Your browser does not support JavaScript!
http://iet.metastore.ingenta.com
1887
banner image
image of Volume 25, Issue 19
Online ISSN 1350-911X Print ISSN 0013-5194

Electronics Letters

Volume 25, Issue 19, 14 September 1989

Volumes & issues:

Volume 25, Issue 19

14 September 1989

Burst error correction in high-speed digital mobile radio communications
  • Author(s): E. Kudoh  and  S. Ogose
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1265 –1266
  • DOI:  10.1049/el:19890847
  • Type: Article
  • + Show details - Hide details
  • p. 1265 –1266 (2)
    In high-speed digital mobile radio communication, transmission performance is severely degraded by frequency-selective fading caused by the delay time spread of multipath propagation. Forward error correction (FEC) is one of the most effective techniques to improve transmission quality. In the letter the effect of FEC on burst errors under frequency-selective fading is evaluated. The FEC effect with diversity reception and interleaving is also investigated.
    Add to favourites
    Export citations
Performance of decision feedback equaliser on measured indoor radio channels
GaAs/AlGaAs power heterobipolar transistor fabricated on silicon substrate
  • Author(s): D. Ueda ; W.S. Lee ; D. Costa ; J.S. Harris
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1268 –1269
  • DOI:  10.1049/el:19890849
  • Type: Article
  • + Show details - Hide details
  • p. 1268 –1269 (2)
    A GaAs/AlGaAs power HBT was fabricated on a silicon substrate, where the thermal conductance is reduced by a factor of 2.8 compared with that on bulk GaAs. Owing to the newly developed monolithically grown ballast resistor over an emitter region, the experimentally fabricated device has shown the highest collector current of over 2.5 A for a device with an active device area of 0.14 mm2.
    Add to favourites
    Export citations
Selective discarding procedure for improved tolerance to missing voice packets
Tunable MQW-DBR laser with monolithically integrated GaInAsP/InP directional coupler switch
  • Author(s): F. Hernandez-Gil ; T.L. Koch ; U. Koren ; R.P. Gnall ; C.A. Burrus
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1271 –1272
  • DOI:  10.1049/el:19890851
  • Type: Article
  • + Show details - Hide details
  • p. 1271 –1272 (2)
    We report the successful monolithic integration of a GaInasp/lnP single-mode ΔK directional coupler switch with a 4-section tunable multiple-quantum-well distributed Bragg reflector laser. We obtain several mW of output power through the switch, with ˜10dB crosstalk either from the internal laser source or with external light injected through the parallel input port.
    Add to favourites
    Export citations
Highly storage-efficient hybrid finite element/boundary element method for electromagnetic scattering
Reducing moment method storage from order N2 to order N
  • Author(s): F.X. Canning
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1274 –1275
  • DOI:  10.1049/el:19890853
  • Type: Article
  • + Show details - Hide details
  • p. 1274 –1275 (2)
    Previously, integral equation-based calculations of electromagnetic scattering and radiation (e.g. moment method calculations) have required a full N × N matrix when there are N unknowns. However, in the letter novel basis and testing functions are presented, for which the resulting matrix is approximately sparse. That is, nearly all of its elements are nearly zero. This kind of technique is expected to reduce typical storage and execution time requirements by orders of magnitude.
    Add to favourites
    Export citations
Improving speech quality of CELP coder
High-power 1.06μm GaInAsP DCPBH lasers
  • Author(s): T. van Dongen ; G.L.A. van der Hofstad ; P. van der Laar ; M. Boermans ; C.J. van der Poel
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1277 –1278
  • DOI:  10.1049/el:19890855
  • Type: Article
  • + Show details - Hide details
  • p. 1277 –1278 (2)
    High-power 106 μm double channel planar buriedheterostructure (DCPBH) lasers have been fabricated by liquid-phase epitaxy. At 20°C, the threshold current is 80 mA and CW output powers of 20 mW can be obtained. Under pulsed operation, quantum efficiencies of 0.37 W/A per facet and maximum pulse output powers of 150mW are realised, while maintaining the lowest-order spatial mode and a symmetrical far-field distribution.
    Add to favourites
    Export citations
First field demonstration of optical submarine cable system using LD-pumped Er-doped optical fibre amplifier
  • Author(s): N. Edagawa ; S. Yamamoto ; Y. Namihira ; K. Mochizuki ; H. Wakabayashi
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1278 –1280
  • DOI:  10.1049/el:19890856
  • Type: Article
  • + Show details - Hide details
  • p. 1278 –1280 (3)
    This is a report on the first field demonstration of an optical submarine cable system using an in-line Er-doped optical fibre amplifier pumped by a 1.47μm laser diode. The experiment was performed at an ocean depth of 3000 m. With a maximum optical repeater gain of 20 dB, l.2 Gbit/s intensity-modulated optical signals were transmitted stably during and after installation and also during recovery of the system. Furthermore, the effectiveness of an automatic-gain-control (AGC) scheme proposed for optical amplifiers was confirmed in a practical environment.
    Add to favourites
    Export citations
Optical heterodyne receiver providing random channel selection
Diffraction-limited in-phase-mode operation from uniform array of antiguides with enhanced interelement loss
  • Author(s): D. Botez ; P. Hayashida ; L.J. Mawst ; T.J. Roth ; G. Peterson
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1282 –1283
  • DOI:  10.1049/el:19890858
  • Type: Article
  • + Show details - Hide details
  • p. 1282 –1283 (2)
    Out-of-phase-mode oscillation is suppressed in a nearly resonant array of antiguides by introducing high transverse radiation losses (≈ 150 cm−1) in the interelement regions. Ten-element devices operate in the in-phase array mode, diffraction-limited up to 2.5 × threshold, and with lobe widths of 1.6 × diffraction limit at 4 × threshold (230 mW total power)
    Add to favourites
    Export citations
Channel switching between receivers of FDM coherent optical star network
  • Author(s): B. Glance  and  O. Scaramucci
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1283 –1285
  • DOI:  10.1049/el:19890859
  • Type: Article
  • + Show details - Hide details
  • p. 1283 –1285 (3)
    We present channel switching results obtained between receivers of an FDM optical coherent fibre star network. The system consists of six optical channels FSK-modulated at 200 Mbit/s and spaced by 2.2GHz. The channels are multiplexed by a 16 × 16 optical star coupler. Two of the multichannel signals exiting this device are demultiplexed by their respective random access digitally tuned heterodyne receivers. Simultaneous switching between pairs of channels is obtained by command of a personal computer controlling both receivers
    Add to favourites
    Export citations
Mixing and detection of RF signals in fibre-optic magnetostrictive sensor
Balanced phase diversity receiver in 565 Mbit/s DPSK transmission system
Design of Hilbert transformers by multiple use of same subfilter
  • Author(s): Y.-L. Tai  and  T.-P. Lin
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1288 –1290
  • DOI:  10.1049/el:19890862
  • Type: Article
  • + Show details - Hide details
  • p. 1288 –1290 (3)
    A method is proposed for the design of linear-phase FIR Hilbert transformers as a tapped cascaded interconnection of identical FIR subfilters. With the proposed method, the design of FIR Hilbert transformers can be determined by the prototype filter and subfilter through transformation; thus it has potential for VLSI realisation. It shows that the number of distinct multipliers required by the proposed method is much less than that designed by direct-form minimax methods.
    Add to favourites
    Export citations
Ten-thousand-hours CW operation of 780 nm high-power AlGaAs laser with thin-tapered thickness active layer
  • Author(s): A. Shima ; H. Saito ; H. Matsubara ; H. Kumabe
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1290 –1291
  • DOI:  10.1049/el:19890863
  • Type: Article
  • + Show details - Hide details
  • p. 1290 –1291 (2)
    It is investigated that the T3 (thin-tapered thickness active layer) structure is effective in reducing the carrier density in the active layer as well as the optical density near the mirror. 780 nm AlGaAs lasers with this structure have been operating under 50°C, 30 mW CW (continuous wave) conditions over 104 h with little degradation. The minimal degradation rate is about 0.45%/103 h.
    Add to favourites
    Export citations
Externally modulated mode-locked laser diodes for microwave transmission links
Effects of postdetection selection diversity reception in QDPSK land mobile radio
  • Author(s): K. Ohno  and  F. Adachi
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1293 –1294
  • DOI:  10.1049/el:19890865
  • Type: Article
  • + Show details - Hide details
  • p. 1293 –1294 (2)
    Postdetection selection diversity reception for Nyquist pulse shaped quadrature differential PSK (QDPSK) signal transmissions is addressed. Average bit error rate (BER) performance with differential and coherent demodulation is analysed for multiple-branch diversity reception under slow multipath Rayleigh fading. Diversity effects in real fading environments are verified by 8 and 16 kbit/s transmissions at 1.45 GHz carrier frequency.
    Add to favourites
    Export citations
Performance analysis of virtual time ICMA/CD
Multilayer perceptron trained using radial basis functions
Multiplexed Mach-Zehnder ladder array with ten sensor elements
Sea trial of submarine optical amplifier repeater system using travelling-wave semiconductor laser amplifier
  • Author(s): S. Yamamoto ; H. Taga ; Y. Namihira ; K. Mochizuki ; H. Wakabayashi
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1299 –1301
  • DOI:  10.1049/el:19890869
  • Type: Article
  • + Show details - Hide details
  • p. 1299 –1301 (3)
    An optical amplifier repeater system consisting of semiconductor laser amplifiers was evaluated in 3000 m deep sea at 820Mbit/s in the 1.5μm wavelength region using 23.5 km of optical submarine cable. The repeater output power was stabilised by the APC system monitoring amplified optical signal power. We confirmed stable digital signal transmission and the reduction of variation in the repeater output power for changes in the polarisation of the input signal.
    Add to favourites
    Export citations
Schottky-biased, optically controlled coplanar waveguide phase-shifter
Carbon-doped base AlGaAs/GaAs HBTs grown by MOCVD using TMAs
Slew rate enhancement technique for CMOS output buffers
  • Author(s): K. Nagaraj
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1304 –1305
  • DOI:  10.1049/el:19890872
  • Type: Article
  • + Show details - Hide details
  • p. 1304 –1305 (2)
    A novel technique for enhancing the slew rate in CMOS amplifiers is described. The slew enhancement is provided by an auxiliary circuit which is activated only during transients. The core amplifier is not stressed with the large transient currents, thus minimising transient power dissipation and also avoiding signal swing problems. A slew rate of 1 V/μs with a 10000pF load capacitance has been achieved, while requiring a quiescent power dissipation of less than 1.5 mW.
    Add to favourites
    Export citations
7 GHz bandwidth optical front-end circuit using GaAs FET monolithic IC technology
  • Author(s): Y. Miyagawa ; Y. Miyamoto ; K. Hagimoto
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1305 –1307
  • DOI:  10.1049/el:19890873
  • Type: Article
  • + Show details - Hide details
  • p. 1305 –1307 (3)
    A GaAs FET monolithic integrated transimpedance preamplifier for 10 Gbit/s optical fibre transmission is realised using a newly developed capacitor peaking technique. A 3 dB bandwidth of 8.6 GHz and 19 dB gain is achieved in S-parameter measurements. A 3 dB bandwidth of 7 GHz and −12.0 dBm sensitivity at 10 Gbit/s are achieved in an optical front-end circuit with a GaInAs pin photodiode
    Add to favourites
    Export citations
Dynamic modelling of distributed-feedback lasers using scattering matrices
Multichannel Ku-band oscillator with dielectric resonators
  • Author(s): D. Paunović  and  A. NešIć
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1308 –1309
  • DOI:  10.1049/el:19890875
  • Type: Article
  • + Show details - Hide details
  • p. 1308 –1309 (2)
    The theory, design and realisation of a multichannel Ku-band oscillator with eight dielectric resonators (DRs) are described. Selection of a single DR is achieved by pin diodes. The oscillator stability, phase noise and signal level are comparable with available high-quality DROs. Stability is better than 3ppm/°C, phase noise is 85–90 dBc/Hz at 10 kHz, and the signal level is 16–18 dBm. The device is compact, simple and cheap.
    Add to favourites
    Export citations
Modified Viterbi equaliser for mobile radio channels having large multipath delays
Theory of two-dimensional ‘fingerprint’ resonators
Probability of error performance of binary suppressed sideband angle modulation
Microwave dielectric resonator tuning with balanced loop-varactor circuit
  • Author(s): A. El-Moussaoui ; S. Kazeminejad ; D.P. Howson
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1314 –1315
  • DOI:  10.1049/el:19890879
  • Type: Article
  • + Show details - Hide details
  • p. 1314 –1315 (2)
    The letter reports a novel electronic tuning method for a shielded dielectric resonator (DR) operating in its dominant mode. The use of a balanced loop structure permits a wider tuning range while maintaining high unloaded Qo. A tuning range of 3MHz at the centre frequency of 950MHz with unloaded Q in excess of 9000 have been obtained. A simple analytical expression is also derived for determining the tuning range of such a structure.
    Add to favourites
    Export citations
Tin-doped n+ InP and GaInAs grown by atmospheric-pressure MOCVD
  • Author(s): C.J. Pinzone ; N.D. Gerrard ; R.D. Dupuis ; N.T. Ha ; H.S. Luftman
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1315 –1317
  • DOI:  10.1049/el:19890880
  • Type: Article
  • + Show details - Hide details
  • p. 1315 –1317 (3)
    Heavily doped n+ InP and GaInAs epitaxial layers have been grown by metalorganic chemical vapour deposition (MOCVD) at atmospheric pressure using tetraethyltin (TESn) as a dopant source. Sn-doped InP and GaInAs layers have been grown with doping levels as high as n300K -⋍ 3·3 × 1019cm−3 and n300K ⋍6·1 × 1019cm−3 respectively. Analysis of the Sn concentration in InP:Sn and GaInAs:Sn layers using secondary ion mass spectrometry (SIMS) shows that all of the Sn is ionised in InP and GaInAs. Hall measurements of Nd − Na at 300 and 77 K. indicate that the Sn is uncompensated up to these levels. SIMS analysis also shows that the use of TESn for the growth of n+ InP and GaInAs layers results in no severe memory effects and that abrupt Sn doping profiles can be achieved.
    Add to favourites
    Export citations
9 GHz bandwidth, 8–20 dB controllable-gain monolithic amplifier using AlGaAs/GaAs HBT technology
  • Author(s): N. Ishihara ; O. Nakajima ; H. Ichino ; Y. Yamauchi
  • Source: Electronics Letters, Volume 25, Issue 19, p. 1317 –1318
  • DOI:  10.1049/el:19890881
  • Type: Article
  • + Show details - Hide details
  • p. 1317 –1318 (2)
    A wideband and controllable-gain amplifier utilising a new parallel feedback technique, which can enhance the bandwidth and can control the gain keeping output DC voltages constant, has been developed using AlGaAs/GaAs HBT technology in monolithic form. This IC achieves a wide bandwidth of DC-9 GHz, and a controllable gain range of 8–20 dB with a total power dissipation of 640 mW at a power supply voltage of 9 V.
    Add to favourites
    Export citations
Throughput efficiency of LAPB/D protocol with multireject error recovery procedure
Electric tuning of semiconductor laser using acousto-optic device
Choice of excitation in electromagnetic missiles

Most viewed content for this Journal

Article
content/journals/el
Journal
5
Loading

Most cited content for this Journal

Print this page
This is a required field
Please enter a valid email address