# Electronics Letters

## Filter Results

Displaying Results 1 - 25 of 51
• ### 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»

• ### Two-phase scheduling for reducing delay variance in space-division packet switches

Publication Year: 1998, Page(s):1386 - 1388
| | PDF (364 KB)

Several scheduling algorithms have been proposed to resolve transmission conflict in space-division packet switches. These algorithms do not consider the queueing delay of the backlog packets in the input adaptors. Consequently, some packets may wait a long time before they are switched, while others do not. The authors propose a two-phase scheduling method to reduce the delay variance. The simula... 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»

• ### DC and RF characteristics of 0.25 μm nonrecessed gate GaAs P-HEMT fabricated by self-aligned gate process

Publication Year: 1998, Page(s):1431 - 1433
Cited by:  Papers (2)
| | PDF (440 KB)

A 0.25 μm non-recessed gate GaAs P-HEMT has been fabricated by using a self-aligned gate process and Pd/Ni/Ge ohmic contact. Despite the non-recessed gate structure, the device showed excellent DC and RF characteristics (average gm,max=395 mS/mm, fT=75 GHz and fmax=190 GHz) with a considerable improvement in device yield and uniformity. The RF performances of th... 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»

• ### 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»

• ### CW-laser crystallisation of amorphous SiC alloys

Publication Year: 1998, Page(s):1430 - 1431
| | PDF (220 KB)

CW-laser crystallisation of amorphous silicon carbon alloys has been performed. It is shown that crystalline SiC can be obtained by irradiating nearly stoichiometric alloys, whereas phase segregation effects occur in silicon-rich alloys View full abstract»

• ### Polarisation anisotropy in asymmetric oxide aperture VCSELs

Publication Year: 1998, Page(s):1401 - 1402
Cited by:  Papers (1)  |  Patents (6)
| | PDF (288 KB)

Strong polarisation discrimination is observed from asymmetric oxide-aperture vertical cavity surface emitting lasers (VCSELs). The polarisation state perpendicular to the longer direction of the slit-shaped oxide aperture dominates when the aperture width is <4 μm. Generally, the mode size for TM polarisation is slightly less than that for TE polarisation, indicating polarisation-dependent ... View full abstract»

• ### Uniform threshold current, continuous-wave, singlemode 1300 nm vertical cavity lasers from 0 to 70°C

Publication Year: 1998, Page(s):1405 - 1407
Cited by:  Papers (32)  |  Patents (24)
| | PDF (336 KB)

The authors describe the first 1300 nm VCSELs which are compatible with commercial datacom performance requirements. These devices operate at CW up to 80°C. The threshold current varies by only ±0.5 mA (±10%) from 0 to 70°C. The devices show >0.38 mW singlemode output and <2.8 V operating from 0 to 70°C. The same devices also demonstrate a 1.25 Gbit/s modulation spe... View full abstract»

• ### Tunable superconducting microstrip filter

Publication Year: 1998, Page(s):1389 - 1390
Cited by:  Papers (2)
| | PDF (244 KB)

An electrically tunable two-pole bandpass filter with incorporated superconductor (YBaCuO) and nonlinear dielectric (SrTiO3) films has been designed and investigated. The filter layout and DC voltage tuning of the filter frequency response are presented View full abstract»

• ### Robust linear prediction of speech signals based on orthogonal framework

Publication Year: 1998, Page(s):1385 - 1386
| | PDF (236 KB)

A linear prediction is formulated via the orthogonal principle to facilitate the incorporation of various error minimisation criteria. A weighting function, which downplays extreme errors, is used to provide a robust estimate lying between the L1 and L2 criteria. Experiments based on synthetic vowels reveal that the proposed method outperforms the L1 and L2 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»

• ### 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»

• ### Low-complexity architecture of rake receiver for multi-code CDMA system

Publication Year: 1998, Page(s):1382 - 1383
Cited by:  Papers (5)  |  Patents (1)
| | PDF (276 KB)

A new low-complexity architecture CDMA rake receiver for multi-code CDMA systems is proposed. It contains shared hardware blocks to reduce hardware complexity. The hardware complexity of the proposed architecture is compared with that of a conventional CDMA rake receiver in terms of the number of Walsh code channels. The result shows that our proposed architecture has a 12 and 18.6% reduction in g... 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»

• ### Bias removal technique for blind source separation with noisy measurements

Publication Year: 1998, Page(s):1379 - 1380
Cited by:  Papers (15)
| | PDF (220 KB)

In blind source separation, measurement noise introduces biases in the estimated coefficients of the separation matrix. A simple modification to an adaptive algorithm for blind source separation is derived that mitigates these biases for reasonable signal-to-noise ratios when the correlations of the noises are known View full abstract»

• ### Channel monitoring, control and equalisation of multichannel fibre transmission system by multisection integrated active filters

Publication Year: 1998, Page(s):1411 - 1413
| | PDF (352 KB)

An integrated four section distributed Bragg reflector filter was employed as a channel filter and power controller/equaliser in an eight channel wavelength division multiplexed (WDM) system. Automatic channel locking and dynamic gain control within a range of 12 dB were achieved with a channel rejection ratio of 20 dB. This device has the potential to be a good candidate to simplify the managemen... View full abstract»

• ### 70 GHz InGaAs metal-semiconductor-metal photodetectors for polarisation-insensitive operation

Publication Year: 1998, Page(s):1421 - 1422
Cited by:  Papers (9)
| | PDF (336 KB)

InGaAs metal-semiconductor-metal photodetectors with 0.2 μm feature size finger electrodes have been fabricated. A pulse response time of 3.8 ps for 1.55 μm light was measured by means of electro-optical sampling. A 3 dB bandwidth of 70 GHz was extracted from the time domain data. Polarisation-insensitive operation under front illumination was obtained by employing semicircular-type finger e... View full abstract»

• ### 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»

• ### Characterising and modelling thermal behaviour of radio-frequency power LDMOS transistors

Publication Year: 1998, Page(s):1428 - 1430
Cited by:  Papers (5)
| | PDF (336 KB)

The thermal behaviour of radio-frequency power LDMOS transistors is analysed. Pulsed characterisation techniques are proposed to provide a straightforward method for determining the device zero temperature coefficient point. An LDMOS technology currently used for power amplification in L-band radiotelephony applications is studied. Load-pull measurements and nonlinear simulations are used to deter... 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»

• ### 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»

• ### Chaos theory and first-order ray tracing in ducts

Publication Year: 1998, Page(s):1388 - 1389
Cited by:  Papers (1)
| | PDF (228 KB)

The author highlights the importance of chaos theory to high frequency electromagnetic scattering problems and provides a novel method for presenting first-order ray theory related to the compound deviation matrix. This is applied to straight ducts of general cross-section and the average rate of reduction of ray intensity is related to the Lyapunov exponent. This allows estimates to be formed on ... 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»

• ### 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»

## 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