Muhammad Taher Abuelma’atti

New Universal Filter with One Input and Five Outputs Using Current-Feedback Amplifiers

A new universal voltage-mode second-order filter circuit is presented. The circuit uses five current-feedback operational amplifiers, two grounded capacitors three grounded resistors and three floating resistors. The circuit can realize all the standard filter functions; lowpass, highpass, bandpass, notch and allpass, without changing the passive elements. The proposed circuit enjoys independent grounded-resistance-control of the natural frequency and the bandwidth, low output impedances, high input impedance as well as low active and passive sensitivities.

A novel three inputs and one output universal current-mode filter using plus-type CCIIs

A novel current-mode current-conveyor based universal filter with three inputs and one output is presented. The circuit uses six plus-type second-generation current-conveyors (CCII+), six grounded resistors and two grounded capacitors. The circuit enjoys the following advantageous features: independent grounded-resistance control of the filter parameters, realisation of all the basic filter functions, low passive sensitivities and high output impedance. Experimental results are included.

New Sinusoidal Oscillators with Fully Uncoupled Control of Oscillation Frequency and Condition Using Three CCII+s

Using Sedra-Smith gyrator (IEEE Transactions on Circuit Theory 17, pp. 132–134, 1970) new realizations for grounded-resistor controlled sinusoidal oscillators using the plus-type second-generation current-conveyor (CCII+) can be systemically derived. Some of the new circuits enjoy the attractive feature of totally uncoupled frequency and condition of oscillation. Experimental and simulation results obtained using PSPICE are included.

Simulation of a mutually coupled circuit using plus-type CCIIs

A new CCII-based circuit for the simulation of mutually coupled circuits is presented. The circuit uses six commercially available plus-type second-generation current conveyors (CCII+s), six resistors and two grounded capacitors. The primary self-inductance, the secondary self-inductance and the mutual inductance can be independently controlled using three different resistors. SPICE simulation results are included.A new CCII-based circuit for the simulation of mutually coupled circuits is presented. The circuit uses six commercially available plus-type second-generation current conveyors (CCII+s), six resistors and two grounded capacitors. The primary self-inductance, the secondary self-inductance and the mutual inductance can be independently controlled using three different resistors. SPICE simulation results are included.

A Grounded-Resistor Current Conveyor-Based Active-R Multiphase Sinusoidal Oscillator

A multiphase active-R sinusoidal oscillator circuit is presented.The oscillator can produce M signals (M being even or odd) equally spaced inphase. The circuit has low component count, uses grounded resistors andenjoys low active and passive sensitivities. The feasibility of convertingthe circuit into a voltage controlled multiphase oscillator is studied.Simulation results are included.

Current-controlled OTA-based single-capacitor simulations of grounded inductors

Two novel schemes are presented for realizing operational transconductance amplifier (OTA)-based current-controlled grounded inductors. While the use of OTAs yields a wide range of electronic tunability, the schemes are temperature insensitive. Experimental results confirming the theory are presented.

Analysis of the effect of radio frequency interference on the DC performance of bipolar operational amplifiers

Fourier-series approximations are obtained for the input/output characteristic of the bipolar differential amplifier with active load and the asymmetrical differential amplifier. Using these approximations, the DC volta ge offset of a differential amplifier subjected to radio-frequency interference (RFI) can be studied and analytical expressions are obtained. These expressi ons can help in optimizing the parameters of the differential amplifier to minimiz e the offset voltage resulting from the RFI.

A new active-C oscillator

A new active-C circuit generating nearly sinusoidal oscillations over a wide frequency range is presented. The circuit uses two operational amplifiers plus four capacitors. The feasebility of generating oscillations using two operational amplifiers only, without using any capacitors, is investigated. Experimental results are included.

New CFOA-based floating immittance emulators

ABSTRACT This paper presents four new topologies for emulating floating immittance functions. Each circuit uses two or three current-feedback operational-amplifiers (CFOAs) and three passive elements. The proposed topologies can emulate positive/negative lossless and lossy floating inductances, and positive/negative capacitance, resistance and inductance multipliers in addition to floating frequency-dependent positive and negative resistances. The functionality of the proposed circuits is verified using the Advanced Design System software and the AD844 CFOA. The simulation results are in excellent agreement with the theoretical calculations.

Harmonic and intermodulation performance of carbon nanotube field-effect transistor-based and single-electron tunnelling transistor-based inverting amplifiers

This article presents a simple mathematical model for the output-voltage/input-voltage characteristics of the carbon nanotube field-effect transistor (CNTFET)-based and the single-electron tunnelling transistor (SET)-based inverting amplifiers. The model, basically a Fourier-series, yields closed-form expressions for the amplitudes of the harmonic and intermodulation components of the output voltage resulting from a multisinusoidal input voltage. The special case of a two-tone equal-amplitude input signal is considered in detail. The results show that the harmonic and intermodulation performance of the CNTFET-based and SET-based inverting amplifiers is strongly dependent on the values of the bias voltage and the amplitudes of the input tones. Moreover, the results show that for the CNTFET-based inverting amplifier, either the relative second-order or the relative third-order intermodulation component is dominant, while for the SET-based inverting amplifier, the relative third-order intermodulation is always dominant. The results also show that all the harmonics and intermodulation products may exhibit minima at different values of the input bias voltages and tone amplitudes.