Your browser does not support JavaScript!
http://iet.metastore.ingenta.com
1887
banner image
image of Volume 23, Issue 13
Online ISSN 1350-911X Print ISSN 0013-5194

Electronics Letters

Volume 23, Issue 13, 18 June 1987

Volumes & issues:

Volume 23, Issue 13

18 June 1987

Multiplexing of interferometric sensors using phase-generated carrier techniques
Fizeau fringe interferometer for fibre outside diameter measurements
New design concept for a narrowband wavelength-selective optical tap and combiner
370 mW, 1.06 μm, CW TEM00 output from an Nd:YAG laser rod end-pumped by a monolithic diode array
Double diffraction by wedges in nonperfectly conducting surfaces
  • Author(s): G. Manara ; R. Tiberio ; G. Pelosi ; P.H. Pathak ; R.G. Kouyoumjian
  • Source: Electronics Letters, Volume 23, Issue 13, p. 671 –672
  • DOI:  10.1049/el:19870479
  • Type: Article
  • + Show details - Hide details
  • p. 671 –672 (2)
    A high-frequency solution is obtained via an extended ray method for the field doubly diffracted in the far zone by a pair of parallel wedges with impedance faces, when they are illuminated by a plane wave perpendicularly incident on the edges. Except for a multiplying special function, this solution is expressed in closed form, which is valid for any incidence and observation aspects.
    Add to favourites
    Export citations
High-power CW operation of 780 nm T3 laser diodes
  • Author(s): A. Shima ; T. Yamawaki ; H. Saito ; H. Matsubara ; T. Murakami ; K. Ohtaki ; H. Kumabe ; W. Susaki
  • Source: Electronics Letters, Volume 23, Issue 13, p. 672 –674
  • DOI:  10.1049/el:19870480
  • Type: Article
  • + Show details - Hide details
  • p. 672 –674 (3)
    Stable laser operation at over 100 mW in the wavelength range of 780nm has been achieved by the T3 structure. The CW light output power at room temperature was over 160mW. The narrow beam divergence of low ellipticity has been realised. The lasers have been in operation for more than 800h at 40mW at 60°C with no significant degradation.
    Add to favourites
    Export citations
Iterative method for obtaining the argument of the dominant complex pole-pair
  • Author(s): S. Puthenpura  and  N.K. Sinha
  • Source: Electronics Letters, Volume 23, Issue 13, p. 674 –675
  • DOI:  10.1049/el:19870481
  • Type: Article
  • + Show details - Hide details
  • p. 674 –675 (2)
    A simple and efficient method is presented for obtaining the argument of the dominant complex pole-pair of a discrete-time system. This new method can be directly applied to either the system characteristic polynomial or the state transition matrix, whichever is available. Moreover, it can easily be extended to extract the values of the arguments of all complex pole-pairs of the system under consideration.
    Add to favourites
    Export citations
Broadband continuously variable microwave phase shifter employing a distributed Schottky contact on silicon
  • Author(s): V.M. Hietala ; Y.R. Kwon ; K.S. Champlin
  • Source: Electronics Letters, Volume 23, Issue 13, p. 675 –677
  • DOI:  10.1049/el:19870482
  • Type: Article
  • + Show details - Hide details
  • p. 675 –677 (3)
    Fabrication details and microwave measurements are presented for the first realisation of a silicon, broadband, voltage-controlled, microwave phase shifter comprising a coplanar, slow-wave, Schottky-contact transmission line. This structure exhibits very little dispersion over the measured frequency range of 1–20 GHz. A voltage-dependent ‘wave compression’ factor is observed that can be varied from 11.7 to 17.0 by varying the bias between −6 and +0.1 V. Even though the device is fabricated on a ‘true’ (lossy) semiconducting substrate, the attenuation per unit length is smaller than that reported for a similar structure fabricated on semi-insulating GaAs.
    Add to favourites
    Export citations
Simple method for analysing finlines with extremely narrow slotwidth and thick fins
Modelling microstrip step discontiuities by the transmission matrix
Optical feed for a phased array microwave antenna
  • Author(s): M. Tamburrini ; M. Parent ; L. Goldberg ; D. Stillwell
  • Source: Electronics Letters, Volume 23, Issue 13, p. 680 –681
  • DOI:  10.1049/el:19870485
  • Type: Article
  • + Show details - Hide details
  • p. 680 –681 (2)
    Microwave signals for all array elements in a phared array microwave antenna are simultaneously generated by spatial sampling of a moving sinusoidal interference pattern formed between two frequency-offset injection-locked laser diodes. The offset and radar frequency of 3.2 GHz were generated by a Bragg cell. A nearly distortionless antenna beam pattern and 180° steering are demonstrated in a linear seven-element array.
    Add to favourites
    Export citations
Capacities of sequences of currently used ternary line codes
Novel type of fibre-optic ring resonator
Nondiffusion and 1.54/μm luminescence of erbium implanted in InP
  • Author(s): P.N. Favennec ; H. L'Haridon ; A. le Corre ; M. Salvi ; M. Gauneau
  • Source: Electronics Letters, Volume 23, Issue 13, p. 684 –686
  • DOI:  10.1049/el:19870488
  • Type: Article
  • + Show details - Hide details
  • p. 684 –686 (3)
    Erbium impurities were implanted in indium phosphide. The Er depth distributions are given for nonannealed and annealed substrates. It is shown that erbium has a very small diffusion coefficient, if any, in InP. The photoluminescence spectra show, after annealing at high temperature, the main erbium emission centred at 1.536μm. This emission is stronger after annealing at 700°C. Our results are the first evidence showing l.54μm emission at room temperature.
    Add to favourites
    Export citations
Narrow pulse measurement of drain characteristics of GaAs MESFETs
  • Author(s): T.M. Barton ; C.M. Snowden ; J.R. Richardson ; P.H. Ladbrooke
  • Source: Electronics Letters, Volume 23, Issue 13, p. 686 –687
  • DOI:  10.1049/el:19870489
  • Type: Article
  • + Show details - Hide details
  • p. 686 –687 (2)
    A measurement technique is presented which uses narrow, fast-rise-time pulses applied to both the gate and the drain of a GaAs MESFET to obtain the drain characteristics of the device. This allows the characteristics of the device to be obtained which correspond to frequencies above those at which surface and substrate traps can respond. The resulting characteristics show significant departures from those obtained using conventional long pulse and DC measurement techniques.
    Add to favourites
    Export citations
Coherent transmission using an external waveguide Bragg reflector laser with direct frequency modulation
  • Author(s): N.A. Olsson ; B.H. Johnson ; H.J. Lee ; C.H. Henry ; R.F. Kazarinov ; D.A. Ackerman ; P.J. Anthony
  • Source: Electronics Letters, Volume 23, Issue 13, p. 687 –689
  • DOI:  10.1049/el:19870490
  • Type: Article
  • + Show details - Hide details
  • p. 687 –689 (3)
    Single-frequency l.5μm semiconductor lasers, formed by butt-coupling of a regular Fabry—Perot laser to an external waveguide Bragg reflector, are shown to have very uniform frequency modulation characteristics under direct current modulation. The laser's frequency modulation characteristics, together with its narrow linewidth (̃ 1 MHz), make coherent transmission possible without external modulators. The laser performance was evaluated in a 417Mbit/s, 102 km, frequency-shift-keying coherent transmission experiment.
    Add to favourites
    Export citations
Alignment of polarisation-maintaining fibres by temperature modulation
Experimental determination of finline post discontinuity parameters: application to stopband and lowpass filters
  • Author(s): P. Saguet  and  A. Essebar
  • Source: Electronics Letters, Volume 23, Issue 13, p. 691 –692
  • DOI:  10.1049/el:19870492
  • Type: Article
  • + Show details - Hide details
  • p. 691 –692 (2)
    The shunt reactance of a finline post discontinuity is shown to be of resonant type. By using an experimental transmission procedure, we have determined accurately the parameters R, L and C of its equivalent circuit. These parameters, in the first approximation, can be considered as frequency-independent. Thus the use of the equivalent circuit in CAD is very easy. Applications to stopband and lowpass filters are described.
    Add to favourites
    Export citations
Bidirectional optical transmission using polarised light waves
Analysis of microstripline coupled to microstrip antenna
Fast CMOS current amplifier and buffer stage
Zero-crossing estimation in signal generation of narrowband digital angle-modulated signals
Laser interferometer using a dual interference method
Efficient frequency-doubling in a poled PVDF copolymer guest/host composite
  • Author(s): J.R. Hill ; P.L. Dunn ; G.J Davies ; S.N Oliver ; P. Pantelis ; J.D. Rush
  • Source: Electronics Letters, Volume 23, Issue 13, p. 700 –701
  • DOI:  10.1049/el:19870498
  • Type: Article
  • + Show details - Hide details
  • p. 700 –701 (2)
    We describe the linear and nonlinear properties of a new polymer composite, which uses a ferroelectric PVDF copolymer host in which an optically nonlinear low-molecularweight guest is dissolved and subsequently aligned using a room-temperature poling process. We have measured the frequency-doubling coefficient d33 of these poled composites at 1-064/mi to be as high as 2-6 × 10−12m/V. In addition, we have shown that this material may be formed into waveguiding structures with an acceptable optical loss (̃5dB/cm), as is needed in many signal processing systems.
    Add to favourites
    Export citations
Low-loss single-mode InP/InGaAsP waveguides grown by MOVPE
8.8 Gbit/s travelling-pulse word generator
Boundary conditions of the electromagnetic field
Improved negative feedback technique to reduce drain conductance of GaAs MESFETs for precision analogue ICs
  • Author(s): W.S. Lee  and  J. Mun
  • Source: Electronics Letters, Volume 23, Issue 13, p. 705 –707
  • DOI:  10.1049/el:19870502
  • Type: Article
  • + Show details - Hide details
  • p. 705 –707 (3)
    An improved negative feedback technique to reduce the absolute magnitude of the frequency-dependent drain conductance inherent in GaAs MESFETs has been demonstrated for low-threshold (less than −1 V) devices. The new dual-threshold arrangement guarantees that the primary device of the self-bootstrapping pair operates at the current saturation region without relying on the existence of early saturation. A factor of 11 reduction in the drain conductance was realised. A simple inverter amplifier of identical composite driver and load has demonstrated 21 dB improvement in voltage gain over that using single FETs.
    Add to favourites
    Export citations
Cramer-Rao lower bound for cascaded adaptive notch filtering
Equivalent circuit for aperture antennas
  • Author(s): A.W. Love
  • Source: Electronics Letters, Volume 23, Issue 13, p. 708 –710
  • DOI:  10.1049/el:19870504
  • Type: Article
  • + Show details - Hide details
  • p. 708 –710 (3)
    The commonly used equivalent circuit based on a constant voltage generator does not correctly characterise scattering by an aperture antenna, nor does its dual, the constant current generator. This long-standing dilemma has been resolved by combining voltage and current sources to form a constant-power source. The power generated by this source is equated to the available power in a plane wave incident on the aperture. The voltage and current of the two sources and their respective internal impedances are then completely determined from a knowledge of the aperture area A0, the impedance ZA, the aperture efficiency η0 and the relative power pattern p(θ, Φ) of the antenna.
    Add to favourites
    Export citations
Erratum: Front-to-back ratio of a smooth metallic-wall conical horn

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