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Online ISSN 1350-911X Print ISSN 0013-5194

Electronics Letters

Volume 26, Issue 22, 25 October 1990

Volumes & issues:

Volume 26, Issue 22

25 October 1990

Monolithic integration of an InP/InGaAs four-channel transimpedance optical receiver array
  • Author(s): W.S. Lee ; D.A.H. Spear ; P.J.G. Dawe ; S.W. Bland
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1833 –1834
  • DOI:  10.1049/el:19901179
  • Type: Article
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  • p. 1833 –1834 (2)
    Fully functional four-channel transimpedance receiver array OEICs have been fabricated on 2″ diameter InP substrates. Each receiver channel has a bandwidth of 200 MHz and an average input equivalent noise current of around 6pA/√(Hz). The array chip is 3.7 mm × 3.2 mm in size and contains 88 components. This is believed to represent the highest level of optoelectronic integration yet reported on InP.
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Absolute phase of the radar target scattering matrix
Physical approach to CMOS module self-timing
Diode laser pumped Er3+ fibre laser operation between 2.7–2.8 μm
Effect of unequal rise and fall times on the autocorrelation function of a PN sequence
  • Author(s): F.E. Churchill
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1838 –1840
  • DOI:  10.1049/el:19901183
  • Type: Article
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  • p. 1838 –1840 (3)
    The rise and fall times of a pseudo-noise (PN) waveform are of concern in a short-range, CW radar such as a missile fuze radar. An inequality creates a spurious pair of sidelobes and a spiky ripple on the sidelobes of the autocorrelation function, which may cause false alarms in the radar. Analytical expressions are presented which relate the spurious responses of the autocorrelation function to the waveform rise and fall times.
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Boundary diffraction coefficients for calculating spurious beams produced by volume gratings
Enhanced relaxation oscillation frequency and reduced nonlinear K-factor in InGaAs/InGaAsP MQW λ/4-shifted DFB lasers
  • Author(s): M. Aoki ; K. Uomi ; T. Tsuchiya ; M. Suzuki ; N. Chinone
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1841 –1843
  • DOI:  10.1049/el:19901185
  • Type: Article
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  • p. 1841 –1843 (3)
    The relaxation oscillation frequency, fr, of 1.55 μm InGaAs/InGaAsP MQW λ/4-shifted DFB lasers was doubled by increasing the carrier injection efficiency into each quantum well, which results from an optimised bandgap energy and optimised thickness of the barrier layers. The nonlinear K-factor which determines the maximum modulation band-width through the damping phenomenon can be reduced by dopting a p-type modulation doped MQW structure in the active layer.
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First-order, switched-capacitor, low-pass filter implemented with GaAs insulated-gate FET switches
Continuously tunable metal-clad ridge-waveguide distributed feedback laser diode
Rocking filter formation in photosensitive high birefringence optical fibres
  • Author(s): P.St.J Russell  and  D.P. Hand
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1846 –1848
  • DOI:  10.1049/el:19901188
  • Type: Article
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  • p. 1846 –1848 (3)
    Parent et al. observed that the refractive index changes induced in optical fibres by Hill grating formation (at 488 and 514.5 nm) were birefringent. A wavelength filter, formed in a simple and novel way by exposing high birefringence fibre to linearly polarised 488 nm light, is reported. Narrow bandwidth operation and high conversion efficiencies are achieved experimentally between the two orthogonal polarisation states of the fibre.
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Metal-semiconductor-metal (MSM) photodetectors fabricated on MOCVD grown Hg1−xCdxTe
  • Author(s): P.W. Leech ; N. Petkovic ; P.J. Gwynn ; G.N. Pain ; J. Thompson
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1848 –1849
  • DOI:  10.1049/el:19901189
  • Type: Article
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  • p. 1848 –1849 (2)
    The fabrication of the first metal-semiconductor-metal photodetectors on Hg1−xCdxTe is reported using MOCVD grown layers on GaAs substrates. An epitaxial CdTe overlayer has been incorporated in the device structure for the enhancement of Schottky barrier characteristics. The interdigitated devices (2.3 μm electrode width, 3.3 μm spacing) exhibited a breakdown voltage of −60 V and responsivities of more than 1.0 A/W at a wavelength of 1.3 μm and bias voltage of 40 V. Over the range of bias voltage examined, the dark leakage current of the detectors was dependent on the choice of contact metal, with minimum values of 10 nA at <1 V for Pt/CdTe/Hg1−xCdxTe.
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Computer design of broadband lumped component microwave phase shifter amplifiers
Generalised formula for optical-amplifier noise and its application to erbium-doped fibre amplifiers
Optical beam former for phased arrays with independent control of radiated frequency and phase
  • Author(s): R. Benjamin ; C.D. Zaglanikis ; A.J. Seeds
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1853 –1855
  • DOI:  10.1049/el:19901192
  • Type: Article
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  • p. 1853 –1855 (3)
    A new beam forming technique for use in optically controlled phased arrays is presented. The system, which is the optical equivalent of the microwave Huggins phase shifter, uses two optical fibre networks to produce a beam having independently specified frequency and aperture phase slope. The theory of the system is presented together with experimental results for a system implemented at the L-band.
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Passive integrated optical polarisation mode-slitter in lithium niobate employing a resonant metal-loaded structure
Wavelength demultiplexing heterojunction phototransistor
  • Author(s): M.S. Ünlü ; K. Kishino ; J.-I. Chyi ; J. Reed ; L. Arsenault ; H. Morkoç
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1857 –1858
  • DOI:  10.1049/el:19901194
  • Type: Article
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  • p. 1857 –1858 (2)
    Experimental and theoretical results on a wavelength demultiplexing receiver composed of an AlGaAs/GaAs heterojunction phototransistor (HPT) integrated within a resonant cavity are reported. A high quality factor cavity was formed using a very thin In0.05Ga0.95As active absorption layer in the collector depletion region of the HPT. Crosstalk attenuations of 15dB for dual and 12dB for triple wavelength demultiplexing were demonstrated. The individual HPTs had an optical gain of 500 at the resonant modes. Theoretical calculations predict crosstalk attenuation levels as high as 40 dB with high reflection mirrors on both ends of the cavity.
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Phase modulation characteristics of 1.5 μm strained-layer multiple quantum well laser amplifiers
Resource allocation in broadband ISDNs
  • Author(s): M. Ilyas
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1860 –1861
  • DOI:  10.1049/el:19901196
  • Type: Article
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  • p. 1860 –1861 (2)
    Broadband integrated services digital networks (BISDNs) have recently received significant attention among researchers in the field of telecommunications. These broadband telecommunication networks are being designed for handling, in their final form, a large variety of digital information, e.g, data, voice, video, facsimile, etc. Asynchronous transfer mode (ATM) has been recommended by the CCITT as a means of providing efficient and fast packet switched communication among BISDN users. It supports a large variety of services in a simple and unified fashion. An efficient and simple, yet effective, technique for resource allocation in broadband networks is presented. This technique was simulated for a network with three types of services and results are presented in terms of call blocking probabilities for several different cases.
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New multilevel complementary pairs of sequences
  • Author(s): S.Z. Budišin
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1861 –1863
  • DOI:  10.1049/el:19901197
  • Type: Article
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  • p. 1861 –1863 (3)
    A general method for construction of multilevel complementary pairs of sequences of arbitrary length is presented. Multilevel sequences of length equal to 2N have greater mathematical regularity than sequences of other lengths. They remain complementary if a symmetric nonlinearity is applied. Multilevel sequences offer an additional degree of freedom for optimising the autocorrelation properties of codes for radar and synchronisation applications. They can also be used as random signals for simulations or system identification.
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Multichannel FSK experiment using an optical amplifier repeater and wavelength tunable direct detection receiver
DC and RF performance of GaAs MESFET fabricated on silicon substrate using epitaxial lift-off technique
  • Author(s): D.M. Shah ; W.K. Chan ; T.J. Gmitter ; L.T. Florez ; H. Schumacher ; B.P. van der Gaag
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1865 –1866
  • DOI:  10.1049/el:19901199
  • Type: Article
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  • p. 1865 –1866 (2)
    GaAs MESFETs have been fabricated on a silicon substrate using a molecular beam epitaxy grown film detached from its growth substrate and attached on a silicon substrate covered with a dielectric. The device processing is done on the silicon substrate. The MESFETs exhibit IDSS = 130 mA/mm, gm=135 mS/mm and for 1.3 μm gate length unity current gain cut-off frequency fτ of 12 GHz. Excellent device isolation with subpicoampere leakage currents is obtained.
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Dual excitation scheme for direct suppression of residual signal in fibre-optic magnetometers
  • Author(s): K.P. Koo ; D.M. Dagenais ; S. Vohra ; F. Bucholtz
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1867 –1868
  • DOI:  10.1049/el:19901200
  • Type: Article
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  • p. 1867 –1868 (2)
    A novel dual-excitation scheme capable of suppressing the residual signal responsible for up-converting low-frequency noise in a fibre-optic magnetometer is reported. This scheme provides a magnetic carrier with spatially varying strength and can reduce both the up-converted interferometer noise and the up-converted transducer noise. With a 5 cm long amorphous wire transducer, 30 dB of residual signal suppression resulting in a signal-to-noise ratio improvement of 25 dB has been obtained for a magnetic signal at 1 Hz when the response using dual excitation is compared with that using single excitation.
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Modelling and simulation of frequency selective fading using switched antenna diversity
140 Mbit/s and 560 Mbit/s FSK heterodyne polarisation diversity receiver using nearly perfect square law demodulators
Efficient up-conversion pumping at 800 nm of an erbium-doped fluoride fibre laser operating at 850 nm
Optimisation of refractive index profile for high gain fibre amplifiers
Optoelectronic switching in travelling-wave MSM photodetectors using photon energies below bandgap
Highly reproducible ridge waveguide multielectrode DFB lasers for optical communication systems
  • Author(s): H. Sundaresan ; S. Kwan ; A. Lord ; W.J. Duncan ; I.D. Henning ; W.A. Stallard ; C. Broughton
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1876 –1877
  • DOI:  10.1049/el:19901206
  • Type: Article
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  • p. 1876 –1877 (2)
    Highly reproducible 1.5μm multielectrode DFB lasers have been fabricated for use as transmitters in frequency shift keying (FSK) transmission systems. These devices were grown using atmospheric pressure metal-organic vapour phase epitaxy and are based on the ridge waveguide structure with a 900μm long cavity. In a 2.4Gbit/s FSK system, sensitivities of −27dBm were obtained for devices from different wafers under identical biasing conditions. This is the first time that mulltielectrode DFB lasers have demonstrated the degree of reproducibility required for practical systems.
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Use of Fourier descriptors for the estimation of general motion in image sequences
Application of Hartley transform to tracking moving objects in noisy environments
4 Gbit/s pin/HBT monolithic photoreceiver
  • Author(s): S. Chandrasekhar ; A.G. Dentai ; C.H. Joyner ; B.C. Johnson ; A.H. Gnauck ; G.J. Qua
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1880 –1882
  • DOI:  10.1049/el:19901209
  • Type: Article
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  • p. 1880 –1882 (3)
    Heterojunction bipolar transistors have been monolithically integrated with a pin photodetector to realise a high speed transimpedance photoreceiver. The OEIC, made from MOVPE-growth InP/InGaAs heterostructures, had a bandwidth of 2.8 GHz with a transimpedance of 750 Ω. It was successfully operated at 4 Gbit/s with a sensitivity of −21 dBm at a wavelength of 1.5 μm.
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39.5 million-way WDM broadcast network employing two stages of erbium-doped fibre amplifiers
Waiting time jitter results for a reduced complexity SONET interface circuit
  • Author(s): T.E. Moore ; R.G. Kusyk ; W.A. Krzymien
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1884 –1886
  • DOI:  10.1049/el:19901211
  • Type: Article
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  • p. 1884 –1886 (3)
    An alternative stuff threshold modulation (STM) synchroniser implementation for SONET interfaces is described. Experimental waiting time jitter measurements are reported for DS-1 which verify the feasibility of the modified design in terms of maintaining jitter generation requirements. This implementation involves less circuit complexity than conventional STM synchronisers and is applicable to all interface designs requiring STM.
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Plane-polar near-field to far-field transformation with the near-field interpolation method
  • Author(s): E. van Lil ; C. Cao ; A. van de Capelle ; K. Van't Klooster
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1886 –1887
  • DOI:  10.1049/el:19901212
  • Type: Article
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  • p. 1886 –1887 (2)
    A major step in the computation required to transform a plane-polar near-field into the far-field is the Hankel transform. One of the simplest ways to circumvent numerical Hankel transform evaluations is the interpolation method which converts the polar grid to a rectangular grid. This method turns out to be the most efficient plane-polar nearfield to far-field transformation method.
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Attractive behaviours of NRD leaky wave antenna with tuning aperture
  • Author(s): A.S. Rong
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1887 –1889
  • DOI:  10.1049/el:19901213
  • Type: Article
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  • p. 1887 –1889 (3)
    A modified configuration of the NRD leaky wave antenna is presented. A tunable aperture is introduced at the radiating open end. The taper in the antenna amplitude distribution (required for sidelobe control) is easily achieved by changing the height of the aperture instead of positioning the dielectric slab. This results in the easy design of such an antenna and the reduction of the requirement on the flexibility of the dielectric slab. Numerical results show that when the height of the aperture is appropriately chosen, the phase constant is almost independent of the distance between the right-hand dielectric-to-air interface and the open end.
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Comment: Exact computation of two port noise parameters
Reply: Exact computation of two-port noise parameters
Microstrip antennas with integrated fibre optic feeds
  • Author(s): D.M. Pozar ; R.W. Jackson ; A. Svitak
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1889 –1891
  • DOI:  10.1049/el:19901216
  • Type: Article
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  • p. 1889 –1891 (3)
    Several techniques for feeding microstrip antennas with RF-modulated lightwave signals using an optical fibre are presented. A photodiode on a ceramic carrier and the appropriate impedance matching circuitry are integrated on the same substrate as the patch antenna element. Configurations using patch antennas with both direct microstrip line feeds and aperture coupling are considered. Experiments with three different configurations demonstrate these techniques.
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Thin wire dipoles—a finite-difference time-domain approach
Modelling DC characteristics of GaAs MESFET devices using a simple and accurate analytic tool
  • Author(s): S.A. Ibrahim  and  S. El-Rabaie
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1892 –1893
  • DOI:  10.1049/el:19901218
  • Type: Article
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  • p. 1892 –1893 (2)
    A simple equation that relates the drain current to the gate and source voltages of GaAs MESFET devices is presented. The proposed equation covers the entire Ids/Vds characteristics with no limitations. The parameters of the equation are evaluated easily using simple analytic tools without optimisation. Results show that the proposed formula gives accurate fitting results compared with the most popular used formula (the Curtice equation). Typical CPU times for evaluating the modelling parameters for a NEC71000 device using the two models are in the ratio of 1:50.
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Error control strategies for cut-through switching network
  • Author(s): C.-J. Chang  and  J.-I. Wang
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1894 –1895
  • DOI:  10.1049/el:19901219
  • Type: Article
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  • p. 1894 –1895 (2)
    Error control strategies for cut-through switching networks are studied. It seems unnecessary to have link control functions at every node in the network because of the wide deployment of an optical transmission system which has qualities of high speed and low bit error rate. Error control performed only at the destination node (ECDN) is proposed. It will compare with error control performed at every node (ECEN) from the viewpoint of transfer delay. It is shown through numerical example that the ECDN performs better than the ECEN if the increment of traffic intensity caused by the error control functions performed at every node is significant. A simulation is also provided to support the validity of the analysis.
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40 Gbit/s optial time-division cell multiplexer for a photonic ATM switch
  • Author(s): M. Tsukada  and  Y. Shimazu
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1895 –1897
  • DOI:  10.1049/el:19901220
  • Type: Article
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  • p. 1895 –1897 (3)
    A novel cell multiplexer for generating time-multiplexed ultrafast optical cells for the photonic ATM cell switch is presented. This multiplexer mainly consists of speed convertors which can compress the intervals of ultrashort optical pulses according to the binary multiplicative principle and make ultrafast optical cells of any length with minimal hardware. Generation of a four-bit 40 Gbit/s optical cell by the speed convertor is demonstrated.
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Application of the FD-TD method to the analysis of H-plane waveguide discontinuities
  • Author(s): Z.-Q. Bi ; K.-L. Wu ; J. Litva
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1897 –1898
  • DOI:  10.1049/el:19901221
  • Type: Article
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  • p. 1897 –1898 (2)
    A direct finite-difference time-domain (FD-TD) method is applied to the analysis of waveguide discontinuities. Both the validity and efficiency of the method ate demonstrated in the case of an H-plane right-angle corner bend with and without dielectric loading. Comparisons of the present results with those obtained using the spectral-domain methods are made and they are shown to be in good agreement.
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Carrier lifetime increase in silicon by gettering with a MeV-implanted carbon-rich layer
  • Author(s): W. Skorupa ; R. Kögler ; K. Schmalz
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1898 –1899
  • DOI:  10.1049/el:19901222
  • Type: Article
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  • p. 1898 –1899 (2)
    The gettering efficiency of silicon implanted with carbon ions in the energy range 0.33–10 MeV was tested by carrier lifetime measurements. After an intentional contamination of the sample back side with gold as a lifetime killer, we found values for the generation lifetime of the minority carriers on the front side higher by 1–2 orders of magnitude as compared with unimplanted silicon.
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Temperature-stable VCO based on operational transconductance amplifiers
Approximate analysis of electromagnetically coupled microstrip dipoles
Comparison of NRZ and AMI coding schemes using three-electrode and conventional DFB laser transmitters in a 636 Mbit/s SF-FSK coherent system
  • Author(s): B. Hoffmann ; N.G. Jensen ; E. Bødtker ; S.K. Nielsen ; B. Broberg
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1903 –1904
  • DOI:  10.1049/el:19901225
  • Type: Article
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  • p. 1903 –1904 (2)
    A comparison of AMI and NRZ coding schemes in a 636 Mbit/s SF-FSK system is performed. The system performances for a 223−1 sequence show that NRZ-coding of a three-electrode DFB transmitter laser and AMI-coding of a conventional DFB transmitter laser are comparable to within 0.5 dB. Both perform 3.5 dB better than NRZ-coding of the conventional DFB laser at a 10−9 bit error rate.
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Asymmetric resonant tunnelling diodes as microwave detectors
  • Author(s): R.T. Syme ; M.J. Kelly ; A. Condie ; I. Dale
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1904 –1906
  • DOI:  10.1049/el:19901226
  • Type: Article
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  • p. 1904 –1906 (3)
    Multilayer resonant tunnelling diodes with asymmetric current-voltage characteristics and the first measurements of such devices as microwave detectors are reported. Their performance is compared with that of conventional detectors in terms of the transfer function and its temperature dependence. In particular a variation of output voltage as low as ±0.3dB over −40°C to +80°C was found.
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Elliptical microstrip antenna on ferrite substrate
Coding and interleaving for meteor-burst communications
Optical tap based on D-fibre
Glass waveguide laser operated around 1.3 μm
DC and microwave performance of OMVPE-grown AlInAs/InP HEMTs
Polarisation insensitive configuration of semiconductor laser amplifier
  • Author(s): M. Sumida
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1913 –1914
  • DOI:  10.1049/el:19901232
  • Type: Article
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  • p. 1913 –1914 (2)
    A new polarisation insensitive configuration of a semiconductor laser amplifier is presented. This configuration achieves polarisation insensitive gain by a bi-directional pass of the split polarised light waves through a laser amplifier. The experiments demonstrate a reduction of the gain difference from 5dB to 0.1dB while attaining a high fibre-to-fibre gain of 12dB and a high saturation fibre output power of +6dBm.
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Polynomial transform fast Hartley transform
  • Author(s): S.C. Chan  and  K.L. Ho
  • Source: Electronics Letters, Volume 26, Issue 22, p. 1914 –1916
  • DOI:  10.1049/el:19901233
  • Type: Article
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  • p. 1914 –1916 (3)
    A fast algorithm for computing the two-dimensional discrete Hartley transform (2D-DHT) based on the polynomial transform is presented. Using a simple relation between the discrete Fourier transform (DFT) and the DHT, it is found that the 2D-DHT can be mapped, by means of the polynomial transform, to a number of one-dimension type III discrete W transforms (DWT-III). An improved fast algorithm for computing the DWT-III is also proposed.
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Asymmetric coplanar-strip transmission lines for MMIC and integrated optic applications
Helical antenna and spiral antenna with fast switch selection of the polarisation sense
Complex modes in lossless nonreciprocal finline
Microwave conductivity of optically excited gap in a semiconductor microstrip
Erratum: Optimum facet reflectivity for high speed lasers
Erratum: Modified configuration for a high-finesse compact loop resonator for semiconductor integrated optics
Erratum: Delay, linewidth and bandwidth limitations in optical phase-locked loop design
Erratum: Full-wave analysis of shielded coplanar waveguide short-end
Erratum: Parametric design features of twin-elliptical-core optical fibres
Erratum: Highperformance algorithmic switched-current memory cell
Erratum: GaAlAs window lasers emitting 500 mW CW in fundamental mode
Corrigendum: Analysis of stripline/slot transition

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