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# Electronics Letters

## Filter Results

Displaying Results 1 - 25 of 26
• ### Satellite-Earth signal depolarisation at 30 GHz in the absence of significant fading

Publication Year: 1977, Page(s):1 - 2
Cited by:  Papers (10)
| | PDF (337 KB)

The depolarisation of a linearly polarised signal at 30 GHz on an earth-satellite link has been observed in the absence of significant copolar fading (< 2 dB). Strong correlation between the depolarisation and radar reflections at high altitude along the satellite look angle has also been observed. View full abstract»

• ### Through pulse measurement technique for assessing the forward echo performance of coaxial cables

Publication Year: 1977, Page(s):2 - 3
| | PDF (248 KB)

A coaxial-cable test system is described that has been designed to meet the specific needs of current investigations into high-bit-rate digital operation over existing line plant. The scheme employs the through transmission of an impulse, with subsequent signal averaging to recover the detail of the echo components contained in the tail of the impulse response. An outline description is given, tog... View full abstract»

• ### Multifrequency tone detection by zero-interval analysis

Publication Year: 1977, Page(s):3 - 4
| | PDF (240 KB)

An algorithm is presented which enables a microprocessor to analyse the zero intervals of the multifrequency signals from a pushbutton telephone. A model has shown that, with a 100 kHz clock, the component frequencies of any signal can be predicted to within Â±1% from a 30 ms sample, but the speech immunity requires improvement. View full abstract»

• ### New voltage-to-frequency convertor with nonlinearity correction

Publication Year: 1977, Page(s):5 - 6
| | PDF (242 KB)

In the voltage-to-frequency convenor presented, the non-linearity error due to the finite discharging time of the integrating capacitor is compensated by using the comparator threshold correction method, in a very effective way. The convertor itself consists of only one op-amp, which performs both functions of integration and comparison. View full abstract»

• ### High speed I2L gate with self-aligned double-diffusion injector

Publication Year: 1977, Page(s):6 - 7
| | PDF (284 KB)

To improve the switching speed of I2L gate, the charge storage in the nÂ¿pÂ¿n transistor should be minimised. For the experimental verification of a high-speed I2L gate, a very small I2L gate with p+ external base and heavily doped emitter regions was fabricated. The minimum propagation delay realised in the gate was 3.2 n s/gate. View full abstract»

• ### High-sensitivity dielectric loss measurements by using superconducting microwave resonators in an oscillator loop

Publication Year: 1977, Page(s):7 - 8
Cited by:  Papers (6)
| | PDF (338 KB)

The method allows easy and highly accurate measurements of microwave resonator parameters. By using superconducting resonators, the loss tangent of polyethylene at 2.2 K and 6.5 GHz was found to be the lowest of any solid so far measured: tan Â¿ = 3.7 Ã 10Â¿7 Â± 7%. View full abstract»

• ### Predictable sample error detector and a planar prediction corrector for removal of isolated transmission errors in Walsh--Hadamard transformed pictures

Publication Year: 1977
Cited by:  Papers (1)
| | PDF (566 KB)

An error detection and correction system is described which will correctly detect the amplitude of a sequency error in a transmitted Walsh--Hadamard-transformed picture, provided no more than one error per block occurs. For a head-and-shoulder picture, a planar prediction corrector will then remove any sequency error whose magnitude is ⩾ (10/256) Δ, where Δ is the quantisat... View full abstract»

• ### Noise performance of microwave GaAs f.e.t. amplifiers at low temperatures

Publication Year: 1977, Page(s):10 - 11
Cited by:  Papers (4)
| | PDF (298 KB)

4 GHz measurements have been made of the noise temperature of Bell Laboratories microwave GaAs f.e.t. amplifiers cooled to liquid-nitrogen temperatures (78 K). An optimum noise temperature of about 30 K (0.4 dB noise figure) was obtained, compared with the room-temperature value of 152 K (1.8 dB). View full abstract»

• ### Modes in s.a.w. grating resonators

Publication Year: 1977, Page(s):12 - 13
Cited by:  Papers (12)
| | PDF (394 KB)

It is shown that s.a.w. gratings on the surface of an isotropic medium may support modes that are confined underneath the grating. The 3-dimensional resonant-mode patterns are derived for the Rayleigh wave in a high-Q-factor resonator consisting of two gratings separated by Â¿/2, where Â¿ is the grating periodicity, in the limit when the grating width is large compared with a wavelength. The reson... View full abstract»

• ### Crosspolarisation from high-altitude hydrometeors on a 20 GHz satellite radio path

Publication Year: 1977, Page(s):13 - 14
Cited by:  Papers (7)
| | PDF (385 KB)

20 GHz signals received from the ATS6 satellite show much higher crosspolarisation than expected from rain alone. Radar data indicate the cause to be hydrometeors above, rather than in, the melting band. During thunderstorms, the crosspolar level can change abruptly at the moment of a lightning discharge. View full abstract»

• ### Interface-recombination-controlled minority-carrier lifetime in n-type gap

Publication Year: 1977, Page(s):14 - 16
| | PDF (443 KB)

The effects of interface recombination on measured minority-carrier lifetime in n-type liquid-phase epitaxial GaP layers have been studied quantitatively. Results are presented for a number of different interface conditions, and analysis shows that the interface recombination velocity is high in all cases. This results in a unique dependence of interface-recombination-controlled lifetime Â¿s, on l... View full abstract»

• ### Single-mode operation of low-attenuation corrugated waveguide

Publication Year: 1977, Page(s):16 - 17
| | PDF (263 KB)

The operation of a corrugated waveguide is described under conditions where the HE11 mode is the only mode of propagation. Its attenuation is then predicted to be significantly less than that of other single-mode waveguides operating at the same frequency. Verification of the theory is provided by resonant-cavity experiments. Results lie within a range which can be accounted for in terms of surfac... View full abstract»

• ### Solution of currents on linear antennas: eigenfunctions and resonance

Publication Year: 1977, Page(s):17 - 19
| | PDF (379 KB)

An expansion of the radiated fields of a linear antenna is given in terms of the eigenfunctions of the differential operator governing the antenna current. The expansion is used to find the solution of the antenna current under resonant conditions. The method proposed is an extension of one given earlier, and eliminates the need to apply boundary conditions to an integral operator. View full abstract»

• ### Derivation of the recursive maximum-likelihood identification algorithm

Publication Year: 1977, Page(s):19 - 20
Cited by:  Papers (1)
| | PDF (282 KB)

It is shown that the recursive maximum-likelihood identification algorithm, which was obtained previously as an online version of the maximum-likelihood method, can be derived in a straightforward way by using a stochastic approximation approach. View full abstract»

• ### Zero temperature coefficients in overtone lithium-tantalate thickness-mode resonators

Publication Year: 1977, Page(s):20 - 21
Cited by:  Papers (1)
| | PDF (306 KB)

The temperature coefficients of the resonance frequencies of thickness shear overtones were computed for lithium-tantalate resonators. Both theoretical and experimental results are described and zero temperature coefficient cuts are exhibited. View full abstract»

• ### Low-frequency behaviour of the Beverage aerial

Publication Year: 1977, Page(s):21 - 22
| | PDF (317 KB)

The rate of attenuation for a wave propagating along a Beverage aerial at low frequency is believed to be proportional to the square root of the frequency. An alternative theory which yields a rate of attenuation proportional to frequency, but independent of ground conductivity, is discussed. Experimental evidence is inconclusive and further measurements are desirable. View full abstract»

• ### Local-oscillator-induced noise in GaAs Schottky mixer diodes

Publication Year: 1977, Page(s):22 - 23
Cited by:  Papers (5)
| | PDF (290 KB)

Increased noise temperature induced by local-oscillator power has been measured in Schottky-diode millimetre-wave mixers at 250 MHz and 4.75 GHz. Electric-field calculations indicate a portion of this noise is due to intervalley scattering in the undepleted epitaxial layer directly adjacent to the Schottky-diode anode. A noise-temperature equation is presented, which accounts for both shot and the... View full abstract»

• ### Static decoupling of multivariable linear systems with slow and fast modes

Publication Year: 1977, Page(s):23 - 25
| | PDF (381 KB)

Singular perturbation methods are used to reduce the design of decoupling controllers for a class of (n+m)th-order multivariable linear systems to the design of decoupling controllers for nth-order reduced systems obtained by ignoring small parasiticÂ¿ parameters in the state equations of the (n+m)th-order systems. View full abstract»

• ### Spatial correlation of field intensity in incoherently illuminated multimode fibres

Publication Year: 1977, Page(s):25 - 26
| | PDF (262 KB)

Numerical results show that in several types of multimode fibre (step index, Selfoc, ring shaped) a spatial ripple is present in the superposition of equally excited guided mode power densities. An analytical discussion of field correlation properties explains why the ripple spatial frequency is proportional to V, as has been observed experimentally. View full abstract»

• ### Error-detection in a d.p.s.k. system

Publication Year: 1977, Page(s):27 - 28
| | PDF (258 KB)

It is suggested that, by a suitable choice of the differential phases in a d.p.s.k. scheme, not only the differential phases can be estimated at the receiver, but also certain errors can be detected. This result is based upon the reflected Gray-code relation satisfied by the signs of certain trigonometric functions. View full abstract»

• ### Improved versatile gigahertz pulse generator

Publication Year: 1977, Page(s):28 - 29
Cited by:  Papers (3)
| | PDF (317 KB)

The high-speed pulse circuit investigated, which mainly consists of a broadband magic T with two step-recovery diodes shunted to opposite ports, is shown to generate versatile pulse trains at gigahertz frequencies (upper limit at about 5GHz). Owing to the availability of two output signals, simple pulse patterns can be produced. View full abstract»

• ### Group delay in graded-index fibres with non-power-law refractive profiles

Publication Year: 1977, Page(s):29 - 31
| | PDF (404 KB)

The group delay of modes in graded-index fibres is often calculated by the method of Gloge and Marcatili. This method can, however, yield misleading results if the refractive profile of a fibre does not strictly follow a power law of the radius, e.g. if it is close to the optimum profile, but has statistical distortions. The letter presents a new method for the calculation of group delay which has... View full abstract»

• ### Techniques for increasing the effective charge-transfer efficiency of tapped c.c.d. registers

Publication Year: 1977, Page(s):31 - 33
| | PDF (479 KB)

A design technique for multitap c.c.d. delay lines is discussed in which the effective charge transfer efficiency is increased over its intrinsic process-dependent value. The technique involves locating tap amplifiers at every alternate bit, and operating the device at twice the normal clock rate. The advantages of the technique are discussed with reference to a 32-tap, n-channel c.c.d. delay line... View full abstract»

• ### Comment on Active RC realisation of a 3rd-order bandpass Butterworth characteristic using equal-valued passive elements`

Publication Year: 1977
| | PDF (130 KB)

First Page of the Article
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• ### Erratum: Microprocessor interfaces

Publication Year: 1977
| | PDF (19 KB)

First Page of the Article
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## 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