Electronics Letters

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• Acoustic bulk-surface-wave transducer

Publication Year: 1969, Page(s):175 - 176
Cited by:  Papers (23)
| | PDF (280 KB)

Bulk and surface waves are strongly coupled at a corrugated surface. Experiments have demonstrated transduction losses of less than 1dB and bandwidths of 20%. Methods of implementation at high frequencies are discussed. View full abstract»

• Use of nonuniform dielectrics on surface-wave structures

Publication Year: 1969, Page(s):177 - 178
Cited by:  Papers (1)
| | PDF (285 KB)

Glines with nonuniform dielectric regions are studied in an attempt to improve performance over that of normal Glines with uniform dielectric regions. Some improvement is predicted for the lines studied; however, the effect of the radial decay rate precludes any general conclusions concerning overall performance of such lines. View full abstract»

• Push-pull operation of transferred-electron oscillators

Publication Year: 1969, Page(s):178 - 179
Cited by:  Papers (4)
| | PDF (304 KB)

Push-pull circuit configurations for GaAs transferred-electron oscillators are described. C.W. X band and pulsed L band devices have been operated in such circuits and have shown as much as 50% increase in output power compared with the sum of the powers obtained from the individual devices. View full abstract»

• Review and comparison of drift-correction schemes for periodic crosscorrelation

Publication Year: 1969, Page(s):179 - 181
| | PDF (428 KB)

The presently available drift-correction schemes are unified and extended. As a means of comparing various schemes quantitatively, the variance of the estimate in the presence of wideband noise is proposed as a performance criterion. View full abstract»

• Simple expressions for the effect of substrate doping on the gain of m.o.s.t.s

Publication Year: 1969, Page(s):181 - 182
| | PDF (259 KB)

Approximate expressions have been derived for the gain falloff of an m.o.s.t. with substrate doping. The expressions compare the mutual conductance on an extrinsic substrate with that on an intrinsic substrate for criteria of equal power dissipation, channel current or gate voltage. For the first two criteria, the approximation gives agreement to within 15% over all practical substrate doping leve... View full abstract»

• Criterion for mode uncoupling in oblique-incidence scattering from radially inhomogeneous cylinders

Publication Year: 1969, Page(s):182 - 183
| | PDF (247 KB)

It is shown that the condition for mode uncoupling is that the product Â¿Â¿ is constant and has the same value inside and outside the cylinder. View full abstract»

• Stability of p.c.m.-oscillator synchronisation systems with sampled error signals

Publication Year: 1969, Page(s):183 - 184
| | PDF (275 KB)

Previous analyses of control-system stability have approximated the p.c.m. synchronisation system to a continuous linear model. The digital nature of the equipment indicates that a sampled model is more appropriate, and it is shown that, with this model, the system gains have to be reduced. A comparison between continuousÂ¿ and sampledÂ¿ stability criteria is made. View full abstract»

• Stability of bulk negative-resistance material

Publication Year: 1969, Page(s):184 - 185
| | PDF (275 KB)

The skin-effect limitation on an amplifier, obtained in a previous communication, is confirmed, but the amplifier is unstable beyond a critical length. The same instability mechanism discussed by Chawla and Coleman operates also in the oscillator case, but since saturation necessarily enters to limit the oscillation, it is not clear whether the full bulk of the material contributes to the output. View full abstract»

• Electron-temperature, density and gas-temperature measurements in an argon afterglow

Publication Year: 1969, Page(s):185 - 186
| | PDF (263 KB)

Microwave and spectroscopic methods of monitoring the time-varying density and temperature of the electrons, as well as the temperature of the neutral background gas, have been applied to an argon afterglow. Electron-ion recombination coefficients were extracted from the decay rate over the electron-density range 1013Â¿1011cmÂ¿3, concerning which little information had previously been reported. View full abstract»

• Efficiency peaking in red-light-emitting gallium-phosphide diodes

Publication Year: 1969, Page(s):186 - 187
| | PDF (326 KB)

Measurements of the variation of efficiency with current of gallium-phosphide diodes emitting light at 690nm have shown a consistent relationship between the peak quantum efficiency and the current at which this peak occurs. This can be related to the number of zinc-oxygen pairs in nearest-neighbour states. View full abstract»

• Theoretical analysis of cylindrical hybrid modes in a corrugated horn

Publication Year: 1969, Page(s):187 - 189
Cited by:  Papers (8)
| | PDF (402 KB)

The propagation behaviour of a corrugated cylinder is considered with particular reference to the application of such structures to hybrid-mode feeds for large reflector antennas. Results are presented which relate to the design of narrow-flare-angle horns of circular cross-section. These include the parametric dependence of a number of special points on the propagation curves. A procedure for ach... View full abstract»

• Analysis of spherical hybrid modes in a corrugated conical horn

Publication Year: 1969, Page(s):189 - 190
Cited by:  Papers (8)
| | PDF (291 KB)

An approximate analysis of fields in a corrugated horn is considered using spherical hybrid modes. Under the special condition where the slots are about a quarter-wavelength deep, the approximations are slight in the far-field region of the horn. Solutions are presented for the lowest-order spherical hybrid modes, and a procedure is described for the determination of the horn radiation pattern. A ... View full abstract»

Publication Year: 1969, Page(s):191 - 192
Cited by:  Papers (1)
| | PDF (292 KB)

An adaptive-delta-modulation system is described taking advantage of the storage of the line digit pattern in the holding register of a delayed-delta-modulation system, to produce a significant improvement in signal/quantisation-noise ratio. View full abstract»

• Cutoff frequency of the TMc11 mode in a hollow conducting elliptical waveguide

Publication Year: 1969, Page(s):192 - 193
Cited by:  Papers (5)
| | PDF (246 KB)

The cutoff wavelength of the TMc11 mode is treated as a function of the eccentricity of the elliptical cross-section. From the exact values calculated on a digital computer, an approximate formula is derived for the function qc11 = f(e) for eccentricities between 0.05 and 0.95. Over this range, the cutoff wavelength is given to an accuracy within 0.14%. View full abstract»

• M.I.S. capacitance in heavy inversion

Publication Year: 1969, Page(s):194 - 195
Cited by:  Papers (1)
| | PDF (223 KB)

The letter deals with a theoretical analysis of the different currents originating in an m.i.s. structure for a heavy inversion region of operation, when a transient low-level electrical perturbation is applied. The expression for the generation-recombination current in the space-charge region is fairly different from that generally used; it is emphasised that the recombination rate is not constan... View full abstract»

• Observation of faults in convertor bridges

Publication Year: 1969, Page(s):195 - 196
| | PDF (307 KB)

A method of simultaneously monitoring the seven valves in a 3-phase Graetz bridge circuit is described. The d.c. smoothing-inductor voltage is observed for this purpose. It is shown that the point of failure on the voltage wave of the malfunctioning valve can be found. View full abstract»

• Experimental evidence of transit-time effects in silicon punch-through diodes

Publication Year: 1969, Page(s):196 - 198
Cited by:  Papers (1)
| | PDF (446 KB)

Small-signal frequency characteristics indicating the effect of hole transit times were measured for `punch-throughÂ¿ pÂ¿vÂ¿p silicon diodes. The transit time was sufficiently long to allow measurements in a relatively low frequency range (0.5Â¿18MHz), thus avoiding parasitic effects. Experimental results for several operating points in the square-law region of the d.c. characteristic agree very w... View full abstract»

• Digital notch filters

Publication Year: 1969, Page(s):198 - 199
Cited by:  Papers (3)
| | PDF (265 KB)

The letter deals with the special class of digital filters that possess a prescribed notch frequency. The present techniques for synthetising such filters rest on the bilinear-transformation method, where the designer is required to synthetise a continuous s plane notch filter, prewarp it, and then apply the transformation. It is shown here that notch filters can be synthetised directly into the z... View full abstract»

• Boundary and volume filtering of linear distributed-parameter systems

Publication Year: 1969, Page(s):199 - 200
Cited by:  Papers (4)
| | PDF (252 KB)

The optimal-filtering problem of linear distributed-parameter systems corrupted by boundary and/or volume stochastic disturbances is considered. The optimal filter is shown to be a generalisation of that previously derived for pure volume noise. View full abstract»

• Resonance absorption of microwave longitudinal phonons in transversally magnetised [100] y.i.g. rods

Publication Year: 1969, Page(s):200 - 201
| | PDF (281 KB)

Gigahertz-region phonons in [100] y.i.g. rods are observed to undergo resonant attenuation if a transverse magnetic bias is applied along the [110] direction. Results obtained are interpreted on the basis of a lamellar magnetic domain structure. View full abstract»

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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.

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Meet Our Editors

Editors-in-Chief

Professor Chris Toumazou
Director of the Biomedical Institute
Imperial College, London, UK

Professor Ian White