By Topic

# Electronics Letters

## Filter Results

Displaying Results 1 - 25 of 38
• ### Q-switching cleaved-coupled-cavity laser with an integrated intracavity modulator

Publication Year: 1984, Page(s):1 - 2
Cited by:  Papers (1)
| | PDF (322 KB)

We describe fabrication and performance of a Q-switching cleaved-coupled-cavity laser with an integrated intracavity modulator. The pulse repetition frequency of this 3-section device was tunable between 320 and 450 MHz with an external microwave injected signal, the modulation depth of the pulsations was 80Â¿100% with a nearly single-longitudinal-mode output spectrum, and the Q-switched light pul... View full abstract»

• ### Selection of the order of Routh approximants

Publication Year: 1984, Page(s):2 - 4
| | PDF (401 KB)

A well known method for estimating in advance the order of a satisfactory Routh approximant does not always yield acceptable results. A simple criterion is thus proposed to check the results of this method. View full abstract»

• ### Acousto-optic diffraction of optical guided waves in crystal quartz

Publication Year: 1984, Page(s):4 - 5
| | PDF (272 KB)

A waveguide supporting a single propagating mode has been fabricated by ion beam modification of X-cut crystal quartz. The gas ion implantation reduced the index of a subsurface layer, and guiding occurred in the surface region. The acoustic properties of the quartz are little affected. Bragg diffraction of guided light by surface acoustic waves was observed with efficiencies of approximately 0.25... View full abstract»

• ### Accuracy of the electromagnetic transient in overhead transmission lines

Publication Year: 1984, Page(s):5 - 7
| | PDF (408 KB)

An examination is made of past, present and possible future results in evaluating the modal form of the transmission-line transient. An exact analysis of the problem has been formulated and a comparison of its accurate evaluation is made with other workers' available results. View full abstract»

• ### Design of a pulse-shaping filter with a specified relationship between jitter and intersymbol interference

Publication Year: 1984, Page(s):7 - 8
Cited by:  Papers (2)
| | PDF (323 KB)

An improved method for the design of pulse-shaping filters is described. Practical relationships between the decision-threshold spacing and the timing tolerance are used to specify the aspect ratio of a rectangle fitted in the eye opening; its size is then maximised. View full abstract»

• ### Three-dimensional rate-distortion function and comparison with some image-coding methods

Publication Year: 1984, Page(s):8 - 9
| | PDF (299 KB)

Based on a 3-dimensional exponential covariance model for image sequences, a 3-dimensional rate-distortion function is obtained, and it is compared with some interframe transform and hybrid coding techniques. The computational problem of 3-dimensional complexity is reduced by the assumption that the covariance function is separable between the spatial and temporal covariances. It is shown that the... View full abstract»

• ### Calibration of a six-port reflectometer using projective geometry concepts

Publication Year: 1984
Cited by:  Papers (6)
| | PDF (450 KB)

Projective geometry concepts are applied to the problem of calibrating a six-port reflectometer with known standards. It is shown that five independent standards are needed. Note-worthy in this technique is the absence of any idealised hardware assumptions or the need for selecting a preferred normalising port. An explicit solution is obtained using only linear equation techniques. View full abstract»

• ### Comment: System reduction by Cauer continued-fraction expansion about s = a and s = ∞ alternately

Publication Year: 1984, Page(s):11 - 12
| | PDF (272 KB)

First Page of the Article
View full abstract»

• ### Reply: System reduction by Cauer continued-fraction expansion about s = a and s = 0 alternatively

Publication Year: 1984
| | PDF (125 KB)

First Page of the Article
View full abstract»

• ### Relation between the Karhunen-Loeve and sine transforms

Publication Year: 1984, Page(s):12 - 13
Cited by:  Papers (1)
| | PDF (249 KB)

In an earlier paper it was demonstrated that the cosine transform can be derived from the optimum (Karhunen-LoÃ¿ve) transform of a first-order Markov source in the limiting case when the adjacent data element correlation coefficient tends to unity. The purpose of the letter is to show that, in the alternative limiting case when the correlation tends to zero, the sine transform results. View full abstract»

• ### Wavelength-dependent optical loss increase in graded-index optical fibre transmission lines

Publication Year: 1984, Page(s):13 - 14
Cited by:  Papers (4)
| | PDF (277 KB)

Wavelength-dependent optical loss increase in GeO2-P2O5-doped graded-index optical fibre transmission lines has been observed. The loss increase is found to depend strongly on the P2O5 concentration. By reducing the P2O5 concentration, loss increases at 1.3 Â¿m can be suppressed to a sufficient extent without any hindrance for practical usage. View full abstract»

• ### Split radix' FFT algorithm

Publication Year: 1984, Page(s):14 - 16
Cited by:  Papers (137)
| | PDF (416 KB)

A new N = 2n fast Fourier transform algorithm is presented, which has fewer multiplications and additions than radix 2n, n = 1, 2, 3 algorithms, has the same number of multiplications as the Raderi-Brenner algorithm, but much fewer additions, and is numerically better conditioned, and is performed in place' by a repetitive use of a `butterfly'-type structure. View full abstract»

• ### Long-wavelength transimpedance optical receiver performance enhancement using cooled germanium avalanche photodiodes

Publication Year: 1984, Page(s):16 - 18
Cited by:  Papers (2)
| | PDF (426 KB)

An optical sensitivity improvement of 1.5 dB was produced by moderate cooling of a commercially available 100 Â¿m p+-n Ge APD in a transimpedance receiver, built on a standard printed circuit board. At 1.3 Â¿m and 140 Mbaud, Â¿45.2 dBm was achieved, making this receiver highly competitive where cooling is permitted. View full abstract»

• ### Formula for feedback gains in eigenvalue control of singular systems

Publication Year: 1984, Page(s):18 - 19
| | PDF (229 KB)

For single-input singular systems the problem of finding an explicit formula for the feedback gains in eigenvalue control has been solved. The formula is easily implementable in a digital computer. View full abstract»

• ### Dispersion characteristics of coupled microstrip with overlay on anisotropic dielectric substrate

Publication Year: 1984, Page(s):19 - 20
Cited by:  Papers (4)
| | PDF (242 KB)

The letter describes how one can obtain the equal effective dielectric constants of even and odd modes on the parallel-coupled microstrip at a frequency by using an anisotropic dielectric substrate with isotropic overlay. The frequency can be varied by using overlays of various thicknesses. The results suggest the possibility of realising a high-directivity coupler in the high-frequency microwave ... View full abstract»

• ### Wavelength-dependent differential modal delay in graded-index fibres

Publication Year: 1984, Page(s):20 - 22
Cited by:  Papers (1)
| | PDF (391 KB)

We present a technique for measurement of wavelength-dependent differential modal delay in a graded-index fibre. The data are used to derive the excitation-dependent zero-dispersion wavelength. The method offers an accurate calibration procedure to determine the zero-material-dispersion wavelength for given dopant concentration. View full abstract»

• ### Novel delay-lock-loop implementation for reduced acquisition time of PN sequences

Publication Year: 1984, Page(s):22 - 24
Cited by:  Papers (1)
| | PDF (525 KB)

Pseudo-noise codes are widely used in spread-spectrum systems. A technique is described which significantly improves the acquisition speed of such codes. This consists of generating a broad discriminator characteristic whose phase may be controlled automatically by the loop filter output. Experimental and computed acquisition trajectories of the new loop are compared with standard loops. View full abstract»

• ### Line fault prediction and location in echo cancelling data transmission systems

Publication Year: 1984, Page(s):24 - 25
| | PDF (332 KB)

Theoretical and practical results are presented which show that the tap coefficients of an echo cancelling modem can be used as an aid to line fault prediction and location. It is indicated that in some cases it is possible to identify a line fault before the transmission performance is seriously impaired. View full abstract»

• ### Novel realisation of an automatic transmit-receive switch and two bandpass filters by a single SAW filter

Publication Year: 1984, Page(s):25 - 27
Cited by:  Papers (1)
| | PDF (615 KB)

In the letter we describe and demonstrate a completely new application of SAW filters in present-day communication systems to realise a kind of transmit-receive switch (TRS). The TRS using the SAW filter works well up to expectations, replacing the required two bandpass filters and an antenna directional coupler. To do this the undesired reverse propagation sidelobe (higher) of a group-type unidir... View full abstract»

• ### Linewidth enhancement factor for quantum-well lasers

Publication Year: 1984, Page(s):27 - 29
Cited by:  Papers (8)
| | PDF (634 KB)

The linewidth enhancement factor Â¿ is calculated for an idealised GaInAs quantum-well laser. Values between 1 and 2 are found for a range of possible lasing energies. Somewhat larger values are expected for GaInAs quantum wells with InP barriers. It is concluded that dramatic reductions in Â¿ are not to be expected for quantum wells. View full abstract»

• ### Am quantum noise in 1.3 μm InGaAsP lasers

Publication Year: 1984, Page(s):29 - 30
| | PDF (291 KB)

Intensity fluctuations for two types of 1.3 μm InGaAsP laser are measured and calculated based on device structural and material parameters and are found to be in good agreement with the quantum-noise-limited level. View full abstract»

• ### Fading in heterodyne OTDR

Publication Year: 1984, Page(s):30 - 32
Cited by:  Papers (34)
| | PDF (463 KB)

The first- and second-order statistics of the Rayleigh back-scatter signal from a single-mode fibre under quasimonochromatic pulse excitation are derived. A fading phenomenon is predicted and observed experimentally. View full abstract»

• ### Optical correlation in Bi12SiO20 at 632.8 nm

Publication Year: 1984, Page(s):32 - 33
| | PDF (498 KB)

Optical image correlation with a low-power HeNe laser has been demonstrated using the phenomenon of degenerate four-wave mixing in Bi12SiO20. Preliminary results for character recognition, using a compact two-dimensional image processor, are presented. View full abstract»

• ### New model for submicron-scale dual-gate TFT

Publication Year: 1984, Page(s):33 - 35
| | PDF (415 KB)

A new model is proposed to represent the submicron-scale dual-gate thin-film transistor (DGTFT) as the association of three single-gate TFTs. The finite-difference method is applied to verify the conditions for which the model is valid, and using a new variant of this technique the quasistatic solution is obtained in an inhomogeneous medium. View full abstract»

• ### Low OH excess loss PCVD fibres prepared by fluorine doping

Publication Year: 1984, Page(s):35 - 37
Cited by:  Papers (4)
| | PDF (632 KB)

Single-mode and multimode fibres have been prepared with PCVD using C2F6 as dopant. With increasing concentrations of C2F6 an exponential decrease of the OH excess loss was found. Ultra-low OH absorption losses of 0.2 dR/km at 1.38 Â¿m have been achieved. 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