Showing papers in "Electronics Letters in 1972"
TL;DR: In this article, two degenerate modes can be excited on a microstrip ring resonator to realize a double-tuned circuit bandpass filter in microstrip technique, which can be used to achieve a better performance than the conventional bandpass filters.
Abstract: It is shown that two degenerate modes can be excited on a microstrip ring resonator. These modes can be used to realise a double-tuned circuit bandpass filter in microstrip technique.
553 citations
TL;DR: In this article, a soft X ray lithographic technique capable of contactless replication of submicrometre linewidth planar-device patterns is described, and a special X ray exposure masks have been developed for the 4-14 A wavelength region.
Abstract: A soft X ray lithographic technique capable of contactless replication of submicrometre linewidth planar-device patterns is described. Special soft X ray exposure masks have been developed for the 4-14 A wavelength region. Elastic-surface-wave-transducer patterns with 1.3 µm electrode spacings were fabricated onto such masks using electron-beam techniques, and were successfully replicated.
169 citations
TL;DR: In this article, the properties of the lowest flexural mode of a wedge-shaped elastic waveguide are discussed and it is shown that this mode can be used as a dispersion-free topographic guide for acoustic surface waves.
Abstract: The properties of the lowest flexural mode of a wedge-shaped elastic waveguide are discussed. It is shown that this mode can be used as a dispersionfree topographic guide for acoustic surface waves. Curves completely characterising the guided mode for any value of the top angle are presented.
119 citations
TL;DR: In this article, a waveguide model for the microstrip line is defined and a method for calculating microstrip discontinuities and T junctions is described, and with the help of this model and the use of orthogonal series expansion, a solution of the above problems is found.
Abstract: A method for calculating microstrip discontinuities and T junctions is described, and a waveguide model for the microstrip line is defined. With the help of this model and the use of an orthogonal series expansion, a solution of the above problems is found. Numerical results for the scattering matrices of both the discontinuities and the junctions are given.
99 citations
TL;DR: In this paper, the I/V characteristic and voltage waveform for a current-driven Josephson junction was investigated, assuming a triangular current/phase difference relationship, and the waveform was investigated for a single current-and-phase-difference relationship.
Abstract: The I/V characteristic and voltage waveform are investigated for a current-driven Josephson junction, assuming a triangular current/phase-difference relationship.
70 citations
TL;DR: A high Q, insensitive, active RC network, usable up to several megacycles, is described, which has similar properties to the circuit proposed by Tarmy and Ghausi, but uses operational amplifiers with single-ended output terminals.
Abstract: A high Q, insensitive, active RC network, usable up to several megacycles, is described. It has similar properties to the circuit proposed by Tarmy and Ghausi, but uses operational amplifiers with single-ended output terminals. The circuit can be realised with only two amplifiers; using three, the two capacitors required can be earthed.
55 citations
TL;DR: In this paper, a new type of charge transfer device (c.t.d.) is presented, where the bulk transport of majority carriers is used, together with a capacitive decoupling of the carriers from the electrode, yields a high transfer efficiency, possibly even up to the gigahertz range.
Abstract: A new type of charge-transfer device (c.t.d.) is presented. The main difference from known c.t.d.s is that the bulk transport of majority carriers is used; this, together with a capacitive decoupling of the carriers from the electrode, yields a high transfer efficiency, possibly even up to the gigahertz range. Experiments agree with expectations.
55 citations
TL;DR: In this paper, a novel dispersive delay line with a time-bandwidth product in excess of 1500 has been developed, which uses the reflection of elastic surface waves from sputter-etched gratings on LiNbO3.
Abstract: A novel dispersive delay line with a time-bandwidth product in excess of 1500 has been developed. The device uses the reflection of elastic surface waves from sputter-etched gratings on LiNbO3. This reflective-array compressor is relatively free of the spurious signals which limit the performance of inter-digital transducer arrays.
55 citations
TL;DR: In this article, the most important characteristics of a waveguide feed with four?/4 chokes offset from the waveguide aperture are discussed, which is useful for illumination of deep paraboloidal reflectors (F/D < 0.35) and shows good E-H plane equality and broad pattern bandwidth.
Abstract: The most important characteristics of a waveguide feed with four ?/4 chokes offset from the waveguide aperture are discussed. This feed is useful for illumination of deep paraboloidal reflectors (F/D < 0.35) and shows very good E-H plane equality and broad pattern bandwidth.
52 citations
TL;DR: In this article, the authors examined the discontinuity between two planar dielectric waveguides by an integral-equation formulation, and the aperture field was approximated by a finite set of discrete modes, characteristic of the region Z < 0.
Abstract: The discontinuity between two planar dielectric waveguides is examined on the basis of an integral-equation formulation. The aperture field is approximated by a finite set of discrete modes, characteristic of the region Z<0. Results are presented for the launching efficiency and reflection at the junction between a solid-state heterojunction laser and an optical waveguide.
46 citations
TL;DR: A series of measurements at 10 GHz giving the performance of IMPATT diodes obtained when varying the parameters of a cap circuit are presented in this paper, with correctly chosen parameters, the circuit is suitable for operation over a 40% bandwidth.
Abstract: A series of measurements at 10 GHz giving the performance of IMPATT diodes obtained when varying the parameters of a cap circuit are presented. The results indicate that, with correctly chosen parameters, the circuit is suitable for operation over a 40% bandwidth.
TL;DR: In this article, a modal-matching method was used to evaluate the transmission and reflection coefficients at a junction between two planar surface waveguides, which represented the junction between a solid-state laser and a planar optical waveguide.
Abstract: A modal-matching method is used to evaluate the transmission and reflection coefficients at a junction between two planar surface waveguides. Results are obtained for parameters which represent the junction between a solid-state laser and a planar optical waveguide. Favourable comparison is made with results obtained from an integral-equation method.
TL;DR: An exact method is given for the temperature determination of devices in circuits analysed by nonlinear-circuit-analysis programs by introducing the ‘thermal-node’ temperatures as well as the node voltages.
Abstract: An exact method is given for the temperature determination of devices in circuits analysed by nonlinear-circuit-analysis programs. The method is based on the simultaneous solution of the electronic and thermal network equations by introducing the ‘thermal-node’ temperatures as well as the node voltages. These voltages and temperatures are arranged in a joint state vector.
TL;DR: In this paper, the authors show how to obtain a maximally flat non-recursive transfer function via a simple classical method that sets derivatives of a rational function to zero, using a special solution to the Hermite interpolation formula.
Abstract: In a recent letter, coefficients for a maximally flat nonrecursive transfer function were obtained via a special solution to the Hermite interpolation formula. This letter, however, shows how these coefficients can also be obtained by a simple `classical? method that sets derivatives of a rational function to zero.
TL;DR: In this paper, the first low-loss liquid-core fiber-optical waveguide with a transmission loss less than 20 dB/km over a wavelength range of greater than 0.8-1.1 μm was made using glass tubing.
Abstract: Low-loss liquid-core fibre-optical waveguides having a transmission loss of 10 dB/km has been made using commercially available glass tubing. The loss is less than 20 dB/km over a wavelength range of greater than 0.8-1.1 μm, and, at the semiconductor laser wavelength of 0.9 μm, has a value of 14 dB/km. This is the first low-loss fibre to be made using glass.
TL;DR: In this article, two techniques for the reduction of triple-transit signals in surface-acoustic-wave devices are described, which are tested experimentally and found to work satisfactorily.
Abstract: Two techniques are described for the reduction of triple-transit signals in surface-acoustic-wave devices. Both have been tested experimentally and found to work satisfactorily.
TL;DR: In this paper, consistent estimates for the parameters of a linear difference equation which describes a system having an output corrupted by correlated noise are obtained using an unbiased objective function and a fast algorithm which employs an iterative least-squares technique.
Abstract: Using an unbiased objective function and a fast algorithm which employs an iterative least-squares technique, consistent estimates are obtained for the parameters of a linear difference equation which describes a system having an output corrupted by correlated noise. The method is applied to a simulated process and compared with the generalised least-squares method.
TL;DR: In this article, the microstrip end effect as a function of width and substrate permittivity was calculated and the excess capacitance associated with the open end was determined using the method of moments.
Abstract: Calculated data, which extend the previous results of Farrar and Adams, are presented for the microstrip end effect as a function of width and substrate permittivity. With a quasistatic approximation, the excess capacitance associated with the open end was determined utilising the method of moments. Good experimental agreement was observed.
TL;DR: In this article, the lower part of the f.m. spectrum in oscillators is discussed and experimental results at 36 GHz are compared with Edson's theory, the discrepancy found is explained by Blaquiere's frequency-amplitude dependence, and the parameter involved in this dependence is evaluated by equating experimental and theoretical linewidths.
Abstract: The lower part of the f.m. spectrum in oscillators is discussed and experimental results at 36 GHz are compared with Edson's theory. The discrepancy found is explained by Blaquiere's frequency-amplitude dependence, and the parameter involved in this dependence is evaluated by equating experimental and theoretical linewidths. The signal-power spectrum is also presented.
TL;DR: In this article, the authors report the experimental demonstration of a colinear interaction between an optical film-guided wave and an acoustic surface wave producing a non-coplanar optical-beam output.
Abstract: We report the experimental demonstration of a colinear interaction between an optical film-guided wave and an acoustic surface wave producing a noncoplanar optical-beam output. With an interaction length of 4 mm and an acoustic-power input of 2.5 W at 86 MHz, 5% of the guided optical wave was scattered out of the film.
TL;DR: In this paper, a rectangular backfire antenna with a dielectric surface-wave structure is studied experimentally and theoretically, which consists basically of two plane rectangular reflectors and a Dielectric structure as a rectangular-waveguide prolongation.
Abstract: A rectangular backfire antenna with a dielectric surface-wave structure is studied experimentally and theoretically. It consists basically of two plane rectangular reflectors and a dielectric structure as a rectangular-waveguide prolongation. The antenna construction is compared with those of ordinary dielectric and horn antennas, which are more than twice the length of the backfire antenna. Simple expressions for the far-field radiation pattern are derived in terms of the near-field amplitude distribution.
TL;DR: In this paper, a 100 ps gallium-arsenide laser pulse was observed to increase in width by only 100 ps in 70 m of a fibre with an internal refractive index gradient (Selfoc).
Abstract: A 100 ps gallium-arsenide laser pulse was observed to increase in width by only 100 ps in 70 m of a fibre with an internal refractive-index gradient (Selfoc). This is shown to be in satisfactory agreement with a simple ray analysis which neglects the index discontinuity at the fibre wall.
TL;DR: In this article, the exact relationship between differential and incremental sensitivity, which provide interesting results regarding the practical significance of differential sensitivity, zero sensitivity and the sensitivity of the network-function denominator, are investigated.
Abstract: The exact relationships between differential and incremental sensitivity, which provide interesting results regarding the practical significance of differential sensitivity, zero sensitivity and the sensitivity of the network-function denominator, are investigated.
TL;DR: In this article, a monomode glass-fibre waveguide has been proposed to make fused joints in which the end faces are lightly fused together after the cores have been aligned for optimum transmission.
Abstract: Various ways of making fused joints in a monomode glass-fibre waveguide have been tried. The highest efficiencies have been about 80%, with a joint in which the end faces are lightly fused together after the cores have been aligned for optimum transmission.
TL;DR: In this paper, experimental evidence is given in support of a dielectric-waveguide model for filaments in gallium-arsenide lasers. But this model is not suitable for the case of a single-heterojunction galliumarasenide laser.
Abstract: Experimental evidence is given in support of a dielectric-waveguide model for filaments in gallium-arsenide lasers. Measurements of the variation with current of the spectral-mode frequencies of a single-heterojunction gallium-arsenide laser have been carried out both below and above threshold. It is suggested that the frequency shifts above threshold are due to the formation of filaments in the laser. Changes in the far-field pattern support this theory.
TL;DR: In this paper, a method for evaluating the coupling between two rectangular waveguides coupled by a slot of arbitrary dimensions in a wall of arbitrary thickness is described, based on the solution, by numerical techniques, of a pair of coupled integral equations.
Abstract: A method for evaluating the coupling between two rectangular waveguides, coupled by a slot of arbitrary dimensions in a wall of arbitrary thickness is described. The method is based on the solution, by numerical techniques, of a pair of coupled integral equations. Results for typical shunt and series slots are presented.
TL;DR: In this paper, a TEM00 mode Nd-CaWO4 laser has been used to produce 400 kW pulses in a single longitudinal mode with a shot-to-shot frequency stability of about 0.01 cm−1.
Abstract: A Pockels-cell Q switch has been operated in a manner analogous to a saturable absorber, thus allowing the simple and reliable selection of a single longitudinal mode. A TEM00 mode Nd-CaWO4 laser has produced 400 kW pulses in a single longitudinal mode with a shot-to-shot frequency stability of about 0.01 cm−1.
IBM1
TL;DR: In this article, the authors show that for a current density of about 1000 A/cm2, the RISetime of the switching transient from zero to the gap voltage is below 38 ps.
Abstract: Josephson junctions with 1 × 3 μm dimensions have no resonances. For a current density of about 1000 A/cm2, the risetime of the switching transient from zero to the gap voltage is below 38 ps.
TL;DR: In this paper, a minimum-variance control law for the case when the input amplitude is constrained is derived, where the input transducer is constrained to a fixed number of transducers.
Abstract: Saturation of the input transducer is a frequently occurring difficulty with minimum-variance controllers. This saturation can lead to serious deterioration in the performance. In the letter, a minimum-variance control law is derived for the case when the input amplitude is constrained.
TL;DR: In this paper, two matched chirps propagating through each other behave as a narrowband filter in wave vector space, with the filter centre moving at a rate proportional to the acoustic velocity and the chirp rate.
Abstract: The generation of Fourier transforms of electronic signals in real time with an acoustic-surface-wave convolver is demonstrated. Two matched chirps propagating through each other behave as a narrowband filter in wavevector space, with the filter centre moving at a rate proportional to the acoustic velocity and the chirp rate.