Electrical Engineers, Proceedings of the Institution of

Filter Results

Displaying Results 1 - 25 of 46
• Intermodulation distortion owing to multipath propagation over f.m./f.d.m. microwave links

Publication Year: 1971, Page(s):1687 - 1690
| | PDF (467 KB)

A theory on intermodulation noise distortion owing to multipath reception in f.m./f.d.m. microwave links is developed for the case when the received signal is Nakagami-Rice distributed, i.e. depends on the addition of a constant signal and a Rayleigh-distributed random signal. The distortion formula derived by Medhurst concerning the small constant echo of short delayÂ¿, is verified as a special ... View full abstract»

• Metrology and radio performance of reflector of chilbolton aerial

Publication Year: 1971, Page(s):1691 - 1697
| | PDF (818 KB)

The techniques used to remeasure the profile of the 25 m paraboloidal reflector on the UK Science Research Council steerable aerial at Chilbolton, Hants, England, are described, and the difficulties in obtaining such measurements are pointed out. Two methods are discussed: first, a specially constructed optical range finder for determining the co-ordinates of points on the reflector with respect t... View full abstract»

• Active loop-dipole aerials

Publication Year: 1971, Page(s):1698 - 1710
Cited by:  Papers (3)
| | PDF (1728 KB)

A theoretical study of the input impedance of active loop-dipole aerials which possess height-reduction properties at resonance is made. This is compared with measurements on an aerial containing a BFY 90 transistor at 200 MHz for which the transistor parameters are available. Reasonable agreement is obtained. The existence of separate power gains and radiation patterns for transmitting and receiv... View full abstract»

• Adaptive equalisation for digital communication

Publication Year: 1971, Page(s):1711 - 1720
Cited by:  Papers (5)
| | PDF (947 KB)

The structure of a conventional nonrecursive equaliser is modified so as to provide the equaliser with an automatic means of maintaining a frame of reference at all times. The output of the new equaliser is effectively the same as that of the conventional equaliser; the two equalisers merely differ in the procedure adopted for computing the forward tap weights. Another principal result is the form... View full abstract»

• Erratum: Loudness ratings of telephone speech paths

Publication Year: 1971
| PDF (77 KB)
• Applications of orthogonal 2-port network to oscillators and filters

Publication Year: 1971, Page(s):1721 - 1722
| | PDF (283 KB)

The orthogonal network is introduced as a fundamental impedance-transforming element and a generalisation of the well known convertor and invertor. The transforming properties are related directly to the geometrical concepts of rotation and reflection and are exploited to give new forms of oscillator and filter. View full abstract»

• Capacitor-fed parallel 'chopper' as a phase-sensitive demodulator

Publication Year: 1971, Page(s):1723 - 1728
| | PDF (875 KB)

The capacitor-fed parallel chopperÂ¿ is shown to make a phase-sensitive demodulator with good zero stability, good linearity and a wide dynamic range for carrier frequencies of up to about 100kHz. Design problems are discussed in detail. A balanced version gives very low zero offsets, and allows fast response with relatively simple filters. View full abstract»

Publication Year: 1971, Page(s):1729 - 1735
Cited by:  Papers (4)
| | PDF (974 KB)

Improvements to ground secondary-radar interrogators, as described, will increase the accuracy of bearing measurements and, at the same time, permit the reduction of the interference with other stations. The system uses monopulse techniques to allow direction finding with errors of 5 minutes of arc r.m.s. at a range of 60 n.m. The proposals made represent a step towards selective interrogation. View full abstract»

• High-frequency backscattering from a metallic disc

Publication Year: 1971, Page(s):1736 - 1742
Cited by:  Papers (9)
| | PDF (935 KB)

The paper treats the backscattered field produced by a plane electromagnetic wave at oblique incidence on a perfectly conducting circular disc. The geometric theory of diffraction is used to obtain the first two terms of the asymptotic expansion at high frequencies. The first term is attributable to direct scatter from the edge of the disc and the second term arises from rays that cross the disc o... View full abstract»

• Finite-element solution of 2-dimensional exterior-field problems

Publication Year: 1971, Page(s):1743 - 1747
Cited by:  Papers (47)
| | PDF (758 KB)

A new method, based on the finite-element method of discretisation and compatible with existing finite-element techniques, is described for the solution of field problems in which the region of prime interest is embedded in an infinitely extending region where Laplace's equation holds. The essence of this method lies in representing the infinitely extending region by a single finite element, which... View full abstract»

• Limitations of error-detection coding at high error rates

Publication Year: 1971, Page(s):1747 - 1748
| PDF (323 KB)
• Radiation from a spherical antenna covered by a layer of lossy hot plasma

Publication Year: 1971, Page(s):1748 - 1749
| PDF (297 KB)
• Attenuation reduction in coaxial cables

Publication Year: 1971, Page(s):1749 - 1751
Cited by:  Papers (1)
| PDF (458 KB)
• Cutoff frequencies in rectangular waveguides containing layers of dielectric in the H plane

Publication Year: 1971, Page(s):1751 - 1753
Cited by:  Papers (1)
| PDF (348 KB)
• Tellegen's theorem as a direct statement of the principle of conservation of energy

Publication Year: 1971, Page(s):1753 - 1754
| PDF (204 KB)
• Design of auxiliary phase windings for resistance-start split-phase fractional-horsepower induction motors

Publication Year: 1971, Page(s):1755 - 1758
| | PDF (378 KB)

The paper presents a new method for designing the auxiliary winding of a resistance-start split-phase type of small (f.h.p.) squirrel-cage motor. It is primarily aimed at helping a practical design engineer to choose an auxiliary winding which uses the minimum of copper while, at the same time, satisfying all specifications. The equations are developed in such a form as to facilitate the graphical... View full abstract»

• Axial forces in induction motors with skewed slots

Publication Year: 1971, Page(s):1759 - 1760
Cited by:  Papers (2)
| | PDF (263 KB)

Equations are derived for calculating the axial force experienced by the rotor of a skewed induction motor due to skew as well as displacement using the concept of energy. The analytical results are compared with those obtained experimentally, and the agreement is found to be good. View full abstract»

• Linear motors with transverse flux

Publication Year: 1971, Page(s):1761 - 1767
Cited by:  Papers (25)
| | PDF (798 KB)

The paper describes a new family of linear machines which may have advantage in applications where the pole pitch is very much greater than the machine width. Compared with the more usual kind of linear motor, in which the magnetic flux lies largely in planes which are parallel to the direction of motion, the new machines, have flux paths lying transversely to this direction. This shortens the mag... View full abstract»

• Dynamic-stability analysis of d.w.r. synchronous generator with feedback-stabilised voltage and angle regulators

Publication Year: 1971, Page(s):1768 - 1774
Cited by:  Papers (1)
| | PDF (745 KB)

Stability studies of a divided-winding-rotor (d.w.r.) synchronous machine, equipped with common types of voltage and angle regulators, and speed governor are made employing the Routh-Hurwitz criterion. The speed governor is found to increase the stability limits. Employing feedback stabilisation in the voltage and angle regulators is found to improve the stability limits, and also permits the use ... View full abstract»

• Sensitivity analysis of d.w.r. synchronous generator

Publication Year: 1971, Page(s):1775 - 1778
| | PDF (475 KB)

The roots of the characteristic equation of a divided-winding-rotor (d.w.r.) synchronous machine equipped with regulators for controlling voltage, torque angle and speed are evaluated. Under different operating conditions, sensitivities of the critical root of the system for small variations in various control parameters are determined. From these results, the effect of the parameters on the root ... View full abstract»

• D.W.R.-synchronous-machine response to unbalanced faults

Publication Year: 1971, Page(s):1779 - 1783
Cited by:  Papers (1)
| | PDF (421 KB)

This short paper describes an investigation into the behaviour of a divided-winding-rotor (d.w.r.) synchronous generator, equipped with regulators for controlling the terminal voltage, torque angle and speed, when subjected to unbalanced short circuits at its terminals. The performance of the machine has been compared with that of a conventionally wound rotor arrangement. It has been observed that... View full abstract»

• Transient-stability studies of d.w.r. synchronous generator

Publication Year: 1971, Page(s):1784 - 1790
Cited by:  Papers (1)
| | PDF (686 KB)

Some transient-stability studies of a divided-winding-rotor (d.w.r.) synchronous generator equipped with regulators for controlling the voltage, torque angle and speed are described. It has been observed that the machine is quite capable of withstanding severe forms of load shedding, and that the angle regulator is quite effective in checking the magnitudes of rotor-angle swings. Other abnormaliti... View full abstract»

• Computer-aided analysis of saturated systems

Publication Year: 1971, Page(s):1791 - 1799
| | PDF (861 KB)

The paper describes mathematical models suitable for digital simulation of saturated systems. The method takes account of the changing saturation at every instant by using the magnetisation curve. The transient behaviour of the transformer is first studied, and the technique is then extended to cover the case of sudden line-line short circuit of the synchronous machine. Computed values are in good... View full abstract»

• Direct digital control of power in h.v. d.c. interconnectors

Publication Year: 1971, Page(s):1800 - 1806
| | PDF (846 KB)

Based on the principle of symmetrical firing of the convertor valves, the paper presents a direct-digital-control scheme which exploits fully the inherent power controllability of h.v. d.c. transmission links. The hardware and operation of the monitoring transducers and integrated logic circuits provided to achieve the necessary accuracy and speed are described. View full abstract»