CCTAs based Current-mode Quadrature Oscillator with High Output Impedances

This article presents a current-mode quadrature oscillator. The proposed oscillator can provide 2 sinusoidal output currents with 90 0 phase difference. It also provides high output impedances that make the circuit able to directly drive load without additional current buffer. The condition of oscillation and frequency of oscillation can be controlled independently and electronically by adjusting the bias currents of the CCTAs. The circuit uses 3 current controlled transconductance amplifiers (CCTAs) and 2 grounded capacitors. The proposed circuit uses only grounded capacitors without additional external resistors, the proposed circuit is considerably appropriate to further developing into an integrated circuit. The results of PSPICE simulation program are corresponding to the theoretical analysis. 