-demultiplexer for 10 Gbit/s fibre optic communication system

Publication Year: 1994, Page(s):1214 - 1216
Cited by:  Papers (6)
| | PDF (244 KB)

A 1:16-demultiplexer based on silicon bipolar 1:4-demultiplexer ICs, which include all requirements for system applications, has been designed and tested. The authors report the design of the 1:4-demultiplexer, which operates up to 14 Gbit/s, and experimental results for the 1:16-demultiplexer at 10 Gbit/s View full abstract»

• Novel multirate adaptive beamforming technique

Publication Year: 1994, Page(s):1194 - 1195
Cited by:  Papers (5)
| | PDF (180 KB)

A novel multirate/sub-band adaptive beamformer based on QMF banks is presented. Computer simulations of the new technique in a BPSK, DS-SSMA mobile radio system demonstrate its superiority, in terms of convergence speed and cancellation performance, over full-band beamforming View full abstract»

• Fast stroke extraction method for handwritten Chinese characters by cross region analysis

Publication Year: 1994, Page(s):1210 - 1212
Cited by:  Papers (2)
| | PDF (272 KB)

A novel stroke extraction method without thinning for handwritten Chinese characters is described. Particular emphasis is placed on analysis of the stroke cross region which has been found to be the critical source of error in stroke extraction. The method gives fast, accurate results and the recognition rate is greatly improved View full abstract»

• Integer-weight neural nets

Publication Year: 1994, Page(s):1237 - 1238
Cited by:  Papers (11)
| | PDF (184 KB)

Integer-weight neural nets (IWNN) are better suited for hardware implementation than their real-weight analogues. The authors present a learning procedure for generating multilayer IWNNs having all weights in the set {-3, -2, -1, 0, 1, 2, 3}. The performance of this procedure was evaluated on XOR, encoder/decoder and the MONK benchmark. The IWNNS were found to be as capable as their real-weight co... View full abstract»

• New chaotic based communication technique with multiuser provision

Publication Year: 1994, Page(s):1206 - 1207
Cited by:  Papers (15)
| | PDF (196 KB)

A novel technique for communicating reliably via the modulation of synthetic chaos is proposed. Point-to-point communication in the presence of additive white Gaussian noise (AWGN) is considered and original results are presented for signal masking, recovery and noise reduction. Extensions of the technique are proposed to cater for multiuser communication. Orthogonality is demonstrated and therefo... View full abstract»

Aims & Scope

Electronics Letters is internationally renowned for its rapid communication of new developments and emerging topics across the broad and interdisciplinary field of modern electronics and electrical engineering.

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Meet Our Editors

Editors-in-Chief

Professor Chris Toumazou
Director of the Biomedical Institute
Imperial College, London, UK

Professor Ian White