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The analysis of step-recovery diode harmonic generators by means of a linear time-varying circuit model of the diode has been advocated previously and it has been demonstrated that a direct analogy exists for the purposes of predicting efficiency, terminating impedances and optimum idler combinations, between the shunt connected SRD and a three-terminal switch where the periodic variation in conductance may be related to the physical properties of the diode. In the present paper it is demonstrated that by suitably modifying the circuit equation to include the d.c. bias essential to the operation of the series connected SRD the linear time-varying circuit model may be applied to this circuit also, resulting in an analysis of comparable generality and ease of application to that obtained for the shunt generators. A basis is thus provided for the analysis of all forms of SRD harmonic generator and for the optimization of diode parameters for defined circuit configurations. [ABSTRACT FROM AUTHOR]

In this paper the following questions are posed and answered with reference to the relation between the input and output signals of a full wave rectifier : (1) Given the mean input and mean output signals what probability density function of input signals achieves the maximum input entropy ? (2) What is this entropy ? (3) How does it compare with the entropy of standard input distributions which achieve the same mean output ? The answer to (1) is a distribution which generalizes the normal distribution by replacing (x2/2σ2) in the exponent by (xv/vMvv), where Mvv is the mean output signal. It is also confirmed that if one orders given distributions either by their entropies or by their variances, then the two orderings will not in general agree. [ABSTRACT FROM AUTHOR]

Tunnelling current contributions to the current from the various valleys in a multi-valley semiconductor have been studied in a Schottky barrier. The effect of doping densities and temperature on current-voltage characteristics for a Schottky diode with a multi-valley semiconductor has been evaluated. It has been found that satellite valleys, specially with low effective mass, contribute significantly to the current.
In the present paper we have neglected the effect of image-force lowering and thus assumed parabolic shape for the barrier potential. The problem of tunnelling through a parabolic barrier has been studied rigorously. We have considered the transmission probability (under WKB approximately) for a multi-valley model as if each valley is interacting individually with the metal. The donor density in the semiconductor is taken to be quite high (degenerate type) and the Fermi-Dirac distribution is assumed for such a case. It is also known that when a semiconductor is degenerated, the main mechanism contributing to current across the Schottky barrier is tunnelling. The ratio of tunnelling current densities from a satellite valley to the lowest valley has been evaluated numerically. [ABSTRACT FROM AUTHOR]

A new method for synthesizing threshold gates is described in this paper. Unlike the existing methods which use RTL structures and suffer from the disadvantages of low signal-to-noise ratio, low operating speed, stringent power supply and component tolerance requirements, this method basically uses a current summing amplifier in conjunction with a differential amplifier chip and overcomes the aforesaid disadvantages of the conventional threshold circuits. The circuit configuration may also be extended to be used as a multi-threshold logic gate.
In the present work a new circuit, which basically consists of a current summing amplifier in conjunction with a high resolution differential comparator chip and a few other components, is described. The circuit provides large fan-in and fan-out capability, wide input voltage tolerance, high signal-to-noise ratio, less stringent power supply and component tolerances. With the addition of a few more components the circuit can be utilized as multi-threshold gates. [ABSTRACT FROM AUTHOR]

The Corbino effect is calculated for concentric cylindrical semiconductor devices which operate under double- and single-injection. For the two carrier structures, the I-V characteristics are represented by an Proportional toV relationship where = (1+pn B)/[1+(B)][1+(B)] and n=2 for the semiconductor regime and n=3 for the insulator regime.
Similar results are obtained for single-injection space-charge-limited current where n=2 and =[1+(B)].
The present paper describes the effects of a transverse magnetic field on the I-V relationships of double- and single-injection structures which have a concentric cylindrical geometry. The device configuration is a hollow-core coaxial semiconductor with carrier injecting contacts at the inner and outer surfaces of the annulus. At low-injection levels, the I-V relationships are linear and a magnetic field applied perpendicular to the radial direction causes the charge carriers to follow spiral path-lengths between the inner and peripheral contacts (Corbino 1911).
As the injection levels are increased, the I-V relationships are no longer linear because the excess carriers injected into the concentric cylindrical semiconductor lead to various double- and single-injection phenomena. The main purpose is to obtain an estimate of the influence of a magnetic field on the I-V characteristics of annular structures which operate under these high-level injection conditions. [ABSTRACT FROM AUTHOR]

The design of a monolithic current-controlled current source (CCS) based on the intrinsic matching properties of similar adjacent transistors is described. Experimental and theoretical results are presented and compared. This CCS has been specially tailored for use in a four-quadrant multiplier circuit discussed in a earlier communication (Scholtzhauer and Viswanathan 1972).
This paper describes a current-controlled current source (CCS) designed as an input driving module for a four-quadrant analogue multiplier (Scholtzhauer and Viswanathan 1972). This application requires a broadband, stable and linear unity current-gain block with high output resistance, low input resistance and low input offset voltage, plus a special-purpose second output. This output should be formed as I = I/( + 1), where I is this auxiliary output, I is the main output and is the common-emitter gain of a single transistor matched with the devices in the multiplier circuit. [ABSTRACT FROM AUTHOR]

The paper presents the analysis of a Darlington composite transistor amplifier in the super-alpha configuration. Equations have been developed to study the variations of voltage gain, current gain, power gain and input impedance with load resistance and frequency. Calculations have been made using the IBM 1130 computer for the case of a typical transistor working under typical operating conditions. Graphs representing these variations have been presented and discussed in detail. This Darlington composite transistor amplifier is found to offer some interesting possibilities for applications at low frequencies up to 1 MHz. Simple, although approximate, empirical formulae have been suggested for making ready calculations of voltage gain and power gain in this frequency range in the useful range of load resistances up to 1 kohm in the case of 1 MHz and 10 kohms in the case of 100 kHz. The maximum voltage and power gains obtainable are about 10 with 1 MHz and 1 kohm limitation an 1 about 100 with 100 kHz and 10 kohms limitation. [ABSTRACT FROM AUTHOR]

Expressions for the radiation fields in a compressible electron plasma medium are derived pertaining to the helical antenna of finite size immersed in it. The current distribution on the helical antenna is assumed to be an out-going travelling wave with an arbitrary phase propagation constant. From these general expressions fields of circular loop and linear antennas can be deduced as particular cases. Further, by letting the plasma frequency approach zero in these general expressions, the electromagnetic fields of the usual helical antenna theory can be obtained. It is, therefore, concluded that the radiation field expressions for a helical antenna given in this paper are of a general nature and cover the cases of circular loops and linear antennas in an electron plasma medium and of the helical antenna in vacuum. [ABSTRACT FROM AUTHOR]

The influence of the collector p-n junction capacitance on the operation of a transistor oscillator and a power amplifier is discussed. These problems are of particular importance in the microwave range, where the values of the other constructive capacitances are minimal. It is shown that the non-linearity of the collector capacitance leads to some peculiarities as typical parametric effects, which have to be taken into account.
This paper deals with the influence of the non-linear collector p-n junction capacitance on a transistor oscillator in the mode of self-oscillation as well as in the mode of external excitation. It is proved that the presence of a non-linear collector capacitance may lead to considerable parametric effects, which have to be taken into account in all cases. The theoretical analysis is carried out by the phase-plane method (Samoylo 1968) using the procedures worked out in Spasov et al. (1972). In this way considerable simplification of the theoretical calculations is obtained. The necessary data are obtained in the first approach. The theoretical results agree well with the experimental results, which will be seen in the following. [ABSTRACT FROM AUTHOR]

Assuming the double exponential nature of the current in the multiple return strokes of a lightning discharge, the radiated electric and magnetic field profiles have been computed with a new approach, at different time intervals. It is found that our calculated values of electric and magnetic field of the primary and the subsequent strokes are in close agreement with the experimental records and theoretical results due to others.
The electromagnetic properties have enabled a number of workers to make detailed analyses of magnetic flux density from multiple return stroke lightning (Hatakeyama 1936, Meese and Evans 1962, William and Brook 1963). Norinder and his co-workers (Norinder and Dahle 1945, Norinder and Knudsen 1957, 1961) gave various data from accurate measurement of the magnetic flux density due to various strokes of a flash. In particular, the number of strokes per flash, surge current in the strokes and magnetic field due to streamer processes were other parameters explored quantitatively by them. Uman and McLain (1970) also presented rigorous mathematical expressions for the estimation of the surge current by the measurement of magnetic flux density from the lightning discharges. But to our knowledge none have evaluated the radiation magnetic field and electric field at very large source distances, useful in multi-station recordings. In the present paper the electric and magnetic fields of the multiple return strokes of a lightning discharge have been calculated at large distances and discussed in detail with the available experimental and theoretical results. Such a theoretical investigation for computation of the magnetic flux density profiles was made by Uman and McLain (1969) for different surge current models of multiple return stroke lightning discharge, limited up to a distance of 200 km from the strokes, using a different technique. [ABSTRACT FROM AUTHOR]

In this paper we consider a model describing the formation of a plasma sheath in the neighborhood of a plane absorbing conducting wall. Expressions are derived for the electric potential in the plasma and for the ion and electron densities. The validity of the model is restricted to cases in which the wall potential is monotonic in time. [ABSTRACT FROM AUTHOR]

Based on the current-voltage transfer characteristic, equations were derived relating the distortion levels the operating conditions and the characteristic parameters of a transistor amplifier. The characteristic of the Darlington composite transistor was determined experimentally, and its harmonic distortion was analysed and compared with its component transistors. Compensation of harmonic distortion by load and source resistance was discussed.
The characteristics of the Darlington composite transistor were studied previously (sec, for example, Suen 1968, Yu and Such 1968, Singh 1969 and 1971, Gupta 1972). This paper discusses the harmonic distortion of the Darlington configuration at low frequencies. [ABSTRACT FROM AUTHOR]

Diodes of Mg contact to both n and p-type Si respectively have been fabricated. I-V characteristics and specific contact resistance R were studied. Specific contact resistance can be reduced by increasing temperature, and decreasing contact area. Diodes of Mg to p-type non-degenerate Si contact possess better rectifying properties than those of Mg to n-type non-degenerate Si. Studies of specific contact resistances for different contact areas reveal the current crowding effect.
The purpose of this paper is to investigate the contact properties between magnesium and a non-degenerate n or p-type Si. [ABSTRACT FROM AUTHOR]

The development of a high power, high frequency, inverter thyristor is described.
The techniques and procedures used to achieve forward blocking recovery times of less than 2 microseconds are summarized, and electrical test data are included to show that other thyristor parameters are not too adversely impaired.
This paper is concerned with the general problems involved in the design of high frequency thyristors, and briefly describes the techniques used to develop this particular device. [ABSTRACT FROM AUTHOR]

The oscillatory behaviour of the magneto-current with forward bias and its variation with temperature and magnetic field have been studied in various semiconductor diodes. The oscillatory magneto-current has been explained in terms of the oscillations in the probability of transition of carriers through the junction due to the formation of magnetic sub-bands in the semiconductor.
The experimental results of increasing amplitude and period of oscillations with magnetic field and the decrease of the same with temperature also have been explained satisfactorily.
The purpose of the present paper is to explain the oscillatory magnetocurrent. With this in view, the effect of intense magnetic field on the forward current characteristics has been studied in various semiconductor diodes at room temperature and liquid nitrogen temperature. The observations have been explained on the basis of the oscillatory probability of transition of charge carriers through the junction caused by the magnetic sub-bands in semiconductors. [ABSTRACT FROM AUTHOR]

The effects of the drift motion of the plasma on the radiated synchrotron power are studied in detail with special reference to the magnetospheric and solar coronal plasmas. It is shown that the radiated power is enhanced in the presence of the drifting plasma.
In the present paper, therefore, we study in detail the characteristics of synchrotron radiation from a drifting homogeneous magnetoplasma. It is seen that drift motion of the background plasma increases the refractive index. It turns out that because of this change the radiated synchrotron power is enhanced. The present theory has been applied to the magnetosphere and the solar corona in order to investigate numerically the effect of drifting plasma on the radiated synchrotron power. [ABSTRACT FROM AUTHOR]

A method is presented for computing the electromagnetic or acoustic scattering by symmetrically notched or wedged circular cylinders under the Neumann boundary condition. A feature of the formulation, which is in terms of an electromagnetic field magnetically polarized in the axial direction, is the ease with which the scattered field may he computed after the necessary matrix inversion. The backscattering cross sections of various notched and wedged circular cylinders with characteristic dimension 0 kb 3.0 are presented for all aspect angles.
This paper presents a method of computing the scattering by a symmetrically notched cylinder under the Neumann boundary condition (soundhard boundary in acoustics). Since the location of the apex of the notch is not restricted to the centre of curvature of the cylindrical surface, the method is equally applicable to notched or wedged cylinders. The scattering is formulated in terms of an electromagnetic field magnetically polarized in the axial direction, with the surface current density on the cylinder being represented by a sum of continuous functions which satisfy the edge conditions at the notch apex (Jones 1964). The Neumann boundary condition is enforced by setting the total field inside the cylinder to zero (Waterman 1965). The ease with which the scattered field may be computed, after the resulting matrix equation has been truncated to finite order and inverted, is a feature of the method. [ABSTRACT FROM AUTHOR]

The paper deals with a taper cum trickle charger which automatically adjusts the charging current proportional to the AH of discharge of the battery. The unique feature of the charger is that the SCR is phase controlled and, unlike other chargers using UJT and SCR, this is not an ON-OFF charger but a proportional charger. [ABSTRACT FROM AUTHOR]

This paper is a critique of some aspects of the theory of norma cold-cathode glow discharges, with special reference to the development of the discharge in a direction normal to the cathode. It is pointed out that a theory of the normal cathode dark space is available on the basis of Poisson's equation and the Boltzmann transport equation, if conditions at both its cathode and negative glow boundaries are supposed known, whether or not the complexity of the Boltzmann computing is minimized by using as far as possible from the beginning the macroscopic Townsend coefficient /p and mobility-type relations, or other convenient approximations. Attention is called to the vital part played by the negative glow plasma, and the possibility of improving sharp-boundary cathode dark space theory by applying a Langmuir-Bohm criterion for positive space-charge to form is considered. A more fundamental approach is however to consider the whole discharge from the cathode to the middle of the negative glow or the anode as one unit. The relation between normal discharges and constricted subnormal discharges requires some clarification, in particular to ascertain if the normal discharge retains some subnormal characteristics, and vice versa, and there is urgent need for more data for the plasma parameters (electron and ion number densities and energy distribution functions, and potential contours) for normal negative glows both with and without completely covered cathodes. [ABSTRACT FROM AUTHOR]

This paper reviews the experimental methods of determination of temperatures of recovering high current spark channels in different stages of the afterglow. Most of the experiments described were performed at atmospheric pressure or pressures sufficiently high that thermal equilibrium among all species is achieved so that the electron, ion and gas temperatures are considered equal. In the early afterglow (within approximately 50 s after spark initiation) when luminosity of the spark is sufficient, spectroscopic methods are employed to determine channel temperatures. In the intermediate stage of the afterglow (50 s-500 s) when luminosity is not sufficient for optical techniques to be employed, measurement, of electrical conductivity or sound or shockwave velocity can be used to derive the gas temperature. In the late afterglow (1 ms after spark initiation) when the gas has recovered to a neutral state, measurements of reignition voltage together with Paschen's law are used to derive gas temperature. [ABSTRACT FROM AUTHOR]

The paper presents design tables for high-pass RC active filters having capacitors of equal value. The functions realized are of the third-order Butterworth and Chebyshov variety. Account is taken of the resistor spread, total resistor sum and of the summed network sensitivity.
The design of equal-valued capacitor filters has been discussed in the literature (Huelsman 1971, Stephenson 1972a, b). The results presented for third-order networks (Huelsman 1971, Stephenson 1972a) have referred specifically to Butterworth functions. [ABSTRACT FROM AUTHOR]

This paper describes the scheme as well as the circuit, details of a phase shifter that can be used to shift the phase of a square-wave signal continuously from degrees to 360degrees. The phase is shifted linearly and continuously by the mere adjustment of a potentiometer, which may be calibrated in degrees. [ABSTRACT FROM AUTHOR]

In this paper sets of necessary and sufficient conditions for simultaneous reducibility to diagonal forms of two or more prescribed Hermitian forms are summarized and the procedure for computation of the required transformation outlined, with a view towards applying these results in various problems of electronics. Application of the results to Foster-type canonic synthesis of networks containing positive and negative resistors, inductors and capacitors is discussed. The theory is also applied towards a solution of a certain problem occurring in the Anderson-Duffin parallel addition of matrices. Furthermore, other possible applications are discussed, and examples included, wherever these serve to illustrate better the procedure. [ABSTRACT FROM AUTHOR]

An active R.C. structure using a fixed gain differential amplifier, two resistors and three one-ports, is presented for the realization of general voltage transfer functions including those having zeros on the positive real axis. The comparative merit of the scheme, with respect to the circuit presented recently by Natarajan (1970), is that, a smaller number of passive circuit elements is required for the synthesis of a general voltage transfer function. A few examples are included to illustrate the synthesis procedures.
In this paper, two active R.C. circuits based on a general structure using a fixed gain differential amplifier, two resistors and three R.C. one-ports for realizing general voltage transfer ratios have been proposed. The procedures for the synthesis of such transfer functions have also been presented with a few illustrative examples. The comparative merit of the circuits with respect to that of Natarajan (1970) is that the number of R.C. one-ports has been reduced from five to three, resulting in a smaller number of passive circuit elements. [ABSTRACT FROM AUTHOR]

Maximum and minimum principles associated with certain electrical boundary-value problems involving homogeneous anisotropic material are derived in a unified manner from the canonical theory of complementary variational principles.
In this paper we derive maximum and minimum principles for the problem described by eqns. (1) and (2) from the theory of complementary variational principles (Arthurs 1970). Our results contain those of Power (1960) as special cases. [ABSTRACT FROM AUTHOR]

In this paper we report a rather simple method of making conductance measurement in the early afterglow of a recovering spark channel and from which the temperatures of the channel are derived. Although we cannot compare the results directly with any previous work, the derived temperatures are not unreasonable. The results, however, should be checked by another non-perturbing technique such as using a weak shock-wave probe. [ABSTRACT FROM AUTHOR]

This paper attempts to investigate the time dependence of the U.H.F. power from the expanding return stroke channel of a lightning discharge at a typical central temperature of 14 000degreesK anti at one and two centimetre radii of the return stroke channel. It is found that the emitted power decays with time as the return stroke channel cools down. The theoretical results are in good agreement with the experimentally obtained values of various workers. [ABSTRACT FROM AUTHOR]

This paper describes a four-quadrant analogue divider making use of photoresistors as voltage-controlled resistances. The range of operation is between -l0 and + 10 volts and the accuracy is within 5% over the useful range.
Analogue division is normally performed by making use of multipliers in a feedback system. Such circuits becomes unstable when the divisor approaches zero. Because of this difficulty, division is normally avoided. However, sometimes ratio of analogue signals are required and one or both may pass through zero. [ABSTRACT FROM AUTHOR]

An analysis by transport theory has been performed for microwave 2nd-harmonic generation using the non-linearity of negative resistance in n-type GaAs under a small-signal excitation. As a result of this analysis, the detailed frequency responses which are affected by the various scattering relaxation times of carriers become clear. Moreover, it is suggested that this multiplying method would be able to operate with very high conversion efficiency, in contrast to the customary large-signal operation.
In this paper a theoretical analysis, using the transport theory, has been performed for the small-signal excitation in the case of n-type GaAs. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of pulse circuits composed of a tunnel diode and a transmission line. The method employed, analysis in the v-i plane, is applied to the self-oscillation mode as well as to that of the one-shot mode. Effects of load and source (bias) impedance, linear and non-linear, are investigated. The analysis of non-linear biasing leads to configurations which present an improved triggering ability, shorter recovery time and less sensitivity to bias voltage variations. [ABSTRACT FROM AUTHOR]

When the channel characteristics of a digital communications system are known, it is possible in theory to modify the system to meet any one of Nyquist's criteria to eliminate intersymbol interference. This paper examines the performance of such a system when signalling rate changes by about 40% about the Nyquist optimum value.
The results are presented in a graphical form in terms of the eye parameters. The cases considered are Nyquist I (with cosine roll-off factor of 0, 025, 050, 075 and 10 respectively) and Nyquist II (with cosine roll-off factor of 0 and 10 respectively). [ABSTRACT FROM AUTHOR]

Oscillation amplitude in a negative resistance (NR) oscillator is usually evaluated by the describing function approach in which the non-linear v-i characteristic of the NR device is approximated by a few terms of a power series expansion. But quite often when Negative Impedance Converters are used to simulate NR, a piecewise linear and symmetric v-i characteristic results. The present paper exploits the above mentioned linearity and symmetry to obtain, to a first-order approximation, a universal curve for determining the oscillation amplitude.
The almost sinusoidal oscillation of a negative resistance (NR) device when connected to a resonant LC circuit is a well understood phenomenon. The first-order solution for the oscillation amplitude can be theoretically determined by the describing function approach (Strauss 1960). This method involves approximating the non-linear device characteristic by a few terms of a power series expansion about the quiescent point. However, when Negative Impedance Converter (NIC) circuits are used to simulate NR, very often a piecewise linear and symmetric curve results. This linearity and symmetry can be exploited to obtain a better accuracy than can be obtained by a power series approach. We employ such a method to analyse the oscillation amplitude in a current-inversion NIC(CNIC) oscillator and show that, to a first-order approximation, an analytic expression for the amplitude can be obtained. [ABSTRACT FROM AUTHOR]

The effect of impurity gradient on the spatial distribution of light emission has been studied. The results obtained show that due to the existence of a retarding field and a spatial distribution of the radiative lifetime, with increasing current the peak of the light emission moves far away from the space-charge region.
In this paper we show that these characteristics of the light emission may be explained on the basis of the spatial distribution of the impurities. [ABSTRACT FROM AUTHOR]

The non-linear propagation of VLF waves in weakly as well as in strongly ionized plasmas has been investigated by solving the Boltzmann transfer equation for charged particle distributions. The wave equation for the electric field has been solved in W.K.B. approximation. A particular reference has been given for ionospheric propagation. The non-linear effects are shown to be of importance even for moderately strong electric fields. The effect of the motion of ions has been found to decrease the non-linearity.
This paper presents an analysis of the non-linear propagation of VLF and ELF waves in magnetoplasmas, taking into account the motion of ions. It has been assumed that only the electrons are responsible for the non-linear phenomenon. This is a valid assumption because of the fact that the mass of the electron is very small as compared to the mass of the ion ; therefore, the energy transfer to other heavier species and to the surroundings is much less in the earlier case than in the latter. [ABSTRACT FROM AUTHOR]

Negative Impedance Boasters (NIBS) are often used for reducing line losses in telecommunications systems at low frequencies. An open-circuit stable negative admittance has therefore been developed from earlier negative resistance circuits which have two field effect transistors as their primary elements. Several alternative versions of the circuit are discussed, of which one provides an adjustable negative admittance value which is independent of frequency in the audio range.
In this paper the new circuits are described and their d.c. terminal characteristics are compared with those of the basic negative resistances. Measurements are also presented which illustrate the very low level of distortion produced by the new circuits. Finally, the experimental a.c. terminal characteristics of the negative admittance circuit are considered and compared with the results of a theoretical analysis for the most favourable position of the transforming capacitor. [ABSTRACT FROM AUTHOR]

Plasma focusing action is observed in two coaxial plasma guns, operating in deuterium in mode 1 operation, one with a non-conducting outer cylinder (gun A) and the other one with a conducting outer cylinder (gun B). For gun A a limiting velocity of 45 cm/sec in the steady propagation region is measured, but despite this low velocity, focusing characteristics in voltage spikes and current dips are observed. This anomalous low velocity is in agreement with a snow-plough model including an ionization retarding force. An estimation of focus radius is made both from framing photograph and voltage spike and current dip, giving a value of 20 mm and 16 mm respectively for 360 kA input current at 03 torr. For gun B at a current of 540 kA and 13 tort ambient pressure, a focus radius of 07 mm is observed from soft X-ray photographs. The energy of the soft X-ray emission is estimated as between 08 and 25 keV.
The main purpose of this paper however is to compare the performance of two coaxial plasma focus guns, both in mode 1 operation, one with a non-conducting outer cylinder (gun A) and the other with a conducting outer cylinder (gun B). Preliminary results have already been reported for gun A (Lee et al. 1972). The dynamics of the current sheet and focus properties of both guns are investigated more deeply in the present experiment. A modified snow-plough model, including an ionization retarding force, is proposed to account for the anomalous low velocities observed in gun A. [ABSTRACT FROM AUTHOR]

The analytic methods for evaluating the time response of irrational transfer functions are incomplete. The graphical approaches for solving the problem are inaccurate. This paper attempts to attack the general inverse Laplace transform problem under the new light shed by the Fast Fourier transform. An algorithm for the inverse Laplace transform is developed. Several typical but difficult cases are studied and the results are extraordinarily satisfactory. [ABSTRACT FROM AUTHOR]

The paper discusses the design of a see-saw astable oscillator constructed with integrated logic circuits. An expression is derived for the frequency of oscillation and various possible applications of the basic circuit are considered. [ABSTRACT FROM AUTHOR]

This is a tutorial paper dealing with the derivation of the Rake (anti-multipath) receiver structure from the point of view of the statistical decision theory. This is in fact the problem of signal detection in additive and multiplicative noise (due to random slow time-varying channel) and as such represents an important case both in theory and practice. Various points of interest related to this problem are discussed. [ABSTRACT FROM AUTHOR]

The closely controlled mutual characteristics of modern low-cost planar transistors permit the design of a novel complementary monostable circuit which has zero standby power dissipation, a predictable pulse duration and which is suitable for use with single power supply logic systems such as transistor logic (TL).
This paper considers the performance of a logic-compatible, saturating, complementary monostable circuit in which the pulsewidth is primarily dependent on the closely defined mutual characteristic of modern bipolar transistors. [ABSTRACT FROM AUTHOR]

This paper describes a time amplifier which can be used for time to amplitude and time to time conversion. This can be adopted for sweep generation, ratio detection etc. [ABSTRACT FROM AUTHOR]

This paper gives the results of experiments aimed at maximizing the efficiency of high power T.W.T.'s with linear slow-wave circuits by depressing the potential of the electron collector. A device for preventing noise deterioration and high current interception on the slow-wave circuit, which usually accompanies the depression of the collector potential, is described. Experimental results are given and from these some approximate relationships are deduced to predict depressed collector performance. [ABSTRACT FROM AUTHOR]

In this paper the transverse voltage drop has been discussed and estimated. For this study the planar structure has been considered and its effects upon the current voltage characteristics of the emitter base junction to explain -fall off at high currents are calculated. [ABSTRACT FROM AUTHOR]

The paper gives an account of the disturbances in the ionosphere due to the acoustic gravity waves produced by thunderstorms. It explains the phenomena that the ionospheric disturbances in the F-region are numerous and much more pronounced than in the E-region. It describes the mode of travelling of ionospheric disturbances due to horizontally moving waves that escape reflection and travel in the ducting mode. The theoretical analysis tallies fairly well with the experimental work of various authors. [ABSTRACT FROM AUTHOR]

It is well known that there is a hysteresis effect in the Schmitt trigger circuit. In the present paper, the author proposes a negative hysteresis threshold circuit which consists of a cathode-coupled trigger circuit with a CR delayed feedback loop. This circuit can be set to remove any hysteresis by adjusting the delayed feedback loop gain.
A non-linear analysis is developed on the above circuit, using the phase-plane method together with the experimental results. [ABSTRACT FROM AUTHOR]

The radiation properties of perfectly conducting filamentary circular loops of arbitrary dimensions immersed in a uniform isotropic, compressible electron plasma are studied theoretically. The current distribution on the circumference of the loop is assumed to be a travelling wave with arbitrary phase propagation constant. The far zone fields of the circular loop are obtained and the radiation resistance is then evaluated for both the electromagnetic and electroacoustic modes. From these general results, the problem is reduced to that of the circular loop in vacuum and the consequent results are found to tally with those available in literature. From the detailed study of fields and radiation resistances as put out in this paper, it is shown that the radiation resistance of both the modes is higher in the case of travelling wave loop than in the case of standing wave loop. It is, therefore, concluded that loop antennas on space vehicles may be fed with travelling wave currents rather than with the usual standing wave currents, since in the former case radiation resistance of the electromagnetic mode is enhanced. [ABSTRACT FROM AUTHOR]

This paper discusses a type of multimode monopulse feed using corrugated circular waveguide. The 'difference' or error-signals are derived from the TE and/or TM modes, whereas the 'sum' or reference-signal is provided by the so-called hybrid modes. The optimization of the overall tracking performance is carried out in two steps. The horn dimensions are first chosen to give the optimum 'difference' mode illumination, then the 'sum' mode efficiency is optimized by shaping the ' sum ' pattern with the aid of higher-order hybrid modes. It is shown that the performance of a corrugated waveguide monopulse feed is, in many respects, superior to that of its conventional counterpart. [ABSTRACT FROM AUTHOR]

This paper presents a detailed description of an experimental corrugated feed horn designed to operate at the focus of a paraboloidal reflector. It is found that the corrugation depth does not critically restrict the bandwidth of the antenna, and the main requirement is that the thickness of the corrugation teeth must be small compared to the wavelength. The radiation pattern of the horn maintains a near-perfect cylindrical symmetry over a 10% bandwidth, and the V.S.W.R. is less than 1-1 within the same bandwidth. The overall efficiency of the antenna system is found to be within 3% of the maximum value predicted by the theory. In addition, the spill-over loss is very small, and is of the order of 3.5%. This indicates that a low-noise, high-efficiency antenna can be designed without the need of a massive and more costly conical horn used in dual-reflector systems to date. [ABSTRACT FROM AUTHOR]

Stochastic approximation techniques have been applied to the estimation of signal parameters by Sakrison (1966) and the authors (1971). This paper is concerned with an algorithm having a non-stationary regression function. Convergence conditions and a mean-square error bound are presented. Its application to feedback communication and coherent estimation of Doppler frequency is discussed in some detail. [ABSTRACT FROM AUTHOR]

Previous work by the authors on large-signal transistor characterization and oscillator design is briefly reviewed before introducing the concept of the transistor complex voltage gain/power (A, A, P) space. This is shown to give insight into a systematic approach to the design of harmonic oscillators on the basis of prescribed operating point, power and frequency.
1. Introduction
Transistor oscillators find extensive application to the generation of nearly sinusoidal (i.e. harmonic) waveforms over a wide range of frequency. The design of transistor oscillators at the lower frequencies is typically characterized by well-tried circuits (e.g. Hartley, Colpitts), the use of crystals for frequency definition, and the value of simple feedback theory as a conceptual aid in design. In contrast, at higher frequencies--and especially in the microwave region--the identification of a lumped equivalent circuit becomes increasingly difficult, limiting non-linearities are now to be found more often within the active device, generated power is of greater importance and feedback concepts are increasingly difficult to apply. Thus, for transistor oscillators operating at high frequencies, what is required is a design basis appropriate to the measurement technique and means of device characterization most suited to this range of frequency. The design basis should, moreover, permit the simple consideration of such oscillator properties as the frequency and amplitude of oscillation, output power and load conductance, under a variety of constraints such as the available active device, the type of embedding , the location of the load and the values of the embedding elements. A design basis attempting to satisfy these requirements, and of potential value in microwave transistor oscillator design, is described in this paper. [ABSTRACT FROM AUTHOR]