Current differencing transconductance amplifier-based current-mode four-phase quadrature oscillator

Abstract

A realization of a current-controlled current-mode four-phase quadrature oscillator based on current differencing transconductance amplifiers (CDTAs) is proposed. The proposed oscillator circuit employs only three CDTAs and two grounded capacitors, which can provide four high output impedance sinusoidal current outputs with four-phase difference. The oscillation condition and oscillation frequency can be controlled electronically and independently by the transconductance gain of the CDTA. PSPICE simulation and experimental results with the commercially available ICs are given to confirm the operation of the proposed oscillator.