Online ISSN
1350-911X
Print ISSN
0013-5194
Electronics Letters
Volume 24, Issue 22, 27 October 1988
Volumes & issues:
-
Volume 59 (2023)
-
Volume 58 (2022)
-
Volume 57 (2021)
-
Volume 56 (2020)
-
Volume 55 (2019)
-
Volume 54 (2018)
-
Volume 53 (2017)
-
Volume 52 (2016)
-
Volume 51 (2015)
-
Volume 50 (2014)
-
Volume 49 (2013)
-
Volume 48 (2012)
-
Volume 47 (2011)
-
Volume 46 (2010)
-
Volume 45 (2009)
-
Volume 44 (2008)
-
Volume 43 (2007)
-
Volume 42 (2006)
-
Volume 41 (2005)
-
Volume 40 (2004)
-
Volume 39 (2003)
-
Volume 38 (2002)
-
Volume 37 (2001)
-
Volume 36 (2000)
-
Volume 35 (1999)
-
Volume 34 (1998)
-
Volume 33 (1997)
-
Volume 32 (1996)
-
Volume 31 (1995)
-
Volume 30 (1994)
-
Volume 29 (1993)
-
Volume 28 (1992)
-
Volume 27 (1991)
-
Volume 26 (1990)
-
Volume 25 (1989)
-
Volume 24 (1988)
-
Volume 23 (1987)
-
Volume 22 (1986)
-
Volume 21 (1985)
-
Volume 20 (1984)
-
Volume 19 (1983)
-
Volume 18 (1982)
-
Volume 17 (1981)
-
Volume 16 (1980)
-
Volume 15 (1979)
-
Volume 14 (1978)
-
Volume 13 (1977)
-
Volume 12 (1976)
-
Volume 11 (1975)
-
Volume 10 (1974)
-
Volume 9 (1973)
-
Volume 8 (1972)
-
Volume 7 (1971)
-
Volume 6 (1970)
-
Volume 5 (1969)
-
Volume 4 (1968)
-
Volume 3 (1967)
-
Volume 2 (1966)
-
Volume 1 (1965)
Volume 24, Issue 22
27 October 1988
Rugged all-fibre endless polarisation controller
- Author(s): G.R. Walker and N.G. Walker
- Source: Electronics Letters, Volume 24, Issue 22, p. 1353 –1354
- DOI: 10.1049/el:19880925
- Type: Article
- + Show details - Hide details
-
p.
1353
–1354
(2)
A polarisation controller comprising four lengths of PM fibre wound onto piezoelectric cylinders has been produced. It is mechanically rugged, has an insertion loss of 1.5 dB, and is capable of endless control between two arbitrary time-varying states of polarisation. Polarisation control has been successfully demonstrated for the first time in a coherent optical transmission system over installed fibre.
Field demonstration of 565 Mbit/s DPSK coherent transmission system over 176 km of installed fibre
- Author(s): M.J. Creaner ; R.C. Steele ; I. Marshall ; G.R. Walker ; N.G. Walker ; J. Mellis ; S. Al Chalabi ; I. Sturgess ; M. Rutherford ; J. Davidson ; M. Brain
- Source: Electronics Letters, Volume 24, Issue 22, p. 1354 –1356
- DOI: 10.1049/el:19880926
- Type: Article
- + Show details - Hide details
-
p.
1354
–1356
(3)
We report the results of a 565 Mbit/s coherent system field trial over 176 km of installed SM fibre. Fully automated endless polarisation control was employed using a novel method and error free operation was achieved with BER readings of better than 10−13.
New noninteractive identity-based key distribution system
- Author(s): S. Tsujii ; K. Kurosawa ; T. Itoh
- Source: Electronics Letters, Volume 24, Issue 22, p. 1356 –1357
- DOI: 10.1049/el:19880927
- Type: Article
- + Show details - Hide details
-
p.
1356
–1357
(2)
The paper presents a new identity-based key distribution system (IDKDS), in which the common keys can be shared without auxiliary communications. The proposed IDKDS can be regarded as an identity-based version of Diffie and Hellman's key distribution system, and is a generalisation of the identity-based cryptosystem (IDC) developed by the authors. The paper also analyses the security of the IDKDS and shows that the IDKDS is practically secure.
Integrated-optical circuit for fibre gyroscope applications
- Author(s): C. Schäffer and G. Stock
- Source: Electronics Letters, Volume 24, Issue 22, p. 1357 –1358
- DOI: 10.1049/el:19880928
- Type: Article
- + Show details - Hide details
-
p.
1357
–1358
(2)
An integrated-optic chip containing two acousto-optic frequency shifters and a TE-pass polariser is presented. All the elements needed for a fibre-optic gyroscope using the frequency-shift method are realised on one LiNbO3 chip.
New pseudorandom/natural code conversion method
- Author(s): E.M. Petriu
- Source: Electronics Letters, Volume 24, Issue 22, p. 1358 –1359
- DOI: 10.1049/el:19880929
- Type: Article
- + Show details - Hide details
-
p.
1358
–1359
(2)
A new pseudorandom/natural code conversion method is proposed. The new method is characterised by a reasonable cost/speed compromise between the known parallel- and sequential-type code conversion methods.
12 GHz FM bandwidth for a 1530 nm DFB laser
- Author(s): R.S. Vodhanel and S. Tsuji
- Source: Electronics Letters, Volume 24, Issue 22, p. 1359 –1361
- DOI: 10.1049/el:19880930
- Type: Article
- + Show details - Hide details
-
p.
1359
–1361
(3)
The FM response of a 1530 nm DFB laser has been measured using a novel birefringent fibre interferometer. The FM response is flat out to 12 GHz when operated at 9mW/facet, corresponding to a linewidth of 15 MHz, and there is a 15–25 ps delay between the FM and AM responses.
Design of highly selective two-dimensional recursive fan filters by relaxing symmetry constraints
- Author(s): Z. Lin ; L.T. Bruton ; N.R. Bartley
- Source: Electronics Letters, Volume 24, Issue 22, p. 1361 –1362
- DOI: 10.1049/el:19880931
- Type: Article
- + Show details - Hide details
-
p.
1361
–1362
(2)
We show for the design of quadrantally symmetric 2-D fan filters that it is unnecessarily restrictive to prescribe exact quadrantal symmetry, which requires that the denominator of the Z-transform transfer function be product-separable. Superior approximately symmetric fan filter designs can be achieved using nonseparable denominators.
Efficient operation of array-pumped Er3+ doped silica fibre laser at 1.5 μm
- Author(s): R. Wyatt ; B.J. Ainslie ; S.P. Craig
- Source: Electronics Letters, Volume 24, Issue 22, p. 1362 –1363
- DOI: 10.1049/el:19880932
- Type: Article
- + Show details - Hide details
-
p.
1362
–1363
(2)
We present the results for diode-array pumped Er3+ doped silica fibres, which lase near 1550 nm. A maximum output power of 8 mW is obtained with a 13% overall efficiency against the launched pump power.
Noise figure for erbium-doped optical fibre amplifiers
- Author(s): R. Olshansky
- Source: Electronics Letters, Volume 24, Issue 22, p. 1363 –1365
- DOI: 10.1049/el:19880933
- Type: Article
- + Show details - Hide details
-
p.
1363
–1365
(3)
A rate equation model is used to calculate the excess noise figure for erbium-doped fibre amplifiers. It is shown that erbium amplifiers can operate with high gain and can have noise figures only 0.2 dB above the quantum limit.
Single-mode 1 × 3 integrated optical branching circuit design using phase-front accelerators
- Author(s): W.Y. Hung ; H.P. Chan ; P.S. Chung
- Source: Electronics Letters, Volume 24, Issue 22, p. 1365 –1366
- DOI: 10.1049/el:19880934
- Type: Article
- + Show details - Hide details
-
p.
1365
–1366
(2)
We propose a novel design for symmetric single-mode 1 × 3 integrated optical branching circuits as optical power dividers using relatively low-index phase-front accelerator regions in the Y-branch structures. By varying the location and the area of such regions, an equally distributed power can be obtained at the three output ports.
Generation of 1180 å period gratings with a Xe ion laser
- Author(s): H.A. Zarem ; M.E. Hoenk ; W.B. Bridges ; K. Vahala ; A. Yariv
- Source: Electronics Letters, Volume 24, Issue 22, p. 1366 –1367
- DOI: 10.1049/el:19880935
- Type: Article
- + Show details - Hide details
-
p.
1366
–1367
(2)
Holographic lithography with the 2315 Å line of a xenon ion laser is used to produce gratings in polymethylmethacrylate. An 1180 Å period grating is made and examined with a scanning electron microscope (SEM). This grating period is appropriate for use as a first-order grating with a GaAs distributed feedback laser.
Hardware fading simulator for a number of narrowband channels with controllable mutual correlation
- Author(s): A. Verschoor ; A. Kegel ; J.C. Arnbak
- Source: Electronics Letters, Volume 24, Issue 22, p. 1367 –1369
- DOI: 10.1049/el:19880936
- Type: Article
- + Show details - Hide details
-
p.
1367
–1369
(3)
A multipath fading simulator with a number of narrowband channels with controllable mutual correlation is described. With this simulator it is possible to test the influence of joint fading statistics of mutually correlated channels on a mobile data communication link with frequency diversity.
New evaluation method for ARQ schemes
- Author(s): M. Nakamura and T. Kodama
- Source: Electronics Letters, Volume 24, Issue 22, p. 1369 –1370
- DOI: 10.1049/el:19880937
- Type: Article
- + Show details - Hide details
-
p.
1369
–1370
(2)
Automatic-repeat-request schemes which provide high system reliability with simple error-control are widely used in data communication systems. This letter presents a new evaluation method for ARQ schemes, which makes it possible to compare performances for various error-control schemes, such as FEC, ARQ and hybrid ARQ, with each other.
Multichannel FM video transmission using travelling-wave laser amplifier in 1300 nm subcarrier multiplexed optical system
- Author(s): W.I. Way ; C.E. Zah ; C. Caneau ; S.G. Menocal ; F. Favire ; F.K. Shokoohi ; N.K. Cheung ; T.P. Lee
- Source: Electronics Letters, Volume 24, Issue 22, p. 1370 –1372
- DOI: 10.1049/el:19880938
- Type: Article
- + Show details - Hide details
-
p.
1370
–1372
(3)
A 1300 nm travelling-wave laser amplifier has been employed to provide a power gain of 10 dB in a subcarrier multiplexed optical communication system which carried 10 broadcast quality C-band satellite FM video signals.
Calculation of multicarrier intermodulation distortion in semiconductor optical amplifiers
- Author(s): R.M. Jopson and T.E. Darcie
- Source: Electronics Letters, Volume 24, Issue 22, p. 1372 –1374
- DOI: 10.1049/el:19880939
- Type: Article
- + Show details - Hide details
-
p.
1372
–1374
(3)
We calculate the level of intermodulation distortion (IMD) produced by an arbitrary number of constant-amplitude carriers passing through an optical amplifier and also present an analytic upper bound on this distortion. For a total output intensity that is 0.1 times the amplifier saturation intensity, the composite IMD can be severe (7–20 dBc) unless a large channel separation (>1 GHz) is maintained.
Integrated optics 90° hybrid on LiNbO3 for phase diversity receivers
- Author(s): D. Hoffmann ; H. Heidrich ; G. Wenke ; R. Langenhorst
- Source: Electronics Letters, Volume 24, Issue 22, p. 1374 –1375
- DOI: 10.1049/el:19880940
- Type: Article
- + Show details - Hide details
-
p.
1374
–1375
(2)
We present an integrated optic eight-port 90° hybrid on LiNbO3 comprising four tunable directional couplers and two phase shifters for adjusting the phases between the output ports. Measurements on the phase stability show phase fluctuations of < ± 5° and a temperature dependence of ≈15°/°C.
Parameter re-estimation in semicontinuous hidden Markov modelling of speech with feedback to vector quantisation codebook
- Author(s): X.D. Huang ; M.A. Jack ; Y. Ariki
- Source: Electronics Letters, Volume 24, Issue 22, p. 1375 –1377
- DOI: 10.1049/el:19880941
- Type: Article
- + Show details - Hide details
-
p.
1375
–1377
(3)
The parameters of the semicontinuous hidden Markov model (SCHMM) can be re-estimated by allowing the codebook to be updated, thus achieving an optimised codebook/model combination. With the optimised codebook, the SCHMM can offer improved recognition accuracy in comparison to both the continuous and the discrete hidden Markov model.
New structure of one-sided switching network
- Author(s): A. Jajszczyk and W. Kabaciński
- Source: Electronics Letters, Volume 24, Issue 22, p. 1377 –1378
- DOI: 10.1049/el:19880942
- Type: Article
- + Show details - Hide details
-
p.
1377
–1378
(2)
A new structure of a one-sided digital switching network composed of triangular switches is proposed. In this structure some triangular switches operate as two-sided ones. The proposed network contains fewer elements than those previously known.
Heterojunction bipolar transistor utilising AlGaSb/GaSb alloy system
- Author(s): A. Furukawa and M. Mizuta
- Source: Electronics Letters, Volume 24, Issue 22, p. 1378 –1380
- DOI: 10.1049/el:19880943
- Type: Article
- + Show details - Hide details
-
p.
1378
–1380
(3)
A heterojunction bipolar transistor (HBT) has been fabricated using the AlGaSb/GaSb material system for the first time. The HBT structure of 100 × 100 μm2 emitter size was made by mesa-etching the molecular-beam-epitaxially grown layers. The device exhibits a current gain as high as 160 at room temperature.
Image segmentation and approximation through surface type labelling and region merging
- Author(s): Y.S. Lim and K.H. Park
- Source: Electronics Letters, Volume 24, Issue 22, p. 1380 –1381
- DOI: 10.1049/el:19880944
- Type: Article
- + Show details - Hide details
-
p.
1380
–1381
(2)
The letter presents a two-stage image segmentation and approximation method for an image coding application. The proposed method is based on the surface fitting of an intensity image by a second-order polynomial function. Experimental results show its much improved performance compared with the method of Kocher-Leonardi.
Robust frame synchronisation using standard VLSI synchronous input/output devices
- Author(s): P.F. Driessen
- Source: Electronics Letters, Volume 24, Issue 22, p. 1381 –1383
- DOI: 10.1049/el:19880945
- Type: Article
- + Show details - Hide details
-
p.
1381
–1383
(3)
A robust frame synchronisation technique is proposed for serial data links which are to be implemented using standard VLSI synchronous input/output (SIO) hardward devices with a built-in 8-bit frame sync collector. This new technique uses a multiple byte marker and additional software for frame sync, and yields up to 4.6 dB improvement on noisy channels where forward error correction is used and only the SIO hardware is available.
Electron velocity enhancement by planar-doped barrier source in GaAs vertical FET
- Author(s): K. Yamasaki ; T. Daniels-Race ; J.R. Wendt ; W.J. Schaff ; P.J. Tasker ; L.F. Eastman
- Source: Electronics Letters, Volume 24, Issue 22, p. 1383 –1384
- DOI: 10.1049/el:19880946
- Type: Article
- + Show details - Hide details
-
p.
1383
–1384
(2)
Experimental evidence of electron velocity enhancement by hot-electron injection into the channel of a GaAs vertical FET has been obtained for the first time. The maximum transconductance and the average electron velocity are 234 mS/mm and 6.4 × 107 cm/s, which are 1.4 and 1.9 times as large as those of a conventional vertical FET.
Fourier-Bessel error performance analysis of 1024-QAM in error burst generating environments
- Author(s): S.A. Kosmopoulos and M.D. Gouta
- Source: Electronics Letters, Volume 24, Issue 22, p. 1384 –1386
- DOI: 10.1049/el:19880947
- Type: Article
- + Show details - Hide details
-
p.
1384
–1386
(3)
A closed form performance evaluation of 1024-QAM in error burst generating channels is demonstrated in the letter. The noise model employed (which closely models atmospheric and ignition noise) consists of the additive mixture noise and a stream of Poisson impulses with amplitude areas distributed according to a bilateral Rayleigh PDF. Our results show that nonGaussian impulsive noise degrades the system performance significantly in comparison with the system performance in cochannel interference and demonstrate that the used Fourier-Bessel series approach is a powerful and very accurate computational tool.
Si/SiGe heterostructure mitatt diode
- Author(s): J.F. Luy ; H. Jorke ; H. Kibbel ; A. Casel ; E. Kasper
- Source: Electronics Letters, Volume 24, Issue 22, p. 1386 –1387
- DOI: 10.1049/el:19880948
- Type: Article
- + Show details - Hide details
-
p.
1386
–1387
(2)
The first experimental results on Si/SiGe heterostructure mitatt diodes are reported. The layers are grown by MBE. At 103 GHz a very low noise CW output of 25 mW is obtained. With an optimisation of the design higher output powers with still low noise operation are expected.
Aging characteristics of AlGaAs/GaAs DFB lasers with a window structure
- Author(s): S. Hirata ; H. Narui ; Y. Mori ; K. Kaneko
- Source: Electronics Letters, Volume 24, Issue 22, p. 1387 –1389
- DOI: 10.1049/el:19880949
- Type: Article
- + Show details - Hide details
-
p.
1387
–1389
(3)
A spectrum-monitored aging test of AlGaAs/GaAs DFB lasers with a window structure has been performed at 50°C under 5 mW output power for 3000 h. The results show a significant improvement in the reliability of the lasers. The mean increasing rate of the driving current was about 4.2% and 83% of the devices maintained stable, single-mode oscillation.
Self-checking time-division switch
- Author(s): J. Tyszer
- Source: Electronics Letters, Volume 24, Issue 22, p. 1389 –1390
- DOI: 10.1049/el:19880950
- Type: Article
- + Show details - Hide details
-
p.
1389
–1390
(2)
An augmentation of a time-division switch is proposed so that this switch has an additional property of fault selfdetection. Data patterns from normal operation (i.e. speech samples and control signals) serve as test patterns and a failure occurrence caused by some intermittent or solid fault can be detected by means of a built-in testing circuit.
Dopant distribution profile to improve performance of superlattice tunnel diode
- Author(s): R.A. Davies ; M.J. Kelly ; T.M. Kerr
- Source: Electronics Letters, Volume 24, Issue 22, p. 1390 –1392
- DOI: 10.1049/el:19880951
- Type: Article
- + Show details - Hide details
-
p.
1390
–1392
(3)
We show how it is possible by careful choice of the dopant profile to improve the performance of a superlattice tunnel diode to give negative differential conductance with good current and voltage swings and a low capacitance.
Speaker adaptive vector quantisation of LPC parameters of speech
- Author(s): K.Y. Lee ; A.M. Kondoz ; B.G. Evans
- Source: Electronics Letters, Volume 24, Issue 22, p. 1392 –1393
- DOI: 10.1049/el:19880952
- Type: Article
- + Show details - Hide details
-
p.
1392
–1393
(2)
Recently, it has been shown that good quality speech at rates as low as 6 Kbit/s can be achieved with CELP and its derivatives. However, in bringing down the bit rate even further these coding schemes have resorted to allocating fewer bits to the quantisation of the LPC parameters. It is known that CELP and its derivatives are sensitive to LPC parameters quantisation errors, and recently various schemes have been proposed to overcome this degradation. In the paper we describe how speaker adaptive vector quantisation (SAVQ) can be applied to the quantisation of LPC parameters and assess its performance when incorporated into a low bit rate coding scheme.
Simple measurement of laser diode spectral linewidth using modulation sidebands
- Author(s): R.D. Esman and L. Goldberg
- Source: Electronics Letters, Volume 24, Issue 22, p. 1393 –1395
- DOI: 10.1049/el:19880953
- Type: Article
- + Show details - Hide details
-
p.
1393
–1395
(3)
Laser diode spectral linewidth is measured by mixing the carrier and direct-modulation sidebands in an all-fibre delayed self-homodyne scheme. The detected signal contains the laser spectral noise at the modulation frequency, thereby obviating the need for optical modulators or large-index direct modulation in other frequency-shifting techniques.
Reactive ion etched InP/GaInAs multiple quantum well rib waveguides grown by solid source MBE
- Author(s): D.A. Roberts ; M.A. Pate ; P.A. Claxton
- Source: Electronics Letters, Volume 24, Issue 22, p. 1395 –1396
- DOI: 10.1049/el:19880954
- Type: Article
- + Show details - Hide details
-
p.
1395
–1396
(2)
Using InP/GaInAs MQW material, grown by solid source MBE, rib waveguides have been fabricated by reactive ion etching in a methane/hydrogen plasma. Single mode propagation losses were found to be as low as 1.4 dB/cm.
Laser-direct-written capacitors and inductors for GaAs monolithic microwave integrated circuit trimming
- Author(s): C.L. Chen ; J.G. Black ; S.P. Doran ; L.J. Mahoney ; R.A. Murphy ; D.J. Ehrlich
- Source: Electronics Letters, Volume 24, Issue 22, p. 1396 –1398
- DOI: 10.1049/el:19880955
- Type: Article
- + Show details - Hide details
-
p.
1396
–1398
(3)
Laser-direct-write deposition of tungsten and laser ablation techniques have been successfully used to modify monolithic capacitors and inductors fabricated on GaAs substrates. The properties of the tungsten inductors and capacitors have been characterised at microwave frequencies and are in good agreement with theory. The new techniques permit postfabrication tuning with precision and versatility that are not achievable by any other method
Low-distortion lock-in discriminator
- Author(s): B.N. Biswas ; D. Mondal ; P. Pal
- Source: Electronics Letters, Volume 24, Issue 22, p. 1398 –1399
- DOI: 10.1049/el:19880956
- Type: Article
- + Show details - Hide details
-
p.
1398
–1399
(2)
A new type of lock-in microwave FM discriminator without using the principle of heterodyning has been proposed. It is simple and produces an almost distortion-free output. Experimental results have been presented in support of the theoretical prediction.
Comment: InP/Ga0.47In0.53As superlattice avalanche photodiode
- Author(s): R.J. McIntyre
- Source: Electronics Letters, Volume 24, Issue 22, page: 1399 –1399
- DOI: 10.1049/el:19880957
- Type: Article
- + Show details - Hide details
-
p.
1399
(1)
Reply: InP/Ga0.47In0.53As superlattice avalanche photodiode
- Author(s): S. Batra ; A. Lahiri ; P. Chakrabarti
- Source: Electronics Letters, Volume 24, Issue 22, p. 1399 –1400
- DOI: 10.1049/el:19880958
- Type: Article
- + Show details - Hide details
-
p.
1399
–1400
(2)
Simple technique to estimate spot sizes from far fields of single-mode fibres
- Author(s): V. Priye ; Y. Gogia ; B.P. Pal
- Source: Electronics Letters, Volume 24, Issue 22, p. 1400 –1401
- DOI: 10.1049/el:19880959
- Type: Article
- + Show details - Hide details
-
p.
1400
–1401
(2)
Accurate estimates of two characteristic spot sizes, Wrms and Wf, based on measurements of far-field angles θ−3 dB and θ−40 dB made on two single-mode fibres of widely differing refractive index profiles (RIPs) are reported. The results including their near-field profiles are compared with those deduced from the measured RIPs of the fibres, and are found to be in good agreement and well within the measurement accuracy.
Most viewed content for this Journal
Article
content/journals/el
Journal
5
Most cited content for this Journal
-
Extreme multistability in a memristive circuit
- Author(s): Bo-Cheng Bao ; Quan Xu ; Han Bao ; Mo Chen
- Type: Article
-
Absorptive frequency selective surface using parallel LC resonance
- Author(s): Qiang Chen ; Liguo Liu ; Liang Chen ; Jiajun Bai ; Yunqi Fu
- Type: Article
-
Partial spectral search-based DOA estimation method for co-prime linear arrays
- Author(s): Fenggang Sun ; Peng Lan ; Bin Gao
- Type: Article
-
Experimental verification of on-chip CMOS fractional-order capacitor emulators
- Author(s): G. Tsirimokou ; C. Psychalinos ; A.S. Elwakil ; K.N. Salama
- Type: Article
-
54 Gbit/s OOK transmission using single-mode VCSEL up to 2.2 km MMF
- Author(s): G. Stepniak ; A. Lewandowski ; J.R. Kropp ; N.N. Ledentsov ; V.A. Shchukin ; N. Ledentsov Jr. ; G. Schaefer ; M. Agustin ; J.P. Turkiewicz
- Type: Article