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Showing papers in "Electronics Letters in 1968"


Journal ArticleDOI
TL;DR: The use of an array of circumferential slots in the outer conductor of a dielectric-clad coaxial cable as a new way to launch a TM0 surface wave on a Goubau line is described in this paper.
Abstract: The use of an array of circumferential slots in the outer conductor of a dielectric-clad coaxial cable as a new way to launch a TM0 surface wave on a Goubau line is described. Its advantage over a conical horn lies in its efficiency depending only on its length, which makes it particularly suitable for use in a high-speed ground transportation system.

150 citations


Journal ArticleDOI
TL;DR: In this paper, an active network is suggested that uses one differential-input operational amplifier and is suitable for realising high-Q factor second-order bandpass functions, but its Q sensitivity to component values is found to be less than the optimum Q sensitivities of the corresponding networks of Huelsman and Antoniou.
Abstract: An active network is suggested that uses one differential-input operational amplifier and is suitable for realising high-Q factor second-order bandpass functions. Its Q sensitivity to component values is found to be less than the optimum Q sensitivities of the corresponding networks of Huelsman and Antoniou. The network has been used to realise a sixth-order bandpass filter in three cascaded stages. Experimental results are given.

83 citations


Journal ArticleDOI
TL;DR: Magnetostatic surface waves are identified in microwave-frequency experiments with a single-crystal y.i.w. slab as mentioned in this paper, and fast waves with k numbers low in the range are observed in a c.
Abstract: Magnetostatic surface waves are identified in microwave-frequency experiments with a single-crystal y.i.g. slab. Slow travelling waves having k numbers that are high in the magnetostatic range are studied in a pulse experiment, and fast waves with k numbers low in the range are observed in a c.w. test.

71 citations


Journal ArticleDOI
TL;DR: In this article, a logical network is proposed, and an example of an iterative array formed using it is discussed, as well as an algorithm based on it for iterative arrays.
Abstract: A logical network is proposed, and an example of an iterative array formed using it is discussed.

41 citations


Journal ArticleDOI
TL;DR: Luenberger's procedure for the design of controllers of linear systems with inaccessible state vectors is extended to deal with time-delay systems.
Abstract: Luenberger's procedure for the design of controllers of linear systems with inaccessible state vectors is extended to deal with time-delay systems.

41 citations


Journal ArticleDOI
TL;DR: In this article, a theoretical estimate of the unloaded Q factor available from half and whole wavelength transmission-line resonators on an Al2O3 substrate was made, taking ohmic losses into consideration as well as the radiation losses from various types of cavity termination.
Abstract: A theoretical estimate has been made of the unloaded Q factor available from half and whole wavelength transmission-line resonators on an Al2O3 substrate. This takes ohmic losses into consideration as well as the radiation losses from various types of cavity termination. It is shown that optimisation of the Q factor of open-circuit terminated resonators demands a critical choice of substrate thickness and line characteristic impedance. Short-circuit terminated cavities generally have a substantially higher Q factor. A measurement technique has been developed, based on lightly coupled transmission probes. This has enabled practical measurements to be made of the unloaded Q factor of various microstrip cavities. Agreement with theory is satisfactory. Q factors up to 600 have been measured.

36 citations


Journal ArticleDOI
TL;DR: In this article, it was proved that an infinite-gain controlled source (of any type) is equivalent to a nullor, and two new gyrator circuits, using operational amplifiers, were realised.
Abstract: It is proved that an infinite-gain controlled source (of any type) is equivalent to a nullor. On using this equivalence, two new gyrator circuits, using operational amplifiers, are realised.

34 citations


Journal ArticleDOI
TL;DR: In this paper, an optical-diffraction modulator, using an electro-optic crystal excited by a periodic array of metallic conductors, is described, and the operation of the device is in some ways similar to that of an acoustoelectric modulator; it differs from it in that it has a bandwidth, potentially very wide, which extends from d.c.
Abstract: An optical-diffraction modulator, using an electro-optic crystal excited by a periodic array of metallic conductors, is described. The operation of the device is in some ways similar to that of an acoustoelectric modulator; it differs from it in that it has a bandwidth, potentially very wide, which extends from d.c. It may therefore find application as a baseband modulator.

33 citations


Journal ArticleDOI
TL;DR: In this article, a model for inversion-layer m.o.t.s is outlined which avoids the usual gradual-channel approximation by the use of 2-dimensional solutions to the Shockley-Poisson and Laplace equations governing the field distribution.
Abstract: A model for inversion-layer m.o.s.t.s is outlined which avoids the usual gradual-channel approximation by the use of 2-dimensional solutions to the Shockley-Poisson and Laplace equations governing the field distribution. Computed I/V and C/V characteristics and potential-distribution; diagrams are shown for a particular device geometry.

31 citations


Journal ArticleDOI
TL;DR: In this paper, a mode of operation of a p-n junction is described which leads to an output voltage linearly related to temperature, independent of device geometry or semiconductor material, and determined only by fundamental physical constants and current.
Abstract: A mode of operation of a p--njunction is described which leads to an output voltage linearly related to temperature, independent of device geometry or semiconductor material, and determined only by fundamental physical constants and current.

30 citations


Journal ArticleDOI
TL;DR: In this article, the theory of Sah, Noyce and Shockley is modified by assuming the recombination centres to be nonuniformly distributed, and a current/voltage relation can be obtained in the form I ∝ exp (eV/mkT), where m lies between 1 and 2.
Abstract: If the theory of Sah, Noyce and Shockley is modified by assuming the recombination centres to be nonuniformly distributed, a current/voltage relation can be obtained in the form I ∝ exp (eV/mkT), where m lies between 1 and 2.

Journal ArticleDOI
S. Ahmed1
TL;DR: In this article, a numerical method is presented from which it is possible to calculate the propagation coefficients of waveguides with arbitrary boundaries and dielectric fillings with arbitrary fillings.
Abstract: A numerical method is presented from which it is possible to calculate the propagation coefficients of waveguides with arbitrary boundaries and dielectric fillings.

Journal ArticleDOI
TL;DR: A practical method is described to determine the modulo-2 feedback shift-register connections for producing advanced (or delayed) versions of a pseudorandom binary sequence.
Abstract: A practical method is described to determine the modulo-2 feedback shift-register connections for producing advanced (or delayed) versions of a pseudorandom binary sequence.

Journal ArticleDOI
TL;DR: In this paper, the stability properties of two gyrator circuits, described by Riordan, are investigated and it is shown that these circuits can attain low-frequency unstable modes of operation.
Abstract: Some stability properties of two gyrator circuits, described by Riordan, are investigated. It is shown that these circuits can attain low-frequency unstable modes of operation. Two alternative gyrator circuits are derived which are shown to be free from low-frequency unstable modes.

Journal ArticleDOI
TL;DR: In this article, a numerical comparison between the admittance of an infinite cylindrical antenna excited by a realistic electric field across a finite gap, and that of a constant electric field in the same gap was made.
Abstract: A numerical comparison is made between the admittance of an infinite cylindrical antenna excited by a realistic electric field across a finite gap, and the admittance found by assuming a constant electric field in the same gap. A simple approximate relation between the two is derived, while a second simple expression shows how the admittance changes as the gap width is varied.

Journal ArticleDOI
TL;DR: An expression for the sum of the sensitivities of a network function with respect to the network components is derived and is shown to be directly related to thenetwork function in certain cases.
Abstract: An expression for the sum of the sensitivities of a network function with respect to the network components is derived. This is shown to be directly related to the network function in certain cases.

Journal ArticleDOI
TL;DR: In this article, it was shown that high-frequency negative resistance can be obtained in a space-charge-drift diode using "punch-through" injection, which is suitable for low-power low-noise applications.
Abstract: It is shown that high-frequency negative resistance can be obtained in a space-charge-drift diode using ‘punch-through’ injection. Efficiencies for power generation of about 20% are estimated for the ideal structure. The device should be suitable for low-power low-noise applications.

Journal ArticleDOI
TL;DR: In this paper, an iterative array is proposed which reduces the multiplication of two binary numbers to one pass through the array and a summation of the outputs produced. But this method is not suitable for counting.
Abstract: An iterative array is proposed which reduces the multiplication of two binary numbers to one pass through the array and a summation of the outputs produced.

Journal ArticleDOI
TL;DR: In this paper, a simplified model is proposed which describes the effect of the stray fields in dielectric surface layers on the dynamical behaviour of domains in thin Gunn-effect semiconductors.
Abstract: A simplified model is proposed which describes the effect of the stray fields in dielectric surface layers on the dynamical behaviour of domains in thin Gunn-effect semiconductors. The stray fields cause an increase in domain capacitance and hence a decrease in build-up time which leads to larger n0L products for stable operation.

Journal ArticleDOI
TL;DR: In this paper, the efficiency of galliumarsenide diodes taking account of all the electron-lattice relaxation processes is calculated for the l.a.s. mode.
Abstract: The efficiency of the l.s.a. mode is calculated for galliumarsenide diodes taking account of all the electron-lattice relaxation processes. The efficiency falls off with increasing frequency and typically becomes negative above 100GHz.

Journal ArticleDOI
TL;DR: This research presents pattern feedback, a new concept in learning networks of adaptive microcircuits, where recognition of an input pattern takes place if a stable model output pattern is generated.
Abstract: Pattern feedback is a new concept in learning networks of adaptive microcircuits. The net is trained to produce a model output pattern. During use, the output patterns are fed back to the input. Recognition of an input pattern takes place if a stable model output pattern is generated.

Journal ArticleDOI
TL;DR: In this article, the summed-sensitivity invariants for the case of active networks are generated using a new method of proof, which can be used also for general physical systems.
Abstract: The generation of the summed-sensitivity invariants for the case of active networks is presented. On using the new method of proof, the summed-sensitivity invariants can be generated also for general physical systems.

Journal ArticleDOI
TL;DR: In this article, two 3-terminal gyrator circuits were derived from two published circuits, and the derived ones cannot attain low-frequency unstable modes, unlike the original ones.
Abstract: Two 3-terminal gyrator circuits are derived from two published circuits. In contrast to the original circuits, the derived ones cannot attain low-frequency unstable modes.

Journal ArticleDOI
K.E. Drangeid1, R. Jaggi1, S. Middelhoek1, Th. O. Mohr1, A. Moser1, Grazia Sasso1, R. Sommerhalder1, Philip Wolf1 
TL;DR: Schottky-barrier field effect transistors have been realized in silicon epitaxial films on high-resistivity silicon substrates as mentioned in this paper, and the 1 μm wide gates are produced by projection masking techniques.
Abstract: Schottky-barrier field-effect transistors have been realised in silicon epitaxial films on high-resistivity silicon substrates. The 1 μm wide gates are produced by projection-masking techniques. The maximum transconductances observed are 42 mA/V per mm gate length; the maximum frequency of oscillation fmax was 8 GHz.

Journal ArticleDOI
TL;DR: An iterative array is proposed which can be used to carry out binary division based on the principle of successive subtraction, where each cell of the array is dependent on the result of subtraction in the array.
Abstract: An iterative array is proposed which can be used to carry out binary division based on the principle of successive subtraction. The function of each cell of the array is dependent on the result of subtraction in the array.

Journal ArticleDOI
TL;DR: In this article, the results of Holt and Fidler for the summed sensitivity of RC passive networks are obtained by an alternative method which allows the results to be conveniently extended to active RC networks and gyrator-RC networks.
Abstract: The results of Holt and Fidler for the summed sensitivity of RC passive networks are obtained by an alternative method which allows the results to be conveniently extended to active RC networks and gyrator-RC networks. The effect of these results on the minimum value of Schoefler's sensitivity criterion is discussed.

Journal ArticleDOI
TL;DR: A 3-port unit that satisfies the requirements of the circulator concept is realised with a differential-input operational amplifier that provides, between two of its ports, a direct measure of reflection coefficient at the third port.
Abstract: A 3-port unit that satisfies the requirements of the circulator concept is realised with a differential-input operational amplifier. It provides, between two of its ports, a direct measure of reflection coefficient at the third port. One unit may be employed as a hybrid transformer; two or more units may be connected in a ring to form an n-port circulator.

Journal ArticleDOI
TL;DR: In this paper, the real image formed by a hologram has been investigated experimentally with a view to overcoming the disadvantages of the present contact-print method of manufacturing microcircuits.
Abstract: The resolution of the real image formed by a hologram has been investigated experimentally with a view to overcoming the disadvantages of the present contact-print method of manufacturing microcircuits. A resolution of 4μm over an area of 2.5 cm diameter has been obtained so far.

Journal ArticleDOI
TL;DR: In this paper, a method for making multiport circulators with active elements which are directly coupled is described, and each port requires one differential amplifier; each circulator can be made with two active elements.
Abstract: A method is described for making multiport circulators with active elements which are directly coupled; each port requires one differential amplifier.

Journal ArticleDOI
TL;DR: Theoretical results for the small-signal microwave conductivity of nInSb at TL = 77°K in the presence of a high d.c. field directed parallel or perpendicular to the microwave field are presented in this article.
Abstract: Theoretical results are presented for the small-signal microwave conductivity of nInSb at TL = 77°K in the presence of a high d.c. field directed parallel or perpendicular to the microwave field. Reasonable agreement with experiments by Richter and Bonek is demonstrated. At frequencies below 50GHz, the parallel microwave conductivity is smaller than the perpendicular one, whereas the opposite is true at 70GHz.