Allpass section-based mixed-mode quadrature sinusoidal oscillator

Abstract

This paper presents a new electronically tunable mixed-mode quadrature sinusoidal oscillator using new allpass section as an building block. The oscillator is consisted of two allpass sections. Each allpass section employs one currentcontrolled current differencing transconductance amplifier and one grounded capacitor. The condition of oscillation and the frequency of oscillation can be controlled independently and electronically by adjusting the bias currents. The oscillator also offers two explicit quadrature voltage and quadrature current outputs into a single topology. The workability of the proposed structure is verified by PSPICE simulators based on 0.25 µm TSMC CMOS process.

New Realization of Quadrature Oscillator using OTRA

“…By substituting W, X, Y, Z from (10), (11), (12) in (7) the characteristic Equation and hence the FO and CO can be obtained which are same as given by (2), (3) and (4) respectively.…”

“…This has led a consistent research effort towards second order QO design using wide variety of active blocks, as is evident from vast literature available [2][3][4][5][6][7][8][9][10][11][12][13][14] .It is well known that higher order networks, provide better accuracy, frequency response and distortion performance [15][16][17] as compared to lower order circuits. Owing to this in recent past few third order QO designs [15], [16], [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] have been reported.…”

Mixed-mode quadrature oscillator using a single DDCCTA and grounded passive components

“…Moreover, the circuit in [11] does not provide inherent control to the condition of oscillation (CO) and the frequency of oscillation (FO). In [14], the mixed-mode QO is constructed by cascading of two all-pass filters. Although the CO and FO of the circuit are independently tunable, it suffers from the use of two active components.…”

“…Such type of QO is the so-called mixed-mode QO circuit. Several realization of mixed-mode QOs based on various active components like differential voltage current conveyor (DVCC) [9], [10], current conveyor (CCII) [11], zcopy current follower transconductance amplifier (ZC-CFTA) [12], current differencing transconductance amplifier (CDTA) [13], current controlled CDTA [14], [15] and differential voltage current-controlled conveyor transconductance amplifier (DVCCCTA) [16] have been received considerable attention. However, the circuits reported in [9]- [13] contain a lot of active and passive components, so these circuits require a large area for fabrication.…”