OTRA Based Voltage Mode Third Order Quadrature Oscillator

Abstract

Two topologies of operational transresistance (OTRA) based third order quadrature oscillators (QO) are proposed in this paper. The proposed oscillators are designed using a combination of lossy and lossless integrators. The proposed topologies can be made fully integrated by implementing the resistors using matched transistors operating in linear region, which also facilitates electronic tuning of oscillation frequency. The nonideality analysis of the circuit is also given and for high frequency applications self-compensation can be used. Workability of the proposed QOs is verified through PSPICE simulations using 0.5 μm AGILENT CMOS process parameters. The total harmonic distortion (THD) for both the QO designs is found to be less than 1%.

Mixed-Mode Third-Order Quadrature Oscillator Based on Single MCCFTA

“…The z 1 -, x 1 -terminals and g m1 are existing terminals and TA of conventional CCFTA [50]. The z 2 -and z c -terminals are the z-copy terminals [13] …”

“…The early system using operational transconductance amplifier (OTA) [30] enjoys electronic tuning capability, but its CO and FO are not decoupled and difficult to control. The QOs using active building blocks such as operational amplifier [31], second-generation current conveyor (CCII) [32][33][34], differential voltage current conveyor (DVCC) [35], operational transresistance amplifier (OTRA) [36], [37], [50], offer orthogonal control of CO and FO, but these structures lack the electronic tuning capability. A number of electronic-controlled third-order QOs have been reported using active building blocks such as current-controlled CCII (CCCII) [38], [39], current difference transconductance amplifier (CDTA) [40], [41], current-controlled CDTA (CCDTA) [42], current-controlled current conveyor transconductance amplifier (CCCTA) [43], [44], OTRA and MOS-C [45], DDCC and VDTA [46], [51], [52], differential voltage current conveyor transconductance amplifier (DVCCTA) [47].…”

Voltage-Mode and Current-Mode Resistorless Third-Order Quadrature Oscillator

“…These circuits were used to design the second-order quadrature current outputs, quadrature voltage outputs, or both quadrature current and voltage outputs. In addition to all of the above second-order quadrature oscillators, several third-order quadrature oscillators have also been proposed [22][23][24][25][26][27][28][29][30][31][32].…”

“…The third-order oscillator in Reference [30] uses three multiple-output differential voltage current conveyors (MO-DVCCs), three resistors, and three grounded capacitors; however, one of the resistors is also a floating connection. The oscillator in Figure 2 of Reference [31] uses three operational transresistance amplifiers (OTRAs), four resistors and three capacitors; however, not all of the resistors and capacitors are grounded.…”

“…However, these circuits [22][23][24][25][26][27][28][29][30][31][32] suffered from one or more of the following drawbacks: (i) the inclusion of three/four active components [22][23][24][26][27][28]30,31]; (ii) the lack of both a voltage-mode and current-mode quadrature oscillator in one circuit topology [22][23][24][25]31]; (iii) the lack of a resistorless oscillator [24,[29][30][31][32]; (iv) the lack of an independently electronically tunable for the oscillation condition and frequency [22,24,30,32]; (v) the lack of amplitude-controllable for output current signal [22][23][24][25][26][27][28][29][30][31][32]; and (vi) the lack of quadrature voltage outputs, quadrature current outputs, and a high-impedance amplitude-controllable current output in one circuit topology [22]…”