By Topic

# Electronics Letters

## Filter Results

Displaying Results 1 - 25 of 51
• ### Current-mode analogue circuit representation of Hodgkin and Huxley neuron equations

Publication Year: 1998, Page(s):1376 - 1377
Cited by:  Papers (11)
| | PDF (256 KB)

A nonlinear current-mode circuit representation, suitable for a laboratorial realisation, of the Hodgkin and Huxley (HH) nerve axon membrane equations is presented. The representation exploits the inherent properties of the recently proposed Bernoulli cell' to calculate the intermediate state variables used in the HH neuron equations View full abstract»

• ### Planar retrodirective array reflector using dual-slot antennas

Publication Year: 1998, Page(s):1374 - 1376
Cited by:  Papers (2)
| | PDF (320 KB)

An X-band planar reflector with a broad responding beam was developed using the Van Atta retrodirective antenna array. The reflector contained four antenna sub-arrays, each with six dual-slot antennas appropriately fed and paired by microstrip lines on the backside of the substrate. Good agreement has been achieved between theoretical and measured results View full abstract»

• ### Microstrip antenna with back-to-back configuration relative to a slot on a ground plane

Publication Year: 1998, Page(s):1373 - 1374
Cited by:  Papers (2)
| | PDF (212 KB)

A new microstrip antenna with a back-to-back configuration relative to a slot on a ground plane is proposed. The proposed antenna has an omnidirectional or bidirectional radiation pattern in a horizontal plane. The characteristics of the proposed antenna were clarified by experiments. The input impedances and radiation patterns were measured as parameters of the slot length. Good input impedances ... View full abstract»

• ### Introduction of multiple nulls in otherwise omnidirectional pattern of circular dipole array

Publication Year: 1998, Page(s):1371 - 1373
Cited by:  Papers (2)
| | PDF (324 KB)

The results are presented of a synthesis procedure for omnidirectional radiation patterns with multiple nulls for circular arrays of vertical dipoles. The gain ripple in the omnidirectional region can be controlled by the use of window functions in the design procedure. The results are verified using the numerical electromagnetics code View full abstract»

• ### Integrated circuit array antenna for short-range communication systems

Publication Year: 1998, Page(s):1370 - 1371
Cited by:  Patents (2)
| | PDF (244 KB)

A novel active array antenna for short-range communication applications is presented. Each element of the array consists of a cold' MESFET which performs both the ASK demodulator and the DPSK reflection modulator functions and which is directly mounted on a rectangular microstrip resonator. The techniques used to fabricate this active antenna provide good performance at low cost and low power con... View full abstract»

• ### Multiplexing architecture for mixed-signal CMOS fuzzy controllers

Publication Year: 1998, Page(s):1437 - 1439
Cited by:  Papers (2)
| | PDF (324 KB)

Limited precision imposes limits on the complexity of analogue circuits, and hence fuzzy analogue controllers are usually oriented to fast low-power systems with low-medium complexity. A strategy to preserve most of the advantages of an analogue implementation, while allowing a marked increment in system complexity, is presented View full abstract»

• ### Dual-frequency slotted rectangular microstrip antenna

Publication Year: 1998, Page(s):1368 - 1370
Cited by:  Papers (21)  |  Patents (24)
| | PDF (328 KB)

By embedding a pair of properly-bent narrow slots close to the non-radiating edges of a rectangular microstrip patch, a novel dual-frequency operation of microstrip antennas using a single probe feed is proposed and experimentally studied. The two operating frequencies have parallel polarisation planes and similar broadside radiation patterns, and the frequency ratio of the two frequencies is cont... View full abstract»

• ### Two-dimensional analysis of carrier-blocking effect on cutoff frequency characteristics of collector-up AlGaAs/GaAs HBTs

Publication Year: 1998, Page(s):1436 - 1437
| | PDF (220 KB)

Two-dimensional simulation of cutoff frequency (fτ) characteristics in collector-up AlGaAs/GaAs heterojunction bipolar transistors is performed for various collector widths and different base-electrode positions. By putting the base electrode closer to the intrinsic collector, the degradation in fτ resulting from the so-called carrier-blocking effect is shown to be su... View full abstract»

• ### Compact low noise receiving antenna

Publication Year: 1998, Page(s):1367 - 1368
Cited by:  Papers (3)  |  Patents (6)
| | PDF (220 KB)

The authors report a novel active integrated receiving antenna providing between 12 and 24 dB gain when referred to a passive equivalent at 1.335 GHz. The antenna is of a compact coplanar form, integrating DC and RF requirements to obtain both high gain and low noise View full abstract»

• ### Short wavelength bottom-emitting vertical cavity lasers fabricated using wafer bonding

Publication Year: 1998, Page(s):1404 - 1405
Cited by:  Papers (8)  |  Patents (2)
| | PDF (292 KB)

Selectively oxidised 850 nm vertical cavity surface emitting laser diodes which emit through transparent n-type GaP and AlGaAs substrates are reported. The short wavelength bottom-emitting lasers are fabricated using a low temperature inert gas wafer fusion process. Compared to top-emitting lasers, the bottom-emitting lasers bonded to n-type AlGaAs substrates show comparable electrical characteris... View full abstract»

• ### Internal temperature distribution measurements in high power semiconductor lasers

Publication Year: 1998, Page(s):1399 - 1401
Cited by:  Papers (6)
| | PDF (392 KB)

A novel technique to measure internal temperature distributions within high power semiconductor lasers with substrates transparent to the laser radiation is presented. The temperature resolution is better than 1°C with a spatial resolution of 1-2 μm. The results show highly non-uniform transverse temperature distributions and significant heating close to the facet at high output powers View full abstract»

• ### CMOS/BiCMOS mixed design using tabu search

Publication Year: 1998, Page(s):1395 - 1396
Cited by:  Papers (1)
| | PDF (276 KB)

The problem of optimising mixed CMOS/BiCMOS circuits is solved using a tabu search. Only gates on critical sensitisable paths are considered. This strategy leads to a circuit speed improvement of >20% with a <3% increase in the overall circuit capacitance. Comparison and experimental results are presented View full abstract»

• ### Second harmonic generation around 0.53 μm of seeded Yb fibre system in periodically-poled lithium niobate

Publication Year: 1998, Page(s):1419 - 1420
Cited by:  Papers (1)
| | PDF (288 KB)

Fibre-integrated, seeded, high-power Yb-doped fibre amplifiers have been used in combination with periodically-poled lithium niobate crystals in simple experimental configurations to give second harmonic generation to the visible both in CW and pulsed formats with conversion efficiencies as high as 41% in compact configurations View full abstract»

• ### Picosecond switching due to electron tunnelling and avalanche in GaAs/AlxGa1-xAs diode

Publication Year: 1998, Page(s):1434 - 1436
| | PDF (344 KB)

A new semiconductor heterostructure diode with an S-type current-voltage characteristic that can be used for high-speed voltage switching is proposed and demonstrated. This behaviour is caused by the electrons tunnelling through the potential barrier and initiating avalanche multiplication in a small energy gap base region View full abstract»

• ### Aperture-coupled microstrip line leaky wave antenna with broadside mainbeam

Publication Year: 1998, Page(s):1366 - 1367
Cited by:  Papers (15)
| | PDF (280 KB)

A microstrip first higher order leaky wave antenna (LWA), centre-fed by an aperture-coupled microstrip with a broadside mainbeam, is presented. The measured bandwidth (23% for VSWR<2:1) is in agreement with the leaky radiation band predicted. The experimental gain patterns, compared with those of a patch antenna fed by the same type of structure, reveal the difference between these two kinds of... View full abstract»

• ### Modified VQ-BTC algorithm for image compression

Publication Year: 1998, Page(s):1390 - 1392
Cited by:  Papers (1)
| | PDF (376 KB)

VQ-BTC is a recent technique used in the coding of image data to combat edge degradation produced by vector quantisation (VQ) or block truncation coding (BTC). However, it has high encoding complexity and needs a large amount of memory to store 31 codebooks at both the encoder and decoder. A modified VQ-BTC (MVQ-BTC) algorithm is presented which achieves a performance close to that of VQ-BTC, but ... View full abstract»

• ### Room-temperature continuous-wave operation VCSEL at 1.48 μm with Sb-based Bragg reflector

Publication Year: 1998, Page(s):1402 - 1404
Cited by:  Papers (4)
| | PDF (424 KB)

The authors present, for the first time, room temperature CW operation of an optically-pumped vertical cavity laser emitting at 1.48 μm, incorporating an Sb-based mirror on InP. The structure also includes strained AlGaInAs quantum wells and a wafer-fused AlGaAs mirror. The input threshold power is 50 mW at 20°C and has a minimum value of 27 mW at 230 K View full abstract»

• ### Continuous-wave operation of singlemode GaInAsSb lasers emitting near 2.2 μm at Peltier temperatures

Publication Year: 1998, Page(s):1398 - 1399
Cited by:  Papers (2)
| | PDF (340 KB)

A continuous-wave regime, lasing near 2.2 μm, has been achieved for single longitudinal mode GaInAsSb double heterostructure lasers mounted on a Peltier cooler. In the pulsed regime the lasers exhibited a characteristic temperature of the threshold current as high as 132 K at heatsink temperatures up to 60°C View full abstract»

• ### Highly sensitive MOSFET gas sensors with porous Pt-SnOx gate electrode for CO gas sensing applications

Publication Year: 1998, Page(s):1393 - 1395
Cited by:  Papers (1)  |  Patents (1)
| | PDF (384 KB)

Novel gas sensing devices based on a porous Pt-SnOx metal-oxide-semiconductor field-effect transistor (MOSFET) for carbon monoxide (CO) gas sensing have been fabricated for the first time. The structure integrates the catalytic properties of porous Pt as the thin catalyst layer and the gas sensing properties of SnOx as the gas adsorptive oxide with surface-sensitive MOSFETs. ... View full abstract»

• ### Fast committee learning: preliminary results

Publication Year: 1998, Page(s):1408 - 1410
| | PDF (380 KB)

Fast committee learning can, to some extent, achieve the generalisation advantages of a committee of neural networks, without the need for independent learning of the committee members. This is achieved by selecting committee members from time-slices of the learning trajectory of one neural network View full abstract»

• ### All-optical limiter circuit based on four-wave mixing in optical fibres

Publication Year: 1998, Page(s):1410 - 1411
Cited by:  Papers (15)  |  Patents (4)
| | PDF (224 KB)

The authors present a novel all-optical limiter circuit based on the nonlinear input/output response of a pumping light wave in four-wave mixing in optical fibres. The response is obtained by controlling the phase-matching conditions. It is confirmed experimentally that the limiter circuit can suppress amplified spontaneous emission noise View full abstract»

• ### Stimulated Raman suppression under dual-frequency pumping in singlemode fibres

Publication Year: 1998, Page(s):1417 - 1418
| | PDF (272 KB)

Suppression of stimulated Raman scattering is demonstrated in a singlemode fibre by single polarised, dual-frequency pumping. The suppression mechanism, based on the spectral asymmetry of the Raman susceptibility, is most efficient when the frequency spacing between the pumps is 26 THz, twice the Raman shift View full abstract»

• ### Optoelectronic characteristics of a-SiC:H-based pin thin film LEDs having a thin Mo buffer layer in contact with p-type a-Si:H

Publication Year: 1998, Page(s):1433 - 1434
| | PDF (244 KB)

To improve the electroluminescence (EL) properties of the a-SiC:H-based pin thin film light-emitting diodes (TFLEDs) with the promotion of hole injection efficiency. A thin Mo metal film was used as a buffer layer to prevent reactions between the ITO (indium-tin-oxide) electrode and the p+-a-Si:H layer. With the formation of semi-transparent Mo silicide after annealing, a lower EL thres... View full abstract»

• ### Further reduced form of Karhunen-Loeve transform for text independent speaker recognition

Publication Year: 1998, Page(s):1380 - 1382
Cited by:  Papers (1)
| | PDF (400 KB)

A text independent speaker recognition system based on the Karhunen-Loeve transform, derived from the split-and-merge algorithm, is proposed. The split-and-merge algorithm is applied to speaker data compression in the time domain. A set of experiments is conducted which gives a 91% recognition rate for 100 Mandarin speakers View full abstract»

• ### Strong birefringence at 1.55 μm of singlemode TE00 and TM00 rib optical waveguide-composed multiquantum well structures

Publication Year: 1998, Page(s):1414 - 1416
Cited by:  Papers (1)
| | PDF (420 KB)

The authors have designed, fabricated and characterised singlemode rib optical waveguides at 1.55 μm with high form birefringence. The core of the waveguide, which is composed of alternate layers of GaAs and AlAs, propagates both TE00 and TM00 modes with good vertical and lateral confinement, and presents a modal birefringence of >0.047 at 1.55 μm. This is an essenti... 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.

Full Aims & Scope

## Meet Our Editors

Editors-in-Chief

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

Professor Ian White