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New Publications are available now online for this publication.
Please follow the links to view the publication.RFIC and MMIC Design and Technology
http://dl-live.theiet.org/content/books/cs/pbcs013e
<p xmlns="http://pub2web.metastore.ingenta.com/ns/">This book gives an in-depth account of GaAs, InP and SiGe, technologies and describes all the key techniques for the design of amplifiers,ranging from filters and data converters to image
oscillators, mixers, switches, variable attenuators, phase shifters, integrated
antennas and complete monolithic transceivers.</p>Hinkley Point neutron flux system
http://dl-live.theiet.org/content/journals/10.1049/jbire.1962.0010
Conventional ion chamber and logarithmic amplifier techniques are employed without involving elaborate and sophisticated instrumenta tion. A minimum of different instrument types has been aimed at. A comprehensive built-in system of operational testing has been designed which obviates the need for portable test gear, and reduces the number of personnel required to carry out such testing.The impact of transistors on the design of reactor instruments
http://dl-live.theiet.org/content/journals/10.1049/jbire.1962.0067
The requirements of reactor instruments demand an unusual emphasis on the philosophy of fail to safety, guaranteed power supplies in all circumstances and reliability over long periods of operation. The special advantages of transistors in the development of these instruments are simplicity of circuit and economy of power required. As a result, a greater emphasis can be placed on a.c. or pulse operation of circuits which, although inherently more complex, can be made much safer than d.c. operation.New instruments designed for the U.K.A.E.A. take their power from a d.c. supply of 50 V centre tapped or from the a.c. mains which considerably eases the provision of stand-by facilities. A description is given of a logarithmic amplifier and period meter with a wide range, fast response and no period overshoot which typifies the approach. A potentiornetric recorder and pulse counting channel are briefly mentioned.Industrial electrical measuring instruments. A review of progress
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1958.0318
The accuracy of measurement of electrical standards
http://dl-live.theiet.org/content/journals/10.1049/jiee-2.1951.0154
An ultra-short lifetime apparatus
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1959.0073
An apparatus is described for measuring the lifetimes of photo-injected excess carriers and surface-recombination velocities in semiconductors by the decay of photo-conductivity. The use of a high-intensity carbon arc, front-surface mirrors (one of which can be rotated at speeds up to 25000 r.p.m.), shaping slits and a relatively long optical lever (18–20 ft) produces a light pulse that is essentially rectangular. The apparatus has been used to measure time-constants from 32 microsec to 6.6 millimicrosec. Curves of photo-conductive rise and decay are shown for indium-antimonide detector cells, a multiplier phototube and high-resistivity silicon.The measurement of transistor characteristics at very high frequencies
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1959.0176
The paper is concerned with the evaluation of transistors suitable for use as small-signal v.h.f. amplifiers. Parameters governing behaviour at very high frequencies are discussed and measurement techniques are described. Results of measurements at 100 Mc/s on two types of v.h.f. transistor are given; from these data, maximum available power gains are calculated and compared with values measured in a practical amplifier circuit.The absolute measurement of low power at 3000 Mc/s
http://dl-live.theiet.org/content/journals/10.1049/jiee-2.1949.0091
Measurement of the active admittances of a triode at 4 Gc/s
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1958.0107
The paper describes the method of measuring the active admittances of the EC 57, a 4 Gc/s microwave triode. The results prove to be in reasonable agreement with the transit-time theory if the current density is sufficiently high.The design of an equipment for measuring small radio-frequency noise powers
http://dl-live.theiet.org/content/journals/10.1049/jiee-2.1952.0042
Introductory lecture
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1962.0105
Some factors influencing the design of broad-band H.F. monopole aerials
http://dl-live.theiet.org/content/journals/10.1049/piee.1963.0220
Some of the factors influencing the design of broad-band monopole aerials for use on shore-station terminals of h.f. band circuits (3–30 Mc/s) are discussed. Two applications are considered in particular; firstly, that of a system suitable for omnidirectional radiation, and, secondly, a system suitable for wide-angle sector radiation. Attention is given to the effects of the aerial configuration on the terminal-impedance characteristic and the radiation patterns. The results of measurements made on various configurations are presented in a graphical form to enable the aerial designer to determine the basic design of a structure for a given requirement. Two typical examples, one for each application of the aerial, are discussed. The design of the associated feeder systems, particularly for transmission circuits, is also discussed.Methods of measuring radio interference from high-voltage insulators
http://dl-live.theiet.org/content/journals/10.1049/piee.1965.0161
A critical study of the methods available for the measurement of radio interference from high-voltage insulators has been made by comparing the results obtained with the various methods for a range of insulators. It was found that the method which measured the noise current through a resistor coupled to the high-voltage system by a capacitor gave consistent results for all insulators. The second method, which measures the noise currents in the earth lead of the insulator, gave results which depended upon the size of the insulators. This method was subsequently modified by using an artificial earth plane connected to the measuring set. The results then approached those of the first method. A third method assumes that the onset voltage of visual corona is the criterion for the onset of radio interference. It was found that some radio interference was generated before visual corona commenced and that the levels at the critical visual corona voltages depended upon the types of insulators used.Effect of gas flow on post-arc gap recovery
http://dl-live.theiet.org/content/journals/10.1049/piee.1964.0032
Spark reignition voltage characteristics have been measured for gaps between stationary electrodes for various controlled speeds of gas flow following d.C. pulsed arc discharges. By varying the gap geometry, electrode material and duration of the initial arc, the influence of both the gas flow and the electrodes on the detailed shapes of the characteristics have been determined and qualitatively explained. A crude theoretical approach is described, in which the variation of spark reignition voltage is satisfactorily accounted for in terms of the average gap density as controlled by the initial electrode heating, the time constants of the conductive cooling of the gas and the electrodes, and the heat transport by the gas flow through the gap.The accuracy of measurement of electrical standards
http://dl-live.theiet.org/content/journals/10.1049/pi-2.1951.0189
The difference between “international” and “absolute” electrical units is explained, and the reason for the change made in 1948 from one system to the other is given. The uncertainty of the electrical units defined in terms of length, mass and time is estimated to be about 20 parts in a million, although the accuracy of comparison of electrical quantities may be as high as one part in ten million. The loss of accuracy in the measurement of voltage, current and power when transferring from direct to alternating current is explained: it is estimated that these quantities cannot be measured at power frequencies to better than one part in 10000.Discussion on “Testing and approval of electrical appliances”
http://dl-live.theiet.org/content/journals/10.1049/piee.1967.0210
Effect of distortion on the Bessel-zero method of frequency-deviation measurement
http://dl-live.theiet.org/content/journals/10.1049/piee.1966.0120
The Bessel-zero technique for f.m. deviation measurement is often used as the standard for the calibration of carrier-deviation and f.m.-signal-generator instruments. Error in the calculation of the deviation arises owing to harmonic distortion in the modulating signal, which results in a change in the value of the modulation index at which the carrier amplitude is zero. Similar errors occur when spurious amplitude modulation arises because of variation in the loading and dynamic impedance of the tuned circuit during frequency modulation. The paper examines quantitatively the effects of both types of distortion on the modulation index. It is considered that, in practice, zeros greater than, say, the 12th, are rarely used, and percentage distortions greater than 10% are very unlikely. Using these assumptions, ‘worst-case’ errors are calculated. The largest error appears to arise from spurious amplitude modulation at the second harmonic of the modulating frequency, and is less than 4% for up to 10% distortion. The actual measurement of the errors is very difficult because they are extremely small. The theoretical analysis confirms this, and indicates the tolerable distortion for a given accuracy of the method.The absolute measurement of low power at 3000 Mc/s
http://dl-live.theiet.org/content/journals/10.1049/pi-3.1949.0051
A general method for the calibration of milliwattmeters operating in the centimetric-wave region is described. Results of measurements at 3000 Mc/s on a thermistor bridge milliwattmeter are given and it is shown that within the present limits of experimental error (estimated as±4%) this instrument gives true power indications. The powers indicated by other forms of milliwattmeter, for equal power inputs, have been determined and the results are summarized. It is concluded that a number of different instruments may be relied upon to indicate true power withing reasonably small limits of error.Simulation of massive inertia loads using feedback techniques
http://dl-live.theiet.org/content/journals/10.1049/piee.1966.0083
A method of simulating any load would be very useful for the testing of many power drives. The paper examines three feedback-controlled systems whereby inertia loads can be simulated without using flywheels. One system, which has been found to be of a type suitable for the simulation of train loads for laboratory studies of the utilisation and control of traction motors, is described in detail.Discussion on “A Royal Air Force Calibration Centre” before the Southern Centre, at Farnborough, 22nd February, 1950
http://dl-live.theiet.org/content/journals/10.1049/pi-3.1951.0046
Testing and approval of electrical appliances
http://dl-live.theiet.org/content/journals/10.1049/piee.1966.0356
The paper describes the development of the Electricity Council Appliance Testing Laboratories, formerly known as the EDA Testing House, and surveys the various schemes associated with the approval of electrical appliances and accessories in the UK. The relationship with international standardising bodies is explained, and the tests specified in the British Standards are compared with those of the international CEE specifications. The extent to which the British and international standards have been brought into agreement is shown.High-frequency properties of four-terminal field-effect transistors
http://dl-live.theiet.org/content/journals/10.1049/piee.1966.0009
The high-frequency properties of the four-terminal field-effect transistor are examined. Using the device charge equations, various intrinsic capacitances are defined, and expressions are obtained for their variation with voltage. From these equations and a knowledge of the intrinsic and extrinsic structure of these devices, an equivalent circuit is proposed, which is shown to be in reasonable agreement with experimental observations.The intergate capacitance is examined in some detail, and an explanation of the very abrupt capacitance changes observed experimentally is given. Careful attention is paid to distinguishing between the device's intrinsic and extrinsic properties and correctly comparing experimental and theoretical results.A Royal Air Force Calibration Centre
http://dl-live.theiet.org/content/journals/10.1049/pi-3.1950.0010
A Calibration Centre has been set up in the Royal Air Force to maintain in calibration the test equipment used on radio and radar equipment. The main object is to provide all aircraft and R.A.F. stations with electrical standards that are known to agree with each other. Part 1 of the paper discusses the general principles governing the design of the Centre, and Part 2 gives some details of the methods and apparatus used.Calibration of d.c. resistance standards and voltage-ratio boxes by an a.c. method
http://dl-live.theiet.org/content/journals/10.1049/piee.1965.0031
Some of the uncertainties and causes of error experienced in the traditional methods of calibrating d.c. resistance standards are discussed, and it is shown that they can be reduced or eliminated by the use of a.c. and inductively coupled ratio devices.Techniques are described whereby the zero-frequency (or d.c.) value of 4-terminal resistors can be readily determined to an accuracy of within 2 parts in 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">7</sup> from a few measurements made at frequencies between 40c/s and 600c/s. A Kelvin-double-bridge network is used, the ratio arms consisting of adjustable inductively coupled dividers having an accuracy and discrimination of at least 1 part in 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">7</sup>.Similar techniques are used in a Wheatstone-bridge network to determine the values of d.c. voltage-ratio boxes. Any ratio between 1 : 1 and 1000 : 1 can be measured directly in one step to an accuracy of within about 1 part in 10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">6</sup>.Experimental results and constructional details of the inductive dividers are given, together with the theoretical considerations underlying the principle of the method.The absolute measurement of low power at 3000 Mc/s
http://dl-live.theiet.org/content/journals/10.1049/pi-2.1949.0118
A general method for the calibration of milliwattmeters operating in the centimetric-wave region is described. Results of measurements at 3 000 Mc/s on a thermistor bridge milliwattmeter are given and it is shown that within the present limits of experimental error (estimated as ±4%) this instrument gives true power indications. The powers indicated by other forms of milliwattmeter, for equal power inputs, have been determined and the results are summarized. It is concluded that a number of different instruments may be relied upon to indicate true power within reasonably small limits of error.Instrumentation for monitoring the drying of power transformers
http://dl-live.theiet.org/content/journals/10.1049/piee.1966.0049
Measurement of the stability of an electric arc
http://dl-live.theiet.org/content/journals/10.1049/piee.1966.0368
The performance requirements of a television monitor receiver (nyquist demodulator) and methods of measurement
http://dl-live.theiet.org/content/journals/10.1049/ree.1965.0096
A high-quality monitor receiver is normally used at television transmitter stations for measuring and monitoring purposes. The performance of this receiver is discussed on the basis of the ideal characteristics, as specified by C.C.I.R., and the characteristics which lie within practical tolerance limits. The problem of testing the receiver is considered, and selected measuring procedures, which have been used in an extensive test service for the Norwegian Telecommunication Administration, are described.Synthetic testing of circuit-breakers
http://dl-live.theiet.org/content/journals/10.1049/ji-1.1942.0032
The measurement of lightning voltages and currents in Nigeria. Part 2: 1938–1939
http://dl-live.theiet.org/content/journals/10.1049/ji-2.1942.0033
This paper gives an account of the results achieved in an investigation into the magnitude of lightning currents and voltages on high-voltage transmission lines in Nigeria and describes a continuation of earlier work started by one of the authors. Three-phase oscillographic and klydonographic records of voltages were obtained, together with magnetic link measurements of lightning currents on pole and lattice mast structures. Continuous records have also been obtained of the interchange of current between the earth and atmosphere during disturbed weather conditions.The measurement of lightning voltages and currents in Nigeria. Part 2: 1938–1939
http://dl-live.theiet.org/content/journals/10.1049/ji-1.1942.0023
Discussion on “Synthetic testing of circuit-breakers”
http://dl-live.theiet.org/content/journals/10.1049/ji-2.1942.0086
Synthetic testing of circuit-breakers
http://dl-live.theiet.org/content/journals/10.1049/ji-2.1942.0021
Circuit-breaker test plants installed during the last few years have sufficed for practically all commercial commitments except in the h.v. ranges, where high interrupting capacity is needed. For these limiting cases, variations of the direct method, and “synthetic” testing, in which the arc current is obtained from one source and the restriking voltage from a separate source, have often been advocated. In particular cases, where the tests have been confined to a single breaker of special type, such methods have been employed with apparently satisfactory results.An investigation was carried out to determine whether synthetic testing as a general means of extending the range of a test plant was economically preferable to a straight extension of the plant. This embraced a study of the requirements of the case and an estimate of the cost of the plant to meet these requirements.A circuit suitable for use with all types of breaker was devised. The restriking voltage was considered as of (1-cosine) form, rising to its peak value in times of 20–100 microsec.The results show that there is little difference in capital cost as between synthetic injection testing and the use of full plant kVA. Moreover, it is by no means certain that the synthetic method is fully equivalent to the direct test and, as clearing up this important question would entail the comparative application of both methods, it is concluded that synthetic methods cannot generally be justified economically.The fixing of confidence limits to measurements
http://dl-live.theiet.org/content/journals/10.1049/ji-1.1944.0112
Standards of electrical measurement
http://dl-live.theiet.org/content/journals/10.1049/ji-1.1942.0104
Following introductory paragraphs dealing with the general character of measurement, units and standards, an account is given of the more recent experimental researches of the standardizing laboratories, and the present legal and international position of the various electrical units, including the m.k.s. system which has recently attracted some attention.Discussion on “The measurement of lightning voltages and currents in Nigeria. Part 2: 1938–1939” before the Transmission Section, 10th December, 1941
http://dl-live.theiet.org/content/journals/10.1049/ji-2.1942.0034
The Weston cell as a house standard of e.m.f.
http://dl-live.theiet.org/content/journals/10.1049/ep.1966.0328
In its stability, accuracy, sensitivity to perturbations and mechanical robustness, the Weston cell is a good example of how a standard should <i xmlns="http://pub2web.metastore.ingenta.com/ns/">not</i> behave. However, with suitable temperature control and precautions against parasitic e.m.f.s, the Weston cell, for all its disadvantages, shows the best long-term stability, and can make a reliable house standard of e.m.f.Standard cells
http://dl-live.theiet.org/content/journals/10.1049/ep.1966.0327
The Weston cell was adopted as the ultimate standard of e.m.f. in 1911, but it was not until after the Second World War, and the increasing demand for reliable and more accurate standards in automation and instrumentation, that its importance became realised on a commercial scale. Today, many tens of thousands of these cells are required each year.Measurement at subaudio frequencies
http://dl-live.theiet.org/content/journals/10.1049/ep.1966.0102
The nature of indicating instruments, circuits and human responses is such that frequencies below 15 c/s call for different techniques of measurement, but is anyone interested in making measurements in this region? We find, in fact, at least three fields of research using signals below this frequency.Standards for electrical measurement
http://dl-live.theiet.org/content/journals/10.1049/ep.1966.0326
It is one of the functions of the science and art of measurement to devise and apply methods of reliably carrying out the counting processes, and of defining and maintaining the magnitudes of the units counted. Some units, like the metre and the kilogramme, appear at first sight to be easy to maintain, as they can be stored on stable material standards. Derived units like velocity, pressure, or the electrical units are in general much more difficult to store, and in many cases can only be transitorily realised by the effect which they produce.Electron detachment in oxygen
http://dl-live.theiet.org/content/journals/10.1049/el_19670113
A new experimental method for determining electron detachment (δ) coefficients in swarm conditions in gases is described. Data are given for oxygen at pressures of 20 and 40torr (<i xmlns="http://pub2web.metastore.ingenta.com/ns/">E/p</i>=40–50 <i xmlns="http://pub2web.metastore.ingenta.com/ns/">V</i> cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup> torr<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup>). δ/<i xmlns="http://pub2web.metastore.ingenta.com/ns/">p</i> varies from 2×10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−3</sup> to about 1.3×10<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−2</sup>cm<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup>torr<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">−1</sup>.The Zener diode—an accurate voltage-reference source
http://dl-live.theiet.org/content/journals/10.1049/ep.1966.0329
The success or failure of many current Earth-satellite and space-exploration programmes is highly dependent on the performance of precision Zener diodes. Military and industrial users of these subminiature semiconductor devices are inheriting the benefits of the necessary applied technology.Measuring up
http://dl-live.theiet.org/content/journals/10.1049/me_19990402
A recent government-sponsored survey found that barely one UK company in ten was aware of the national measurement services available, The author outlines a new programme set up to change that statistic.Measurement science versus measurement technology in the engineering curriculum
http://dl-live.theiet.org/content/journals/10.1049/esej_19970308
Measurement education within many engineering curricula may be described as `elementary' and `traditional'. In this paper it is argued that this style of presentation, with its emphasis on `recipe' and traditional measurements, is increasingly inappropriate for the requirements of modern engineering practice. This paper outlines two contrasting undergraduate units (subjects) in which measurement engineering is presented in a generic but systematic manner within two separate degree courses in electrical/electronic (and other) engineering. Both these subjects emphasise the science of measurement and measurement system design rather than the technology involved, this provides the student with a basis for, and some experience in, applications spanning a wide range of measurement requirements.A Royal Air Force calibration centre
http://dl-live.theiet.org/content/journals/10.1049/jiee-2.1950.0020
Industrial electrical measuring instruments
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1958.0238
The design of an equipment for measuring small radio-frequency noise powers
http://dl-live.theiet.org/content/journals/10.1049/pi-3.1952.0033
The paper discusses the design of an equipment for the continuous recording of the very small r.f. noise powers received from the sun and the galaxy.It is first shown how a noise power can be described in terms of an equivalent temperature, and how cable attenuation affects the noise power measured at the end of an aerial feeder. The fundamentals of the measurement of noise power are considered; it is shown that the minimum detectable power is determined by the receiver noise and by the ratio of input and output bandwidths of the receiver. The practical difficulties inherent in the measurement have been overcome by the design of a self-balancing equipment in which a locally generated noise power is continuously adjusted to equality with the incoming power.A description of such an equipment is given; the design of the r.f. switch, the local noise source, the receiver and the control circuits for the noise source are considered in some detail.The performance of the equipment is analysed in terms of its accuracy, its response to a step function of input and the fluctuations of its output indication. Experimental determinations of the performance are found to compare reasonably well with theory.Suppression of subsidiary absorption in polycrystalline ferrite
http://dl-live.theiet.org/content/journals/10.1049/el_19660236
Results of an investigation into suppression of the subsidiary absorption in a polycrystalline-ferrite phase shifter, by means of a modulated static magnetic field, are presented. Good agreement with theoretical predictions is observed, and conclusions are drawn regarding the practical use of this technique.Surface-wave probe for measuring electron densities in a gaseous plasma
http://dl-live.theiet.org/content/journals/10.1049/el_19650013
A dielectric rod enveloped in gaseous plasma can act as a supporting structure for electromagnetic surface waves. The dielectric constant of the plasma and hence the electron number density in the vicinity of the rod may be determined from measurements of the phase-change coefficient of the EH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">11</sub> mode supported by the plasma-clad rod. Measurements of radial density distribution have been carried out in an unmagnetised argon afterglow plasma at 35Gc/s and compared with double-probe measurements.Aperture field of a leaky-wave antenna of finite length
http://dl-live.theiet.org/content/journals/10.1049/el_19660054
An anomaly in the radiation field of a leaky-wave slot antenna is apparent when experimental and theoretical results are compared. An investigation of the field along the aperture of the antenna, in which experiment is supported by theory, indicates that this is probably due to the continuous excitation of a TEM wave along the slot itself.