Showing papers in "International Journal of Electronics in 1998"
TL;DR: In this article, four new topologies, all separately able to realize eight main types of inductors employing only grounded passive components, are presented and ideal and non-ideal impedance functions are given and an application example is shown.
Abstract: Grounded inductor simulation using op-amp or current conveyors is well known. Most of the presented topologies in the literature require certain element matching constraints, floating passive elements, or they employ active and passive components more than necessary to implement a specific type of grounded inductor. In this study, four new topologies, all separately able to realize eight main types of inductors employing only grounded passive components, are presented. For the topologies, ideal and non-ideal impedance functions are given and an application example is shown. Some experimental results are included to verify theory.
80 citations
TL;DR: In this paper, a voltage-and current-mode multifunctional biquads using OTAs and two capacitors are presented. But the voltage-mode circuits are capable of realizing three different simultaneous responses; while the currentmode version can realize four filtering outputs (lowpass, bandpass, highpass and notch) simultaneously.
Abstract: Novel voltage- and current-mode multifunctional biquads using OTAs are presented. The proposed circuits utilize only three OTAs and two capacitors. The voltage-mode circuits are capable of realizing three different simultaneous responses; while the current-mode version can realize four filtering outputs (lowpass, bandpass, highpass and notch) simultaneously.
56 citations
TL;DR: In this paper, a new current-mode current-controlled filters are proposed to realize low-pass, high-pass and band-pass responses, where the bias currents of CCCIIs can be adjusted.
Abstract: New current-mode current-controlled filters are proposed. The proposed realization requires three dual-output positive/negative-type current-controlled current conveyors (CCCII±) and can simultaneously realize low-pass, high-pass and band-pass responses. Realization of notch and all-pass responses is feasible. The parameters ω0, ω0/Q0 and the band-pass gain can be controlled by adjusting the bias currents of CCCIIs. The proposed realizations enjoy low sensitivities.
48 citations
TL;DR: In this paper, a CFOA-based triangular/square wave generator is presented, and the feasibility of obtaining linearly voltage controlled oscillation is explored, and experimental results are included.
Abstract: A new CFOA-based triangular/square wave generator is presented. The circuit uses one CFOA, two grounded resistors, one floating resistor and one grounded capacitor. The feasibility of obtaining linearly voltage controlled oscillation is explored. Experimental results are included.
43 citations
TL;DR: In this article, a simple current-mode analogue multiplier/divider circuit using only two second-generation current-controlled current-conveyors is presented, which can perform multiplication and division without changing its topology.
Abstract: A simple current-mode analogue multiplier/divider circuit using only two secondgeneration current-controlled current-conveyors is presented. No resistors, no capacitors and no MOS transistors are required. The circuit can perform multiplication and division without changing its topology. Results obtained using SPICE simulation are included.
40 citations
TL;DR: In this paper, a multiphase sinusoidal oscillator circuit is presented, which can produce N signals (N being even or odd) equally spaced in phase, and enjoys low active and passive sensitivities, and independent control of the frequency and condition of oscillation.
Abstract: A multiphase sinusoidal oscillator circuit is presented. The oscillator can produce N signals (N being even or odd) equally spaced in phase. The circuit has a low component count, uses grounded resistors and capacitors and enjoys low active and passive sensitivities, and independent control of the frequency and the condition of oscillation.
37 citations
TL;DR: A new design for a threshold logic gate, based on clocked cross-coupled inverters, and the way to optimize the implementation of threshold functions using this gate are presented.
Abstract: In this paper we present both a new design for a threshold logic gate, based on clocked cross-coupled inverters, and the way to optimize the implementation of threshold functions using this gate. The main characteristics of the threshold gate are low power consumption (it does not consume static power) and high speed.
32 citations
TL;DR: Several static and dynamic CMOS circuit design styles are evaluated in terms of area, propagation delay and power dissipation to identify the trade-offs possible during the design phase to improve the circuit power-delay product.
Abstract: An important issue in the design of VLSI circuits is the choice of the basic circuit approach and topology for implementing various logic and arithmetic functions. In this paper, several static and dynamic CMOS circuit design styles are evaluated in terms of area, propagation delay and power dissipation. The different design styles are compared by performing detailed transistor-level simulations on a benchmark circuit using HSPICE, and analysing the results in a statistical way. Based on the results of our analysis, some of the trade-offs that are possible during the design phase in order to improve the circuit power-delay product are identified.
30 citations
TL;DR: In this article, six tunable sinusoidal oscillator topologies, two of them known from the literature, are proposed using only CMOS operational transconductance amplifiers (OTAs) and grounded capacitors.
Abstract: In this study, six tunable sinusoidal oscillator topologies, two of them known from the literature, are proposed using only CMOS operational transconductance amplifiers (OTAs) and grounded capacitors. The oscillator configurations have the properties of oscillation frequency control using the transconductance gain without affecting the oscillation condition, the suitability for very large scale integration (VLSI) since they are composed of only OTAs and grounded capacitors, and the capability of operation at high frequency. For the proposed topologies, the non-ideality effects of an OTA such as finite output conductance, and finite bandwidth are investigated, and for one of the proposed OTA-C oscillator circuits the maximum output signal level is determined using a simple formula that does not cause clipping and the slew-rate-limiting problem. The theoretical results are verified by SPICE simulation results. The oscillator topologies are simulated with the SPICE computer program and the resulting output v...
29 citations
TL;DR: In this paper, a new current-mode multi-function filter using only two operational amplifiers, four operational trans-conductance amplifiers (OTAs) and one multiple-output third-generation current-conveyor (CCIII±) is proposed.
Abstract: A new current-mode multi-function filter is proposed. The filter uses only two operational amplifiers, four operational trans-conductance amplifiers (OTAs) and one multiple-output third-generation current-conveyor (CCIII±). Without using any external passive elements, lowpass, highpass, bandpass, notch and allpass responses can be realized without changing the circuit topology and without any matching or cancellation conditions. The parameters ωo and ωo/Qo, can be electronically tuned by adjusting the bias currents of the OTAs. The proposed circuit enjoys low sensitivities.
28 citations
TL;DR: In this paper, it was shown that low-sensitivity active filters employing the current conveyor (CCII) or the current feedback operational amplifier (CFOA) as the active element can be generated directly from passive RLC filters.
Abstract: It is shown that low-sensitivity active filters employing the current conveyor (CCII) or the current feedback operational amplifier (CFOA) as the active element can be generated directly from passive RLC filters. New current-mode filters using CCII and voltage mode filters using the CFOA are generated from three alternative passive RLC filters. The proposed circuits have the advantage that compensation of the dominant parasitic elements of the CCII or the CFOA can be easily achieved. PSpice simulation results are included.
TL;DR: In this paper, a new approach to the generation of current mode Wien-type oscillators using the current conveyor is introduced, which is based on replacing the generalized current negative impedance converter in the conventional Wien oscillator by a well-known equivalent circuit realized using thecurrent conveyor.
Abstract: A new approach to the generation of current mode Wien-type oscillators using the current conveyor is introduced. The proposed method is based on replacing the generalized current negative impedance converter in the conventional Wien oscillator by a well-known equivalent circuit realized using the current conveyor. A family of four new current mode oscillators employing grounded capacitors derived from the corresponding classical op amp Wien oscillator family is given. The proposed oscillators have the attractive advantage that the condition of oscillation and the frequency of oscillation can be independently controlled without affecting each other. PSpice simulation results supporting the theoretical analysis are given.
TL;DR: In this article, the possibility of tuning the frequency of a coaxial gyrotron by moving the inner conductor in the axial direction was investigated, and a 1.5MW coaxial GYR at 140GHz with the TE28,16 operating mode was considered as an example.
Abstract: The possibility of tuning the frequency of a coaxial gyrotron by moving the inner conductor in the axial direction is investigated. A 1.5MW coaxial gyrotron at 140GHz with the TE28,16, operating mode is considered as an example.
TL;DR: A fast tabular technique for Boolean to fixed-polarity Reed–Muller logic conversion that eliminates the time-consuming step of cancelling pairs and makes the method much more efficient than thetabular technique.
Abstract: We have developed a fast tabular technique for Boolean to fixed-polarity Reed–Muller logic conversion. The idea is derived from the popular tabular technique but the processes of generating new terms and cancelling pairs are vastly different. The feature of bit-by-bit operation in the tabular technique has also been changed. In our technique, an index table is used to capture the number of occurrences of initial and new terms. This instant updating process eliminates the time-consuming step of cancelling pairs and makes the method much more efficient than the tabular technique. In addition, the fast tabular technique possesses inherent parallelism since different minterms can be processed concurrently and added to the index table independently. Our method is applicable to any number of variables and is suitable for manual computations as well as computer programming. Some comparison results are given, and we believe our technique has achieved the best time and space complexities so far.
TL;DR: In this paper, a bandpass-low-pass filter using a current feedback op-amp and MOS transistors operating in the non-saturation region is presented, which employs six CFOAs and realizes balanced-input balanced-output bandpasslowpass responses with independent control of Q. PSice simulation results for the proposed balanced input balanced output MOS-C filter are also given.
Abstract: A new bandpass-lowpass filter using a current feedback op.-amp. (CFOA) and MOS transistors operating in the non-saturation region is presented. The filter employs six CFOAs and realizes balanced-input balanced-output bandpasslowpass responses with independent control of Q. PSice simulation results for the proposed balanced-input balanced-output MOS-C filter are also given.
TL;DR: A general procedure for the description of power electronic circuit dynamics is proposed, with the intention of control system design and discrete-time system simulation.
Abstract: A general procedure for the description of power electronic circuit dynamics is proposed, with the intention of control system design and discrete-time system simulation. The approach is especially suited to be used along with computeraided analysis and synthesis software packages such as MATLAB. The various modelling steps are illustrated by an application to a DC/DC converter under different control strategies.
TL;DR: In this paper, an improved active-feedback CMOS cascode current mirror is introduced which has a very accurate current reflection ratio, while achieving the same output impedance as that of an equivalent conventional activefeedback CAFCCM and a wider and optimal output dynamic range.
Abstract: An improved active-feedback CMOS cascode current mirror is introduced which has a very accurate current reflection ratio, while achieving the same output impedance as that of an equivalent conventional active-feedback cascode current mirror (CAFCCM) and a wider and optimal output dynamic range. The design can be made with even lower power consumption than CAFCCM and similar chip area. The technique can also be implemented in bipolar and BiCMOS integrated circuit design. The new structure does not need an additional constant current source as CAFCCM does. With these features, the circuit is suitable for use in high precision analogue integrated circuit design; especially in design of currentmode and low-voltage integrated circuits.
TL;DR: A new FPGA architecture called PGA-STC (programmable gate array for implementing self-timed circuits) is described, using a programmable delay element to implement both data and control sections of asynchronous systems efficiently and without hazards.
Abstract: This paper describes a new FPGA architecture called PGA-STC (programmable gate array for implementing self-timed circuits). PGA-STC differs from Montage (Hauck et al. 1994) in using a programmable delay element to implement both data and control sections of asynchronous systems efficiently and without hazards. Implementation of macromodule-style self-timed circuits with bundled-data communication in PGA-STC is discussed. Details of the architecture and the technology mapping are presented with illustrative examples.
TL;DR: In this article, thermal oxidation at 673-873k of RF sputtered Ta2O5 films was studied and a decreasing trend in the leakage current was found upon increasing temperature from 673 to 873K.
Abstract: Ta2O5 thin films (13-260nm) on p-Si have been prepared by thermal oxidation at 673-873K of RF sputtered Ta films. Conduction and dielectric properties of the layers have been studied employing Al-Ta2O5-Si capacitors. A decreasing trend in the leakage current was found upon increasing temperature from 673 to 873K. Layers with dielectric constant in the range 25-32 are easily obtained. A minimum conductivity, which corresponds to a leakage current density of about 10-7 A cm-2 at an applied field of 0.5 MV cm-1, was detected for films oxidized at the highest oxidation temperature. The oxide properties are discussed in terms of the presence of an unavoidable SiO2 layer between Si and Ta2O5 and of bond defects in the oxide.
TL;DR: In this article, three different approaches to design continuous-time currentmode ladder filters using multiple output current integrators are presented, based on simulating node voltages, state variables, or loop currents of passive RLC ladder filter prototypes.
Abstract: Three different approaches to designing continuous-time current-mode ladder filters using multiple output current integrators are presented. These approaches are based on simulating node voltages, state variables, or loop currents of passive RLC ladder filter prototypes. Node voltage and state variable simulations yield more compact structures than that obtained using loop current simulation. Possible CMOS implementations are presented and their performance characteristics are investigated using SPICE simulations. Scaled filters, using the constant field scaling law, are found to operate properly at low supply voltages, down to 1.0V.
TL;DR: In this paper, an integrable CMOS square-rooting circuit based on a class AB configuration is described, which achieves a wide dynamic range and a wide-band capability.
Abstract: An integrable CMOS square-rooting circuit based on a class AB configuration is described. The circuit achieves a wide dynamic range and a wide-band capability. The accuracy of the circuit is also high over the entire dynamic range. Simulation and experimental results demonstrating the characteristic of the proposed circuit are also included.
TL;DR: In this article, the linear DC dark and photo-currentvoltage characteristics observed for as deposited (Ts=25°C) and annealed (Ta=70°C), thermally-evaporated selenium s a films in the temperature range 150-300K were used to deduce the respective temperature dependencies of the dark-conductivity σdark and photo conductivities σph of these samples.
Abstract: The linear DC dark- and photo-current-voltage characteristics observed for as deposited (Ts=25°C) and annealed (Ta=70°C) thermally-evaporated selenium s a films in the temperature range 150-300K were used to deduce the respective temperature dependencies of the dark-conductivity σdark and photo-conductivity σph of these samples. Both XRD and SEM studies confirmed the amorphous state ph of the as-deposited films and the hexagonal-like polycrystalline structure of the annealed films. The ln σ versus 1/T plots of the highly resistive amorphous selenium (a-Se) samples revealed only one thermally-activated process in the region 250-300K for both σdark and σph with an activation energy Eσ= 0.73eV, dark ph sigma and 0.49eV, respectively. This has been interpreted considering the conduction models based on the existence of the inherent charged defect centres (dangling bonds D−, D+) in the band tails. The conductivity of the annealed specimens was at least three orders of magnitude larger than that of the as-depos...
TL;DR: In this article, a six-layered spherical lens with different sphere radii was theoretically constructed and practically developed for designing the Luneberg lens, and the optimum dielectric variation function was obtained, from which the simpler new expression e>j = (ej-1 ej+1)1/2 is also derived.
Abstract: A six-layered spherical lens with different sphere radii was theoretically constructed and practically developed for designing the Luneberg lens. The optimum dielectric variation function is obtained, from which the simpler new expression e>j = (ej-1 ej+1)1/2 is also derived. The electric field in space is shown for the cases of N = 6, 30. Experimental verification is also made.
TL;DR: In this paper, eight universal integrator-based OTA-C filters for the realization of third-order transfer functions are presented, which can realize arbitrary transmission zeros, contain only grounded capacitors and have the minimum number of components.
Abstract: Eight universal integrator-based OTA-C filters for the realization of third-order transfer functions are presented. Four architectures are based on voltage-mode IFLF and LF OTA-C configurations and input distribution and output summation OTA networks. The other four are composed of current-mode FLF and LF OTA-C structures and input distribution and output summation OTA networks. Very simple design formulas are demonstrated. These filters can realize arbitrary transmission zeros, contain only grounded capacitors and have the minimum number of components. They are also insensitive to tolerances and non-idealities of OTAs and capacitors.
TL;DR: In this article, a simple and reliable class E inverter for induction heating applications is proposed, whose topology presents only one power electronic switch and control strategy is based in switch current sensing.
Abstract: A simple and reliable class E inverter for induction heating applications is proposed. Its topology presents only one power electronic switch. Control strategy is based in switch current sensing. The circuit model behaviour is analysed, and the limits of normal operation and components aspects (construction, stresses etc.) are also discussed. Computer simulations are presented and compared with results measured on the operational prototype, in order to validate both the theoretical model and computer simulation.
TL;DR: In this paper, a design method of current-mode (CM) band-pass ladder filters is presented based on the simulation of the passive RLC ladder networks using currentmode biquad blocks.
Abstract: A design method of current-mode (CM) band-pass ladder filters is presented. The proposed method is based on the simulation of the passive RLC ladder networks using current-mode biquad blocks. Three scaled impedance functions are chosen to generate the biquadratic transfer functions. Based on these scaled impedance functions, three CM band-pass filters are obtained and implemented using OTAs. As an example, a sixth-order Chebyshev band-pass filter is designed and simulated using HSPICE.
TL;DR: Two universal active filters with current gain, one having three inputs and a single output and the other having a single input and three outputs, using a pair of four terminal p-type active current conveyors (CFCCII p s), are presented in this article.
Abstract: Two universal active filters with current gain, one of which has three inputs and a single output and the other of which has a single input and three outputs, using a pair of four terminal p-type active current conveyors (CFCCII p s), are presented. The proposed circuits offer the following advantageous features: universal currentmode filter realization from the same configuration; no requirements for critical component matching conditions or cancellation constraints in realizing the lowpass, band-pass, high-pass and notch filter responses; use of only two grounded capacitors suitable for integration; use of only grounded or virtually grounded resistors for adjustment; high output impedance and low sensitivity performance.
TL;DR: In this paper, nonlinear Eulerian hydrodynamical equations of a helix travelling-wave tube were formulated and their solutions obtained by the method of successive approximation, which was applied to the problem of second harmonic generation in the device and its conditioning.
Abstract: Nonlinear Eulerian hydrodynamical equations of a helix travelling-wave tube were formulated and their solutions obtained by the method of successive approximation. The method was applied to the problem of second harmonic generation in the device and its conditioning. The present Eulerian approach, unlike the Lagrangian one, did not give a picture of electron overtaking and that of the position of electron bunch relative to the RF phase, nor did it account for saturation effects caused by the defocusing of the RF wave from the electron bunch. Nevertheless, the approach was found to be less encumbered and it took less computer time than Lagrangian approach as it avoided large-scale numerical integration and gave closed-form solutions. It also exhibited saturation effects by the inclusion of the third-order nonlinearity in the analysis. Second harmonic generation in the device was correlated with the dispersion and interaction impedance characteristics of the slow-wave structure as well as with Pierce's velo...
TL;DR: In this article, a comment on the paper using a single FTFN is made on the current-mode quadrature sinusoidal oscillator using single FFTN.
Abstract: This brief communication is a comment on the paper Current-mode quadrature sinusoidal oscillator using single FTFN
TL;DR: In this article, high-input impedance bandpass, lowpass, and high-pass filters using two fourterminal floating nullors (FTFNs) are presented, among these filters, the bandpass and lowpass filters require only grounded capacitors which are suitable for monolithic integration.
Abstract: High-input impedance bandpass, lowpass, and highpass filters using two fourterminal floating nullors (FTFNs) are presented. Among these filters, the bandpass and lowpass filters require only grounded capacitors which are suitable for monolithic integration. All the proposed high-input impedance filters have active and passive sensitivities no greater than unity. Experimental results are given to verify the theoretical analysis.