# Electronics Letters

## Filter Results

Displaying Results 1 - 25 of 62
• ### Higher-order time-varying allpass filters for signal decorrelation in stereophonic acoustic echo cancellation

Publication Year: 1999, Page(s):88 - 90
Cited by:  Papers (7)
| | PDF (324 KB)

A new technique is presented for decorrelating the input signals in stereophonic systems by means of time-varying allpass filters. The controllable and almost linear phase response of higher-order allpass filters is exploited in this context and a particular type of time variation is used to vary the parameters of such filters. Simulation results are presented based on real stereophonic signals an... View full abstract»

• ### Algorithm for robot position tracking using ultrasonics

Publication Year: 1999, Page(s):87 - 88
| | PDF (200 KB)

Extending previous work on ultrasonic robot tracking, a new geometric position-calculation algorithm is introduced. This removes the need to locate the ultrasonic receivers at fixed positions on orthogonal axes, equidistant from the origin, and offers substantial advantages in terms of improved accuracy and flexibility View full abstract»

• ### High-fT n-MODFETs fabricated on Si/SiGe heterostructures grown by UHV-CVD

Publication Year: 1999, Page(s):86 - 87
Cited by:  Papers (11)
| | PDF (220 KB)

The authors present high-frequency results of n-channel MODFETs fabricated on high-mobility Si/SiGe strained layer heterostructures grown by ultrahigh vacuum chemical vapour deposition (UHV-CVD). Devices with gate length Lg=0.2 μm and drain-source separation L ds=0.9 μm displayed unity current gain cutoff frequencies as high as fT=45 GHz (47 GHz) at Vds<... View full abstract»

• ### All-optical 2R regeneration based on interferometric structure incorporating semiconductor optical amplifiers

Publication Year: 1999, Page(s):59 - 60
Cited by:  Papers (10)  |  Patents (2)
| | PDF (240 KB)

All-optical 2R regeneration in an SOA-based interferometric Michelson structure using a novel technique is experimentally demonstrated. An output extinction ratio of ~10 dB is measured for an input extinction ratio of 6 dB and a noise suppression capability of ~4.5 dB is obtained, clearly demonstrating the feasibility of this technique View full abstract»

• ### Numerical solution of time-dependent coupled-wave equations using split-step algorithm

Publication Year: 1999, Page(s):84 - 85
Cited by:  Papers (5)
| | PDF (188 KB)

A novel method adopting a split-step algorithm is used to numerically solve the time-dependent coupled-wave equations, which are frequently used in the analysis of photonic devices including DFB/DBR structures. The new split-step algorithm is shown to be much more accurate and efficient than the conventional algorithm View full abstract»

• ### Polarisation independent all-optical demultiplexing using four wave mixing in dispersion shifted fibre

Publication Year: 1999, Page(s):72 - 73
Cited by:  Papers (6)  |  Patents (3)
| | PDF (240 KB)

A novel polarisation independent demultiplexer based on four wave mixing in a dispersion shifted fibre is proposed using a short, highly birefringent fibre in a forward and backward propagation scheme to allow polarisation diversity operation. The device has been tested with a 4×10 Gbit/s optical time division multiplexing transmitter. Polarisation dependency is less than 0.5 dB and the BER ... View full abstract»

• ### 40 Gbit/s single channel dispersion managed pulse propagation in standard fibre over 509 km

Publication Year: 1999, Page(s):57 - 59
Cited by:  Papers (2)  |  Patents (4)
| | PDF (408 KB)

Error free propagation of a single polarisation optical time division multiplexed 40 Gbit/s dispersion managed pulse data stream over 509 km has been achieved in standard (non-dispersion shifted) fibre. Dispersion compensating fibre was used after each amplifier to reduce the high local dispersion of the standard fibre View full abstract»

• ### Large-signal compression-current measurements in high-power microwave pin photodiodes

Publication Year: 1999, Page(s):82 - 84
Cited by:  Papers (10)
| | PDF (316 KB)

The authors present the first large-signal compression measurements surface-illuminated pin microwave photodetectors. The maximum RF power delivered by the photodiodes was +12, +17 and +20 dBm for bandwidths of 25.3 and 1 GHz, respectively View full abstract»

• ### Learning algorithms for minimum cost, delay bounded multicast routing in dynamic environments

Publication Year: 1999, Page(s):24 - 25
Cited by:  Papers (4)
| | PDF (216 KB)

Distributed stochastic learning automata (SLA) are used to grow' minimum cost delay bounded multicast trees in a dynamic membership environment. It is found that learning automata, which use minimal state information and require only local connectivity knowledge, provide reduced costs over shortest path approaches and comparable static costs to alternative algorithms, by learning to minimise the ... View full abstract»

• ### Analogue CMOS high-frequency continuous wavelet transform circuit

Publication Year: 1999, Page(s):4 - 5
Cited by:  Papers (4)
| | PDF (328 KB)

A 16-channel analogue CMOS high-frequency continuous wavelet transform circuit has been realised. The circuit performs a time-frequency decomposition of a high-frequency input signal. A 100 MHz operating frequency, 45 MHz bandwidth, and 40 mW/channel power dissipation have been achieved using a 0.5 μm CMOS process View full abstract»

• ### Polarisation-independent all-optical circulating shift register based on self-phase modulation of semiconductor optical amplifier

Publication Year: 1999, Page(s):70 - 72
Cited by:  Papers (2)
| | PDF (348 KB)

The authors propose and experimentally demonstrate polarisation-independent all-optical circulating shift register (CSR) based on self-phase modulation of a semiconductor optical amplifier, which is very insensitive to the polarisation of the input pulse train and requires very low switching energy (~176 fJ). An all-optical 91 bit CSR was constructed for an input pulse stream at 2.897 GHz, and a h... View full abstract»

• ### Compact building blocks for artificial neural networks

Publication Year: 1999, Page(s):56 - 57
Cited by:  Papers (2)
| | PDF (268 KB)

A four quadrant analogue multiplier, an activation function and a differentiator intended for the implementation of backpropagation algorithms are proposed. The priorities for the design are low-power, low-voltage, and minimum silicon area. Breadboard results, showing good agreement with the theoretical ones, are reported View full abstract»

• ### Widely tunable long-period fibre gratings

Publication Year: 1999, Page(s):81 - 82
Cited by:  Papers (20)  |  Patents (3)
| | PDF (224 KB)

The authors report the realisation of a new type of long-period fibre grating with an enhanced temperature sensitivity of 8O nm/100°C by the use of specially-designed fibre structures incorporating polymers. These new gratings should enable broadly tunable filters for communications systems View full abstract»

• ### 1.5 μm InGaAlAs-strained MQW ridge-waveguide laser diodes with hot-carrier injection suppression structure

Publication Year: 1999, Page(s):41 - 43
Cited by:  Papers (2)
| | PDF (296 KB)

The authors have developed a ridge-waveguide laser diode (LD) with a layer structure which suppresses hot-carrier injection into separate confinement heterostructure layers as well as effectively confining carriers in the multiquantum well layers. Fabricated LDs show low threshold currents and improved temperature characteristics due to a decrease in the leakage current outside the ridge-waveguide... View full abstract»

• ### Investigation of sensor failure with respect to ambiguities in linear arrays

Publication Year: 1999, Page(s):22 - 23
Cited by:  Papers (1)
| | PDF (208 KB)

An approach to the calculation of the maximum number of ambiguous generator sets of directions of arrival which exist in linear arrays is presented for the first time. A new performance index is also proposed which characterises the importance' of each sensor with respect to ambiguities in the presence of sensor failure View full abstract»

• ### Dual-polarised uniplanar conical-beam antennas for HIPERLAN

Publication Year: 1999, Page(s):2 - 4
Cited by:  Papers (4)
| | PDF (308 KB)

A dual-polarised conical-beam microstrip antenna, with a strictly uniplanar conductor pattern, is realised as an array of three square patches whose corners meet a central feed point. For the second polarisation the antenna functions as a series fed array View full abstract»

• ### Non-binary convolutional codes for turbo coding

Publication Year: 1999, Page(s):39 - 40
Cited by:  Papers (66)  |  Patents (3)
| | PDF (208 KB)

The authors consider the use of non-binary convolutional codes in turbo coding. It is shown that quaternary codes can be advantageous, both from performance and complexity standpoints, but that higher-order codes may not bring further improvement View full abstract»

• ### Optimisation of dispersion-induced power penalty mitigation in millimetre-wave fibre optic links

Publication Year: 1999, Page(s):69 - 70
| | PDF (228 KB)

The authors investigate the dispersion-induced power penalty (DIPP) in millimetre-wave fibre optic links. It is shown that the modulation index of the local oscillator driving signal at the harmonic upconverting Mach-Zehnder electro-optic modulator affects the quality of the DIPP mitigation View full abstract»

• ### Fair queueing algorithm with rate independent delay for ATM networks

Publication Year: 1999, Page(s):19 - 20
| | PDF (180 KB)

A new scheduling algorithm based on self-clocked fair queueing is proposed. The algorithm employs an array of sorting bins for managing the virtual finishing time of connections and uses token buckets as a behaviour-indicator. It remedies the drawbacks of existing fair queueing algorithms and is able to reserve bandwidth to connections while guaranteeing a class-dependent and rate-independent dela... View full abstract»

• ### Input switch configuration suitable for rail-to-rail operation of switched op amp circuits

Publication Year: 1999, Page(s):8 - 10
Cited by:  Papers (48)  |  Patents (5)
| | PDF (284 KB)

A switch configuration to be used at the input of switched op amp circuits is introduced. The circuit is an extension of the gate-source bootstrapping technique such that rail-to-rail operation of the input switch becomes possible. Simulations show the usefulness of the proposed circuit down to 0.9 V View full abstract»

• ### Improved group signature scheme based on discrete logarithm problem

Publication Year: 1999, Page(s):37 - 38
Cited by:  Papers (1)  |  Patents (1)
| | PDF (248 KB)

In 1998, an efficient group signature scheme (the Lee-Chang scheme) was proposed based on the discrete logarithm problem. In this scheme, different group signatures of a signer for different messages contain some identical information. Once one group signature is identified, all previous group signatures are also identified at the same time. This is impractical for applications of group signatures... View full abstract»

• ### RF tunable attenuator and modulator using high Tc superconducting filter

Publication Year: 1999, Page(s):55 - 56
| | PDF (200 KB)

A small path for both control current and radiofrequency (RF) current has been introduced into a high Tc superconducting filter. The interaction between the control current and RF current made the insertion loss of the filter sensitive to the amplitude of the control current. This structure has been used as an RF tunable attenuator and a modulator. 5 dB attenuation range was achieved. The maximum ... View full abstract»

• ### Frequency downconverter for high-capacity fibre grating based beamformers for phased arrays

Publication Year: 1999, Page(s):66 - 67
Cited by:  Papers (2)
| | PDF (240 KB)

A novel all-optical microwave frequency downconverter is proposed which overcomes the effect of the optical beat-noise in X-band grating-based multi-beam phased arrays allowing a significant extension of the number of beams as well as minimum number of optical interconnects View full abstract»

• ### Low-cost microlens array for long-period grating fabrication

Publication Year: 1999, Page(s):79 - 81
| | PDF (432 KB)

A low-cost technique using commercial UV-grade fibres to construct a microlens array that is suitable for the mass-production of long-period gratings is reported. The array can withstand in excess of 1 J/cm2 per 20 ns pulses of 248 nm laser light. The growth rate of long-period gratings fabricated using the array is four times faster than that possible using a metal mask View full abstract»

• ### Electromagnetic penetration into 2D multiple slotted rectangular cavity: TE-wave

Publication Year: 1999, Page(s):31 - 32
Cited by:  Papers (1)
| | PDF (192 KB)

Electromagnetic wave penetration into a two-dimensional rectangular cavity with multiple slots in an infinite conducting plane with a finite thickness is investigated. The Fourier transform and a mode-matching technique are used to obtain simultaneous equations, which are solved to represent the scattered and penetrated fields in series forms suitable for numerical computations 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