Jiun-Wei Horng

High-input impedance voltage-mode universal biquadratic filter using three plus-type CCIIs

A new three-input single-output voltage-mode universal biquadratic filter with high-input impedance using only three plus-type second-generation current conveyors (CCIIs) is presented. The proposed configuration uses only two capacitors and two resistors and can realize all the standard filter functions, that is, high-pass, bandpass, low-pass, notch, and allpass filters without changing the passive elements. The proposed circuit has no requirements for component matching conditions. The use of only plus-type CCIIs simplifies the configuration.

Current conveyors based allpass filters and quadrature oscillators employing grounded capacitors and resistors

Six quadrature oscillator (QO) circuits are proposed. They are implemented through the proposed second-generation current conveyors (CCIIs) based high input impedance first-order allpass filters and the integrators as the building blocks. Outputs of two sinusoids with 90^o phase difference are available in each of the proposed quadrature oscillators. The oscillation condition and oscillation frequency of each proposed quadrature oscillator are independently controllable through grounded resistors. All proposed circuits employ only grounded capacitors and resistors. The use of only grounded capacitors and resistors is ideal for integration. Experimental results are also included.

Quadrature oscillators using CCIIs

Three third-order quadrature oscillators are proposed. Outputs of two sinusoids with 90° phase difference are available in each quadrature oscillator circuit. The oscillation condition and oscillation frequency of each proposed quadrature oscillator are orthogonal controllable. All proposed circuits employ only grounded capacitors. The use of only grounded capacitors is ideal for integration. Experimental results are included to confirm the theoretical analysis.

High-Input and Low-Output Impedance Voltage-Mode Universal Biquadratic Filter Using DDCCs

A new three inputs and single output voltage-mode universal biquadratic filter with high-input and low-output impedance using three plus-type differential difference current conveyors, two grounded capacitors and two grounded resistors is presented. The proposed circuit offers the following features: realization of all the standard filter functions, that is, high-pass, bandpass, low-pass, notch, and all-pass filters, no requirements for component matching conditions, the use of only grounded capacitors and resistors, high-input and low-output impedance and low active and passive sensitivities.

Novel universal voltage-mode biquad filter with three inputs and one output using only two current conveyors

A new universal voltage-mode second-order filter with three inputs and one output employing two current conveyors, two capacitors and three resistors is presented. With the same number of passive elements, the new filter employs one less current conveyor than the latest published paper. Also, the new filter does not need a voltage follower. The new circuit still offers the following advantageous features of the published filter of this category: realization of all-pass, notch, high-pass, bandpass and low-pass signals from the same configuration, no requirements for component-matching conditions, orthogonal control of ω0 and Q, low active and passive sensitivities.

A sinusoidal oscillator using current-controlled current conveyors

Two new RC sinusoidal oscillators using two plus-type second generation current conveyors (CCII+s), two capacitors and two resistors are presented. From one of the proposed CCII+ based oscillators, by replacing the CCII+s and resistors by second generation current controlled conveyors (CCCIIs), a new current controlled oscillator using only two CCCIIs and two grounded capacitors can be obtained.

Voltage-mode highpass, bandpass and lowpass filters using two DDCCs

A new configuration for realizing voltage-mode highpass, bandpass and lowpass filters, simultaneously, using two differential difference current conveyors (DDCCs), two grounded capacitors and two grounded resistors is presented. The proposed circuit offers the following features: realization of highpass, bandpass and lowpass signals from the same configuration, no requirements for component matching conditions, the use of only grounded capacitors and resistors, high input impedance, low active and passive sensitivities and simpler configuration due to the use of only two DDCCs and four passive components.

Voltage-mode universal biquadratic filter with one input and five outputs using OTAs

A new voltage-mode universal biquadratic filter with one input and five outputs is presented. The new circuit uses one triple-output OTA, one dual-output OTA, three single-output OTAs and two grounded capacitors. This circuit offers the following features: high input impedance, realizing all the standard filter functions; lowpass, bandpass, highpass, notch and allpass, simultaneously, orthogonal controllability of ωo and Q, and low active and passive sensitivities.

First-order allpass filter and sinusoidal oscillators using DDCCs

A voltage-mode first-order allpass filter using one differential difference current conveyor (DDCC), one grounded capacitor and one floating resistor is presented. No passive component matching constraints are required. Because the output impedance of the proposed allpass filter is low, the output terminal can be directly connected to the next stage. Using the proposed first-order allpass filter as a basic building block, a new quadrature oscillator and even-phase sinusoidal oscillators can be obtained. The simulation results confirm the theoretical analysis.

High input impedance voltage-mode universal biquadratic filters with three inputs using plus-type CCIIs

Two new configurations for realizing high input impedance voltage-mode universal biquadratic filters are presented. Each proposed universal biquadratic filter with three inputs is composed of three plus-type CCIIs and can realize all the standard filter functions, that is, highpass, bandpass, lowpass, notch and allpass filters. In spite of the active components, the first proposed configuration uses five passive components, the second proposed configuration uses three capacitors and three resistors. The use of only plus-type CCIIs simplifies the configurations.