Showing papers in "International Journal of Electronics in 1973"
TL;DR: In this paper, an error analysis showed that, because the equivalent pressure-gap procedure involves essentially a null method, far greater accuracy can be obtained than with the usual conductivity method, and consequently this should allow the angle, though small, through which an electron avalanche is tilted at atmospheric pressure by a crossed magnetic field.
Abstract: Electron-molecule collision frequencies in nitrogen obtained from a conductivity method are found to agree well with earlier values obtained by other workers using the same method and with those from our recently developed equivalent pressure-gap procedure. Complete agreement with our theory is obtained at moderate equivalent reduced electric fields, whilst an experimental excess of 9% and a short fall of 27% at low and high (E/p)z respectively can be accounted for. Using the collision frequency values in a corrected formula predicted sparking voltages agree reasonably well with experiment. An error analysis shows that, because the equivalent pressure-gap procedure involves essentially a null method, far greater accuracy can be obtained than with the usual conductivity method, and consequently this should allow the angle, though small, through which an electron avalanche is tilted at atmospheric pressure by a crossed magnetic field to be accurately determined
29 citations
TL;DR: A new form of microwave integrated circuit seems realizable utilizing propagating magnetic waves in epitaxial films of yttrium iron garnet (YIG) as mentioned in this paper, which is complementary to that of surface acoustic waves with the advantage of operation up to 10 GHz.
Abstract: A new form of microwave integrated circuit seems realizable utilizing propagating magnetic waves in epitaxial films of yttrium iron garnet (YIG) The technology is complementary to that of surface acoustic waves with the advantage of operation up to 10 GHz Both dispersive and non-diapersive properties may be realized with the magnetic waves by using suitably coded, spatially periodic, transducers The confinement of energy to thin magnetic films permits the fabrication of tapped delay lines A matrix array of transducers, in conjunction with the anisotropic nature of magnetic wave propagation, has permitted the fabrication of electronically steerable delay lines The spatial profiles of these magnetic beams have been measured by surface probing techniques Selective etching of the YIG samples allows magnetic waveguides and directional couplers to be integrated with the other devices for signal processing purposes
26 citations
TL;DR: In this paper, it was shown that for a variety of boundary conditions (zero or finite recombination in the end regions (Davies 1963, Schlangenotto and Gerlach 1972), infinite surface recombination velocity at an ohmic contact (Choo and Mazur 1970), the OCVD after an initial very rapid transient settles down to a simple decay governed essentially by the bulk lifetime τB of the L-region or an effective lifetime τc respectively.
Abstract: The open-circuit voltage decay (OCVD) of excess carriers injected into the low-doped region of a P+LN+ diode during heavy forward bias, can give a direct measure of the effective carrier lifetime in this region. The complete transient solutions for the excess carrier density valid both for d.c. forward bias current flow and for the OCVD after abrupt cessation of the current, show that for a variety of boundary conditions—zero or finite recombination in the end regions (Davies 1963, Schlangenotto and Gerlach 1972), infinite surface recombination velocity at an ohmic contact (Choo and Mazur 1970)—the OCVD after an initial very rapid transient settles down to a simple decay, governed essentially by the bulk lifetime τB of the L-region or an effective lifetime τc respectively. The diodes investigated had π- or v-type L-regiona with their P—N junctions made by diffusion and their L—H junctions by alloying. Apart from an extremly rapid initial transient, the OCVD measured was linear and showed two regions of di...
26 citations
TL;DR: In this article, a procedure for yielding a digital sequence for the Hilbert transform is presented, where the input sequence is assumed to be periodic, which yields a finite transformed sequence, and a simplified version of this last transformation is presented.
Abstract: Hilbert transforms are useful in a variety of applications. In order to use digital techniques in these applications, when the input is a digital sequence, a procedure directly yielding a digital sequence for the Hilbert transform would be necessary. Such a procedure is presented in this paper. The transformed sequence is, however, infinitely long and so the computation required for the inverse operation can be very tedious. To overcome this the input sequence is assumed to be periodic, which yields a finite transformed sequence. Also presented are much simplified, though approximate, versions of this last transformation.
22 citations
TL;DR: A canonic circuit, using the second generation current conveyor is described for realizing an all-pass or a notch characteristics.
Abstract: A canonic circuit, using the second generation current conveyor is described for realizing an all-pass or a notch characteristics.
21 citations
TL;DR: In this article, an algorithm for the inverse Laplace transform is developed. But the algorithm is not suitable for the case of the Fast Fourier transform and the results are unsatisfactory.
Abstract: 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.
18 citations
TL;DR: In this article, a Dyadic Green's function appropriate to radiation of sources in a uniaxially anisotropic medium is derived in terms of Fourier integrals and evaluated asymptotically using a method recently developed by Lighthill which has the advantage of showing clearly how the fur field depends on the shape of the dispersion surfaces.
Abstract: A Dyadic Green's function appropriate to radiation of sources in a uniaxially anisotropic medium is derived in terms of Fourier integrals. The integrals are then evaluated asymptotically using a method recently developed by Lighthill which has the advantage of showing clearly how the fur field depends on the shape of the dispersion surfaces. As RII illustration, the electrical field due to an oscillating dipole is worked out.
17 citations
TL;DR: In this paper, an analysis of the lens-like property of plane and spherical zone plate antennas is made, and source distance-image distance relations are derived, and expressions for the focal lengths are also obtained.
Abstract: An analysis is made of the lens-like property of plane and spherical zone plate antennas, and source distance-image distance relations are derived. Expressions for the focal lengths are also obtained. The source-distance discriminating property of the spherical zone plate antenna is studied and computations for the axial variation of intensity for the plane and the spherical zone plate antennas are mode for various situations.
17 citations
TL;DR: In this article, the feasibility of a multiplex system based on the unique properties of solitons has been, successfully demonstrated, and the system is composed of non-linear LC networks which are equivalent to a one-dimensional anharmonic lattice, and have investigated experimentally the recurrence phenomena for a pair of soliton trains of which the amplitudes are independently modulated.
Abstract: The feasibility of a multiplex system based on the unique properties of solitons hoe been, successfully demonstrated. The system is composed of non-linear LC networks which are equivalent to a one-dimensional anharmonic lattice, and we have investigated experimentally the recurrence phenomena for a pair of soliton trains of which the amplitudes are independently modulated. The recurrence phenomena could be used for secure communications.
16 citations
TL;DR: In this article, the sparking potentials and swarm coefficients were measured in Freon and Freon-air mixtures over the range of 24·3 times 10-16≤ E/N ≤ 303 times 10−16 V cm2.
Abstract: The sparking potentials and swarm coefficients ( ionization and attachment coefficients) were measured in Freon and Freon-air mixtures over the range of 24·3 times 10-16≤ E/ N ≤ 303 times 10-16 V cm2. Addition of Freon increased the sparking potential, and the rate of increase of the attachment coefficient with increasing percentage of Froon in the mixture was much larger than the rate of change of the first ionization coefficient.
13 citations
TL;DR: In this paper, it is shown theoretically that distributed IMPATT structures can be used as resonant lengths of active transmission line if particular care is taken to choose the substrate thickness and resistivity correctly in order to minimize losses.
Abstract: It is shown theoretically that distributed IMPATT structures can be used as resonant lengths of active transmission line if particular care is taken to choose the substrate thickness and resistivity correctly in order to minimize losses In contrast to discrete IMPATT structures, a relatively high substrate resistivity is required for the travelling wave structures Such self-resonant oscillating structures can have an input admittance of the same order as the total depletion layer negative conductance, since the shunting effect of the depletion layer capacitance has automatically been tuned out Thus, for a given value of circuit impedance the distributed structure can be much larger in area, and output power than the corresponding discrete IMPATT It is shown theoretically possible to produce a 450 W pulsed device with an input impedance of −1Ω, although a 100 W device with an input impedance of −4Ω might be a more practicable objective
TL;DR: In this paper, a number of formulae describing the characteristics of spherical and plane zone plate antennas are derived and a considerable reduction in the aperture dimension can be achieved by using a spherical zone plate antenna.
Abstract: The possibility of a microwave spherical zone plate antenna has been discussed. A number of formulae describing the characteristics of spherical and plane zone plate antennas are derived. Both the plane and spherical incident wave-fronts are used in the derivation of the formulae. Numerical results comparing the spherical and plane zone plate antennas have been given. It is found that a considerable reduction in the aperture dimension can be achieved by using a spherical zone plate antenna.
TL;DR: In this paper, two new types of L-R mutators are defined, referred to as type lb and type 2b, and the realization of these active building blocks are given using the second-generation current conveyor.
Abstract: Two new types of L-R mutators are defined here. These are referred to as type lb and type 2b L-R mutators. The realization of these active building blocks are given here using the second-generation current conveyor.
TL;DR: In this paper, the expansion coefficients for a set of basic wavefunctions due to sources situated on the plane of symmetry of a prism of arbitrary angle and refractive indox are analyzed.
Abstract: Iterative formulae are presented for the expansion coefficients for a set of basic wavefunctions due to sources situated on the plane of symmetry of a prism of arbitrary angle and refractive indox (which can be complex). The treatment applies to the diffraction of an electrically polarized wave by a dielectric wedge. The formulae are shown to be computationally convenient. The basic wavefunctions can be built up into wavefunctions due to localized sources. The analysis can be related straightforwardly to situations of technical interest if the faces of the prism are in tho far field of the source. It is suggested that the method introduced here would be useful for checking the accuracy of ray-optical techniques in the vicinity of tho apex of a prism. The method is shown to support a previous contention that free modes cannot exist in a penetrable prism.
TL;DR: In this paper, the authors view the input capacitance of a mosfet amplifier stage as an integral part of a microstrip transmission line, leading to a distributed amplifier of simple design.
Abstract: Viewing the input capacitance of a mosfet amplifier stage as an integral part of a microstrip transmission line, leads to a distributed amplifier of simple design. With today's mosfets, a bandwidth in excess of 500 MHz can be achieved ; it will be possible to extend this bandwidth substantially in the future by the use of mosfets with lower input capacitance. In addition, some data are given on transmission lines employing substrates of high dielectric permittivity.
TL;DR: In this article, a two-stage transistor emitter-follower circuit and a suitable matching network is described for high-radiance electroluminescent diodes in optical communication systems.
Abstract: The application of high-radiance electroluminescent diodes in optical communication systems will require efficient, high-current, high-speed modulation circuits capable of driving the low-impedance diode load. A technique which has proved to ho useful in driving such diodes at a 100 Mb/s rate, using a two-stage transistor emitter-follower circuit and a suitable matching network, is described.
TL;DR: In this article, the energy transport velocity of electromagnetic waves is reformulated to interpret energy transport of non-piano waves by extending the classical concept of the stored energy flow of plane waves.
Abstract: The energy transport velocity of electromagnetic waves is reformulated to interpret the energy transport of non-piano waves by extending the classical concept of the stored energy flow of plane waves. The dyadic phase velocity, dyadic energy velocity, and stored energy vector are proposed. A new concept of eddy power flow is given, with which a well-known contradiction of energy transport velocity in waveguides can be solved.
TL;DR: In this paper, two coaxial plasma guns, operating in deuterium in mode 1 operation, one with a nonconducting outer cylinder and the other with a conducting outer cylinder, were measured, with a limiting velocity of 4-5 cm/μsec in the steady propagation region.
Abstract: 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 4-5 cm/μsec 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 o 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 1-6 mm respectively for 360 kA input current at 0-3 torr. For gun B at a current of 540 kA and 1-3 torr ambient pressure, a focus radius of 0-7 mm is observed from soft X-ray photographs. The energy of the soft X-ray emission is estimated as between 0-8 and 2-5 keV.
TL;DR: In this article, it was shown that only the zeroth-order term of the series expansion of the autocorrelation for the noise voltage is of importance for the oscillator noise spectrum.
Abstract: The non-stationary noise generator of a large-signal IMPATT oscillator is studied. It is shown that only the zeroth-order term of the series expansion of the autocorrelation for the noise voltage is of importance for the oscillator noise spectrum. The zeroth-order term is determined by an integral of the square of the Green's function for the total voltage from a generation of a pair of carriers weighted by the mean generation rate A PIN diode model with a fixed rectangular voltage is studied numerically. The short-circuit noise current is shown to be inversely proportional to the reverse saturation current,Js. The possibility of improving the noise properties by increasing Js is discussed.
TL;DR: In this paper, an approximate non-linear theory for difference frequency generation in a beam-plasma device under the application of two r.f.c. modulating signals on the beam at two different frequencies was developed.
Abstract: An approximate non-linear theory, neglecting thermal velocities and collisions of the plasma electrons, has been developed for difference frequency generation in a beam-plasma device under the application of two r.f. modulating signals on the beam at two different frequencies. For a given d.c. beam-charge density to plasma-charge density ratio, the difference frequency component of current density is calculated as a function of distance from the input end in terms of d.c. beam current density and a.c. current densities impressed on the beam at the input end of the device. Two cases have been considered ; in one, individual mixing frequencies amplify, and in the other they do not, but the value of the difference between the two mixing frequencies is less than the maximum amplinable frequency of the system. For the latter case, the value of the difference frequency should be chosen closo to the the frequency at which the device gives considerable gain as an amplifier. The possibility of sum frequen...
TL;DR: In this article, a transient model for a Silicon-Controlled Rcctifier is proposed, which is an extension of the Ebbers-Moll two diode equivalent circuit for a transistor.
Abstract: A transient, model for a Silicon-Controlled-Rcctifier is proposed. The model is an extension of the Ebbers-Moll two diode equivalent circuit for a transistor. Small signal measurements of the short-circuit current gain with the device biassed as an n-p-n (Hook) transistor in the common-base configuration, allow separation of the anode and cathode-junction time constants. The small-signal low-frequency current gains obtained from those measurements are seen to be unrealistic for use in the model since they are measured under conditions of low injection. Typical values for these current gains under high injection are then proposed and used in the prediction of the turn-on process. The predictions are compared with the experimentally obtained turn-on curves for two different devices find reasons for the differences between them are proposed.
TL;DR: In this paper, the temperature profiles in wall-stabilized atmospheric pressure arcs in argon, nitrogen and argon-nitrogen mixtures were obtained at currents of 26 A and 30 A using spectroscopic techniques.
Abstract: The temperature profiles in wall-stabilized atmospheric pressure arcs in argon, nitrogen and argon-nitrogen mixtures have been obtained at currents of 26 A and 30 A using spectroscopic techniques. The temperature profiles were measured using both the absolute intensity of spectral lines and the absolute intensity of the continuum radiation. Good agreement between the two methods is found in argon but there is a considerable discrepancy in nitrogen. This is attributed to the existence of a N- ion. The temperature profiles and previously measured potential gradients are then used in conjunction with calculated values of the electrical conductivity to obtain the thermal conductivity of several argon-nitrogen mixtures. The results obtained are in good agreement with previously published data for the pure gases and show the gradual formation of an arc core and the increase in axis temperature as the gas mixture is varied from pure argon to pure nitrogen. Another result of these investigations is to show the im...
TL;DR: It is shown that the performance of a corrugated waveguide monopulse feed is, in many respects, superior to that of its conventional counterpart.
Abstract: This paper discusses a type of multimode monopulse feed using corrugated circular waveguide. The ‘ difference ’ or error-signals are derived from the TE01, and/or TM01 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.
TL;DR: In this article, a method for measuring the mode conversion coefficients of overmoded rectangular waveguide components utilizing trapped-mode absorption resonance phenomena is described, which is derived from transmission and reflection coefficient measurements made at the output and input of a simple over-moded system.
Abstract: A method for measuring the mode conversion coefficients of overmoded rectangular waveguide components utilizing trapped-mode absorption resonance phenomena is described. The mode conversion coefficients are deduced from transmission and reflection coefficient measurements made at the output and input of a simple overmoded system which consists of We taper transitions from single to overmoded guide, the test component and lengths of overmoded guide. The insertion loss of the component with respect the H10 mode, and the higher order mode suppression produced by the inclusion of a mode filter in the system may also be measured. Approximate estimates of higher-order mode attenuation coefficients may also be ascertained.
TL;DR: In this article, the authors used waveguide Green's functions to derive integral representations for the reflected and the transmitted field in a rectangular waveguide and solved the integral equations numerically by employing a method of moments.
Abstract: The redaction and transmission of electromagnetic waves by a slant interlace Between two media in a rectangular waveguide is investigated. By using suitable waveguide Green's functions, integral representations for the reflected and the transmitted field are derived. In the same way integral equations for the unknown field distributions in the interface are obtained ; in these integral equations the Green's functions and their first-order derivatives occur as kernel functions. The integral equations are solved numerically by employing a method of moments. Because the series representing the kernel functions are poorly convergent, techniques for accelerating the convergence have been used. As an example, the amplitudes of the reflection and the transmission factors of the propagating modes are computed in case the dominant mode is incident on a slant air/dielectric interface and the electric vector is parallel to the interface.
TL;DR: In this paper, the behavior of the interface-state density in plasma oxidized silicon dioxide on silicon MOS structures has been investigated as a function of annealing temperature and time for anneals in an ambient of dry nitrogen.
Abstract: The behaviour of the interface-state density in plasma oxidized silicon dioxide on silicon MOS structures has been investigated as a function of annealing temperature and time for anneals in an ambient of dry nitrogen. It was found that the interface-state density decreases with increasing annealing time and temperature, saturating at a temperature of approximately 950°C and a time of approximately one hour. In situ r.f. sputter-cleaning prior to oxidation produces dielectric films of uniformly high and reproducible dielectric strength of up to 107 volts/em, in contrast to most chemical cleaning processes which typically yield lower dielectric strengths and greater variability.
TL;DR: In this article, a general RC oscillator circuit using positive and negative RC elements is derived from a well-known LC oscillator circuits and the active RC network is shown to represent the equivalent circuits of many existing RC oscillators, such as twin T and Wienbridge oscillators.
Abstract: A general RC oscillator circuit using positive and negative RC elements is derived from a well-known LC oscillator circuit. The active RC network, thus obtained, is shown to represent the equivalent circuits of many existing RC oscillators, such as twin T and Wienbridge oscillators.
TL;DR: In this article, the authors analyzed the transition layer of the exponential p-n junction, taking into account the mobile carriers in this region, and the d.c. theory of the junction capacitance was compared with experimental data obtained on implanted silicon junctions.
Abstract: The exponential p-n junction shows some peculiarities, which make its theoretical study interesting. In this paper some characteristics of the transition layer of such a junction are analysed, taking into account the mobile carriers in this region. Following a method introduced by Sab, the Poisson-Boltzmann equation is linearized using a parameter α, which is a measure of the relative importance of the fixed, ionized impurity space charge compared with the mobile carrier charge in the transition layer of the p-n junction. The width of the transition layer, on the left and on the right of the junction, the built-in voltage, the total potential difference across the transition region and the total capacitance are derived. The d.c. theory of the junction capacitance is compared with experimental data obtained on implanted silicon junctions : ft satisfactory agreement is found.
TL;DR: In this article, coupledmode theory is used to describe the interaction between Blow electromagnetic waves and drifting carriers in a semiconductor using Pierce's one-dimensional model of the travelling-wave tube.
Abstract: Coupled-mode theory is used to describe the interaction between Blow electromagnetic waves and drifting carriers in a semiconductor using Pierce's one-dimensional model of the travelling-wave tube. The resulting equations are solved to obtain the gain of the device. The effects of both collision and diffusion are included in the analysis. The effect of changing the velocity parameter and its optimum value are discussed. The power associated with each mode is also calculated.
TL;DR: In this article, odd and even mode propagation characteristics for coupled strip transmission lines in a layered dielectric medium are calculated using the Rayleigh-Ritz procedure, where Green's functions are used in setting up a variational expression.
Abstract: Odd and even mode propagation characteristics are calculated for coupled strip transmission lines in a layered dielectric medium. Green's functions are used in setting up a variational expression. The charge distributions on the centre strips are expanded in a cosine series. Calculation of mode capacitances, impedances and phase velocities is then carried out using the Rayleigh-Ritz procedure. Design data for any combination of dimensional or material parameters can be determined using the computer programme.