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# Electronics Letters

## Filter Results

Displaying Results 1 - 25 of 28
• ### Dual frequency microstrip antenna

Publication Year: 1983, Page(s):357 - 358
Cited by:  Papers (1)
| | PDF (256 KB)

A single-feed dual-frequency microstrip antenna is reported. It can be impedance-matched independently at the two frequencies of operation. The tested antenna has a VSWR of 1.33 at 2.32 GHz and 1.12 at 9.425 GHz. The configuration reported here can be impedance matched over a wider frequency range using standard impedance-matching techniques. View full abstract»

• ### Generalised lattice transformation for crystal filters

Publication Year: 1983, Page(s):358 - 359
| | PDF (269 KB)

Crystal lattice filters are usually based on the transformation of a lowpass Brune section to a second-order lattice section. This letter describes a generalisation, which transforms n Brune sections simultaneously into a lattice of order 2n, and which offers advantages for high-order filters, or filters with complex transmission zeros. View full abstract»

• ### Multimode interference mechanism in V(z) curves obtained by acoustic line-focus beam

Publication Year: 1983, Page(s):359 - 361
Cited by:  Papers (4)
| | PDF (445 KB)

The multimode interference mechanism in the acoustic material signatures of V(z) curves, which generally deforms the dip intervals and the shape, is investigated theoretically and experimentally for the acoustic line-focus beam. It is shown, taking a (111)-Si substrate as an example, that V(z) curves associated with multiple leaky waves are represented as a superposition of elemental V(z) curves w... View full abstract»

• ### Heterodyne OTDR at 0.82 Â¿m

Publication Year: 1983, Page(s):361 - 362
Cited by:  Papers (2)
| | PDF (322 KB)

We report on a heterodyne OTDR measurement on a single-mode fibre at a wavelength of 0.82 Â¿m using a stabilised semiconductor laser. In the actual set-up the dynamic range was limited by polarisation noise. View full abstract»

• ### Longitudinal-mode characteristics for 1.3 Â¿m GaInAsP/InP DFB lasers just below the threshold current

Publication Year: 1983, Page(s):362 - 363
Cited by:  Papers (4)
| | PDF (270 KB)

The stopband and the Bragg wavelength in a DFB laser were clearly observed by measuring longitudinal-mode characteristics just below the threshold current. It became clear that the first-order longitudinal-mode oscillation did not always occur. Coupling coefficients Â¿ for the DFB laser were deduced to be 10 to 40 cmÂ¿1 from the stopband width. View full abstract»

• ### Fast hardware implementation of the Winograd Fourier transform algorithm

Publication Year: 1983, Page(s):363 - 365
Cited by:  Papers (7)
| | PDF (377 KB)

We describe a novel partitioning of small Winograd DFTs into two identical subunits, each of which computes a real-input DFT. A bit-serial arithmetic single IC implementation in semicustom or custom LSI is described. A fast hardware WFTA is then proposed which is efficient for complex or real input data. View full abstract»

• ### Determination of minority carrier lifetime and effective back surface recombination velocity in BSF silicon solar cells from transient measurements

Publication Year: 1983, Page(s):365 - 367
| | PDF (454 KB)

The method of determining the base lifetime Â¿B and the effective surface recombination velocity Seff in a BSF solar cell from the transient decay of open-circuit voltage and short-circuit current is extended to include emitter recombinations. If the emitter recombinations in modern Si solar cells are neglected in interpreting the experimental data, the experimental value of Seff is found to be in... View full abstract»

• ### (GaAl)As/GaAs heterojunction bipolar transistors with graded composition in the base

Publication Year: 1983, Page(s):367 - 368
Cited by:  Papers (18)
| | PDF (284 KB)

The first fabrication and high-speed operation of a three-terminal (AlGa)As/GaAs heterojunction bipolar transistor with graded bandgap base is reported. Cutoff frequencies up to 16 GHz have been achieved in devices fabricated from material made by molecular beam epitaxy. This work demonstrates the feasibility of using a graded (AlGa)As base to enhance the speed of heterojunction bipolar transistor... View full abstract»

• ### Simple formulas giving temperature profiles in active layer of stripe-geometry laser diode without oxide barriers

Publication Year: 1983, Page(s):368 - 370
| | PDF (401 KB)

The simple, approximated formulas describing the temperature distribution in the active layer of the stripe-geometry laser diode without oxide barriers has been derived in this letter. View full abstract»

• ### 0.81 Â¿m band AlGaAs/GaAs double-channel planar buried-heterostructure laser with large optical cavity

Publication Year: 1983, Page(s):370 - 371
| | PDF (339 KB)

0.81 Â¿m-band AlGaAs/GaAs double-channel planar buried-heterostructure laser diodes with large optical cavity have been developed as light sources for use in analogue optical fibre communication systems. Linear light-output/current characteristics and a single-longitudinal-mode spectrum at a modulation frequency f = 100 MHz with modulation index m = 0.9 have been attained. View full abstract»

• ### Reduction of sidelobe level of reflector antennas by covering feed struts with a periodic structure

Publication Year: 1983, Page(s):371 - 373
Cited by:  Papers (1)
| | PDF (456 KB)

A periodic structure has been investigated and optimised which can be used to cover the struts of reflector antennas in order to reduce the far sidelobes caused by scattering from the struts. View full abstract»

• ### Use of a 252Cf source in cosmic ray simulation studies on CMOS memories

Publication Year: 1983, Page(s):373 - 374
Cited by:  Papers (4)
| | PDF (301 KB)

A laboratory 252Cf source has been found to provide a convenient and satisfactory technique for evaluating the susceptibility of VLSI static RAMs to cosmic-ray-induced single-event upsets. The calibration and use of the system are described, and results for some commercial CMOS RAMs are presented. View full abstract»

Publication Year: 1983, Page(s):374 - 376
| | PDF (377 KB)

The performance of two nondissipative devices used as feed elements for adaptive uplink depolarisation control in 18 GHz TV feeder links is analysed. The operational parameters under the presence of heavy precipitation are evaluated and practical limitations are discussed. View full abstract»

• ### Capacitance/voltage characteristics of semiconductor-insulator-semiconductor (SIS) structure

Publication Year: 1983, Page(s):376 - 377
| | PDF (267 KB)

Ideal capacitance/voltage curves of Si(2)-SiO2-Si(1) structure are computed in the absence of surface states and oxide changes with the SiO2 thickness, conductivity types, impurity concentrations of Si(1) and (2) as parameters. Impurity concentrations of Si(1), (2) and SiO2 thickness can be estimated from the measured capacitance/voltage curves by comparing them with the calculated ones as is the ... View full abstract»

• ### Coupled microstrip parallel-gap model for improved filter and coupler design

Publication Year: 1983, Page(s):377 - 379
Cited by:  Papers (3)
| | PDF (438 KB)

The parallel gap formed by the open end of a section of coupled microstrip lines is described analytically by its even and odd mode equivalent fringing field lengths. These are given as functions of line width, gap width and substrate dielectric constant. The use of these parameters in filter and coupler design is outlined briefly. View full abstract»

• ### Linear algebra and extended mappings generalise public key cryptographic knapsack algorithms

Publication Year: 1983, Page(s):379 - 381
| | PDF (423 KB)

The original Merkle-Hellman knapsack algorithm is the most practical of the public key algorithms, but is considered insecure. Improvements have been proposed. In the letter the improvements are unified and extended using linear algebra and extended mappings. View full abstract»

• ### Comment: Modified canonic ladder realisation of IIR digital filters

Publication Year: 1983
| | PDF (232 KB)

First Page of the Article
View full abstract»

Publication Year: 1983, Page(s):381 - 382
| | PDF (232 KB)

First Page of the Article
View full abstract»

• ### TE11 modes in straight and curved circular waveguide with deformedÂ¿ cross-section

Publication Year: 1983, Page(s):382 - 383
| | PDF (252 KB)

The two polarisations of TE11 modes are shown to be non-degenerated in a circular waveguide when its cross-section is conveniently deformedÂ¿. So the crosspolar discrimination is improved in such a curved guide. This permits the use of this structure as an antenna feeder at frequencies about 12 GHz. View full abstract»

• ### High-resolution mapping of pn-junctions by computer-processed EBIC-signals

Publication Year: 1983, Page(s):383 - 385
Cited by:  Papers (1)
| | PDF (443 KB)

Computer processing is introduced to increase resolution in EBIC measurements. View full abstract»

• ### Temporal and spectral characteristics of rapidly gain-switched GaAs/GaAlAs buried-heterostructure lasers

Publication Year: 1983, Page(s):385 - 387
Cited by:  Papers (2)
| | PDF (475 KB)

The temporal and spectral output of GaAs/GaAlAs buried-heterostructure lasers under excitation with 60 ps electrical pulses is investigated for different DC bias conditions. Optical pulses comparable in width to the electrical pulses can be obtained only if the DC bias is below or close to threshold, where multimode emission is observed. For DC bias well above threshold the laser remains single-mo... View full abstract»

• ### Composition control in proton-exchanged LiNbO3

Publication Year: 1983, Page(s):387 - 388
Cited by:  Papers (7)
| | PDF (271 KB)

The amount of hydrogen in Li1Â¿xHxNbO3 layers prepared by proton exchange of LiNbO3 in benzoic acid melts can be limited by adding lithium compounds to the melt. Limiting exchange prevents surface damage, a problem primarily affecting y-cut substrates, and reduces scattering in exchanged guides. View full abstract»

• ### Feedback-induced noise in index-guided semiconductor lasers and its reduction by modulation

Publication Year: 1983, Page(s):388 - 390
Cited by:  Papers (6)
| | PDF (392 KB)

We report a reduction in feedback noise of 15Â¿20 dB by direct modulation of the laser with a 2Â¿5 mA modulation current. The reduction is almost independent of modulation frequency in the frequency range from 50 MHz to 200 MHz, but depends on the external cavity length. The external cavity lengths considered are 5Â¿15 cm. View full abstract»

• ### Asynchronous multiplexing for an optical-fibre local-area network

Publication Year: 1983, Page(s):390 - 392
Cited by:  Papers (9)
| | PDF (349 KB)

By trading some of the very high bandwidth capability of an optical-fibre channel it is possible to produce an attractively simple asynchronously multiplexed local-area network. View full abstract»

• ### Control of locally testable duplex system for large-scale implementation

Publication Year: 1983, Page(s):392 - 393
| | PDF (271 KB)

In the letter the control of a duplex system is presented. This is characterised by the locality of the testing devices and by easy expandability to a larger system with large-scale attributes. The control suggests the viability of a VLSI chip implementation by a modular design. 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