By Topic

# Electronics Letters

## Filter Results

Displaying Results 1 - 25 of 64
• ### System approach to disparity estimation

Publication Year: 1995, Page(s):871 - 873
Cited by:  Papers (2)
| | PDF (236 KB)

A system approach to disparity estimation using dynamic programming is presented. The four step system can calculate a dense corresponding map between a stereo pair with parallel or nonparallel camera geometry. Results are presented with CCIR 601 format stereo images View full abstract»

• ### Application of common gate and common drain circuits to microwave active filtering

Publication Year: 1995, Page(s):889 - 891
| | PDF (272 KB)

Active filtering has been an area of interest for several years. Well-stabilised commercial MMIC processes with reasonable costs now exist (with multichip projects). The authors report the design of a narrowband active MMIC bandpass filter centred about 4 GHz View full abstract»

• ### Searching for the best linear approximation of DES-like cryptosystems

Publication Year: 1995, Page(s):873 - 874
| | PDF (172 KB)

The authors show that the problem of searching for the best characteristic in linear cryptanalysis is equivalent to searching for the maximal weight path in a directed graph. Under certain restrictions, the best characteristic can be easily obtained even on a personal computer View full abstract»

• ### Multiplexed polymer-based chirped grating lenses working at 632.8 nm wavelength

Publication Year: 1995, Page(s):911 - 912
| | PDF (168 KB)

A multiplexed waveguide hologram containing two off-axis chirped grating lenses working at 632.8 nm was demonstrated on a glass substrate. Focal lengths of 35 and 37 mm were experimentally confirmed. The nature of phase modulation of the holographic medium allows the formation of multiplexed waveguide lenses on the same waveguide emulsion area. The graded index (GRIN) characteristic of the guiding... View full abstract»

• ### Bandpass characteristics of new dual-mode microstrip square loop resonators

Publication Year: 1995, Page(s):891 - 892
Cited by:  Papers (85)
| | PDF (208 KB)

A new type of dual-mode microstrip square loop resonator is proposed for the design of compact microwave bandpass filters. The associated characteristics of mode splitting are described. A novel bandpass filter, consisting of such a dual-mode resonator having a 1.2% bandwidth at 1.52 GHz was designed and fabricated. The measured filter performance is presented View full abstract»

• ### Burst-error correcting algorithm for Reed-Solomon codes

Publication Year: 1995, Page(s):848 - 849
Cited by:  Papers (6)  |  Patents (1)
| | PDF (164 KB)

A new decoding algorithm for burst errors in Reed-Solomon codes is given. This algorithm is shown to be more efficient than previously proposed methods View full abstract»

• ### First demonstration of laser computed tomography of human tooth by coherent detection imaging

Publication Year: 1995, Page(s):874 - 876
Cited by:  Papers (1)
| | PDF (252 KB)

The optical heterodyne technique with an argon laser as the source is used to obtain the first laser tomographic images of an extracted human tooth. The different layers of the internal structure of tooth such as dentine and pulp cavity can be clearly discerned with submillimetre resolution View full abstract»

• ### Observation of infrared intersubband emission in optically pumped quantum wells

Publication Year: 1995, Page(s):912 - 913
Cited by:  Papers (4)
| | PDF (176 KB)

Mid-infrared intersubband emission is investigated in GaAs/AlGaAs asymmetric coupled quantum wells exhibiting an energy separation between the ground and first excited subbands close to the LO-phonon energy. The authors show that an infrared emission occurs between excited subbands under intersubband optical pumping View full abstract»

• ### Computing the half-plane pull-in range of second-order PLLs

Publication Year: 1995, Page(s):845 - 846
Cited by:  Papers (4)
| | PDF (160 KB)

A definition is given for the half-plane pull-in range Ω2 of a second-order PLL with imperfect integrator. A formula for approximating Ω2 is not available. However, an iterative computational algorithm is presented for computing Ω 2, and it is applied to a simple example View full abstract»

• ### Role of recursive convolutional codes in turbo codes

Publication Year: 1995, Page(s):858 - 859
Cited by:  Papers (4)  |  Patents (2)
| | PDF (176 KB)

Recently proposed turbo codes' yield very good performance in combination with simple iterative decoding strategies. They can be thought of as parallel concatenated coding schemes employing systematic convolutional codes as constituent codes linked by an interleaver. A distinctive feature of turbo codes is that they use, as constituent codes. Recursive convolutional codes. Through the application... View full abstract»

• ### Fast image domain fractal compression by DCT domain block matching

Publication Year: 1995, Page(s):869 - 870
Cited by:  Papers (15)
| | PDF (188 KB)

Fractal image compression entails a computationally costly search for matching image blocks. It is proposed that a block be represented by its DCT coefficients, which may be made invariant to many of the usual block transforms. Owing to the energy packing properties of the DCT, the efficiency of an existing multidimensional nearest neighbour search is improved View full abstract»

• ### Improved source resistance in InP-based enhancement-mode HEMTs for high speed digital applications

Publication Year: 1995, Page(s):925 - 927
Cited by:  Papers (4)
| | PDF (264 KB)

A new approach to reducing the source resistance in InP-based InAlAs-InGaAs enhancement-mode HEMTs is developed using Pt-based buried-gate technology. Source resistance as small as 0.2 Ωmm is obtained, which results in an excellent transconductance of 1170 mS/mm for a 0.5 μm long gate enhancement-mode HEMT View full abstract»

• ### Method of lines for analysis of waveguide structures with multidiscontinuities

Publication Year: 1995, Page(s):892 - 893
Cited by:  Papers (5)
| | PDF (164 KB)

An efficient full-wave analysis, based on the method of lines, is performed on waveguides with multidiscontinuities. Three-dimensional hybrid mode analysis is used. The spectrum of the reflection coefficient for a periodic structure is provided as an example and is in good agreement with published results. Compared to other methods, the algorithm is stable in numerical computation for a large numb... View full abstract»

• ### Tunable travelling-wave laser with a linear cavity configuration

Publication Year: 1995, Page(s):895 - 896
Cited by:  Papers (1)  |  Patents (2)
| | PDF (160 KB)

A travelling-wave laser with a linear configuration cavity has been demonstrated. The travelling-wave operation is provided by orthogonality of the polarisation states of counterpropagating waves. In a fibre version of the scheme proposed, lasing was obtained at 1.559-1.564 μm, and wavelength tuning was performed by a loop polarisation controller. A linewidth of less than 15 MHz and maximum out... View full abstract»

• ### Allocation of unequal-spaced channels in WDM lightwave systems

Publication Year: 1995, Page(s):898 - 899
Cited by:  Papers (4)  |  Patents (3)
| | PDF (192 KB)

To reduce four-wave-mixing crosstalk in wavelength-division multiplexing (WDM) lightwave systems, an algebraic algorithm for finding the frequency locations of unequal-spaced channels is reported. This algebraic approach allows certain classes of optimum' channel locations to be obtained much faster than when using the recently reported computer exhaustive search View full abstract»

• ### Excimer laser writing of submicrometre period fibre Bragg gratings using phase-shifting mask projection

Publication Year: 1995, Page(s):901 - 902
Cited by:  Patents (4)
| | PDF (196 KB)

Submicrometre period, first-order Bragg gratings have been written in optical fibre, for the first time to the authors knowledge, by projecting a phase-shifting mask. Gratings with a peak reflectivity of 85% at a Bragg wavelength of 1530 nm were recorded using single pulses from a broadband KrF excimer laser View full abstract»

• ### Hybrid transmission of analogue PAL and digital 64-QAM CATV channels

Publication Year: 1995, Page(s):904 - 905
Cited by:  Papers (4)
| | PDF (160 KB)

A system experiment for fibre optic hybrid transmission of analogue CATV BK 300 and 1.8 Gbit/s with 64-QAM channels has been realised. It has been shown that additional transmission of 1.8 Gbit/s of compressed digital video (MPEG) using 64-QAM is possible without a significant degradation of the laser clipping rate. Measured bit error rates are compared with simulation results based on impulsive c... View full abstract»

• ### Cell loss recovery method in B-ISDN/ATM networks

Publication Year: 1995, Page(s):849 - 851
Cited by:  Papers (7)  |  Patents (1)
| | PDF (236 KB)

Presents a method to recover the consecutive cell losses due to buffer overflow in high-speed networks such as B-ISDN. The method is based on forward error correction (FEC) transmission of parity cells, and used by the decoder at the receiving side to reconstruct lost cells, together with data cells at the sending side. It recovers up to 18 consecutive cell losses in ATM networks. The missing cell... View full abstract»

• ### 40 Gbit/s AlGaAs/GaAs HBT 4:1 multiplexer IC

Publication Year: 1995, Page(s):876 - 877
Cited by:  Papers (18)
| | PDF (184 KB)

An experimental high speed 4:1 multiplexer integrated circuit capable of handling four simultaneous data channels without external delay lines is presented. The experimental circuit features an inherently fast two-stage configuration, with operation up to 40 Gbit/s demonstrated in an advanced AlGaAs/GaAs heterojunction bipolar technology. The system clock frequency is half the bit rate with only o... View full abstract»

• ### Single pulse fabrication of fibre Bragg gratings using a phase-conjugated KrF excimer laser

Publication Year: 1995, Page(s):885 - 886
Cited by:  Papers (2)  |  Patents (3)
| | PDF (180 KB)

A phase-conjugate mirror was used in the amplifier section of a KrF excimer laser to fabricate fibre Bragg gratings in singlemode Ge-doped silica core fibres with an uncompensated interferometer. Reflectivities as high as 26% and FWHM linewidths of 5.5 GHz at 0.817 μm were obtained in as-drawn fibre with a single pulse exposure View full abstract»

• ### TORUS-switch: a scalable internal speed-up ATM switch architecture and its 5 Gbit/s switch LSI

Publication Year: 1995, Page(s):906 - 908
Cited by:  Papers (3)  |  Patents (1)
| | PDF (276 KB)

A high speed and scalable ATM switch architecture, the TORUS-switch, is proposed. The switch is an internal speed-up crosspoint switch with cylindrical configuration. The self-bit-synchronisation technique is adopted to achieve high speed cell transmission without requiring high-density implementation technology. Distributed contention control based on the fixed output-precedence scheme is adopted... View full abstract»

• ### Improved syllable-based continuous Mandarin speech recognition using intersyllable boundary models

Publication Year: 1995, Page(s):853 - 854
Cited by:  Papers (1)  |  Patents (1)
| | PDF (192 KB)

A novel approach to compensate for the intersyllable coarticulation effect on continuous Mandarin speech recognition by supplementing the syllable HMM models with intersyllable boundary models is proposed. Experimental results show that the syllable recognition errors of a speaker-dependent recognition task are reduced by 24% View full abstract»

• ### Enhanced photosensitivity in lightly doped standard telecommunication fibre exposed to high fluence ArF excimer laser light

Publication Year: 1995, Page(s):879 - 880
Cited by:  Papers (8)  |  Patents (10)
| | PDF (184 KB)

The core refractive index of Corning SMF-28 optical fibre exposed to ArF laser pulses increases with the square of the fluence per pulse. Bragg gratings with a refractive index modulation amplitude higher than 10-3 have been obtained. This is an order of magnitude improvement over previously reported values for this type of fibre in the absence of treatment to enhance the photosensitivi... View full abstract»

• ### Simple technique for fabricating limited coupler gratings by holographic method using standard thick photoresist

Publication Year: 1995, Page(s):914 - 915
| | PDF (156 KB)

The fabrication of photoresist gratings is considered. A solution to the problem of `transversal standing waves' is given and appears simple and versatile View full abstract»

• ### Efficient dithering of sigma-delta modulators with adaptive bit flipping

Publication Year: 1995, Page(s):846 - 847
Cited by:  Papers (3)  |  Patents (5)
| | PDF (156 KB)

A new technique is presented for dithering single bit sigma-delta modulator (SDM) A/D and D/A converters in the digital domain. The system operates by detecting and randomising the limit cycle oscillations responsible for baseband tones. The system is efficient to implement in hardware and does not surfer from the analogue dither that is required in conventional SDM A/D converters 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